Silicon

PV Panel Embodied Energy

• embodied energy of 1000 MJ/kg or 300 kWhr! [1]
  • Similar for amorphous silicon [2]
• Compare to steel at 20 MJ/kg [3], and 200MJ/kg more than this for aluminum [4]
• How many grams of silicon are needed for 1kW of PV panels? 2 kg [5], based on 2g/W.
• 5% of weight of PV is silicon [6]. 76% is glass, 10% is aluminum, and 10% is EVA.
• Embodied energy of EVA is about 80 mega joules per kilogram [7]

Total for 1kW of PV

• 600 kWhr for 2 kg of silicon
• 3kWhr per kg for glass, or 90 kWhr for 30 kg glass. [8]
• About 40 kWhr per my of EVA/aluminum x 8 kg = 320 kwhr
• Total 1010 kWhr
• 365*6kWhr~2100 kWhr/yr
• Payback is thus 1/2 yr with only the above.
• This matches results from Fraunhofer 2021, close enough - .7-1.4 year payback time. [9]

Links

• DIY Glacial Acetic Acid
• Wikipedia says 585 kWhr/m2 of PV panels? [10]