Just and Sustainable PV Recycling

Transcription

1 Just and Sustainable PV Recycling Dustin Mulvaney, Ph.D. Technical Advisor, Silicon Valley Toxics Coalition Postdoctoral Researcher, University of California, Berkeley Envisioning Sustainable Solar Technology Forum on Solar Recycling Palo Alto, June 15, 2011

2 Preventing an PV-waste crisis Rare and precious metals in PV include: tellurium, indium, silver, molybdenum, ruthenium... Toxic metals in PV include: compounds of lead, cadmium, selenium...

3 Peak Everything! Sustainable Resource Conservation Urgent action is now clearly needed to sustainably manage the supplies and flows of these specialty metals given their crucial role in the future health, penetration and competitiveness of a modern high-tech, resource-efficient Green Economy. Achim Steiner, Executive Director, United Nations Environmental Programme Less than 1% of Indium & Tellurium is recycled (UNEP 2011)

4 Green Jobs in the clean energy economy Raising levels of recycling worldwide can... contribute to a transition to a low-carbon, resource-efficient Green Economy while assisting to generate green jobs, Achim Steiner, Executive Director, United Nations Environmental Programme

5 How can we estimate how much PV waste and when? Key Questions: How much PV was produced? How much does each PV module weigh? (tons/mwp) How much production waste? number of damaged/defective modules? How long will the PV modules operate? Values for various parameters are often unavailable. Estimates have high levels of ex ante uncertainty.

6 Waste Flow From Small Scale (10MWp) Manufacturing Facility production ends legacy waste broken, defective PV modules Fthenakis 2000

7 Federal Ministry for the Environment, Nature Conservation and Nuclear Safety s estimate of PV waste volume in Europe

8 PV Cycle founded

9 PV Cycle founded

10 Anticipating PV Waste Streams PV modules are expected to become a critical part of the waste stream in years, when a large number of EoL modules become available for recycling (Choi and Fthenakis 2010)

11 What can be recycled from PV waste? Glass cullet, high value for float glass Glass cullet, low value downcycled glass products Silicon wafers/granulates (embodied energy) Silver, indium, tin, molybdenum, nickel, zinc Copper, aluminum, steel Plastic components (junction boxes) CdTe filter cake (tellurium recovery; cadmium?) CIGS filter cake (selenium, gallium, indium, copper)

12 Recycling Techniques - Physical o Crushing o Attrition o Density separation o Flotation o Adsorption o Radiation o Metal separator - Chemical o Acid/base treatment o Solvent treatment - Thermal o Incineration o Pyrolysis o Melting, slagging o Energy recovery

13 What can be done with PV waste? How can high value materials be recovered? Does dedicated PV recycling make more sense than bulk processing with other (electronic) waste streams? Should there be different waste streams for thin film, silicon-based PV waste?

14 Some smelting operations can recover many metals Umicore smelting/refining operations

15 Aluminum recycling is widespread...

16 Cradle to cradle glass recycling is possible for some PV technologies, but there are obstacles for others (impurities, toxic dust)

17 Life Cycle Impacts of Using Recycled Silicon Wafers (Muller, Wambach, & Alsema 2006)

18 Indicators for just and sustainable PV recycling Environmental (low energy use, little toxic emissions, high metal recovery rates, low use of fresh water, low energy transportation) Social (job creation for unemployed; create highly skilled jobs; healthy and safe jobs) Economic (low net costs; low capital costs, local economic growth) (adapted from UNEP 2009)

19 Conclusion: Towards just and sustainable PV recycling Recycling has multiple benefits: resources & energy, environmental justice, green jobs More collaborations are needed across sectors to encourage design for environment/recycling Distant time horizons suggest that mandatory recycling will be required to encourage participation, eliminate free riders, avoid economic penalties for good product stewards