Consumers can find three options of water heater system on the market right now: gas water heater, electric water heater and solar water heater. Solar water heater converts sunlight into heat energy to heat up the water for needs of daily life or production.

As opposed to gas and electric water heater, solar water heater is a major application of solar technology. It features safety and environmentally friendliness, resulting in its wide popularity. China accounts for 1/3 of world’s annual energy consumption and 1/3 of China’s energy consumption is from buildings. Solar water heater absorbs radiant energy from the sun to supply heated water to support daily activities and manufacturing needs.

As non-reusable energy dries, countries that see the energy challenges ahead will encourage more environmentally friendly products such as solar power heaters, posting a thread to traditional gas and electric water heaters.

Gas water heating rate can be classified into volumes like 5 liters, 7 liters and 8 liters, etc., meaning the water amount that can be heated up 25℃within 1 minute. If the original temperature of the water is 25℃, then the water is heated up to 50℃within 1 minute.

Electric water heaters can classified into volumes like 30 liters, 60 liters and 90 liters etc.. Comparing an 8 liter gas water heater with a 40 liter electric water heater, the results differ in that the former can provide constant 8 liters of heated water while the latter heats up the whole 40 liters of water and awaits 30 minutes to reheat the same amount of water.

A solar water heater, under conditions of average temperature of 15.7℃, 2014 exposure hours and solar radiant energy of 111.59 kcal per square meter, can generate 9.37×106 KJ to heat 53.5 tons of water up 35℃, assuming 2 square meters of absorbing area. If an average person uses 50 kg during a shower, it means he or she can take 1070 showers per year or 2.93 showers per day.