But that is exactly what is happening. Each seller can offer their price and each bidder can also offer their price. And since running a gas turbine is more expensive than wind power they are forced by the market to turn their gas turbines off when there is wind. However when there is only a little wind they can power up their gas turbines and sell to the highest bidder. But since there is also a little bit wind, the wind power people can also sell to that highest bidder. That is how it happens that suddenly wind power is just as expensive as the gas turbines, because there is simply not as much wind power to go around for all the people that need electricity.