Australia is the world’s second-largest exporter of coal, which plays an outsized role in its economy and politics. But the country has also quietly become a renewable energy powerhouse.

About 1 in 4 Australian homes have rooftop solar panels, a larger share than in any other major economy, and the rate of installations far outpaces the global average. The country is well ahead of Germany, Japan and California, which are widely considered leaders in clean energy. In California, which leads U.S. states in the use of solar power, less than 10 percent of utility customers have rooftop solar panels.

Most Australians who have embraced solar do not appear to have done so for altruistic reasons like wanting to fight climate change. Many are responding to incentives offered by state governments in the absence of a coordinated federal approach, a sharp drop in the price of solar panels in recent years and an increase in electricity rates.