It depends on solar energy and the efficiency of your equipment. Generally speaking, the amount of solar radiation on sunny days is 2 1-27mj/m2, but it is almost cloudy or even less cloudy. If solar panels are used, the efficiency is 13- 16%, then it is about per square meter 1 kwh in a day; If it is a solar water heater, the efficiency is about 45%, then the collected energy is about 1 1MJ. Of course, this is a particularly sunny situation, which is generally out of reach.