Electricity can be stored directly for a short time in capacitors, somewhat longer electrochemically in , and much longer chemically (e.g. hydrogen), mechanically (e.g. pumped hydropower) or as heat. The first pumped hydroelectricity was constructed at the end of the 19th century around in Italy, Austria, and Switzerland. The technique rapidly expanded during the 196.
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A supercapacitor (SC), also called an ultracapacitor, is a high-capacity , with a value much higher than solid-state capacitors but with lower limits. It bridges the gap between and . It typically stores 10 to 100 times more or than electrolytic capacitors, can accept and deliver charge much faster than batteries, and tolerates many more
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