Tucked inside Republicans' massive domestic policy bill is an excise tax for wind and solar projects, a provision that came as a surprise not just to the renewable energy industry, but to numerous senators who are crafting the legislation.

Senate Republicans revealed a new tax for solar and wind energy this weekend, in the latest version of a bill that could be passed as early as Monday afternoon.

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