Eco-Solar Factory: 40%plus eco-efficiency gains in the photovoltaic value chain with minimised resource and energy consumption by closed loop systems

M.P. Bellmann, R. Roligheten, G.S. Park, J. Denafas, F. Buchholz, R. Einhaus, I. Lombardi, B. Ehlen,

K. Wambach, P. Romero, A. Bollar

1

Content

• Importance of Eco-manufacturing

• Strategies for enhanced process efficiency

• Repurposing of waste products

• Environmental impact

2

Importance of Eco-manufacturing

3

*The evolution of PV waste in Europe, May 2013, SandtConsulting and European Centre for the Recycling of Solar Energy (CERES). Photo: [PVCYCLE]

Market outlook for the next decades: cumulative installed capacity worldwide based on different scenarios

Importance of Eco-manufacturing

4*Assumptions: high-ren scenario, market 100% c-Si, no technological improvements from today to 2030

Expected resource consumption and savings by 2030 (in Megatonnes). (Note: worldwide silver resources in 2014 belong to 0.52 Mt.)

• Maximising resource and process efficiency

• Introducing design for repair, reuse and recycling

5

General approach

Eco-Solar roadmap

6

Argon purge gas recycling

• 3-5 million m3 of argon are used per 1GWp of silicon wafer output

• Recycling systems from the Semicon-industry to refined and expanisve

• Alternative solutions based on chemical looping combustion

• Objective: Recycling rate > 95%

Reusable crucibles based on advanced Si3N4 ceramics

7

Recovery & reuse during Si-ingot crystallisation

• Silica crucibles can be only used once (cracks after usage (a))

• Up to ~30% to the conversion from poly-Si to the as-grown ingot

• Objective: > 10 x reuse for Cz and DS

Treatment of spent Fixed Abrasive Sawing (FAS) slurry

Anode material in Lithium Ion batteries 8

Recovery & reuse of Si-kerf-loss

• Only the coolant is recycled by today

• Separated Si-kerf-loss is landfilled or used as low grade alloying compound in foundry applications

• No value at the moment is extracted from this material

• Objective: reduction of Si-waste by 80% due to reutilization as Si-feedstock or other high end markets

Si-powder

Si-granules

Si-pellets

mc-Si

sc-Si

Silver Cell-doctor

9

Remanufacturing & resource efficiency in cell processing

DI-Water

• Solar cell architectures

• Interconnection schemes

• Metallization pastes that contain less silver

• Objective: 66% savings of silver

Current solar cell design

• de-ionised water is used in several cleaning steps

• Objective: 90% recycling rate

10

Module design for remanufacturing (NICE)

Disassembly "end-of-life" modules for recovery of module components Organics

• EVA for encapsulation

• PVF in backsheets

• 90% less organics

• frameless module

• 60% less aluminium

Aluminum

11

REPURPOSING OF WASTE PRODUCTSHigh pure graphite Ceramic tiles

Steel wires Glass

Broken cells

Living Lab – Establishment of Pan Industrial Material Reuse Opportunities

Preliminary LCI baseline of the module production Carbon footprint

12

Environmental impact

*D. Yue et al., Domestic and overseas manufacturing scenarios of silicon-basedphotovoltaics: Life cycle energy and environmental comparative analysis, Solar Energy 105:669, 2014.

Technology for a better society

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 679692.

E-mail: Martin.Bellmann@sintef.no