| Themes > Science > Chemistry > General Chemistry > Energy > Solar Energy > Solar Energy Storage Devices |
Because of the intermittent nature of solar radiation as an energy source, excess solar energy during periods of small demand must be stored in order to meet demands when solar energy availability is insufficient. Besides simple water and rock storage systems, more compact devices that rely on the phase-change characteristics of eutectic salts (salts that melt at low temperatures) can also be used, particularly in cooling applications. Batteries can serve as storage devices for excess electric energy produced from wind or photovoltaic devices. A broader concept is the delivery of excess electric energy to existing power networks and the use of these power networks as supplemental sources when solar availability is insufficient. The economics and reliability of such a scheme, however, place limits on this alternative. |