They are frequently built using feed-in tariffs, which guarantees that electricity will have a positive fixed price. Otherwise they're basically impossible to f

They are frequently built using feed-in tariffs, which guarantees that electricity will have a positive fixed price. Otherwise they're basically impossible to finance because as you say the generation marginal cost is zero so they'd just have to accept any price otherwise and lose money for the investors. https://en.wikipedia.org/wiki/Feed-in_tariff https://en.wikipedia.org/wiki/Feed-in_tariff