Solar panels are cheap and getting cheaper. A recent study found that the cost per kilowatt-hour of solar has fallen below coal and gas. Even a recent US tariff on Chinese solar cells and modules (the components that make up solar panels) hasn’t been enough to make a dent in the solar industry.
Now, researchers from the Massachusetts Institute of Technology (MIT) have built a model to quantify which factors contributed the most to cost-per-watt changes for solar panels since the 1980s.
The results were that better module efficiency was the No.1 cause of declines in solar panel cost per watt between 1980 and 2012, with money from government and private research and development contributing to the bulk of those efficiencies. By 2001, however, economies of scale started playing more of a role in solar panel cost declines.