Using electricity, hot water is heated in an insulated tank. Tanks come in a variety of sizes and can be installed internally and externally. Units less than 160 litres can generally recover continuously and are ideal for households that only require small amounts of water throughout the day, rather than delivering large amounts in one go. Larger systems (greater than 160 litres) generally use off-peak electricity, meaning that water is heated overnight ready for use the next day. This reduces the electricity usage of the household.
Generally cheaper to purchase and install, electric hot water systems have a higher ongoing energy cost and a higher impact on the environment than other options.