reinventing renewable energy - university of wisconsin ... · reinventing renewable energy...

Toward a Technology Strategy for Improving Security,Creating Jobs & Reducing Emissions

Reinventing Renewable Energy

Discussion PaperJuly 2009

2 Reinventing Renewable Energy – July 2009

An Invitation to Participate

Accelerated technological progress is essential to grow the role of renewable resources in meeting the world’s energy needs and aspirations. In collaboration with diverse stakeholders, the American Council On Renewable Energy (ACORE) and the Electric Power Research Institute (EPRI) are working to create a renewable energy technology strategy out-lining the research, development, demonstration, and deployment (RDD&D) needed in the short, medium, and long term to improve the performance and expand the use of today’s renewable energy technologies, accelerate the development and commercial availability of advanced options, and discover and pursue the innovations that will power and fuel the future.

EPRI’s focus is on electricity generation, delivery, and utilization, while ACORE is interested in all aspects of renewable energy development and use. Therefore, the strategy spans the full spectrum of resources and technologies including but not limited to biomass energy, power, and fuels; geothermal energy and power; hydro and ocean power; solar energy and power; certain waste-to-energy forms; and wind power. It also covers the complete chain and circular progression of RDD&D activities, ranging from fundamental science to commercial optimization, as shown in the figure at right.

This discussion paper compiles RDD&D topics identified by ACORE and EPRI with initial input from diverse stakeholders. The topics focus on technology, but technical progress will be paced by political, eco-nomic, environmental, and social factors that also merit significant research attention.

This compilation is only a starting point toward defining and implementing the RDD&D required to grow the role of renewable energy. Across all renewables and within individual resource and technology areas, much additional work is needed—first to dig more deeply into the technical issues; then to establish priori-ties based on their potential to yield quantitative improvements in cost and performance and substantial increases in deployment and use over time; and finally to specify RDD&D timelines, milestones, resource requirements, and roles and responsibilities.

Priority-setting is complicated by significant variations in resource availability, technological applicability, market conditions, and policy environments at regional, national, and global scales and by different objec-tives and functions at individual and organizational levels. Consistent with the conclusion that no silver bullet exists for addressing critical energy-related issues, ACORE and EPRI with this discussion paper seek to highlight the breadth and depth of specific renewable energy RDD&D needs, plus an overarching require-ment for public-private investment in basic science and technology research.

Continued stakeholder participation will be essential to ensure that the technology strategy is responsive to the needs of diverse constituencies, from renewable energy technology developers to electricity and fuel pro-viders, from researchers to advocates, from agencies to industries, from policymakers to the public. To that end, your perspective on this discussion paper and on RDD&D priorities for the near, medium, and longer terms will be very much appreciated.

Please send along your written comments, and join us in supporting collaborative development of a renew-able energy technology strategy for improving security, stimulating economic growth, and reducing carbon emissions in the United States and around the world.

Rob ChurchVice President of Industry Research & Analysis [email protected]

Clark GellingsVice President of Technology [email protected]

3Reinventing Renewable Energy – July 2009

basic science & technology

research

component development

productdevelopment

testing &demonstration

commercialdevelopment

deployment& integration

operation &maintenance

Range and Progression of RDD&D Activities for Renewable Energy Technologies


future electricity, transportation, and fuel infrastructures and within natural and human systems. Other technologies are seeing early or accelerating deployment but are still sub-stantially constrained by technical limitations. Yet others are progressing but await fundamental breakthroughs before they can be considered commercially viable.

Over the past several decades, renewable energy op-tions have been researched, developed, and enhanced by significant government funding directed toward basic science and advanced concepts. For the more commercial technologies, private sector investment focused on design, engineering, manufacturing, installation, integration, opera-tions, and maintenance issues has yielded lower-cost and higher-performance components and systems. Today, given the varying status and potential of individual options, the re-newable energy technology challenge spans the research, development, demonstration, and deployment (RDD&D) spectrum.

In this complex and dynamic environment, increased co-ordination and cooperation among government agencies, industry groups, and other stakeholders are required to en-sure that public and private resources are invested wisely, and substantial and sustained RDD&D commitments are needed for renewables to secure an expanding share of domestic and global energy markets in a cost-competitive, reliable, scalable, and sustainable manner.

Today, renewable resources are both essential energy producers and important drivers of progress at the na-tional and global levels. Projections for the future vary considerably, but most observers anticipate that commer-cial renewable energy technologies will make growing contributions to the world’s energy supply and use mix in coming decades due to continuing innovations, improving cost-competitiveness, expanding policy mandates, and enduring challenges relating to energy security, fuel price volatility, climate change, and sustainability.

In fact, the renewable resource base is more than suf-ficient to meet aggregate U.S. and global energy needs now and into the future. However, there remains a mas-sive gap between available resources and ones that currently can be harnessed in economically, environmen-tally, and socially acceptable ways. Technical progress is critical to fill this gap.

Because renewable energy options—often considered collectively—are largely unrelated from a technological perspective, organized efforts to expand their contributions demand an appreciation of each option’s current status and potential, as well as its limitations and advantages for specific applications. Some technologies are mature, but further work is needed to improve their cost and perfor-mance and to effectively integrate them within current and

Overview & Organization


This discussion paper organizes RDD&D needs by renew-able energy resource and underlying technology area, spanning electricity generation, transportation, and heating and cooling applications. Because all advanced technolo-gies will be deployed in a larger technical and societal context, the final section addresses cross-cutting needs relat-ing to renewables integration within electricity grids and fuel delivery networks, as well as social, political, economic, and environmental systems.

The initial version of this paper was prepared based largely on information provided by ACORE and EPRI and on con-versations at a meeting at EPRI headquarters in Palo Alto, California, on February 10-11, 2009. The meeting was organized by Clark Gellings of EPRI and Rob Church of ACORE around the topics identified above.

Invited attendees included Gerry Braun and Merwin Brown of the California Institute for Energy & the Environment, Terry Peterson of Solar Power Consulting, Chris Powicki of Water Energy & Ecology Information Services (WEEinfo), Vijay Vital of Arizona State University, and Mike Webber of University of Texas at Austin. Additional EPRI attendees included Roger Bedard, Luis Cerezo, Doug Dixon, Gary Golden, Bryan Hannegan, Andree Houle, Tom Key, Cara Libby, Chuck McGowin, Richard Menar, Jeff Phillips, Stan Rosinski, Robert Schainker, and Kent Zammit.

The initial version of the paper was released on February 25 during a special session—“Developing a New R&D Plan for Renewable Energy Technologies”—at RETECH 2009, a conference organized by ACORE and held in Las Vegas, Nevada. RETECH attendees were invited to review the paper, as were EPRI and ACORE members, advisors, and staff and additional stakeholders in the renewable energy and electricity sectors. Comments received through June 2009 were incorporated.

Chris Powicki of WEEinfo, Stan Rosinski of EPRI, and Elizabeth Hooper of Hooper Design prepared this discus-sion paper. The contributions of each individual identi-fied above—and of the many others who have offered feedback and input— are gratefully acknowledged, but ACORE and EPRI are solely responsible for its content.

Resource & Technology Areas Page

Bioenergy 6• Biopower: Solid Biomass;

Landfill & Digester Gas;Liquid Fuels

• Transportation Biofuels: Ethanol; Biodiesel; Algae

• Bioheat Geothermal Energy 11• Power Generation: Hydrothermal; Hot Dry Rock/ Enhanced Geothermal• Heating & Cooling

Solar Energy 14 •Power Generation: Photovoltaics; Concentrating Solar Thermal• Heating & Cooling

Waste to Energy 19• Municipal Solid Waste• Waste Heat

Water Power 21• Conventional Hydro• Hydrokinetic: River, Tidal & Ocean Current; Wave

Wind Power 24• Onshore• Offshore

Integration 28• Electricity Transmission & Distribution • Fuel Delivery & Storage • Hybrid Systems/Novel Concepts • Social, Political, Economic & Environmental Systems


Bioenergy

Growth in bioenergy will be influenced strongly by resource utilization issues and the pace of progress in fuels and technologies for the power generation, transportation, and heating sectors.

Comprehensive understanding of direct and indirect life-cycle impacts and of market interactions will help ensure sustainable bioenergy production, optimize resource allocation among energy sectors, and lessen competition with food, feed, fiber, and other critical land uses.

New fuel sources, processing methods, conversion systems, and operations and maintenance (O&M) practices will increase efficiency, reduce costs, and improve environmental performance for existing and new biopower capacity. Advanced technologies also will drive an economical, scalable, and sustainable expansion in the manufacturing of transportation biofuels, bioheat sources, and bioproducts for diverse applications.

Improved delivery infrastructure and utilization tech-nologies will enable market growth for low-carbon fuels and conversion systems.

Public-private investments in basic science, technology development, and proof-of-concept and field verifi-cation testing will be required before innovations in biopower, biofuel, and bioheat are ready for commer-cialization. The list below identifies RDD&D topics for growing the role of bioenergy in meeting the world’s needs and aspirations. Resource Assessment & Optimization

Policies mandating increased reliance on biofuels for trans-portation have focused attention on critical resource utiliza-tion challenges influencing all bioenergy applications.

• Assessment tools for evaluating resource availability and sustainability, fuel cost and market volatility, reliability and security of supply, and strength of supply chain over varying temporal and geographic scales and climate change scenarios for bioenergy resources and uses

• Comprehensive life-cycle and market analysis frameworks for consistent evaluation of competition among different bioenergy applications, agricultural and timber production, resource conservation, and sustainable economic development at the regional, national, and global levels

• Comparative analysis of the relative economic, envi-ronmental, health, and climate impacts of growing and using alternative bioenergy sources and technologies for power generation (including cofiring and dedicated plants), for transportation (including biopower for plug-in hybrid vehicles and biofuels for conven-tional vehicles and hybrids), and for heating (in-cluding cogeneration and district and distributed heating systems)

• Measurement and modeling tools for conducting indirect land use (ILU) and full fuel cycle carbon footprint (FFCCF) analyses for bioenergy, fossil fuel, hydro-gen, and other technologies for transport, electricity, and heating applications

• Standards and certification and accreditation methods to characterize ILU, FFCCF, renewable portfolio stan-dard (RPS) eligibility, and other sustainability crite-ria for bioenergy sources and production methods

• Advanced science and technology for bioenergy produc-tion, processing, conversion, delivery, and use to mini-mize adverse impacts and increase productivity

Biopower

The primary commercial bioenergy technology for electricity generation is combustion of solid biomass alone and in combination with fossil energy sources,

Technology Status• Biomass Combustion, Di-

gester Gas & LFG: Commer-cial & Mature

• Biomass Cofiring: Early Commercial

• Biomass Gasification & Pyroly-sis: Pre- to Early Commercial

Current Deployment• > 8 GW in the US and ~ 50

GW globally

Resource Potential• Resources are huge and

globally abundant but subject to competition

Critical Issues• Resource supply, reliability,

and cost• Conversion efficiency• O&M cost reduction• Environmental and social

impacts

Biopower Facts & Issues


U.S. Bioenergy & Waste Resources Based on Current Land Use (Source: NREL)

while gasification and pyrolysis systems are emerg-ing. Fuels include residues from forests and woodlots and from the wood, paper products, agricultural, and wastewater industries, and, in the future, trees and grasses grown as dedicated feedstocks. Landfill gas (LFG) and digester gas systems are also commercially mature but resource-constrained. Innovations are needed to reduce costs, increase efficiency, and expand potential applicability.

1. Fuel Production, Collection, Processing & Transportation

The majority of biomass generating capacity is sited at industrial plants with a ready source of inexpen-sive fuel and is operated in combined heat-and-power (CHP) mode to improve unit economics. Many dedicated generating plants exist, are under construction, or planned with nameplate capacity up to about 100 MW. New technologies are needed to expand biopower fuel sources and markets and to mitigate fuel-related costs and issues.

• Naturally optimized or genetically engineered tree, grass, and algae crops to increase energy content, match characteristics with conversion processes, and reduce fuel variability and costs

• High-yield, short-rotation energy plantations adapted

to local circumstances and to less productive and fal-low lands to expand fuel supplies, reduce resource competition, and lower costs

• Tools for comprehensive assessment of waste materials, by-products from manufacturing processes, and other potential fuel sources to determine viability for biopower production from cost, emissions, and RPS perspectives

• Pre-processing, drying, and densification systems to reduce handling and transportation costs and expand fuel markets to national and global scales

• Torrefaction process testing and cofiring demonstra-tions to evaluate costs and benefits for different biomass fuel-coal mixtures

• Advanced pyrolysis, liquefaction, and other processing technologies for converting solid biomass into liquid fuels and for combining different fuel streams to fa-cilitate storage, transport, and energy conversion

• Genetically engineered bacteria and advanced enzymes to accelerate anaerobic digestion of biomass for im-proved handling and higher-efficiency combus-tion processes

• Aggregation and optimization of fuel collection and transportation systems to reduce handling costs

• Advanced treatment and conversion technologies for LFG and digester gas to improve fuel quality, process economics, and marketability and to reduce costs


2. Advanced & Hybrid SystemsConventional biomass combustion technologies suffer from low thermal efficiency, while the bio-energy fraction in cofiring applications at pulver-ized-coal plants is generally limited to about 5% due to O&M challenges. Innovations are required to improve energy capture, expand applicability, and take advantage of biopower’s status as a dispatch-able generation option with potential for reducing greenhouse gas emissions.

• Development and large-scale demonstration of biomass gasification and pyrolysis plants, with and without CHP, to support technology optimization

• Cofiring technology development and testing at frac-tions of 25% and more with a range of alternative coals and biomass fuels to quantify impacts on cost, O&M, environmental performance, and by-prod-uct utilization

• Analytical tools for combined biomass/coal processing, combustion, and gasification technologies to optimize tradeoffs among fuel cost, plant productivity, O&M cost, CO2 emissions, RPS compliance, and other factors

• Assessment and demonstration of biopower-based retrofit and repowering options for coal-fired capac-ity to reduce CO2 emissions and meet RPS re-quirements

• Testing and demonstration of biomass integration with gas-fired technologies, including high-temperature air-to-gas heat exchangers and recuperators for externally fired gas turbines, to increase energy conversion ef-ficiencies and support climate and RPS objectives

• Advanced materials and components engineered for high-temperature, high-pressure biopower systems to improve efficiency and to reduce both costs and emissions

• Design optimization and testing for conventional bio-power, cofiring, gasification, and pyrolyis plants with carbon capture and storage capability to establish potential for carbon-negative technology

• Testing and demonstration of biomass CHP and bio-char co-production and utilization as a carbon-nega-tive technology

• Advanced combustion turbine systems for converting LFG, digester gas, and other gaseous and liquid fuels into electricity and heat

• Hybrid solar-biopower units and wind-biopower plants for taking advantage of synergistic technology attributes to reduce fuel use and firm up variable generation

• Integrated biorefinery concepts for generation of biopower, biofuels, heat, and other products

Global Primary Productivity Changes as Indicators of Potential Bioenergy Resources (Credit: NASA)


Technology Status• First Generation:

Commercial• Cellulosic Ethanol &

Advanced Biodiesel: Pre-Commercial

• Algae: Pre-Commercial

Current Deployment• ~ 6.5B gallons of US

ethanol production and ~13B gallons globally

• ~ 700M gallons of US biodiesel production and ~ 4B gallons globally



Critical Issues• Resource supply, reliability,

and cost• Environmental/social impacts• Conversion efficiency• Process throughput• Cost reduction• Infrastructure development

Transportation Biofuels Facts & Issues

• Advanced mobile biopower stations for lower-cost forest thinning

3. Deployment, Operations, Maintenance & Integration

Immediate needs are to build on experience at fossil generation facilities to address the O&M require-ments associated with increase use of biomass fuel for cofiring and at dedicated plants.

• Sampling and measurement techniques, predictive tools, and advanced O&M strategies for assessing and mitigating biomass cofiring impacts on fuel feed and combustion systems to reduce efficiency and avail-ability losses and expand applicability

• Methodologies for managing the effects of increased cofiring fractions on environmental control systems and fly ash utilization practices to reduce O&M costs and maintain compliance with applicable air quality, water quality, and waste management standards

• Laboratory and field studies, unobtrusive and easily deployable nondestructive evaluation (NDE) tech-niques, and advanced analytical tools to support predictive modeling and proactive management of slagging and fouling issues and component lifetimes

• Operating strategies and reliability-centered mainte-nance programs for plants firing up to 100% biomass to reduce O&M costs and failure rates

• Best practice siting and design tools for green-field projects to secure reliable fuel supplies, address environmental and safety concerns, improve inte-gration, and streamline permitting and approval processes

• Programmatic and cumulative impact assessments for quantifying benefits and evaluating and mitigat-ing the possible effects of widespread biopower deployment on food, feed, and fiber production, environmental quality, and other resource man-agement issues

Biofuels for Transportation

First-generation biofuels—including corn-based ethanol and biodiesel derived from virgin and used vegetable oils and animal fats—have the potential for significant incremental improvement. Cellulosic ethanol and advanced biodiesel fuels require gains in conversion efficiency, process throughput, and infrastructure development. Technology priorities for

algae-based fuels, which offer the prospect for revolu-tionary breakthroughs in sustainable resource man-agement, include species engineering and advances in oil extraction and processing. For all biofuels, advanced delivery and utilization technologies are needed to support market expansion.

1. Corn, Sugar & Oilseed FuelsCrop productivity (bushels per acre), energy con-version efficiency, and process economics represent key areas for technological progress.

• Naturally optimized and genetically modified species and advanced harvesting and processing equipment to accelerate the growth and increase the energy density and productivity of fuels and to reduce their embodied energy content

• Bacteria, enzymes, re-mineralized compost, biochar, and other organic additives to increase productiv-ity while minimizing use of fossil-fuel-based fertilizers.

• Advanced conversion processes and integrated biore-finery designs to employ renewable energy, mini-mize resource inputs and wastes, and efficiently produce plant-based fuels as well as food, feed, fertilizer, pharmaceutical, and other products

2. Cellulosic Ethanol & Advanced BiodieselInnovations in production of crops and other feed-stocks, processing methods, biofuel performance and cost, and industrial scaleup are required for commercialization.


• Dedicated energy crops capable of growing on less pro-ductive, arid, and degraded lands to reduce resource competition, provide high energy density, and match fuel characteristics with energy conversion processes

• Planting and harvesting strategies optimized for non-agricultural settings to increase biofuel production

• Novel biological, chemical, mechanical, and thermal treatment and conversion pathways offering high process throughput at low costs, as well as value-added products

• Optimal fuel chemistries and blends suitable for dif-ferent transportation applications, for widespread distribution, and for use in different climates

3. AlgaeSpecies screening, algae growth, biomass harvest-ing and handling, energy extraction, and fuel processing advances will pace progress toward development of third-generation biofuels, including hydrogen.

• Species optimized for rapid growth, limited space requirements, limited resource inputs, ease of conver-sion, and waste utilization to minimize costs and impacts while generating high-energy fuels and high-value products for different applications

• Comparative analysis and optimization of open pond and bioreactor systems for different physical envi-ronments and socioeconomic conditions

• Novel, low-energy dehydration, separation, and extrac-tion processes to produce high yields

• Process designs and demonstrations integrating bio-fuel production, fossil generation, wastewater treat-ment, and other functions to maximize synergies and reduce costs

4. Delivery & UtilizationAdvanced infrastructure for delivering fuel to consumers and novel technologies for converting stored energy into mobility and power are needed in order for biofuels to realize their full potential.

• New blending pumps and other innovations for ad-

dressing transportation and refueling challenges and optimizing fuel mixes for specific needs

• Filling, on-board storage, and engine modifications as needed to support the use of higher biofuel blends in legacy vehicles

• Higher-compression engines and other new technolo-gies for taking advantage of ethanol’s high octane levels and for exploiting other potentially useful fuel characteristics

• Novel engine designs optimized for specific fuels and for high-use applications to enable broad biofuel penetration in diverse transportation markets

Bioheat

Traditional biomass sources supply the basic energy needs of more than 2.4 billion people around the world, while commercially harvested wood, pelletized fuels, and liq-uids such as biodiesel represent proven and clean heating options in modern stoves, furnaces, and boilers. Sustain-ably sourced heating fuels and advancing technologies re-quire broader application around the world, and gaseous bioheat sources may enable use of existing infrastructure.

• Low-cost fuel processing, fuel distribution, and energy conversion systems and designs to facilitate adoption of modern, efficient technologies and to reduce re-source pressures and harmful emissions associated with traditional bioheat practices

• Advanced heating and CHP technologies, blending process-es, testing programs, and application guidance for biodiesel and other liquid fuels to optimize efficiency, reduce costs, and mitigate seasonal constraints on fuel use

• Production processes and ancillary technologies allow-ing distribution and use of gaseous biofuels via natural gas infrastructure to reduce barriers to widespread bioheat applications

Technology Status• Solid Fuels: Commercial &

Mature• Liquid & Gaseous Fuels:

Early Commercial to Pre-Commercial

Current Deployment• Widespread in the US and

globally



Critical Issues• Market transformation• Pollution control• Conversion efficiency• Resource supply, reliability,

and cost• Cost reduction• Environmental/social impacts

Bioheat Facts & Issues


Geothermal Energy

Technology Status• Hydrothermal: Commercial • HDR/EGS: Pre-Commercial

Current Deployment• ~ 3 GW in the US and ~10

GW globally

Resource Potential• Resources for near-

term development are substantial but geographically limited and may be in remote areas

• Resources deep under-ground are huge but chal-lenging to access

Critical Issues• Pre-development costs• O&M cost reduction • Water use• Resource management• HDR/EGS demonstration

Geothermal Power Facts & Issues

Increasing geothermal power generation will require further progress in locating and extracting energy from hydrothermal reservoirs, as well as advances in hot dry rock/enhanced geothermal system (HDR/EGS) technology. Applications of geothermal heating and cooling systems will gain an increasing share of space conditioning markets due to attractive econom-ics and technological progress.

New technologies adapted from the oil and gas indus-tries to detect, characterize, tap, and manage hydro-thermal resources will reduce project development risks and costs and extend project lifetimes. Innova-tive energy conversion cycles and improved O&M procedures will increase the efficiency and decrease the cost of conventional geothermal power produc-tion plants, while HDR/EGS development will enable substantial increases in generating capacity from underground resources.

Advanced technologies will make direct-use geother-mal heating and cooling systems more prevalent and ground-source heat pumps more cost-effective.

Public-private investments in basic science, technology development, and proof-of-concept and field verifica-tion testing will be required before innovations are ready for commercialization. The list below identifies RDD&D topics for growing the role of geothermal en-ergy in meeting the world’s needs and aspirations.

Electricity Generation

Conventional dry- and flash-steam hydrothermal technologies are mature, while much of the recently installed or planned geothermal capacity relies on advanced energy conversion cycles to generate elec-tricity from lower-temperature resources. HDR/EGS systems are being developed to harness the high- temperature resources located deep underground.

1. Mapping & Exploration Geothermal resources suitable for electricity gen-eration are generally not well characterized, and subsurface exploration is costly. Effective, nonintru-sive capabilities are required for improved resource assessment, prospecting, and mapping.

• Comprehensive databases and fine-grained models to accurately and cost-effectively locate and char-acterize sites with recoverable and sustainable resources

• Advanced subsurface characterization technologies and intelligent “no drill” prospecting tools to identify re-sources with no surface indications and to reduce exploration risks and costs

2. Advanced & Hybrid Systems With increased attention to conventional hydro-thermal systems, continued HDR/EGS progress, and widespread availability of low-temperature resources come the need for assessment, develop-ment, and field demonstration of novel concepts and emerging technologies.

• Hydraulic stimulation, fracture detection, fracture permeability, reservoir validation, and long-term monitoring studies to support future siting and deployment of HDR/EGS systems under varying geological conditions

• Large-scale HDR/EGS demonstration projects to establish risk and potential and support the evaluation and optimization of reservoir creation, monitoring, and management technologies

• Advanced heat transfer fluids, binary and Kalina cycles, heat exchangers, direct contact condensers, and dry cooling technologies to harness lower- temperature resources, substantially improve energy conversion efficiency, and reduce water usage


U.S. Geothermal Temperatures at ~ 6 km Depth (Credit: DOE)

• Underground flash-steam plants for in-reservoir energy production

• Hybrid geothermal-oil/gas production wells and retrofit geothermal applications at abandoned wells to reduce development costs

• Geothermal-assisted fossil and bioenergy plant steam cycles to reduce fuel costs and CO2 emissions

• Hybrid geothermal-fossil generation-CO2 capture plants for co-located energy production and carbon storage to improve reservoir management capa-bilities and reduce energy penalties

• Analytical tools for modeling and comparing advanced geothermal concepts, applications, components, and systems to inform R&D investment and technol-ogy development

3. Development, Operations, Maintenance & Integration

Improved siting practices, “down-hole” technolo-gies, and above-ground systems are required to improve the economics of hydrothermal plants and future HDR/EGS installations.

• Best practice project siting and design tools to maxi-mize sustainable resource recovery, provide grid support, minimize conflicts, and streamline per-mitting and approval processes

• Advanced horizontal, deep-hole, and smart drilling techniques to reduce development costs and pro-vide access to abundant resources

• Enhanced reservoir engineering, fine-resolution moni-toring, and proactive management methods to maxi-mize energy production consistent with sustain-able resource development

• Laboratory and field studies, end-guided wave tech-nology for well pipes, other NDE techniques, and advanced analytical tools to support predictive modeling and proactive management of com-mon degradation processes and failure modes for in-service components without impacting unit availability

• New materials, linings, coatings, and ruggedized components for reliable long-term performance in corrosive and aggressive brines and other harsh environments

• Preventive and reliability-centered maintenance pro-grams and knowledge-based solutions and tools for reducing O&M costs and failure rates and man-aging component lifetimes

• Programmatic and cumulative environmental impact assessments for identifying and mitigating the possible effects of widespread deployment on water resources, seismic activity, and other issues


Global Seismic Activity as Indicator of Geothermal Resources (Credit: USGS)

Resource Potential• Resources available for

direct use are substantial but geographically limited

• Resources for GSHP use are huge and globally abundant

Critical Issues• Market transformation

Geothermal Heating & Cooling Facts & Issues

Heating & Cooling

Geothermal heating and cooling are widely applied around the world. Hot water available at or near the Earth’s surface is tapped directly to heat residential and commercial buildings, provide low-temperature process heat, and deliver district heating services. Ground-source heat pumps (GSHP) are employed for extracting useful energy from constant-temperature soil and water to provide space heating and cooling, as well as water heating. Because current technolo-gies are underutilized in some areas where they are very economical, increased awareness and evolution-ary advances promise to expand geothermal system deployment.

• Detailed resource data and application guidelines for deploying direct-use systems and GSHP technologies in different soil and groundwater environments

• Enhanced components, designs, and installation meth-ods and new process heating applications to reduce the capital costs and increase the penetration of direct-use systems

• Advanced ground loops, higher-efficiency heat pumps, and improved distribution system technologies and installation practices to increase GSHP efficiency, reduce costs, and expand deployment for individual buildings and for district heating and cooling applications

• New solar-assisted GSHP designs to improve system economics, enhance technology performance, and grow markets

Technology Status• Commercial & Mature

Current Deployment

• Widely used in some areas of the world


• Anti-reflective nanocoatings and other advanced materials and processing methods to increase energy capture, minimize thickness, and reduce manu-facturing costs

2. Thin-Film TechnologyBasic and applied research are required to take full advantage of new materials and processes.

• Polycrystalline silicon films, nanocoatings, trans-parent conducting oxides, multi-junction designs, manufacturing innovations, and other approaches for achieving near-term increases in efficiency

3. Concentrating PV Technology Advanced materials and processing methods pro-vide opportunities to improve the performance and expand the applicability of concentrator systems.

• High-efficiency multi-junction cells, improved optics, novel device designs, and advanced tracking for more economical and efficient systems

4. Third-Generation PV Technology Concepts existing largely as theoretical constructs need to be advanced beyond very early stages of experimental testing.

• Spectrum division, spectrum shifting, and kinetic en-ergy capture for revolutionary efficiency gains

Solar Energy

Technology Status• 1st Generation Crystalline

Silicon PV: Commercial & Mature

• 2nd Generation Thin-Film PV: Early Commercial

• 3rd Generation PV: Pre-Commercial

Current Deployment• ~ 1 GW in the US and ~ 10

GW globally


globally abundant

Critical Issues• 1st Generation: Cost reduction • 2nd Generation: Efficiency

and lifetime• 3rd Generation: Proof of concept• Grid integration• Manufacturing and

deployment capacity

Photovoltaics Facts & Issues

Deployment of solar photovoltaics (PV), concentrat-ing solar thermal (CST) electric, and solar thermal heating and cooling will accelerate at a rate paced by technological advances and other factors leading to increasingly attractive economics.

New crystalline silicon, thin-film, and concentrating PV technologies offering higher efficiencies and lower costs will expand distributed and central-station in-stallations, while PV breakthroughs will revolutionize energy supply, delivery, and use practices. Advanced PV system designs and components will create novel applications and deliver premium power, grid sup-port, and other functionalities. For CST, new con-centrator, conversion, and storage technologies and hybrid plant designs and processes will improve the economics of large-scale power generation, facilitate grid integration, and expand applicability.

Both PV and CST technologies will benefit from cross-cutting advances in deployment, O&M, and integra-tion technologies. Meanwhile, advanced technologies will make distributed solar thermal systems for water heating and space conditioning more cost-effective while expanding district heating applications.

Public-private investment in basic science, technology development, and proof-of-concept and field verifica-tion testing will be required before innovations in solar power generation and heating are ready for commer-cialization. The list below identifies RDD&D topics for growing the role of solar energy in meeting the world’s needs and aspirations.

Electricity Generation: Photovoltaics

PV deployment is expanding rapidly, in the United States and around the world, due largely to gener-ous subsidies and continuing improvements in cost and performance. First-generation, wafer-based PV modules dominate current markets but offer moderate efficiency (10 to 20%), remain expensive to manufac-ture, and have limited breakthrough potential. Low manufacturing costs and high production flexibility are expanding deployment for early thin-film modules de-spite relatively low efficiencies of 5 to 15%. Third-gen-eration PV concepts offer the potential to be more than twice as efficient as today’s best commercial products.

1. Crystalline Silicon TechnologyContinued evolutionary progress is needed to re-duce costs and expand deployment.


Global Average Daily Insolation for Photovoltaic Power Generation & Solar Thermal Heating & Cooling (Credit: Matthias Loster, University of California, Berkeley)

5. Deployment & IntegrationAccounting for about 50% of the up-front cost of today’s PV systems, balance-of-plant (BOP) com-ponents, installation practices, and interconnection requirements represent a drag on the rapid growth in both supply-side and consumer-sited applica-tions. Innovations in these areas are needed to reduce costs across all scales, transform distributed PV into a grid asset, and accelerate widespread deployment.

• Module-integrated inverters, novel support structures, upgradable system designs, and other innovations for reducing installed PV costs

• Master controllers, advanced inverters, and multifunc-

tional grid interfaces to maximize energy output, improve power quality and reliability, and serve communications, control, metering, storage, and grid support functions

• PV-Direct Current (PV-DC) applications, systems, buildings, and micro-grids to increase the efficiency and lower the costs of PV production for motor, lighting, plug-in hybrid electric vehicle, and other applications

• Integration of PV, demand response, and smart grid capabilities to provide grid operators with options for addressing intermittency while managing loading

• Advanced controllers to transform distributed PV installations into virtual power plants capable of ful-filling grid requirements relating to real and reac-tive power, voltage, and other key parameters

• Hybrid systems integrating PV with wind, other gen-eration options, and storage technologies to address solar variability and provide dispatchability

• Building-integrated PV systems to generate energy from roofing, shading, and other structures and defray installation costs

• Devices integrating PV with thermoelectric materials to provide electricity, heating, and cooling

• Grid-independent PV-powered devices and products for outdoor lighting, battery charging, consumer electronics, and other applications


Electricity Generation: Concentrating Solar Thermal (CST)

CST power is drawing increasing attention as a large-scale generation option with potential energy storage capability. Parabolic trough, central receiver, linear Fresnel, and dish/engine technologies integrate similar components in different high-temperature configurations, but the former is the only option with a proven record in large-scale applications. 1. Concentrators

Technology Status• Parabolic Trough:

Commercial• Central Receiver, Dish

Engine & Linear Fresnel: Pre- to Early Commercial

Current Deployment• ~500 MW in the US and

globally

Resource Potential• Resources are substantial

but geographically limited, and sometimes located in areas remote from the grid

Critical Issues• Cost reduction • Demonstration • Scale-up • Grid integration• Water use

Concentrating Solar Thermal Facts & Issues

Mirror arrays strongly influence the cost and per-formance of all CST systems, creating a ubiquitous need for novel reflector materials, designs, and systems.

• Aluminum reflectors, advanced optical materials, transparent plastic substrates, new reflector designs, and other innovations for easier manufacturing and assembly and improved efficiency and reliability

• Smaller heliostats to reduce costs for central receiv-er technology

• Improved tracking accuracy and PV-assisted tracking mechanisms to increase output and reduce energy losses

2. Energy Conversion & Storage To date, limited effort has been made to optimize receiver, heat transfer, electricity production, and energy storage components in CST systems. Op-portunities for substantial cost-performance gains exist at both the component and system levels, and possibilities for expanding the technology’s appli-cability to areas with a lower-quality resource base deserve exploration.

• First-principles thermodynamic models to support design, analysis, and optimization of advanced concepts, components, and systems and to inform R&D investment

U.S. Direct Normal Radiation for Concentrating Solar Thermal Electric (Credit: NREL)


Global Direct Normal Radiation for Concentrating Solar Thermal Electric (Credit: ISET)

• New designs, more selective materials and surfaces, and absorptive coatings to increase energy capture by receiver tubes under optimal and sub-optimal solar resource and weather conditions

• Novel heat transfer fluids and advanced Brayton and

Rankine cycles for parabolic trough and central receiver designs

• Advanced cycles and alternative cooling technologies for minimizing water needs and facilitating siting

• New engine and system configurations for centralized and distributed applications of dish/engine technology

• Single-tank thermocline molten salt storage systems for central receiver and trough plants

• Steam, crystalline graphite, ceramics, concrete, phase-change materials, advanced salts, and other media and systems for improving thermal storage at parabol-ic and central receiver plants and allowing energy storage at linear Fresnel and dish/engine plants

• Integrated parabolic trough/central receiver plant designs for taking advantage of low-temperature steam from the former system to feed the latter system

• Advanced materials for high-temperature, ultra-high-efficiency operation of central receivers

3. Hybrid SystemsRenewed interest in CST technologies has led to development of a number of hybrid plant concepts that need detailed design assessment and, where appropriate, field demonstration for retrofit and green-field applications.

• Solar-augmented fossil plant steam cycles, solar-steam-driven ammonia chillers for combustion tur-bine inlet air cooling, and high-temperature air from central receivers for preheating pressurized air or for direct use in combustion turbines to reduce fuel consumption and CO2 emissions

• Solar steam for regenerating CO2 capture solvents at fossil plants and for high-temperature heating at industrial facilities to improve process economics

• CST hybrids with biomass, geothermal, and wind

power to balance energy production and improve grid integration


• Best practice project siting and design tools to maximize energy capture, provide grid support, minimize conflicts, and streamline permitting and approval processes for central-station projects

• Programmatic and cumulative environmental impact as-sessments for identifying and mitigating the possible effects of widespread component manufacturing and technology deployment on materials supplies, water resources, wildlife species, aesthetics, and other issues

• High-resolution, time synchronous resource profiles and advanced forecasting tools, visualization methods, and control capabilities for predicting solar resource avail-ability across varying temporal and geographic scales, understanding coincidence with demand, managing ramp rates, and taking advantage of ancillary service capabilities

• Dust-resistant coatings and automated cleaning methods to decrease energy losses and O&M requirements

Solar Thermal Heating & Cooling

For decades, low-temperature solar thermal systems have proven to be cost-effective water and space heating solutions. Countries where the technology has lagged behind in adoption represent developing markets, and novel technologies and applications are emerging to expand deployment.

• Novel flat-plate and evacuated-tube system absorbers, heat transfer fluids, and circulation systems to reduce costs while providing active water and space heat-ing and low-temperature process heating

• New passive solar components, BOP equipment, and distributed and district system designs to expand ap-plicability for heating and space conditioning

• Advanced collectors, refrigerants, dessicants, cycles, and systems for delivering space cooling services at lower costs

• New stand-alone solar heat pump, hybrid solar-fossil heat pump, and solar-assisted GSHP designs to improve economics and grow markets

• Building-integrated solar thermal systems, hybrid solar thermal-PV applications, and advanced design tools to optimize absorber layout, roof and building surface utilization, and energy production for site-specific needs

4. Development, Operations, Maintenance & Integration

Real-world experience with CST technology is limited, creating the need for field verification tests, demonstration projects, and the collection and shar-ing of knowledge developed based on commercial installations.

• Large-scale demonstration projects for central receiver and linear Fresnel plants, storage innovations, and hybrid systems to support technology assessment and optimization

• Best practices, integrated sensors and diagnostics, un-obtrusive and easily deployed NDE technologies, and other advances to optimize performance, reduce O&M costs, and extend life for concentrator, con-version, storage, and BOP components

Electricity Generation: Cross-Platform

Some technology assessment, project siting and de-sign, permitting and integration, and O&M needs are common to PV and CST systems.

• Analytical tools for modeling and comparing advanced PV concepts and applications, CST components and sys-tems, and hybrid technologies to inform R&D invest-ment and technology development

• Standardized test protocols and facilities for consistent evaluation and field demonstration of emerging technologies


Current Deployment• Widely used in some areas

of the world


globally abundant

Critical Issues• Market transformation• Deployment capacity

Solar Thermal Heating & Cooling Facts & Issues


Waste to Energy

Global Population Density as Indicator of Waste to Energy Resources (Credit: CIESIN/CIAT)

Application of waste-to-energy technologies will increase as global population growth creates the need to extract more of the useful energy embodied in what would otherwise be unused or discarded resources.

Advanced technologies will continue to enhance the efficiency with which municipal solid waste (MSW) is transformed into energy while increasing recycling and reducing pollutant emissions. Waste heat recov-ery innovations will provide ways to capture and use the energy produced by building systems, machines, and industrial processes and then allowed to dissipate into the ambient environment.

Public-private investments in basic science, technology development, and proof-of-concept and field verifica-tion testing will be required before innovations are ready for commercialization. The list at right identifies RDD&D topics for growing the role of waste to energy in meeting the world’s needs and aspirations.

Municipal Solid Waste

MSW technology is mature, with economics favor-ably influenced by tipping fees for waste disposal that translate to a negative fuel cost. Advances are needed to address the distributed nature of fuel resources and

the efficiency limitations and O&M challenges associ-ated with power generation technologies.

• Analytical tools for life-cycle analysis of source-based vs. centralized separation to determine the best approach for specific applications

Technology Status• Commercial to

Pre-Commercial

Current Deployment• > 2 GW of MSW capacity

in US and many times that globally

Resource Potential• Resources are substantial,

broadly available, and growing

Critical Issues• Fuel handling• Conversion efficiency• Pollution control• Cost reduction

Waste to Energy Facts & Issues


• Collection and sorting innovations to reduce transpor-tation and handling costs, maximize recycling and energy recovery, and improve worker and plant safety

• New source-based and centralized fuel processing, blend-ing, and pelletization technologies to improve trans-portation and handling, enhance fuel quality, and reduce emissions

• Advanced O&M practices and environmental control systems to increase power plant availability, man-age costs, and maintain compliance with stringent standards

• Direct combustion, fluidized-bed combustion, gasifica-tion, pyrolysis, and carbon capture process engineering to increase energy recovery and reduce costs and emissions from centralized generating facilities

• Advanced MSW processing and energy conversion technologies for distributed and community-scale generation applications

• Development, assessment, and testing of MSW cofiring in coal-fired plants to reduce emissions and minimize adverse impacts on unit economics

• Accurate measurement techniques for calculating the bio-mass content of mixed wastes to support RPS eligibil-ity determinations

• Tools for comprehensive assessment of waste materials, manufacturing process by-products, and other potential fuel sources to determine their viability for power generation from economics, emissions, and RPS perspectives

• Best practice siting and design tools for green-field proj-ects to address public concerns, improve integra-tion, and streamline permitting and approval

• Programmatic and cumulative environmental impact assessments for quantifying benefits and evaluat-ing and mitigating possible effects of widespread deployment on resource management issues

Waste Heat

Energy recovery is increasingly applied in buildings to reduce heating and cooling system losses and com-monly practiced at power plants and other industrial facilities to increase productivity. Continuing progress in higher-efficiency, lower-cost technologies and pro-cess innovations is required to expand deployment.

• Improved heat transfer fluids, advanced cycles, and new designs to increase energy capture and expand low-temperature applications

• Novel thermoelectric materials, components, and systems for converting waste heat into electricity

• Pre-treatment systems for waste steam and exhaust gases to reduce fuel variability and mitigate corrosion problems

Global Industrial Output as Indicator of Waste Heat Resources (Credit: CIA)


U.S. Undeveloped Low-Power, Low-Head Hydro Sites (DOE)

Water Power


Current Deployment• ~ 100 GW in the US and

> 700 GW globally

Resource Potential• Untapped resources are

substantial but geographi-cally limited and some-times located in areas remote from the grid

Critical Issues• Resource optimization• Permitting and relicensing • Fish passage and protection• Environmental and social

impacts• Small hydro cost reduction

Conventional Hydro Facts & Issues

Conventional Hydro

Existing hydro and pumped storage facilities face environmental and O&M issues. Efforts to add incre-mental capacity at high-head plants, to harness abun-dant but untapped low-head resources, and to deploy new central-station facilities in the developing world are challenged by siting and permitting issues. New technologies are needed to balance energy, environ-mental, and societal values.

• High-temporal-resolution resource data and new resource assessment tools to support capacity additions at existing facilities, facilitate development of new projects, and account for the potential impacts of water supply constraints and climate change

• Integrated near- and long-term meteorology, river/stream flow, and load forecasting and management tools to bal-ance power production, grid support, fish protection, flood control, water quality, and other objectives

• High-efficiency, fish-friendly turbines to increase ef-ficiency and boost output while protecting wildlife populations at existing and new facilities

• Small-hydro technologies and advanced turbine designs optimized for low-head environments to allow for energy capture at dams, impoundments, and other locations currently lacking hydropower capacity

Water power may continue to represent the world’s leading source of renewable electricity if conventional hydro tech-nologies advance and emerging hydro-kinetic devices are commercialized.

New turbine technologies and O&M tools will deliver efficiency gains, en-hanced environmental performance, and cost reductions at existing hydro and pumped storage facilities. Improved as-sessment, permitting, and development methodologies and energy conversion systems will enable capacity additions at both current and green-field sites.

Novel in-stream hydro, tidal, ocean cur-rent, and wave energy technologies will provide access to currently untapped resources in natural environments and water conveyance systems.

Public-private investments in basic science, technology development, and proof-of-concept and field verifi-cation testing will be required before innovations in conventional hydro and hydrokinetic technologies are ready for commercialization. The list below identifies RDD&D topics for growing the role of water power in meeting the world’s needs and aspirations.


• Flow measurement techniques and hydrau-lic modeling tools for water intake and other structures to optimize existing configura-tions and to support the development of new technologies

• Innovative structures and components, such as aerating turbines, engineered based on biological, water quality, and energy capture con-siderations to improve species passage and survival efficiency and to mitigate poten-tial dissolved oxygen and water tempera-ture problems

• Damage-resistant materials and coatings for preventing cavitation and erosion in turbines and extending the lifetime of generators

• Improved control, O&M, dam safety assessment, and life optimization strategies for increasing the value and extending the lifetime of existing plants

• Assessment of conventional hydro plant operations, pumped hydro ramp rates, ancillary service values (e.g., frequency regulation and VAR support), and wind and solar integration opportunities to improve grid sup-port capabilities

• Hybrid reservoir/hydro plant operating and scheduling strategies and designs integrating water-energy supply and storage functions to support capacity additions, provide ancillary services, and increase societal benefits

• Variable-speed and high-voltage generator technology to improve integration by providing ancillary services and to improve efficiency by reducing transformer and breaker losses

• Best practice project siting, design, and relicensing tools to develop sustainable water resource management strategies, minimize conflicts, improve grid inte-gration, and streamline permitting and approval processes

Global Navigable Rivers as Indicator of Conventional Hydro & Hydrokinetic Resources (Credit: European Commission, Global Environment Monitoring)

• Programmatic and cumulative impact assessments for quantifying benefits and evaluating and mitigating the possible effects of widespread deployment on fish and eel populations, water resources, green-house gas emissions, and other issues

• Standards and certification and accreditation methods to characterize the sustainability credentials of hydro-power sources and production methods

Hydrokinetic

Emerging in-stream river, tidal, and ocean current technologies convert the kinetic energy of largely hor-izontal water flows into electricity, while wave energy systems generally harness the up-and-down motion of water molecules as waves pass through them. The numerous technologies competing to establish com-mercial potential face many common challenges.

• Centralized test facilities in diverse aquatic environments and overall performance testing and measurement stan-dards for consistent evaluation and field demonstra-tion of emerging technologies

• Device and array models and analytical tools for com-paring alternative technologies and optimizing design tradeoffs to inform R&D investment and technology development

• Proof-of-concept testing and design optimization for advanced energy conversion, mooring, and foundation technologies and hybrid wind-hydrokinetic devices to


Technology Status•Pre-Commercial

Current Deployment•< 1 GW globally

Resource Potential• Untapped resources are

huge but geographically limited and sometimes located in areas remote from the grid

Critical Issues• Siting and permitting• Environmental impacts• Field testing and demonstration• Cost reduction• Grid integration• Survivability and long-term

performance

Hydrokinetic Facts & Issues

Global Annual Mean Wave Resource Power Distribution (Credit: Canadian Hydraulics Center, National Research Council of Canada)

balance cost, productivity, efficiency, durability, integration, and environmental impacts in different aquatic settings

• Advanced, ruggedized sensors and accurate and cost-ef-fective resource modeling and forecasting tools to assess regional and site-specific development potential, variability over different time scales, coincidence with demand, ramp rates, likelihood of extreme events, effects of resource extraction, and impacts of climate change

• Project-level, programmatic, and cumulative environ-mental impact assessments for quantifying benefits and evaluating and mitigating possible effects on hydrodynamics, fisheries, marine birds and mam-mals, safety, navigation, and other issues

• Array design methodologies, advanced controls, and O&M strategies to optimize energy extraction and minimize impacts on natural and engineered water flows, wave conditions, and ecological functions

• Best practice project siting and design tools to maximize energy capture, provide grid support, minimize conflicts, and streamline permitting and approval processes

• Direct-drive generators, protective coatings and materi-als, accelerated survivability testing methods, and NDE technologies for helping components withstand harsh marine conditions and for reducing O&M costs

• Superconducting cables, high-voltage DC microgrids, ad-vanced power electronics, and other devices and designs for improving project economics and grid integra-tion while moving bulk power underwater over long distances

• Advanced construction, interconnection, and O&M technologies and practices to reduce installation and ownership costs


Sustaining the rapid expansion in wind energy deployment will depend on continued advances in technology. Progress is needed both in turbine com-ponents and in deployment, integration, and O&M technologies for land-based and offshore wind farms.

Taller towers will provide access to better wind resources, while innovative tower designs will reduce manufacturing and transportation costs and introduce new functionalities. Advances in rotor and blade technology will increase energy capture, decrease capital and O&M costs, alleviate siting bar-riers, and expand applicability. Foundation, plat-form, tower, rotor, and blade technologies optimized for marine environments will make abundant wind resources accessible and offshore projects more eco-nomical in waters of any depth.

For all wind applications, new drive train and power electronics technologies will minimize parasitic energy losses, increase reliability, reduce integration barriers, and provide grid support. O&M advances will reduce costs, enhance market participation and grid integration, and prevent failures.

Public-private investments in basic science, technology development, and proof-of-concept and field verifica-tion testing will be required before innovations are ready for commercialization. The list below identifies RDD&D topics for growing the role of wind power in meeting the world’s needs and aspirations.

Turbine Components1. Towers & Foundations

The recent run-ups in energy and steel prices and the continuing challenges in manufacturing, transporting, installing, and maintaining turbines underscore the need for new materials and designs to increase hub height (>120 m), reduce weight and cost, facilitate deployment, improve reliability, and support grid integration.

• Composite materials, space frame designs, and other innovations for reducing costs, increasing capaci-ty factors, maintaining and improving structural integrity, and enhancing aesthetics

• Self-erecting towers, tower designs incorporating heavy-lift derrick cranes, and other innovations for allowing greater height transportable by con-ventional means, easing deployment in difficult terrain, and facilitating O&M

• Towers incorporating small, cost-effective compressed air energy storage (CAES) systems for use in reduc-ing the ramp rates associated with variable wind conditions and in supporting grid integration without compromising reliability

• Tower, foundation, and anchoring technologies for small wind turbines to reduce costs and expand applicability

• Analytical tools for optimizing tower and foundation design tradeoffs among raw material, manufac-turing, and installation costs, as well as tower performance and functionality

2. Rotors & Blades The quest for ever-larger machines and the per-sistent failure problems associated with today’s technologies place a premium on new materials, coatings, designs, and controls to improve per-formance and reliability and to reduce costs and impacts across all turbine sizes.

• Composite and hybrid materials, innovative blade and rotor designs, and advanced control capabilities to in-crease swept area, improve energy capture in low-velocity and turbulent conditions, decrease stress in heavy winds, reduce lifetime costs, expand applicability, and ease transport and installation

Technology Status• Onshore: Commercial &

Mature• Offshore: Early Commercial

to Pre-Commercial

Current Deployment• > 20 GW in the US and > 100 GW globally

Resource Potential• Land-based and offshore

wind resources are huge, geographically dispersed, and sometimes located in areas remote from the grid

Critical Issues• Cost reduction• Long-term reliability • Grid integration• Resource accessibility• Siting and permitting • Offshore development and

survivability

Wind Power

Wind Power Facts & Issues


• Direct drives, distributed topologies, variable-speed designs, permanent magnet generators, and other innovations for improving the performance and reliability of drive train components

• Advanced test centers for performance and reliabil-ity assessment of drive train components

• Silicon carbide devices, other advanced solid-state power electronics, and new circuit designs to lower cabling and interconnection costs, protect turbine components, maintain system stability, reduce the risk of voltage collapse, and provide grid support

• Novel controllers to transform wind projects into virtual power plants capable of fulfilling grid reli-ability requirements relating to real and reactive power control, voltage control, and fault ride-through capability

4. Offshore Systems

Projects offshore face unique siting, deployment, operating, maintenance, and integration challenges, creating demand for designs, components, and systems optimized to reduce costs, improve perfor-mance, increase survivability, and expand energy capture in aquatic environments.

• Improved blade manufacturing and fabrication pro-cesses and advanced testing facilities to improve reliability and reduce costs

• Novel blade designs and coatings for reducing drag, noise, and visibility to decrease stress, increase ef-ficiency, and improve aesthetics and acceptability for turbines of all sizes

• Self-cleaning blades to reduce O&M costs and increase worker safety by avoiding the need for manual cleaning

• LIDAR-based wind monitoring and blade control for sensing near-field upwind conditions and adjust-ing blade pitch and yaw to improve efficiency, reduce stress in turbulent and heavy winds, mod-erate ramping speeds, and allow for the shedding of load to facilitate grid integration

3. Drive Trains & Grid Interfaces Gearbox and generator components have proven prone to premature failure, and power handling and control capabilities have become increasingly important as wind energy achieves significant levels of penetration. These developments highlight the need for new designs and technologies at both the individual turbine and wind farm levels.

U.S. Wind Resource Map (Credit: NREL)


• Alternative methods for assessing offshore wind resources and for delivering, installing, and maintain-ing turbines in marine settings to minimize project siting, development, and O&M costs

• Comprehensive data and maps addressing bathymetry,

wave and storm conditions, seafloor substrates, criti-cal habitats (for bird, mammal, fish, and other spe-cies), commercial and recreational fishing, air and sea navigation, archeological and cultural sites, and other natural and human factors to avoid conflicts and support project siting and development

• Protective coatings, materials, and systems and ac-celerated survivability testing methods for helping rotors, blades, controls, drive trains, and electrical systems withstand harsh marine conditions

• Design assessment tools for deepwater projects, mega-turbines (5 to 10 MW), and hybrid offshore wind-wave-tidal energy systems to guide technology development activities

• Advanced blade, rotor, and tower configurations and foundation, platform, and anchoring systems to make projects in transitional and deep waters economi-cally feasible

• High-power, direct-drive generators integrating su-perconducting wire to enable smaller, lighter, and more efficient drive trains and larger (10 MW) turbines

• Superconducting cables, high-voltage DC microgrids, advanced power electronics, energy storage innova-tions, and other devices and designs for improving project economics and grid integration while moving bulk power underwater and over long distances

• Analytical tools for optimizing offshore wind system design tradeoffs among raw materials, manufactur-ing, installation, and O&M costs and wind speed, water depth, and grid proximity considerations

Project Development, Operations, Maintenance & Integration

1. Siting, Design & Permitting As the best resources get harnessed and levels of penetration grow, so too do the challenges associ-ated with identifying good sites and developing land-based wind farms, offshore projects, and community-scale installations consistent with the objectives of turbine owners, grid operators, and local stakeholders.

• High-resolution, time-synchronous, field-validated wind resource maps and profiles to support assess-ment at different tower heights and to account for micro-climate conditions

• Advanced wind resource assessment tools to reduce project development risks by accurately and cost-effectively predicting land-based and off-shore conditions across project lifetimes in terms of average velocity, resource variability, energy production, and coincidence with demand

• Best practice project siting and design tools to maximize energy capture, provide grid support, manage conflicts, and streamline permitting and approval processes

• Pulsed microwave warning systems, lighting designs,

and other approaches for managing turbine-wildlife interactions to protect species and habitats

• Programmatic and cumulative environmental impact assessments for evaluating and mitigating the possible effects of widespread deployment on climate and weather patterns, wildlife, aesthetics, and other issues

2. Plant Productivity & Grid Integration Once turbines are deployed, improved situation awareness and control capabilities and advanced technologies are needed to integrate energy pro-duction objectives with grid reliability needs and support economical and efficient operation of wind generation, other power plants, and transmission and distribution systems.

• Distributed data collection networks, LIDAR sens-ing of upwind conditions 8 to 10 km away, advanced forecasting tools, and improved visualization methods for understanding resource availability, opera-tionalizing production data, reducing needs for backup generation, and supporting scheduling and planning over multiple time scales (hourly, daily, weekly, monthly, annually, and across 10- and 20-year horizons)

• Farm-wide, real-time performance monitoring, predic-tion, and production optimization tools for tracking and tuning individual turbines to maximize out-put, manage ramp rates, and back off generation as appropriate

• Centralized control room criteria and operating guide-lines for balancing production and grid support functions on a site-specific basis


• Innovative power system planning and operations tools, including probabilistic planning methods, models of wind generator and wind farm dynam-ics, wind forecasting and scheduling tools, and energy storage technologies (see Integration, p. 28, for more detailed discussion)

• Integrated wind production and fast-response storage/generation systems to better match variable output with load

3. Operations & MaintenanceRising O&M costs over the lifetime of deployed turbines demonstrate that current understanding and management of materials degradation and component failure mechanisms are insufficient. New knowledge and tools are required to increase reliability and avoid premature failure without impacting capacity factors.

• Laboratory and field studies, unobtrusive and easily deployable NDE techniques such as shearography for blades, and advanced analytical tools to support predictive modeling and proactive management of common degradation processes and failure modes for in-service wind turbine components and materials

• Advanced condition monitoring systems to address design-related turbine failure modes by comparing operational loads with the reference design load spectrum

• Sensors, diagnostics, and NDE tools integrated within turbine components for automated condition as-sessment to reduce O&M costs and improve worker safety

• Field measurement and verification studies for new turbine systems and industry-wide loading, reli-ability, and failure databases for existing components to support performance assessment and O&M optimization for sensors, controls, motors, drives, gearboxes, blades, rotors, towers, and electrical equipment

• Preventive and reliability-centered maintenance programs and knowledge-based solutions and tools for reducing O&M costs and failure rates, manag-ing component lifetimes, and improving worker health and safety

Global Wind Resource Map (Credit: 3TIER)


Integration

Renewable resources will continue to be harnessed and advanced technologies deployed within both technical and societal contexts. The rate of adoption and scale of penetration will be determined by the ex-tent to which renewables can be seamlessly integrated within existing and evolving energy infrastructures and social, political, economic, and environmental systems. Effective and economical integration will occur if technology development and deployment account for it and stakeholders desire, anticipate, and accommodate it.

Within the electricity sector, large-scale renewables de-ployment will require expanded transmission capacity while installations of wind, solar, and other variable re-sources will introduce new dimensions to transmission planning and operations. Advanced technologies—incorporated within renewable energy systems, grid interfaces, and the grid itself—will make integration easier and less costly and will endow the grid with im-proved power handling and control capabilities. At the distribution level, widespread deployment of PV, small wind, and other technologies will create both challeng-es and opportunities. New technologies for integrating distributed and central-station resources will maintain performance and reliability and enable effective energy management, market access, service delivery, and grid planning and operations.

For certain transportation and heating applications, successful integration of renewables with existing fuel delivery systems will prove critical to market penetra-tion. For others, renewables will supplant existing infrastructure, consistent with the objectives of poli-cymakers, consumers, and other stakeholders. Tech-nological innovations will facilitate integration and, as appropriate, create alternative modes of producing energy and delivering energy services.

New technologies also will help inform the critical de-cisions influencing renewables deployment that will be made by policymakers, agencies, the private sector, consumers, and the public.

Public-private investment in basic science, technology development, and proof-of-concept and field verifica-tion testing will be required before innovations are ready for practical application and commercialization. The list at right identifies cross-cutting RDD&D top-ics for integrating renewables within energy, human, and natural systems to grow their role in meeting the world’s needs and aspirations.

Technical Systems

1. Electricity Transmission Planning & OperationsThe majority of capacity additions for renewable electricity generation will be in the form of large plants requiring access to the transmission grid and to power markets. Advanced technologies and planning and operating tools are needed to pro-vide access, handle additional power flows, and afford smart grid capabilities that will account for the unique behaviors of variable-output generators while improving both system-wide efficiency and reliability.

• High-voltage DC transmission, ultrahigh-voltage AC and DC transmission, low-sag conductors, high- temperature superconductors, and other innovations to reduce costs while moving more power

• Underground transmission systems and compact system designs to facilitate siting and permitting processes for new capacity and system upgrades

• Analytical tools for modeling transmission system expansion and operation at continental, national, and regional scales to support planning for high levels of wind and solar penetration

• Advanced energy storage technologies, including fly-wheels, batteries, CAES, pumped hydro, phase-change materials, and hydrogen production, for mitigating swings in output, firming up renewable generat-ing capacity, using off-peak energy to serve peak loads, and creating new markets

• Best practice siting and design tools and programmatic and cumulative environmental impact assessments to streamline permitting and approval processes for new transmission lines

Technology Status• Commercial to Pre-

Commercial

Critical Issues• Cost allocation• Wide-area planning and

operations• Intelligent automation• Stakeholder participation• Informed decision-making

Integration Facts & Issues


• Cost allocation, strategic benefit analysis, and stake-holder participation tools to facilitate assessment, valuation, development, and permitting of new transmission and storage capacity

• Statistical and probabilistic tools to assist grid opera-tors in identifying new flow patterns, anticipating constraints, and planning for large-scale renew-ables deployment

• Comprehensive regional frameworks to account for the ramp rates and ancillary services of renewable genera-tion options, determine capacity and reserve require-ments, and assess the costs of maintaining reliability and allowing redispatch to support integration on project-specific and cumulative bases

• Methods for determining and mitigating impacts—in terms of fuel consumption, cycling stresses, air emis-sions, costs, and other factors—of operating fossil or other plants to maintain reliability at high levels of renewables penetration

• Integration solutions for inter-area transfer of wind and solar generation, including capabilities for dy-namic scheduling across interties and for pooling balancing area responsibilities and resources

• Analytical tools for aligning renewable energy produc-tion with grid support and for aligning market prices with ancillary service values to provide plant own-ers with incentives for improving reliability

• Advanced short-term, 24-hour, and longer-term resource profiles and forecasting tools for wind and solar generation at micro-climate and larger scales to support planning, make variable units dispatch-able, allow for shorter transaction frequencies, reduce integration costs, and enable high levels of penetration

• High-temporal-resolution solar and wind data, for periods from seconds and minutes, to enhance un-derstanding and modeling of resource variability, ramp rates, and other key factors

• Distributed data collection networks, synchrophasor-based monitoring systems, and improved visualization methods for wide-area situation awareness and real-time control

• Detailed generator, load, and grid models and fast-

response generation and demand resources to im-prove understanding of dynamic interactions and to better accommodate variable generation

• Dynamic, real-time thermal rating systems and op-erational capabilities to accommodate additional power flows and facilitate market access while maintaining reliability

• Intelligent protection, islanding, and restoration sys-tems to prevent cascading failures associated with uncontrollable generators

Credit: NASA


• Advanced training simulators to assist operators in understanding and responding to standard and unusual behavior from wind and solar capacity

• Fault current limiters and other advanced controllers to provide grid support and address and isolate problems induced by variable generators

2. Electricity Distribution Planning & OperationsWidespread deployment of distributed genera-tion—particularly PV—will affect markets served by conventional electricity infrastructure, impose new demands on the grid, bring about changes in consumer behavior, and create opportunities across diverse business categories. Advanced technologies are needed to enable high levels of deployment in current radial distribution systems and to transform distributed generators into assets within the evolv-ing smart grid.

• New analysis and planning methods for predicting the effects of high penetration levels to identify potential problems or benefits and to set limits as appropri-ate at the circuit and system levels

• Improved PV and inverter models and forecasting methods to understand and account for steady-state and dynamic behavior, fault response and ancillary service capabilities, impacts of clouds and pollution, and effects on distribution system performance over timeframes ranging from mil-liseconds to seasons

• Advanced circuit designs and siting, forecasting, and operating tools to anticipate and mitigate adverse impacts associated with high penetration levels, maximize grid support value, and deliver pre-mium power services

• Automated distribution systems and interface devices incorporating low-cost and secure communications, metering, protection, and controls to provide smart grid capabilities and protection and coordination functions

• Interconnection and other technologies for mitigat-ing problems created by grid-tied renewables, such as ground fault overvoltages from wind generators and voltage variations from distributed PV

• Consensus codes and standards and universal com-munications infrastructure and protocols to ensure interoperability between the grid and renewable energy systems

• Comprehensive frameworks for understanding and quantifying the effects of distributed PV on energy

use, peak loading, reliability, and other factors to sup-port integration on project-specific and cumula-tive bases

• Localized energy networks, DC microgrids, and DC mini-grids integrating renewables with energy stor-age, demand response, and premium power technolo-gies to increase efficiency and improve power quality and reliability

• Residential, commercial, industrial, and transportation end uses and demand response capabilities integrated with renewables to match loads with generation and provide grid support

3. Fuel Delivery & StorageDistributed solar and geothermal heating systems avoid the need for large-scale fuel delivery and storage, whereas current bioenergy sources for transport and heating applications face infrastruc-ture barriers due to compatibility issues, handling requirements, and transportation costs. New tech-nologies are needed to ensure that advanced etha-nol and biodiesel, algae-based fuels, and methane and hydrogen produced using biological sources or renewable electricity will be able to utilize exist-ing networks or evolve efficient and cost-effective means of serving end users.

• Proactive assessment and modeling of infrastructure requirements for bioenergy sources and other renew-ably derived fuels to define needs and identify opportunities for addressing delivery and storage challenges during the technology development process

• Assessment of existing infrastructure for natural gas and other fuels to determine potential for delivery and storage of renewable energy sources and to identify fuel quality constraints, define qual-ity standards, and develop fuel processing and cleanup solutions

• Advanced distribution systems for solar thermal heat-ing, geothermal heating, and renewable CHP technolo-gies to expand retrofit and green-field applica-tions of district heating

4. Hybrid Systems & Novel Concepts Integrating variable-output sources such as wind and solar together and with other renewable, fossil, and nuclear generation options and storage technol-ogies can create energy production profiles that bet-ter match demand and help address other integra-tion challenges. Synergistic green energy systems, as well as innovative ideas for harnessing natural and human energy flows, need to be explored.


• Hybrid systems that integrate variable-output renew-ables together and with other generation and storage technologies to yield aggregate output profiles and dispatch characteristics that minimize integration requirements and provide grid support

• Novel generators and motors, mechanical systems, electronic pulsing circuits, and ambient energy devices exploiting nanotechnology and the laws of phys-ics to capture energy flows in natural and man-made environments

• Methods for directly locking solar energy into carbon bonds to create new types of fuels analogous to bio-energy sources but without requiring the growth of complex organisms that represent a relatively inefficient way to transform solar energy into useful energy

Social, Political, Economic & Environmental Systems

1. Modeling Global, national, and state policies will expand the role of renewables in the world’s energy supply mix, while physical climate change will alter the availability of wind, solar, hydro, and bioenergy resources. New technologies are needed to improve understanding of how these factors will influence renewables deployment, as well as security, reli-ability, cost, environmental quality, greenhouse gas emissions, and sustainable development.

• Modeling energy supply, delivery, and use systems and markets—and the deployment and operation of central-station and distributed renewables and other advanced tech-nologies—at various scales to assess the impacts of market, policy, and technology variables

• Modeling the impacts of climate change on the location, abundance, and vari-ability of renewable resources to inform technology planning and investment

2. Decision-MakingDecisions made by policymakers, business executives, consumers, the public, and other stakeholders will largely determine how renewables are employed for meeting energy needs. To foster political, economic, and social conditions conducive to accel-erated renewables deployment, new technologies are needed to integrate the “public good” aspects and techni-

cal attributes of renewable energy sources within the decision-making frameworks employed by diverse stakeholders.

• Renewable energy technology assessment frameworks to inform technical and business planning and decision-making by incorporating current data and near-, mid-, and long-term projections of capital, O&M, fuel, and other costs and addi-tional performance indicators (efficiency, capacity factor, availability, lifetime, land and water use, emissions, etc.)

• Cradle-to-grave (full fuel cycle) greenhouse gas mea-surement methods for renewable, fossil, and nuclear energy sources and technologies to support compar-ative analysis of public-private investments in climate mitigation options on a consistent basis

• Life-cycle cost analysis tools accounting for internal-ized and externalized factors, including energy secu-rity, climate change, environmental quality, and social equity, to inform decisions relating to renewables and other energy supply options

• Comprehensive frameworks for assessing stakeholder decision-making processes to determine the influ-ence of alternative policies, regulations, codes, standards, incentives, and business models

• Methods and tools for communicating risks, support-ing tradeoff analyses, and influencing opinions to build acceptance for renewables deployment

Credit: Scottish Alliance for Geoscience, Environment, and Society

Sponsors

ACORE, The Outlook on Renewable Energy in America: Volume II: Joint Summary Report. Washington, DC: 2007.

Brown, Merwin, “New Transmission Technologies for Renewable Integration.” Presented to i4Energy Seminar, December 15, 2008, Berkeley, CA. Brown, Merwin, et al., Transmission Technology Research for Renewable Integration, California Institute for Energy and Environment, University of California, September 2008. EPRI, Renewable Energy Technical Assessment Guide—TAG-RE: 2007. Palo Alto, CA: 2008. 1014182. EPRI, Program on Technology Innovation: Evaluation of Solar Thermal Energy Storage Systems. Palo Alto, CA: 2009. 1018464.

American Council on Renewable Energy

1600 K Street NW, Suite 700 Washington, DC 20006202.393.0001www.acore.org

Electric Power Research Institute

3420 Hillview AvenuePalo Alto, California 94304-1338800.313.3774www.epri.com

EPRI, Solar Photovoltaics: Expanding Electric Generation Options. Palo Alto, CA: 2008. 1016279. EPRI, Distributed Photovoltaics: Utility Integration Issues and Opportunities. Palo Alto, CA: 2008. 1018096. EPRI, Human Performance Management and Optimization: Strategic R&D Directions for Human-Centered Technologies, Tools, and Methods. Palo Alto, CA: 1004665. 2002. Sandia National Laboratories, Renewable Systems Interconnection Study: Advanced Grid Planning and Operations. SAND2008-0944P, February 2008. U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, Renewable Systems Interconnection Distributed PV Activities: Multi-Year Research Plan (MYRP) FY2008-FY2013, 2008.

Sources

Electric Power Research Institute 3420 Hillview Avenue, Palo Alto, California 94304 • PO Box 10412, Palo Alto, California 94303 USA 800.313.3774 • 650.855.2121 • [email protected] • www.epri.com

© 2009 Electric Power Research Institute (EPRI), Inc. All rights reserved. Electric Power Research Institute, EPRI, and TOGETHER...SHAPING THE FUTURE OF ELECTRICITY are registered service marks of the Electric Power Research Institute.

Printed on recycled paper in the United States of America

1019521 July 2009

reinventing renewable energy - university of wisconsin ... · reinventing renewable energy...

Documents