Wind is not constant so wind turbines do not always run at nominal outputs.
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All of the renewable energy comes either directly or indirectly from the sun.
Fossil fuels are renewable,that is,they draw on finite resources that will eventually dwindle,becoming too expensive or too environmentally damaging to retrieve.
The word energy can have many different applications,such as when one speaks of the amount of energy (stamina) children have.
The refrigeration system in the central plant of a central system is usually in the form of a heater package with an outdoor condensing unit.