Luyang water tankless high temperature wall-mounted solar power has been tested by the state to increase the thermal efficiency by 40%, and the water temperature is 20 degrees higher in the same terms. It is more usable in winter and has. was exported to the United States.
The mass of water is 100 kilograms.
When exposed to sunlight for 70 minutes, the solar energy received by 2 square meters is 300*70*60*2=2520000 joules
The current technical level of the solar energy received by ordinary products can only account for 48%. For hot water, Luyang tankless wall-mounted solar power model, which is currently the best-selling model in China, can reach 57%.
Assuming 80%, that's 2016,000 joules of heat. The specific heat of water is 4,200 joules/kg.degrees. The temperature of 100 kilograms of water is 2,016,000/4,200/100 = 4.8 degrees.