In a strategic reserve, a select few resources – usually fossil fuel plants close to retirement – are kept open in case their capacity is needed to fill gaps. These plants are put in a stand-by reserve and are not allowed to participate in electricity markets, instead getting paid by a central authority to simply be available and ensure they can be activated quickly during critical periods. Germany, for example, currently has a strategic reserves mechanism
This mechanism seems quite similar to the one that was proposed by Stonehaven for taking gas out of the market so it no longer sets the price.