Electric hot water systems can be storage, electric assisted or instant systems.
Electric storage systems heat the water in the tank and as the hot water is drawn out from the tank, it is replaced with cold water, which triggers the reheating process. Storage tanks under 100 litres are powered continuously while tanks over 100 litres have the option of off-peak electricity which is cheaper and will heat up at night time. Electric heated storage tanks are relatively cheap to buy and install, but is usually the most expensive to run. Instant electric hot water systems simply heat the water as it is required and require 3 phase electrical connection.
Safeguard Plumbers can provide you with expert advice and help you decide on the best system for you.