What is Solar Energy?

Since the birth of life on earth, it has survived mainly on the thermal radiant energy provided by the sun. This energy source is known as solar energy. Solar energy is a huge, clean and non-polluting renewable energy source that is now generally used as a source of electricity generation. As fossil fuels are dwindling and people are paying more and more attention to environmental protection and sustainable development, solar energy has become an important part of the energy used by human beings and continues to develop. PowerHome will bring you a detailed introduction of solar energy in this blog.

Technical Principle of Solar Energy

The continuous process of nuclear fusion reaction inside the sun produces solar energy. Specifically, the nuclear reaction of hydrogen fusion into helium inside the sun continuously releases huge amounts of energy and radiates energy into cosmic space, which is solar energy.

Nuclear fusion reaction

The average solar radiation intensity in Earth's orbit is 1,369 w/m2, and the circumference of the earth's equator is 40,076 km, which can be calculated to mean that the earth receives up to 173,000 TW. The standard peak intensity at sea level is 1 kw/m2, and the average annual radiation intensity at a point on the earth's surface over 24 h is 0.20 kw/m2, which corresponds to 102,000 TW of energy. Although the energy radiated by the sun into the earth's atmosphere is only one part in 2.2 billion of its total radiant energy, half of which is reflected or absorbed by the atmosphere, it is already as high as 173,000TW, meaning that the sun irradiates 5 million tons of coal, or 1.465x10^14 joules of energy, to the earth every second.

The vast majority of the energy required by humans comes directly or indirectly from the sun. Plants release oxygen and absorb carbon dioxide through photosynthesis and convert solar energy into chemical energy to be stored in their bodies. Fossil fuels such as coal, oil, and natural gas are also primary energy sources that have evolved from ancient plants and animals buried in the ground over long geologic ages. Broadly speaking, the earth's wind energy, water energy, ocean temperature difference energy and biomass energy all belong to solar energy, but the general understanding of solar energy for the narrow sense, that is, limited to the sun's radiant energy of the photothermal or photovoltaic direct conversion.

Application Methods of Solar Energy


Solar photovoltaics refers to the process of converting light energy from solar radiation into electrical energy, and one of the most common ways of doing this is by utilizing the photovoltaic effect, which converts sunlight into electricity through photovoltaic modules (solar panels). A solar power panel, as the name implies, is a power generator that produces direct current electricity when exposed to sunlight, and consists of solid photovoltaics cells made almost entirely of semiconducting materials such as silicon. If you'd like to learn more, we offer a detailed description of how solar panels work.

Utilized in photovoltaic

Simple solar cells can power a watch or a computer, while more complex solar power systems can power houses, traffic lights and surveillance systems, as well as being integrated into the power grid. Solar panels can be made in different shapes to generate more power. PV modules can be used on rooftops and building surfaces, and are even used as part of windows, skylights or shading devices.


Modern solar thermal technology polymerizes sunlight and uses its energy to produce hot water or steam. Common ways to utilize solar thermal energy are solar water heaters and solar power plants. Solar water heaters supply hot water for daily use by absorbing the heat energy from solar radiation and transferring it to a water storage tank, and solar power stations use reflectors to concentrate the sun's heat energy to produce high temperatures, which are then converted into steam, which drives a generator to produce electricity.

Utilized in photothermal

Advantages & Disadvantages

Solar energy offers many advantages:

  • Renewability: Solar energy is an energy source that never runs out; solar radiation is continuous and is not limited by geographic or political factors. In contrast to traditional energy sources such as fossil fuels and nuclear energy, which have limited availability and environmental pollution problems, solar energy can be continuously utilized, reducing dependence on finite resources.
  • Low-carbon and environmental protection: Solar energy does not produce harmful substances such as carbon dioxide and other greenhouse gases during its utilization, and does not pollute the atmosphere, making it a truly green energy source.
  • Wide applicability: Solar energy has a wide range of applications and can be used for power generation, heating, hot water supply and many other fields. Especially for areas without grid access or unstable power supply, solar energy is an ideal energy choice. 

Despite its many advantages and wide range of applications, solar energy also faces a number of challenges:

  • High cost: The cost of solar power equipment and systems remains high, limiting their large-scale application and popularization. Although solar technology has made great progress, cost reduction is still an important issue that the solar industry needs to address.
  • Affected by energy density: The intensity of solar radiation has seasonal and geographical differences, which have a certain impact on the utilization of solar energy. In regions with low energy density, such as high latitudes or frequently cloudy and rainy regions, solar energy capacity is low, requiring larger photovoltaic panels.

As technology continues to advance and the pursuit of environmental sustainability continues, the outlook for the solar industry becomes even more promising. In the future, solar energy technology will continue to improve efficiency, reduce costs and complement other sources of energy to provide clean and reliable energy for mankind. If you want to benefit from solar energy too, buy a portable solar generator now and start your low-carbon off-grid lifestyle!

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