Hello Bao! Solar water heaters do not require electricity; They heat the water using solar energy. The working principle of a solar water heater is to use solar energy to heat water, and then store the heated water in a water tank for domestic use. When there is enough solar energy, solar water heaters can provide enough hot water without the need to connect to electricity. However, if the weather is cloudy and rainy or the solar energy is insufficient, the heating effect of the solar water heater will be affected. At that time, heating can be assisted by connecting to electricity.