The UK system has a "capacity auction", separate from the spot price, which covers dispatchable generation.

"Through the auction, government has procured 49.26GW of capacity at a clearing price of £19.40kW" (second link). Note units are kW not MWh.

http://www.nationalgridconnecting.com/keeping-the-lights-on/

https://www.gov.uk/government/news/the-first-ever-capacity-m...