‘Cradle To Grave’ Assessment Of PV Technologies

Scientists at Australia’s Charles Darwin University have conducted a cradle-to-grave life cycle assessment (LCA) of the four most widely used PV technologies;

  • monocrystalline silicon (mono-Si),
  • multi-crystalline silicon (multi-Si),
  • amorphous silicon (a-Si) and
  • cadmium telluride (CdTe).

The LCA was based on the ‘ReCiPe’ life cycle impact assessment method first developed by academics in 2008. This method utilizes a total of 21 indicators to evaluate the environmental impacts of a technology or product on three higher levels:

  1. human health,
  2. biodiversity and
  3. resource scarcity

The indicators focus on single environmental problems, such as climate change.

Manufacturing of the three silicon-based PV technologies were found to have larger impacts, with processes including quartz reduction, silicon purification, wafer and panel production, inverter, mounting, other electrical installation production.

And after this, 30 years in operation, energy consumption, pollutant emission, transportation, waste treatment process, end-of-life dismantling, landfilling and recycling.

The scientists found that the CdTe technology has the lowest life cycle impact, followed by amorphous, multicrystalline and monocrystalline silicon.

The lower impact of the CdTe thin-film technology is attributable to the lower consumption of materials and chemicals in its overall life cycle processes.

“In addition, the only significant emission that exists in the whole inventory of CdTe technology is the discharge of cadmium ions  into water.

The amount of this emission is relatively low compared with the life cycle emissions of other PV plants,” they further explained.

The group stated that it intends to include other PV technologies such as CIGS, perovskite and organic PV in future LCA studies.

Reference- PV Magazine, Environmental Science and Pollution Research, Wikipedia