The Sun is an inexhaustible source of safe and affordable energy with great potential for the future. The fossil fuels needed to generate electricity are only 40-50% efficient; the rest burns up and pollutes the atmosphere.
The efficiency of solar energy is up to 40%, depending on the types of solar cells used. It is necessary to use special panels to turn sunlight into electric current, and they form solar power plants of various capacities. This material is about how these installations work and how solar energy conversion to electricity occurs.
How Do Solar Panels Function and What Are They?
Solar panels are combined semiconductor photocells that convert the sun’s energy into a direct electric current. They consist of a certain number of cells with different nominal loads. A panel’s maximum battery performance is possible when cells are at right angles to sunlight.
Several structural details ensure the performance of the elements:
- Charge controller: This is the heart of the solar station, designed to regulate voltage and current, and prevent overcharging and undercharging of the battery.
- Battery: In this unit, the installation generates the current accumulated and transmitted in the required power for further use.
- Inverter: It is responsible for the conversion of the available direct current in the battery into alternating current to regulate loads.
Solar panels convert light energy from sunlight into various forms of energy: fuel, electricity, and heat. For this, photovoltaic cells are in use. Each solar cell is made from two silicon layers; the other materials are metal and glass.
The upper part is made of tempered glass, which is an insulator. It is necessary to use the material to protect other layers from the influence of the environment and the ability to transmit sunlight.
Further, solar energy transfer moves to an anti-reflective coating that captures and collects photons. This coating locates under silicon semiconductors, which reflect the rays.
Photovoltaic cells convert solar energy into electricity thanks to silicon layers. The first combines with a small amount of phosphorus, and such a compound forms an additional n-type electron. The second layer is doped with boron and creates a p-type electron. Doping is necessary to increase electrical conductivity, and a net charge appears as an electric current when these layers are in contact.
Above and below the silicon layers are metal grids and plates. Solar power conversion happens like this:
- Energy hits the plates.
- They heat up and release electrons.
- The electrons actively move along the conductors.
- Conductors transfer charges to batteries.
Solar panel energy conversion takes place in the silicon wafer itself. Three methods can be used in its production:
- Amorphous: The modules are flexible and unpretentious to the place of installation but have low efficiency.
- Polycrystalline: More affordable and productive in cloudy weather.
- Monocrystalline: More expensive but more efficient.
Individual photocells are connected to a single electrical circuit for solar conversion, providing high-power electricity to power electrical appliances. All photovoltaic cells have a special attachment to the frame. In the event of a malfunction, changing the entire battery is unnecessary, but only individual plates.
How Do Solar Cells Change Into Electricity?
Solar panels allow you to convert photons into electricity, heat, and fuel. Solar fuel accounts for 11% of all fuel produced worldwide; even less heat is used for space heating and water heating. But the demand for converting solar energy to electricity is increasing every year.
The advantages of solar power plants are the generation of green energy, low maintenance costs, the 30-year service life of installations, and mobility allowing installation of the structure in different places and sizes.
Source: Good Energy
But there is also a downside. Sunlight hits the plates intermittently, and the intensity of the glow also varies, depending on the season and weather. The difficulty is that batteries only provide direct current (DC) and require an inverter to convert it to alternating current (AC). Another disadvantages is the high price of equipment. However, the costs will pay off within 3-4 years.
It is possible to describe the principle of operation of SES and how solar energy is converted into electricity at several points.
Step 1. The panels are activated by sunlight.
Rays fall on the solar panels and penetrate through the upper glass layer to the photovoltaic cell, which converts sunlight into energy. The hit of a photon provokes the release of n-type and p-type electrons in both silicon surfaces. They move freely through the layers, taking each other’s place.
Source: Clean Energy Reviews
Their constant active movement and return to their layers along the wires form a voltage in the external circuit. Electron migrations lead to the charge of photocells, one becomes positively charged, and the second one becomes negatively charged. That is how electricity appears.
Step 2. Electrical current is produced by the cells.
The first step of solar energy conversion describes how photovoltaic cells convert the sun’s energy into electricity. The next step is to store the energy in the battery. The battery is accumulating charge. The controller constantly monitors the battery charge level, eliminating the risk of overcharging. If the charge indicator drops, the controller turns on the solar module and, in the opposite case, turns off the panel.
Step 3. Electrical energy takes a different form.
Next, the inverter connects to the work. Solar panel energy transformation requires the transformation of direct current into alternating current. The device allows you to get a voltage of 220 V at the output, which is necessary to power electrical appliances.
Step 4. Converted electricity powers your house.
When solar energy is converted to electricity with the required voltage, it is possible to connect household electrical appliances. To meet the electricity needs of the whole house, it is important to correctly calculate the maximum allowable power of the panels and compare it with the request.
The installation’s power does not depend on the total potential of all photo modules but on the inverter’s rating. Knowing what energy conversion is occurring in a solar panel and what power supply threshold the inverter withstands, it is easy to calculate the required number of panels to construct an independent solar power plant.
Step 5. Usage is measured by a net meter.
When solar cells convert the sun’s energy into electrical energy, the whole process reflects on the counter, a mandatory element of the solar station. Using devices makes measuring the voltage, capacity, and condition of the battery, power indicator, and current possible. The meter measures the energy produced by the solar panels and the load consumed by the user.
If solar panels’ energy conversion provides more electricity than the owner of the station needs, it is appropriate to install a bidirectional meter. It will record the electricity exported to the central grid and used by the home.
We figured out how solar panels convert light energy from sunlight into electrical energy, and it’s only a matter of perspective. The problem now lies in the high cost of photo modules. But the market for alternative energy to fossil fuels is growing rapidly, and products are becoming more accessible to many people.
The environmental friendliness of electricity generation and the ability to work efficiently even on cloudy days and snowfalls point to the fast prospect of a transition to clean energy. According to experts, by 2050, solar power will generate more than 60% of the world’s electricity.
Frequently Asked Questions
Is solar energy exhaustible, or is it a limitless resource?
There was no decrease in solar activity over the entire period of observation of the star. Scientists optimistically determine the energy resource of the Sun, and according to their calculations, the energy will last for several billion years. Every person is free to use solar power, so installing of solar modules is the way to energy independence.
How cost-effective is it to install a solar station at home?
Solar energy converter is not cheap, and that’s why so many people have not yet decided to install a solar energy system (SES) in their homes. Payback of stations for home consumption averages four years, and it all depends on the power of the system and the amount of electricity generated. After this period, the owners no longer spend money on paying for heat and electricity. When installing powerful stations, excess electricity can be sold to the state and receive a double benefit from SES.
What energy conversion occurs when a solar panel uses light to provide power to a house?
The process of converting solar energy into electricity includes several stages, including the following:
– The panel captures the sun’s rays falling on the surface.
– The modules are heated, and electrons are released in the silicon layers.
– Their movement leads to the generation of voltage converted into electric current.
– The current goes through the conductors to the battery.
– An inverter changes direct current to alternating current.
The output is a current with a voltage of 220 V, to which you can connect electrical appliances.
The energy of the future – why is solar energy called that?
There is a misconception that solar energy conversion is possible only through installing solar power plants. But humanity has been passively using solar energy for a long time. After all, it is necessary for plants’ photosynthesis, the appearance of wind and water in natural reservoirs, and the warming earth.
Modern technologies are trying to extract the maximum benefit from a natural source. The difficulties so far are only in turning it into an energy form that can be accumulated, stored, and transported in the right direction.