The Importance of Capacity Factor

By Kolby Hoagland | November 29, 2012

The size, or nameplate capacity of a power plant alone does not necessarily mean that it produces a large or small amount electricity. The amount of electricity that a power plant actually produces and what it could potentially produce if the plant were run at capacity over an entire year offers a ratio that is known as the capacity factor. The capacity factor of a biomass power plant is an important part of understanding how much feedstock is required and how much electricity the power plant actually delivers to the grid or to onsite electrical equipment. Numerous aspects within and outside the biomass power sector influence the capacity factor of biomass power plants: ability to ramp power production, grid demand, plant maintenance, feedstock availability, etc.. The interactive map below shows biomass power plants in the US that burn solid biomass and their associated capacity factors, according to EPA’s eGrid 2012. The sizes of the circles depict the nameplate capacities of the biomass power plants while the shade of circles indicates their respective capacity factors. The larger the dot, the greater the nameplate capacity of the power plant and thus how much power it can produce at full throttle, but, as the map depicts, the largest biomass power plants do not necessarily produce the greatest amount of electricity. According to EPA’s eGrid 2012, American Ref-Fuel of Delaware Valley, a 90MW plant and not the largest plant, generated the most electricity over the year with a capacity factor 0.77, producing over 600,000 MW hours of electricity.