Widely available, these types of electric water heaters are the most common, installation is fairly straight forward (for a professional) and quite often the least expensive. They include a large water tank that stores hot water for use on demand. The water is heated by electric heating elements.
These provide hot water on demand by heating water as it travels through the unit. This makes them quite efficient as you’re only using energy when you need it. Larger households with significant hot water needs can experience issues as a tankless system won’t keep up with demand. However, you can install multiple units to overcome these issues. They don’t take up much space. They are rated in terms of how much water is heated per minute e.g. 4.6 litres/min and should be selected as such opposed to the tank size in a storage water heater.
This style of water heater is unique in that is uses heat in the air or in the ground to heat water. This means that electricity is only used to move heat from the ground or air to the water, making them very energy efficient. Heat pumps can use up to 60% less electricity than traditional water heaters. They can be quite large, so you’ll need more space for heat pumps. Because this water heater style relies on pulling heat from the ground or air around it, it will not work very well in cold spaces like basements or in climates where it is excessively cold for long periods throughout the year. They can also be expensive, but it’s a great investment knowing you’ll spend far less on your heating bills.