UNSW EngineeringSchool of Photovoltaics and Renewable Energy Engineering (SPREE)Systems and Policy Group

PV Everywhere

Renew Canberra Meeting 29th May 2019

About me

• Jose Bilbao

• Grew up in Santiago, Chile, many years ago

• Did a BE in Electrical Eng and a MEngSc in MRI at PUC Chile

• I did my PhD at UNSW http://www2.pv.unsw.edu.au/videos/Jose-Bilbao-18May2017/seminar.php

• Currently I’m a lecturer at SPREE and the course coordinator for three courses (LCA, PV systems design, Hybrid RE systems)

• SPREE Student Experience Coordinator

• Research interest in PV systems

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3

PV Everywhere

(low cost electrification)

Health

• Refrigeration• Heating and cooling• Disinfection

Water

• Water pumping• Water purification• Water desalination• Sewage• Water treatment

Food

• Agrivoltacis• Water pumping• Processing and

packaging

Manufacturing

• Clean mining• Thermal processes• Clean processes

Mobility

• Electric charging• V2G• PV on cars,

motorbikes, bicycles,..

Buildings

• Ultra efficient DC houses

• Facades (BIPV)• PVT heating and

cooling

Waste

• PV recycling• Design for recycling• Circular economy• C2C

U.S. Secretary of Energy Steven Chu at WREF 2012 roughly said that:

~We can debate when renewable energy will be the main source of energy, but not if it will happen… This is not because RE is

green/sustainable, but because it will be cheaper~

https://www.youtube.com/watch?v=zCCyW7blB78

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Why PV everywhere?

Why PV everywhere?

https://www.solarchoice.net.au/blog/solar-power-system-prices

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PV efficiency

Best cell and best module

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Average module efficiency

Photovoltaics Report by Fraunhofer ISE

PV learning curve

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Experimental phase Industry

development

Mass-production

LCOE projections in Australia

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https://publications.csiro.au/rpr/download?pid=csiro:EP189502&dsid=DS1

Bottom line, PV and Wind are the cheapest way to generate electricity, even with storage!

And it will keep getting cheaper!

Australia Utility Scale PV Pipeline

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www.cleanenergyregulator.gov.au

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PV Everywhere

(low cost electrification)

Health

• Refrigeration• Heating and cooling• Disinfection

Water

• Water pumping• Water purification• Water desalination• Sewage• Water treatment

Food

• Agrivoltacis• Water pumping• Processing and

packaging

Manufacturing

• Clean mining• Thermal processes• Clean processes

Mobility

• Electric charging• V2G• PV on cars,

motorbikes, bicycles,..

Buildings

• Ultra efficient DC houses

• Facades (BIPV)• PVT heating and

cooling

Waste

• PV recycling• Design for recycling• Circular economy• C2C

PV waste will be a significant challenge in the future

Source: IEA/IRENA, 2016

• Global e-waste = 41.8 million metric tonnes (record set in 2014).

• Annual PV waste was 1000x less

• By 2050, PV waste could exceed 10% of the record global e-waste.

• We should not repeat mistakes of e-waste – major reputational risk for PV.

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Cumulative Value Creation:

Cumulative Value Creation:

Circular Economy:

Circular Economy:

Source: IEA/IRENA, 2016

We need a new C2C PV industry

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Mass recovery of silicon PV module recycling over thepast 20 years.

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Deng et al. A techno-economic review of silicon photovoltaic module recycling. Renewable and Sustainable Energy Reviews 109 (2019) 532–550.

PV recycling technology

Generation 1

• Down-cycling: recycling PV module using mechanical process (similar to WEEE recycling process).

Generation 2

• Hybrid down-cycling & up-cycling: delamination of PV modules for recover whole piece of glass, other contents goes to mechanical process (e.g. WEEE recycling process)

Generation 3

• Up-cycling and reusing: recover all the valuable components of a PV module for their direct reuse in PV modules or other products

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Delamination – Removal of EVA

Three ways of delamination:

• Thermal treatment

• Chemical treatment (organic solvents)

• Mechanical treatment (e.g. hot knife)

• Combination of the above

Typical structure of silicon PV module (Rycroft, 2016)

Current work

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EVA changes its structure after lamination

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Experiment – Organic/inorganic solvents

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Weight of EVA

(g)

Solvent

Concentration

Volume of solvent

(ml)

Period

(hours)

X1 1,2-Dichlorobenzene 0.0385 99% 10 3

T Toluene 0.0985 99% 10 3

C Choline Chloride 0.1015 70% 10 3

X2 NaOH 0.1131 70% 10 3

X3 KOH 0.0881 70% 10 3

Solvents

Hydrophilic - Polar Hydrophobic - Non-polar

Acetone Lacquer thinner

Ethanol Toluene

Isopropanol Petroleum benzine

Methyl ethyl Ketone 1,2-Dichlorobenzene

Methyl isobutyl Ketone Tetrahydrofuran

Ethylene glycol Trichloroethylene

Chemical treatment – One-cell module in Toluene

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After 24 hours After 1 week

Glass is clean

Backsheet is clean

0

100

200

300

400

500

0 50 100 150 200 250

Tem

pe

ratu

re (

de

gre

e C

)Time (minutes)

Thermal treatment – Double-glass module

Before After

Ramp-up rate: 5 deg C/min

Maximum Temp: 480 deg C

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Thermal treatment – Glass-backsheet module test 2

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Thermal treatment – Glass-backsheet module test 4

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Recover of metals – Chemical leaching

Sample Weight: 0.1094 gSample Ag Al Cu Ni

Original Contents (ug) 634.86 10529.12 3.04 67.88

Recovered material (ug) 664.48 9711.72 4.42 36.51

% of recovery 104.67% 92.24% 145.39% 53.79%

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LCA and the circular economy

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EoL comparative assessment using LCA

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Lunardi et al. (2018). Comparative Life Cycle Assessment of End-of-Life Silicon Solar Photovoltaic Modules. Applied Sciences, vol 8, 1396, doi:10.3390/app8081396

EoL comparative assessment using LCA

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Lunardi et al. (2018). Comparative Life Cycle Assessment of End-of-Life Silicon Solar Photovoltaic Modules. Applied Sciences, vol 8, 1396, doi:10.3390/app8081396

EoL comparative assessment using LCA

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“for recycling to be the best option, it must be no more than 80 km further away than a landfill or incineration plant…”

27

PV Everywhere

(low cost electrification)

Health

• Refrigeration• Heating and cooling• Disinfection

Water

• Water pumping• Water purification• Water desalination• Sewage• Water treatment

Food

• Agrivoltacis• Water pumping• Processing and

packaging

Manufacturing

• Clean mining• Thermal processes• Clean processes

Mobility

• Electric charging• V2G• PV on cars,

motorbikes, bicycles,..

Buildings

• Ultra efficient DC houses

• Facades (BIPV)• PVT heating and

cooling

Waste

• PV recycling• Design for recycling• Circular economy• C2C

HeatElectricity

Thermal Collector

PVT

PV +

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Affolter et al. 2006. PVT Roadmap – A European guide for the development and market introduction of PV-Thermal technology, PV Catapult Project.

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PVT-water (covered or uncovered)

PVT-air (covered or uncovered)

Shockley-Queisser limit ~ 33% for single junction (32% Si)

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http://www.vicphysics.org/documents/events/stav2005/spectrum.JPG

Multijunction SQ limit ~ 49%

At best ~50% of solar energy is converted to heat, not to electricity

Efficiency (SQ) limit depends on the cell temperature

Generally, the efficiency of solar cells decrease with temperature

Most of the energy is converted to heat → increases cell/module temperature

So, cooling a PV module is a good idea!

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Dupré, Vaillon, Green, 2015. Physics of the temperature coefficients of solar cells. Solar Energy Materials and Solar Cells, 140, 92-100

Therefore, PVT is a good idea, right??

1) Decrease the temperature of the cell/module by cooling it with a fluid

2) This increases the efficiency of the cell (more electricity!)

3) We can use the ‘waste’ heat for other purposes (we get heat too!)

4) Profit!*

*In theory yes, but first we need to read the fine print

PVT is not a new idea, the first publication on the subject was by Wolf in 1976 (40 years ago!).

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PVT potential

• High energy density: PVT systems use less space to deliver the same energy than side-by-side systems (PV + SHW)

• Potential reduction of installation cost

• High combined efficiency between 60-80%

• Lower PBT and EPBT compared to PV

• Generate most of the power for a normal house

• Potential uses in commerce and industry

• Architectural uniformity

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Bergene and Lovvik, 1995Elswijk et al.2004,

How much efficiency do you want?

• High temperature rise results in low thermal and electrical efficiency (bad)

• So, it’s better to have a low temperature rise, with high thermal and electrical efficiency (good)

• But then, how useful is low temperature heat??

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Bambrook 2011. Thesis: Investigation of photovoltaic / thermal air systems to create a zero energy house in Sydney

Efficiency

Normalised temp rise

PVT is about trade-offs (the fine print)

Heat

Electricity

Efficiency

Temperature rise (Exergy)

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More useful???

PVT/water system for developing countries

Water tank 100L

20 W submergible pond pump

Thermocouples in inlet, outlet, back of panel, flow sensor, Pyranometer, etc…

Standard panel (same model) as control (12% efficiency at STC)

System worked 24/7 – daily reset

(heating water during the day, cooling water during the night)

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Experimental data: PVT vs PV electricity output

The PVT system outperformed the PV module, due to higher efficiency (cooling)

Except on July (stagnation ‘experiment’, i.e. no flow)

So, what to do when no more heat is needed??

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Transient model

Example of outlet temperature – model vs experiment

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Bilbao & Sproul 2015. Detailed PVT-water model for transient analysis using RC networks, Solar Energy, 115, 680-693

DHW system in Sydney - Covered vs uncovered

Uncovered Covered

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Series or parallel (thermal) configuration does matter, but effect is small

Covered system provide a higher combined output (but electricity output is greatly reduced)

PVT works, but it really depends on the application!

Sky cooling (measured data)

-5

0

5

10

15

20

25

Jan-12 Feb-12 Mar-12 Apr-12 May-12 Jun-12

Syd

ney

Te

mp

erat

ure

(°C

)

Tamb Avg_day (°C) Tsky Avg_day (°C)

Tamb Avg_night (°C) Tsky Avg_night (°C)

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-545

-809-862

-1126

-1045-1085

-1200

-1000

-800

-600

-400

-200

0

Jan Feb Mar Apr May Jun

Ave

rage

dai

ly N

igh

t R

adia

tive

Co

oli

ng

(Wh

/m2)

Night sky cooling simulation results

0

200

400

600

800

1000

1200

1400

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Ave

rage

Nig

htl

y R

ad

iati

ve C

oo

lin

g W

h/m

2

SYDNEY SINGAPORE TUCSON HAMBURG

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• Uncovered PVT systems can be used

for night radiative cooling.

• Night radiative cooling potential from

400 Wh/m2 to 900 Wh/m2 per night.

• It is possible to provide cooling through

the whole year.

• The percentage of radiative and

convective cooling depends on many

variables (+10% to 20% can be

obtained from convective cooling).

PVT solar cooling system

• PVT roof will provide heating during winter

• Cooling in summer via desiccant and IEC

Ground coupled PV/T desiccant air cooling cycle

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Guo, Bilbao, Sproul. Ground Coupled Photovoltaic Thermal (PV/T) Driven Desiccant Air Cooling. 2014 Asia-Pacific Solar Research Conference

PVT seems like a very good idea

• High energy density per area

• High Thermal + PV efficiencies (potentially)

• Co-generation and even tri-generation possibilities

But…

• Complex (plumber + electrician + 2x standards)

• Needs to be tailored for each application – ‘right’ application

• Not great penetration or market (first panel in 70s)

• Hence, currently PTV systems are expensive and rare

Yet, low cost PVT, BIPVT and high efficiency cells might change this

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Cell efficiency vs Temperature coefficient

Panasonic Champion SHJ cell

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Bilbao, Dupre, Johnson. On the effects of high efficiency solar cells and their temperature coefficients on PVT systems. PVSEC-25, Busan, November 2015

Cell

Eff. (%)

Module

(Wp)

Temp.

Coeff

(Pmpp%/K)

Medium 20% 290W -0.38%

High 30% 435W -0.22%

Higher 40% 580W -0.05%

Simulation example – DWH in Sydney (1yr data)

Similar trend between cover and uncovered systems (compared with previous results)

Amount of thermal energy output could be ‘tuned’ depending on the application

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Simulation example – DWH in Sydney (1yr data)

PV performance does not ‘suffer’ as much, because of low temperature coefficients

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PV Everywhere

(low cost electrification)

Health

• Refrigeration• Heating and cooling• Disinfection

Water

• Water pumping• Water purification• Water desalination• Sewage• Water treatment

Food

• Agrivoltacis• Water pumping• Processing and

packaging

Manufacturing

• Clean mining• Thermal processes• Clean processes

Mobility

• Electric charging• V2G• PV on cars,

motorbikes, bicycles,..

Buildings

• Ultra efficient DC houses

• Facades (BIPV)• PVT heating and

cooling

Waste

• PV recycling• Design for recycling• Circular economy• C2C

Agrivoltaics

Potential of:

• Increasing land efficiency

• Reducing water use

• Improving crop yield and quality

» Wind protection

» Frost protection

» Shading

• Providing farmers with additional revenue stream

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Early results from around the world - Germany

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Source: Fraunhofer ISE

Early results from around the world - France

• Wineries are threatened by climate change

• Use smart shading to limit excess of light and heat:

» Preservation of aromatic profiles of wines

» Alternative to irrigation during dry periods for vineyards with no access to water: 20% of water saving

» Preservation and even increase of yields: fight recurring drops of grape yields related to climate change

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Source: https://sunagri.fr/agrivoltaics/wine-growing/

Early results from around the world - Japan

• Called “solar sharing”

• Modules are around 3 mts height

• 33% shading

• Manual tilting mechanism

• “Small” areas (1000 m2) but with high yield

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Source: https://solar-sharing-japan.blogspot.com/p/basic-information-about-our-project.html

Agrivoltaics in Australia?

• ITP Renewables, UNE and UNSW are looking for funding for a desktop feasibility study

• Agrivoltaics seem to bring many benefits for crops in arid zones

• Also potential for high density horticulture and green houses

• Looking to carry out several demonstration projects in Australia

» Different climates

» Different crops

» Different technologies

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https://www.conservationmagazine.org/2014/07/agrivoltaics/

Thanks for your attention!

Dr Jose Bilbao

j.bilbao@unsw.edu.au

SPREE Systems and Policy group

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And even more applications!

55

PV Everywhere

(low cost electrification)

Health

• Refrigeration• Heating and cooling• Disinfection

Water

• Water pumping• Water purification• Water desalination• Sewage• Water treatment

Food

• Agrivoltacis• Water pumping• Processing and

packaging

Manufacturing

• Clean mining• Thermal processes• Clean processes

Mobility

• Electric charging• V2G• PV on cars,

motorbikes, bicycles,..

Buildings

• Ultra efficient DC houses

• Facades (BIPV)• PVT heating and

cooling

Waste

• PV recycling• Design for recycling• Circular economy• C2C

PV on cars

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Masuda et al. Static concentrator photovoltaics for automotive applications. Solar Energy 146 (2017) 523–531

PV on cars

• Hyundai Ioniq gives ~7.2 km/kWh

• Tesla model 3 gives ~6.4 km/kWh

• Prius gives ~ 8.8 km/kWh

• So 2.1 kWh provides a range between 13 km to 18 km

• Close to provide enough energy to 50% of the trips (in Japan)

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Masuda et al. Static concentrator photovoltaics for automotive applications. Solar Energy 146 (2017) 523–531