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RAELRAEL Wind Group Projects

Christian Casillas, Stephen Pepe and

Daniel PrullRAEL lunch seminar,

UC Berkeley2/14/2007

Renewable and Appropriate Energy Lab Wind Group

RAELRAEL Lab

• Moving to in January 2009

• Temporary office space in Evans Hall

• New lab space in RFS– 30’ by 50’ workspace

w/ mezzanine, sink, loading dock, painting fume hood


RAELRAEL Lab

• New lab space in RFS– Large field w/

unobstructed bay winds

– Tower being designed

– 6.78 m/s BAAQMD wind speed at 10m


RAEL

Global Renewables Facts


RAELGlobal Renewables Facts

REN21. 2006. “Renewables Global Status Report 2006 Update” (Paris: REN21 Secretariat and Washington, DC:Worldwatch Institute)


RAELGlobal Renewables Facts


• 2004 renewable power capacity totals 160 GW worldwide*– ~4 percent of global power sector capacity– Developing countries account for 70 GW

• Renewable energy generated as much electric power worldwide in 2004 as one-fifth of the world’s nuclear power plants*

* Excluding large hydropower


RAELTop Renewable Countries



RAELExisting Wind Capacity


RAEL

Wind Cost Trends


RAELSmall Wind Sector

• Small wind turbines only account for an estimated 30 MW or 0.05% of total installed capacity

• Design issues:1. inefficient designs comparedwith utility-scale counterparts

1. consumer noise and reliability concerns2. expensive towers, inverter, batteries3. economies of scale


RAEL

Turbine Testing Facility


RAEL

Why Small Wind Turbines?• Small wind industry is growing • Small wind turbines face several obstacles to

greater use, including:– Performance specifications are not standardized and

manufacturers report performance specifications that are optimistic and inconsistent

– Consumers do not have user-friendly tools to compare turbines or accurately estimate energy performance

– Consumers need greater assurance of safety, functionality, and durability for a product that requires significant investment

– Agencies providing financial incentives lack performance assurance, which in some cases has resulted in the lack of support for small wind financial incentives


RAEL

RAEL Turbine Testing Lab• Draft Interstate Renewable Energy

Council (IREC) standard– Test for performance (torque, power

curve), safety, duration (wear & tear), noise

• AWEA certification• CEC Emerging Renewables Program


RAEL

California Energy and Power• 10kW machine• Savonius Rotor (drag type)

– Unidirectional• Injection molded design• ~6’ rotor

• Designed to be built in ‘windwall’ arrays


RAEL

Generator and MotorTest Stand


RAEL

Appropriate Design of Small Turbines for Rural

Electrification


blueEnergy-manufacturing turbines in Bluefields, Nicaragua

• Founded in 2004• Workshop and Office in Bluefields, NI• 4 full-time employees in NI• Have had over 70 volunteers• Have produced 4 500W and 4 1kW

machines• 3 pilot project sites in NI

blueEnergy pilot sites

Punta de Aguila: Charging Station Model

500W Capacity Machine. Installed in Aug 2004. Charges batteries for 6 home systems.

Pearl Lagoon: Fixed Public School Model

500W Capacity Machine. Installed in 2005

INATEC: Urban Backup Model

Primary power source for blueEnergy workshop

Backup power to school security lights and power users in the school administration building

Turbine Design

Permanent Magnet RotorStationary Induction Coils PM Generator

=+

Hand Carved Wooden Blades Gravity controlled furling mechanism

Ease of Production

The simplicity of the design is easy to be built with minimum specialized skills and equipment, but is this

design appropriate for mass production?

What are the economics of these machines?

2006 Summer Sustainability Institute, New Mexico

Other Design Considerations

• Blade material: Wood vs. fiberglass or plastic composite

• Rotor bearing: Moving to quality assured units

• Tower height: Increasing height can increase power output but at a cost of complexity and additional materials.

• Tower Size: Will have to upgrade tower strength as turbine diameter gets too big

Estimated Power Production at Bluefields Site

00.5

11.5

22.5

33.5

44.5

0 2 4 6 8 10

Ave

kW

h/da 2.4m

3.6m

Economies of Scale In Turbine Design

* Estimates made using real wind speed data at INATEC site and an estimated efficiency of 20%

Estimated doubling of energy production for an increase of 10 - 25% in production costs. How do costs scale with production capacity, and material pricing trends?

Ave

kW

h/da

y

Sep Oct Nov Dec Jan Feb Mar Apr May

3v2πρr21CP =

RAEL Small Turbine Characterization Project

Independent Test Facility at Richmond Field Station Using AWEA Draft Standards

• Power Curve Measurement

• Acoustic Noise Measurement

• Duration (Min Reliability Test)

• Strength and Safety

SOURCE: Adegas, et al. Power Curve of small wind turbine generators-laboratory and field testing. Paper presented at World Climate and Energy Event, Rio de Janiero, Brazil. 2003

Wind Speed (m/s)

Pow

er (W

)

Accountability Standards for Current Small Turbine Producers

•Testing facility can be utilized as a proving ground fornew prototypes and design modifications

•Compile a standardized set of production data

•Begin a matrix analysis of $/kWh vs size/production scale/technology for small wind turbines

• Use in comparison to competing technologies (solar/diesel) in rural settings

Create a Data Set Needed to Quantify the Viability of Small Turbines for Rural Electrification

RAEL

EWB-SFP-ATDT / AIDG / RAELPico-Turbine Design


RAEL

Appropriate Technology Design Team

RAELWind

Group

AIDG-sponsored workshop

Design

Cha

lleng

e

Design

Cha

lleng

e

Technical LeadershipTechnical Leadership

Fina

l Des

ign

Fina

l Des

ign

Turbines

Turbines

GuatemalanCommunity


RAEL


RAEL

ROTORWind Power

toMechanical Power ALTERNATOR

Mechanical powerto

Electrical Power


RAEL

No Permanent Magnets

No Permanent Magnets


RAELSelf-Excited

Induction Generator

(+)As simple and robust as PM generators

Already common in wind turbines

(-)Must be supplied with reactive power:

Requires a grid tie, or capacitor bank

for self-excitation


RAELSelf-Excited

Induction Generator

(?)Can it be very small?

Can it be axial flux?

Can it be hand-made?

Never tried on a sub-kW turbine

Efficient despite loose tolerances?

Virtually all commercial generators are radial flux:

Axial flux machines much easier to make by hand:


RAELModeling a Self-Excited Induction Generator System


RAELEWB Rotor Modeling

Utility Scale HAWT• Rotor design for utility-scale HAWT explored

extensively through industry since 1970’s• Most design work done using blade element theory

(BET) • airfoil performance perfected through wind tunnel

tests

Small HAWT and VAWT• typically designed without the luxury of an expensive

wind tunnel• lag behind the large scale machines in efficiency• Designed by ‘handi-craft’

RAELEWB Rotor Modeling

Our design:• Savonius or H-Type

• ADAMS modeling software• NREL Design codes


RAEL

Tethered (High Altitude) Wind Designs


RAEL

TWES: Sky WindPower• Proposed design 240kW w/ 35ft dia. blades.• Future design: 1.5MW with 88’ rotors


RAEL

TWES: Sky WindPower• Autorotation VAWT theory


RAEL

TWES: Magenn PowerMARS 4.0


RAEL


M ag e n n Po w e r A ir Ro to r s Siz e Diam e te r (fe e t) L e n g th (fe e t) Op e r atin g He ig h t ( f t)T ar g e t

Pr ice USDYe ar in Fu ll Pr o d u ctio n

1 kW MA RS (Camper, Boater Siz e) 1kW 6.5 19.5 50-150

To Be Determined 2007

4 kW MA RS (Cottage & Home Siz e) 4kW 13 39 150-400 $9,999 2006

10 kW MA RS (Large Hous e Siz e) 10kW 18 54 200-500To Be

Determined 2007

50 kW MA RS (Large Farm Siz e) 50kW 25 75 200-500To Be

Determined 2007

100 kW MA RS (Up to 15 homes ) 100kW 53 159 400-800To Be

Determined 2007


Determined 2008


Determined 2009

1.6 MW MA RS (up to 300 homes ) 1.6MW 67 200 400-925To Be

Determined 2009


RAEL


• Magnus airship – fully designed and patented


RAEL


• Generates lift via He & Magnus effect


RAEL

TWES: Atmospheric Properties


RAEL

TWES: Research AssistantWhat’s been done:• Literature Study (NREL)• Hybrid Model• Initial Atmospheric Model

What needs to be done• Empirical cost, weight, sizeand power correlations in Excel• e.g. power vs. weight, blimp capacity vs. cost, etc.


RAEL

RAEL Wind Lab Future Work• Testing Lab:

– purchase remaining testing equipment – set up testing facility at RFS (tower, etc)– begin testing Blue Energy or Shangduturbine– test CE&P turbine (~6 to 8 months)– Keep testing!

GIS MappingADAMS DesignTWESDesign for developing communities?


For more blueEnergy or AIDG Project info, visit:

www.blueenergy.org

www.aidg.org

Or contact:

Mathias Craig, Executive DirectorSan Francisco, California, United States

[email protected]: +1 202 744 5840Fax: +1 801 730 9576

Contact InformationFor more RAEL Wind Project

Info, visit:

http://rael.berkeley.edu/projects

Or contact:

Dan [email protected]

Christian [email protected]

Stephen [email protected]


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