Electricity is used in Heat Pumps simply to power a compressor and fan. The compressor compresses gas into a liquid, causing it to heat up (in the same way a bicycle pump gets hot when a tyre is pumped up). This heat is then transferred to circulating water which is stored in a geyser. In the next part of he cycle the gas evaporates, resulting in it cooling down. Here, a fan blows air over the cold gas-filled piping, which extracts "free" heat from the ambient temperature and causes the gas to warm up again. The gas is then compressed once more, releasing the extracted heat to warm the water and the cycle continues as before. Result: Energy-efficient water heating at a third of the cost of electro-element heating.
A hot water heat pump typically produces up to 4 times more heat energy than the electrical energy it consumes. So by connecting a heat pump to your existing hot water cylinder you can divide your hot water consumption by 4. Unlike solar a heat pump is not directly dependant on the sun and therefore it can operate day and night, winter and summer, ensuring you the highest possible saving and still giving you piping hot water 24/7.