The amount of energy that a power plant produces or could produce under ideal conditions. Power is given in watts or in multiples (kilowatts, megawatts). We may encounter the term installed power output, which indicates how much energy a power plant is capable of delivering under ideal conditions. For a thermal power plant, two types of power output are often specified, thermal and electric. The thermal power output indicates how much heat the plant has produced in the reactor, e.g. by burning coal or fissioning uranium. This heat is then used to produce steam, which turns a turbine that turns a generator that produces electricity. Because the thermal cycle is only about 40 percent efficient at most, the plant’s electrical output is always less than its thermal output. For example, a power plant with a thermal output of 3,000 MWt may have an electrical output of only 1,000 MWe. Since the power plant itself usually needs electricity for its operation, we can also encounter the term net power output, which is the electricity supplied by the power plant to the grid.