Maybe you have seen solar panels installed on the roofs of houses and buildings but you really know How is solar energy used to make electricity, keep reading and you will learn about this physical process.
How is solar energy used to make electricity
Solar energy is produced by nuclear fusion reactions that take place within the Sun. It reaches Earth in the form of solar radiation, which can be used in a number of ways.
Solar energy reaches Earth in the form of solar radiation. It can be processed in the photovoltaic, photothermal or photochemical conversion process. The advantages of solar energy include its unlimited resources and versatility, thanks to which it is used almost anywhere on Earth.
Solar energy comes from the nuclear fusion reaction that takes place inside the Sun. It comes to us in the form of solar radiation, which is a type of renewable energy. It is readily available energy, but its flux density is low and depends on where on Earth, the season, and the day. Man has been using solar energy almost always, in a planned or accidental way. Initially, it helped warm the body, dry clothes, and when people took advantage of the fire, they used the storage of solar energy for decades in the form of biomass.
Modern technologies enable the efficient acquisition and processing of solar energy for utility purposes. Solar energy today takes the form of installation solutions, architectural concepts, used building materials, and much more.
Currently, the sun is considered to be the greatest energy and fuel potential. The power of the energy they emit is estimated at 3.9 × 10 20 MW. Only part of it reaches the Earth’s surface, but it is still many thousands of times greater than the total energy produced on our planet. Solar energy can be used in three ways: to generate electricity, to produce heat or in the photosynthesis process to obtain chemical energy.
How is solar energy used to make electricity ? The solar radiation reaching the Earth has a spectrum similar to the radiation from a black body with a temperature of about 5700 K. The wavelength of the radiation reaching the Earth is about 100-4000 nm, which means It contains part of the ultraviolet, visible light, infrared and radio waves. The maximum power of radiation that penetrates the outer layers of the atmosphere that can be obtained for 1 m 2 is on average 1367 W / m 2 .
However, due to the elliptical orbit of the Earth, the different angle of the axis of rotation of the planet and the thickness of the atmosphere, the amount of energy that reaches the surface of the Earth can reach up to 1000 W / m 2 .
The radiation that reaches the Earth can be divided into:
- Total radiation : it is the sum of diffuse and direct radiation.
- Direct radiation : it is the radiation that comes directly from the solar disk. It reaches a certain surface of the Earth in the form of parallel rays that pass through the atmosphere without affecting it.
- Scattered radiation : emitted by the atmosphere as a result of repeated refraction of sunlight.
How is solar energy used to make electricity : Obtaining energy from solar radiation
We can use solar energy in 3 ways: by photovoltaic conversion, chemical or photochemical conversion.
- Photovoltaic conversion: we use it in photovoltaic cells , also popularly known as photovoltaic cell or solar cell. These are devices that directly convert the energy of solar radiation into electricity. This replacement is possible thanks to the use of pn-type semiconductor connectors. When a photon falls on a silicon wafer, it is absorbed by the silicon, causing the electron to slip out of position and move. This movement is the flow of electric current. Photovoltaic cells are used, among others in:
- installations for the production of electricity in single-family homes;
- calculators, solar lamps, watches;
- Passive photothermal conversion: it is a direct conversion of the energy of solar radiation into thermal energy. There are several types of heating systems, such as:
- Direct acquisition of heat: it can be done through large glazed surfaces mounted on the south side, where the low sun in winter heats the interior of the rooms;
- system with collector and storage walls – heating is carried out through storage collectors mounted on the south walls, made of materials with high heat accumulation. This wall absorbs solar energy, converts it into heat and then stores it in its volume;
- greenhouses, oranges: this system consists of extending the collector and the storage wall, moving the transparent cover away from the wall. The space thus obtained can be used, for example, as a greenhouse or winter garden.
- Active photothermal conversion: consists of converting the energy of solar radiation into another form of energy with the use of specially constructed devices. These devices, called solar collectors, are available in various versions, which can differ in price, performance, and level of technological advancement. Popular types of solar collectors are:
- flat collectors,
- vacuum manifolds,
- Photochemical conversion: conversion of the energy of solar radiation into chemical energy. It is used on a large scale only by living organisms in so-called photosynthesis.
Advantages and disadvantages of using solar energy.
The most important advantages of this type of system are:
- unlimited energy resources (solar radiation) – you can get them even when it rains or is cloudy;
- no need to use fuel or transport energy;
- the possibility of direct conversion into various forms of energy (heat, electricity);
- correctly installed panels do not require maintenance or problems;
- the versatility of this technology means that it can be installed almost anywhere after selecting the right modules;
- Photovoltaic installations have a negligible negative impact on the natural environment due to the absence of contamination with residues and combustion products.
Disadvantages of solar energy:
- cyclicality and uneven use (available energy depends on time of day and season);
- the intensity value depends on the angle of incidence of the solar rays;
- relatively high cost of devices;
- quite low efficiency of photovoltaic modules;
- dependence of solar radiation on atmospheric pollution, cloudiness.
How is solar energy produced?
Next we will talk about How is solar energy used to make electricity . The sun can be our great source of clean, renewable and cheap energy. You have to take advantage of the more than five billion years of life that remain. We explain how the sun’s rays will be transformed into electricity for your plugs.