Energy security

Rooftop solar could provide nearly half of US electricity demand

A major new study has significantly lifted the potential of rooftop solar PV in the United States, saying rooftop solar alone could provide 40 per cent of all the electricity needs of the world’s biggest economy, and around half if module efficiencies continued to improve.

The study by the National Renewable Energy Laboratory says the estimated potential from rooftop solar has been revised upwards by more than 80 per cent since the last study in 2008, mostly because of improvements of module efficiencies, building availability and solar modelling.

In all, NREL estimates potential rooftop solar installed capacity at 1,118 gigawatts (GW) and generation of 1,432 terawatt-hours (TWh). This would account for 39 per cent of all electricity sales, but could go higher – to around 50 per cent – if higher module efficiencies were taken into account.