6. Solar thermal energy (How to capture solar heat?)

Sun not only brings light but also appreciable warmth. While some people can’t get enough of it, others feel too hot very quickly during midsummer. Mankind has always oriented their houses to the sun’s direction: in the cool north and in the mountains the open side of the house usually faces the sun, while in hot regions the entry and windows tend to face away from the sun.
How many 100 W light bulbs match the energy of the midsummer’s sun at high noon, and how many on a winter day?
Sun collectors can capture solar energy. Ideal, really, but sun collectors are still not suitable to be the only energy source for the supply of thermal energy.