Definition
Ramp rate is the speed at which a power source — or a controllable load — can change its output, typically expressed in megawatts per minute (MW/min) or as a percentage of rated capacity per minute. It quantifies flexibility: a grid must continuously match supply and demand, and resources with fast ramp rates can follow rapid swings in net load, such as the steep evening drop in solar output.
Why technologies differ
Batteries, hydro, and some gas turbines ramp almost instantly, while large coal and thermal plants are far slower — a big fossil unit may move only about 1% of its capacity per minute. A grid can have plenty of total capacity yet still face reliability problems if too few resources can change output fast enough to track net-load movement. Ramp-rate limits are also imposed on inverter-based resources to prevent abrupt output changes that stress the system.
The mining angle
A mining load is itself an exceptionally fast-ramping, fully controllable resource: rigs can curtail in seconds. This is why Bitcoin miners are valued for demand response and grid balancing — their ramp rate as a flexible load far exceeds that of most generators, letting them soak up surplus and shed quickly when the grid is tight.
Related glossary entries include automatic generation control and droop control.
In Simple Terms
Ramp rate is the speed at which a power source — or a controllable load — can change its output, typically expressed in megawatts per…