Grid battery
A large battery connected to the power grid that charges when electricity is plentiful and discharges when it is short.
A power grid must balance generation and consumption at every moment. The more solar and wind there is, with output that depends on the weather, the more equipment is needed to store surplus electricity for later. A 2011 review by Bruce Dunn and colleagues sorted out which battery types suit which uses and identified cost and lifetime as the keys to adoption[1].
Unlike a car battery, a grid battery does not move, so weight and size matter little. Low cost, long life and safety matter instead. Lithium iron phosphate and sodium-ion batteries suit charge and discharge over a few hours; batteries made of cheap materials, such as iron-air, suit several days. The technologies are sorting themselves by use.
Related terms
- Lithium iron phosphateA type of lithium-ion battery with an iron-phosphate positive electrode. It uses no cobalt or nickel and is cheap, hard to ignite and long-lived.
- Iron-air batteryA battery that draws electricity as iron rusts in air and turns the rust back into iron when charged. Its materials are extremely cheap, suiting it to storing energy for days.
- CurtailmentSwitching off or reducing solar or wind output that could have been generated, because demand or grid capacity is insufficient.