TABLE OF CONTENTS No form of generation will generate power or heat continuously. This variability in generation sources is of benefit to grid operators, because it means that there are a number of options available to balance supply with demand as it varies during the day, the week and the year. A diverse electricity supply industry with a variety of sources of electricity supplying the industry at different scales is the most robust.
Utilities use the term load factor to compare the different outputs of power-generation plants. Load factor is generally the amount of power produced by the plant compared with its theoretical maximum output, but this may also be referred to as 'capacity factor', implying that it measures how much of its total capacity the plant is supplying.
There are many reasons why a generator has a load factor of less than 100 per cent. They stop generating in the case of renewable energy if there is no 'fuel' it is dark (in the case of photovoltaics), say, or between tides (for tidal power). In the case of rotating machinery, even if fuel is continuously fed into the power-generating plant then regular stops are scheduled to allow the plant to be maintained.
Even devices with no moving parts and continuous supplies of fuel such as a fuel cell supplying heat and power may be stopped, or the power output varied over time, depending on the needs of the customer.
This is one reason...
