Capacity Firming
Using energy storage or backup generation to guarantee that a renewable energy source can deliver a consistent, dispatchable power output regardless of weather or time of day.
Why It Matters
Capacity firming makes renewable energy more valuable to the grid. Utility-scale solar + storage projects now compete with gas peaker plants on reliability.
Related Terms
Dispatchable Generation
Power plants that can be turned on, off, or adjusted in output on demand by grid operators. Natural gas, hydropower, nuclear, geothermal, and batteries are dispatchable. Wind and solar are "variable" (weather-dependent).
Battery Storage
A system that stores excess solar energy for use when the sun isn't shining, providing backup power during outages.
Peaker Plant
A power plant that operates only during periods of peak electricity demand — typically natural gas simple-cycle turbines that can start up in 5-15 minutes. They run a few hundred hours per year and charge premium electricity rates.