Solar energy refers to the thermal radiation of the sun (see three ways in which heat travels: radiation), mainly in the form of the sun's rays. It is commonly used in modern times to generate electricity or provide energy for water heaters.
Since the birth of life on earth, it has been possible to survive mainly by the thermal radiation provided by the sun. Since ancient times, humans have also known how to dry things with the sun as a way to make food, such as salt and salted fish. With the decrease of fossil fuels, solar energy has become an important part of human energy use and has been developing continuously. The utilization of solar energy has two ways: photothermal conversion and photoelectric conversion. Solar power generation is a new renewable energy. Broadly speaking, solar energy also includes wind energy, chemical energy and water energy on earth.
1.The main classification
Photovoltaic panel modules are power generation devices that generate direct current when exposed to sunlight,
It consists of solid photovoltaic cells made almost entirely of semiconductor materials, such as silicon. Simple photovoltaic cells power watches and computers, while more sophisticated photovoltaic systems provide lighting, traffic lights and monitoring systems for homes that are connected to the grid. Photovoltaic panel modules can be made into different shapes, and the modules can be connected to generate more electricity. Photovoltaic panel modules can be used on rooftops and building surfaces, and even as part of Windows, skylights or shelters. These photovoltaic facilities are often referred to as photovoltaic systems attached to buildings.
According to a survey, the number of photovoltaic modules installed in 2012 will decline for the first time in more than 10 years, as overcapacity shrinks the profits of the world's top five manufacturers. The average forecast of six analysts by bloomberg is for 24.8GW of photovoltaic modules to be installed in homes and businesses worldwide. That is equivalent to about 20 nuclear reactors, but down 10 per cent from the 27.7gw of new photovoltaic installations. Bloomberg new energy finance estimates that installations have grown 61% a year since 1999.
Modern solar thermal technology combines sunlight and USES its energy to produce hot water, steam and electricity. In addition to using appropriate technology to capture solar energy, buildings can also use the sun's light and heat energy by incorporating appropriate equipment, such as large south-facing Windows or building materials that absorb and slowly release the sun's heat.
(1) universal: the sun shines on the earth without geographical limitations, whether land or sea.
No matter high mountains or islands, are everywhere, can be directly developed and used, easy to collect, and without mining and transportation.
(2) harmless: the development and utilization of solar energy will not pollute the environment, it is one of the cleanest energy, in today's increasingly serious environmental pollution, this point is extremely valuable.
(3) huge: the amount of solar radiation reaching the earth's surface each year is equivalent to about 13 trillion tons of coal, the largest amount of energy available in the world today.
(4) longevity: based on the rate of nuclear energy produced by the sun, there are enough hydrogen reserves to last for billions of years.