Interestingly, heating systems can even store energy – thanks to hot water storage tanks. Storing hot water is a good means to store energy, as water accumulates a lot of heat per unit of weight.
A hot water storage tank can help reduce energy consumption as it takes less energy to keep water warm (once it has already been heated) than it takes to heat cold water. Hot water cylinders can also help provide demand response services to the grid by allowing consumers to heat water with electricity when prices are lower. Energy is then stored in the tank in the form of hot water, ready to be used for washing or to heat the house when it is needed. Another advantage is that the energy from renewables, such as solar thermal, can be stored when available in abundance and used later.