Solar panels typically generate electricity at only around 13% of their stated capacity. For windmills, it's around 22%. And those figures vary by month.

A Republican plan heading to a vote in the Senate would quickly end incentives for clean energy and impose new taxes on some wind and solar projects, while boosting production of coal used to make ste

Wind and solar companies were already bracing for Congress to end federal subsidies. But the Senate bill goes even further and penalizes those industries.