How is Solar Energy Produced? - Turning the Sun into Electricity

Solar energy, although not particularly new in terms of technology, is a relatively new source of large-scale energy production. In their basic form, solar panels harness the sun's energy and create electricity. However, if you are wondering "how is solar energy produced," below, we explore how technology can harness the sun's rays and convert them into electricity.

For decades, scientists have been looking for sustainable types of energy production². Solar energy presents many of the advantages of renewable energy. We can harness its energy and create electricity for as long as the sun shines in the sky.

As technology evolves, how solar power produces electricity will become more efficient. This type of renewable energy is reliable and allows us to move away from fossil fuels, reducing their polluting impacts and helping to mitigate the worst of climate change.

So, how is solar energy produced?

There Are Two Main Sources of Solar Energy

To understand how solar panels work, it is worth knowing that there are two main types⁵. The first is Solar Thermal. This utilizes the sun's heat and transfers it to another medium, which is often a liquid.

The next is Solar Photovoltaic PV. This captures the energy of the sun and then transfers this directly to electricity. This is the typical system often seen on houses and in solar arrays on farms.

Photovoltaic Arrays Explained

Photovoltaic arrays are a group of PV cells that join together. This allows them to create more energy than a single cell on its own.

Solar cells are made from silicon that has been specially treated to consist of positive and negative sides. This makes it possible to transmit electricity. A solar cell joins several other photovoltaic cells through metal connectors to a larger area to capture solar energy. These then connect to a frame for support, ultimately creating a PV module. The modules join together to form a PV array with a single electrical output.

Solar Panels Convert Sunlight to Energy

Creating solar energy all begins with solar panels. Many consider these to be the most crucial aspect of creating solar power. Any solar electric system will rely on solar panels. Most panels use silicon cells such as monocrystalline or polycrystalline. A panel will house the silicone cells before a glass case covers them.

As solar energy relies on solar radiation or sunlight to create electric power, its position is vital. They have to have maximum sun exposure, allowing as much sunlight as possible to reach the panel.

So, the electrons receive a negative charge when the sunlight hits the silicon layer on top of the panel. This results in them becoming attracted to one side of the silicon cell. This, in turn, creates an electric current that moves through the wiring within the panel.

This type of energy production is known as the photovoltaic effect¹. So, solar panels generate electricity from sunlight by freeing up electrons. This forms the basis of how solar systems produce electricity. Effectively, the more sunlight that reaches the panel, the process intensifies and increases, creating more electricity.

There are different solar panels available, and they will create electricity at different rates. As far as renewable energy types go, solar power is one of the more reliable sources of AC electricity available at the moment.

Inverters Make it Possible to Use Electrical Energy

Once the reaction has occurred, and the sunlight has reacted with the silicon, the energy transfer process takes place. The solar energy system will consist of an array of cables. All these cables will terminate at an electrical box known as an inverter, also known as a fused array combiner. The system's setup will differ between domestic solar power systems and power stations. However, the principle is almost the same.

Fuses protect the module cables individually within the electrical box or combiner box as it is known. They also protect the connections that pass the power to the inverter. At this stage of the process, the electricity is known as a direct current (DC). To turn this into usable electricity, the system will convert this to an alternating current (AC). This makes it possible for homes and workplaces to use electricity.

Most electronic devices are unable to use a DC electricity current, and it also means that it is not possible to return it to the electric grid⁴.

However, solar arrays do not create power consistently, meaning the amount can vary. This is all down to the amount of light that reaches the PV cells.

So, to deal with these problems, the inverter and transformer correct them by altering the type of electrical power and the amount that the system supplies. Therefore, the inverter will convert DC electricity to AC electricity, making it possible for electric appliances or the electrical grid to use the power.

Controlling Photovoltaic Arrays

One aspect of learning how solar energy is produced is understanding how solar energy technologies maximize the amount of sunlight that reaches the system. The amount of energy a solar system produces will relate to the position of the PV array; therefore, a solar tracker or array controllers are used³.

The tracker will follow the sun through light sensors, while the controllers will move the PV arrays based on the output from the solar tracker. This ensures that the panels maximize the capture of solar energy and the most sun to generate as much solar energy as possible. 

The sun has enough power to power the entire world. Unlike fossil fuels, one of the many advantages of solar energy is that it is readily available and limitless. Therefore, it will not run out any time soon. The potential of this renewable energy source is the technology, which is improving yearly.

As the world unites to seek a significant reduction in greenhouse gas emissions, solar energy is a viable replacement and possibility.

Solar energy is a clean energy source, and as it can provide us with as much energy as we need, it can help drive emissions down.

After installing solar panels, the operation costs remain low, and there is no fuel to burn. However, producing and disposing of solar panels at the end of their useful life is not without its eco-footprint. Click on to read more about the environmental impact of solar energy, where we explore these issues in more detail.

Solar Panel Technologies

As we now know, most solar panels contain crystalline or polycrystalline silicon. However, solar energy and the technology surrounding it are evolving at an impressive rate. Research and improvement are ongoing as we seek effective ways to collect solar energy.

Cadmium telluride (CdTe) solar panels use a different material than the usual silicon. The efficiency rating is not as high, but it can capture the sun's energy in shorter wavelengths.

Copper gallium indium diselenide solar panels are more efficient than CdTe panels. As a result, they are now a promising option, although the production costs are high. These panels rely on copper-based material to create electricity.

Organic Photovoltaic Cells (OPV) solar panels rely on organic material. This has a small amount of potential to replace the likes of silicon or copper. However, the technology does need to improve. Using a thin vapor layer or solution, they can create an electrical current using sunlight. However, this type of system presently has a shorter life span and lower efficiency.

While these systems all can generate electricity, they are a small section of the solar market. Currently, silicon-based systems are the most popular choice. In addition to a solar panel system, many solutions also need to consider solar battery storage to store excess energy when the sun is shining for days when it is not.

Other types of solar energy exist, such as solar thermal power and concentrated solar power (CSP), used for large-scale solar installations. Here, a central collector captures solar energy directed to it using mirrors or lenses. The heated collector is used to heat liquid used to spin turbines resulting in energy generated.

Conclusion

Solar energy has come a long way since its very beginning. It is now a prominent energy source that is growing in popularity at home and for companies using more renewable energy.

Wind farms are becoming common, and more homeowners are choosing to harness the sun's power. The ability to use the limitless amount of sunlight, as well as the reduction in greenhouse gases, make this a leader when it comes to renewable energy.

In the future, more homes will install solar panels as a matter of course, and coupled with increased energy efficiency, our moves to less polluting energy production look within reach.