From the 6th century to the 17th century, Europe experienced great industrial development, which required a lot of energy and power. During this period, the development of agriculture also needed other power to replace human and animal power. Solar energy is being considered for industrial drainage of water in mines and irrigation in agriculture. How can water harness the sun's energy? Scientists have their way.
In 1615 a French engineer named Descaux invented the first pump powered by solar energy. But this kind of pump can not pump water continuously even in sunny days, and has no practical value. Later, another French engineer, Belidol (1697-1761), designed a solar-powered pump that could pump water continuously.
His pump consisted of a hollow ball and pipes connected to the water source. Before pumping, the water is injected into the hollow ball of the pump. The height of the water surface is required to reach the AB plane of the ball top, so that the pump can pump water as long as it is sunny. Why, you may wonder, can you pump water in this way? It turns out that during the day, sunlight heats the air at the top of the hollow sphere. The air expands and the pressure increases, and the water flows to the upper tank (or some other place, such as farmland) through the one-way valve above. At night, there is no sunlight, the temperature drops, the air inside the hollow ball cools and shrinks, and the pressure drops below the atmospheric pressure. Then, the water in the water source is pumped into the hollow ball through another one-way valve (water only goes in but not out) under the ball (pump). When the sun comes out the next day, the pumping process is repeated.
Belidol's solar-powered pump is so ingenious that it pumps water automatically and continuously. But the solar pump also has a fatal disadvantage, it can only work in sunny days, in rainy days, it will "rest", so it is not convenient to use. With the advent of steam powered pumps, solar-powered pumps were squeezed out of the market and became "science toys" like machines for a time.
But solar-powered pumps have flourished again since the oil shocks of the 1970s. One is that solar energy can replace part of oil as power. Second, it can reduce environmental pollution. Because diesel and gasoline pumps emit large amounts of carbon dioxide and other harmful gases, solar pumps do not have this problem, to protect the environment. In 1974, the University of Florida in the United States of The Study of a very simple structure of the solar pump, its moving parts only two one-way valves, is in fact from more than 200 years ago belidor solar pump improved from a pump. At the same time, the British havel atomic energy research institute has developed a kind of known as the Buddha luo dai within 3 solar pump, it USES a very simple heating air cylinder closed cycle instead of boiling apparatus used in the United States at the university of Florida, is a kind of improved and solar pump, pumping efficiency is increased.
According to the "European Development Fund" in 1989 statistics report, since 1983, the world's solar pump to increase nearly a thousand units every year, now the world has installed at least 6000 units of solar pump, mainly in the lack of power supply in rural use.