Rooftop solar drives out coal, wind and grid-scale solar

Australia’s 3.5 million rooftop solar installations are pumping out so much energy on sunny days that they’re sending wholesale electricity prices into negative territory, forcing large-scale wind and solar farms, as well as coal plants, to reduce generation. Over the past 30 days, rooftops contributed 14.6 per cent to the grid. Bundled together with other renewables such as solar farms, wind and hydro, they generated 42 per cent of the country’s energy over the same period, according to OpenNEM.org.au. Australia could do more to capitalise on rooftop solar, experts say. In South Australia’s electricity market last year, 24 per…