Merit Order and Wind Output

A wholesale power market clears hourly as a uniform-price auction: generators are dispatched cheapest first until demand is met, and every dispatched MWh is paid the marginal cost of the last (most expensive) dispatched unit. Demand is a fixed 60 GW and ramping or network constraints are ignored. Every plant bids its marginal cost.

Available plants:

In a particular hour, 20 GW of wind is also available at (essentially) zero marginal cost and is dispatched first.

Give three numbers as a comma-separated list: (1) the clearing price in $/MWh without wind, (2) the clearing price in$/MWh with the 20 GW of wind, (3) the reduction in the total hourly bill paid by consumers (all 60 GW at the clearing price), in millions of dollars.