The International Energy Agency task force has issued a new report, revealing that residential solar PV with battery storage has the potential to reduce emissions up to ten times compared to coal generated electricity.
Australia is participating in a research program with the International Energy Agency to assess the lifecycle of residential PV and battery systems to quantify their environmental impacts.
The analysis found the lifetime emissions for a 10kW rooftop system with a 10kWh battery, were 84 CO2-eq/kWh – nearly ten times less than the 820 CO2-eq/kWh emissions from burning coal, and five times less than the 490 CO2-eq/kWh emissions from natural gas.
Around half of the impact for a residential PV and battery system comes from the PV panel production, while the battery production contributes around 25 per cent of the total emissions.
The choice of the PV panel technology was found to have a significant influence, with thin-film technology out-performing silicon in sustainability.
For batteries, their lifetime and storage capacity had a major influence on their environmental impact.
Batteries with longer lifetimes showed better sustainability outcomes, while batteries with increased storage capacity showed negative outcomes, associated with the production of additional battery cells.
The report tested 10kWp rooftop PV systems with 10kWh battery storage in Central Europe where annual yield is 1000 kWh/kWp. As the annual yield for PV systems is higher for most of Australia, it is expected that the emissions for an equivalent residential system would be even lower.
Different battery sizes, battery technologies and PV panel technologies were also considered.
Additional findings showing the benefit of solar over gas came from a review of the delivery of grid electricity in California from 2016 to 2030. In this analysis, the use of utility-scale battery storage will be an order of magnitude better than the emissions and air quality impact of using natural gas generation.
To read the full report, Environmental LCA of Residential PV and Battery Storage Systems, click here.