life cycle analysis of solar and inverters

LCA or Life cycle analysis for solar panels and inverters has been done by a number of companies and research institutions to know if a renewable energy system is as green as they are made out to be. Fraunhofer Institute did an LCA on a Fronius inverter model GEN24 PLUS in a system. They concluded carbon was fully recovered in less than 11 months, in Sydney, Australia. The system included 10kW pv panels. With 8kW of Maxeon panels LCA payback was 0.52 years.

Life Cycle Analysis of Various Energy Sources

Fuel SourcegCO2e/kWheNotes & Explanation
Wind5-8Most emissions from construction steel and concrete
Nuclear6-110
Uo to 200
Mining and enrichment markedly change emissions. As rich ore bodies are mined out, more energy is needed for less rice ore bodies.
80 years of supply left.
Solar38Using Maxeone 40 year panels and Fronius inverter 8kW
Gas500Fossil methane
Oil800Bunker oil and oil fired boilers induce a range of other pollutants
Coal1000Calculation of emissions from mining may underestimate total emissions by 2 or more times
Life Cycle Analysis is based on the production phase (including sourcing of raw materials), the use phase and the End-of-Life (EoL) phase

Life cycle analysis for Solar panels and Inverters?

Life cycle is based on the whole process

  • The production phase (including sourcing of raw materials)
  • The use phase
  • The End-of-Life (EoL) phase
life cycle analysis for solar panels and inverters for whole of life carbon
LCA of an inverter https://www.fronius.com/~/downloads/Solar%20Energy/Whitepaper/SE_WP_LCA_GEN24_Plus_EN.pdf

LCA of Inverter in System

life cycle analysis for solar panels
Figure 2 from the report : Relative contribution of the PV inverter (Australian scenario) and PV modules to the carbon footprint (“PV system perspective”)

Life Cycle Analysis of PV Cells

SolarQuote reports on Maxeon, a panel they sell. They quote Maxeon’s panels sustainability report. Maxeon engaged an external consultant to carry out an assessment of the Maxeon 3’s’ energy payback time (EPBT). This included the cumulative energy demand (CED) over all life cycle stages of the panel and considered local grid efficiencies for different locations around the world.

Maxeon 3 solar panels were determined to have an energy payback time of less than a year; ranging from 0.13 – 0.45 years for ground-mounted modules (50MW installation) and 0.27 – 0.92 years for 8kW residential rooftop systems. In Australia (Sydney), the EPBT was 0.26 years for the ground mount system and 0.53 years for the rooftop installation.

Conclusion

Using electricity from a PV system with a Symo GEN24 10.0 Plus in Australia would induce an average carbon footprint of 38.0 g CO2-eq/kWh. In comparison, using electricity from the Australian grid mix would result in a carbon footprint in the range of 600-1000 g CO2-eq/kWh (approx. 15-25 times higher, due to coal use, among other things).

In comparison, as a rough estimation, the CO2 emissions saved by the whole PV system over 20 years (not only the inverter) are equivalent to approx. 600 planted trees. Another rough comparison is possible with gasoline cars where an averaged use of 5 l/100 km is considered. Based on the ecoinvent database, the benefit of a PV system using the Fronius Symo GEN24 Plus 10.0 in Australia for 20 years (benefit of the whole PV system, not just that allocated to the inverter) would save the CO2 emissions equivalent of approx. 1,800,000 km travelled by car. For the same PV system use scenario, there would be a CO2 emissions saving equivalent to approx. 100 roundtrip flights Vienna-New York18. The values for trees, car trips in km, and plane trips are included here simply as a means of comparison and are not standardized or reviewed values.

References

  1. Maxeon Panel Sustainability Report https://mediaroom.maxeon.com/2022-06-30-Maxeon-Solar-Technologies-Releases-2021-Sustainability-Report-with-Energy-Payback-Time,-Long-Term-Targets
  2. Average based on: https://www.electricitymap.org/map,
  3. Ecoinvent = https://www.cleanenergyregulator.gov.au/NGER/National%20greenhouse%20and%20energy%20reporting%20data/Data-highlights/2020-21-published-data-highlights
  4. Nam et al. 2016: “Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam” (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4910975/)
from https://www.dw.com/en/coal-the-end-is-nigh-or-is-it/a-59929238