A government program intended to support the take-up of alternative energy sources was supporting Sunnova Energy's (NYSE: NOVA) stock on Thursday. On news that Sunnova had won this backing from the federal government's Department of Energy (DoE), investors traded the stock up by almost 15% on the day. The DoE is providing a partial loan guarantee of up to $3 billion to Sunnova, which covers 90% of the $3.3 billion of solar energy loans the company is planning to originate.