Category: Earth Sciences

Understanding Solar energy

What is solar energy?

Converting the sunlight (not heat) into electrical energy is known as solar energy. Presently Photovoltaic cells are the most popular method of capturing the sunlight and converting it into electrical energy that we can use for domestic applications. However, the electric power produced by the photovoltaic cells or more commonly known as solar panels is direct current or DC, and this needs to be converted to alternating current or AC for residential applications. Solar panels made up of PV cells have a long life cycle and can, therefore, serve you for several decades. One reason why solar energy has gained immense popularity in recent times is the fact that there is a global awareness on producing clean energy. As mentioned on Eurosolar Global website, increased demand has also lead to the drop in prices for most solar power systems.

How is solar energy produced?

One method of producing solar energy is thermal. This process concentrates the sun rays to convert the light into heat. The heat generated is then carried to a steam generator. The steam engine, in turn, produces electricity for domestic and industrial consumption. Thermal solar energy can also be used to eliminate hazardous waste, heat water, heat buildings and dry agricultural produce.

Fresnel lenses are employed in solar concentrators used for the production of thermal power with the help of solar energy. These lenses appear similar to a dart board and each ring in the lens focuses on scattered sunlight to make it significantly powerful beams. The effect is analogous to a magnifying glass and the concentrated sunlight powers the steam generator to produce electricity.

Solar panels with photovoltaic cells

The second method uses solar panels comprised of photovoltaic cells and has gained immense popularity in recent times and is a direct source of electricity. This system comprises of silicon cells which are known for their strength as a semiconductor material, and there is no dearth of availability of silicon on the earth’s surface. These cells are wired together to form the panels and wired subsequently to a circuit. When sunlight falls on the silicon cells, the panels generate electrical energy. Multiple solar cells are necessary since a single cell cannot produce enough electricity. An array of cells known as modules is therefore employed, and several such modules make up your domestic solar installation. Depending on your needs several panels can be installed on your rooftop and connected to a converter.
More recently, there has been a thrust in developing batteries that can store the converted solar energy for use during the night or cloudy days. In some regions, any excess power produced can also be transferred to the grid and converted into cash. While the initial cost of installing solar panels is high, it can serve you for several years. Moreover, solar panels need no maintenance, except an occasional cleaning to remove dust and other particles from the surface of the panels.

Solar energy: how it works

Solar energy is produced through the interaction between photons and electrons. Photons provide the building block to produce solar energy. Photons hitting the solar panel reflect off the panel, gets absorbed or passes through the panel. Photons absorbed by the panel generate electrical energy. When the panels have absorbed an adequate amount of photons, electrons start emitting from the panel.
The silicon cells emit electrons and gather atop the cells producing an imbalance in charge. Each half of the silicon cell is divided into negative and active photons. This is similar to the terminals of a battery which has positive and negative terminals. Thus, when the solar cells are connected to an appliance, it receives electricity. When this is put to commercial or domestic use, the electrical energy produced by solar cells is converted to alternating current with the help of an alternator that forms part of your solar power system installation.

Solar energy facts

Solar is the biggest source of renewable energy and the raw material which is sunlight is perennially available and inexhaustible as long as the universe lasts. Solar energy can be converted for domestic use instantly which means you can avoid a generator when you install a solar panel on the rooftop. Maintenance needs for the solar installation are near zero, and no supervision is required to produce solar power. Your solar energy system also does not come with any moving parts which mean that you won’t have to bother about regular lubrication of the equipment. Most solar power systems work tirelessly for periods ranging between 20 and 30 years. The environmental impact from solar power generation is minimal since it does not produce any waste.
The only factors that can be held against solar energy are that it cannot produce any energy when you are hit by smog, cloudiness or fog. Further, only a fraction of the sunlight that falls on the panels is converted into electrical energy. While the first part is inevitable, technological advances can impact the second part. In the future, evolving technology might help produce more energy per square meter of installed solar panels.

Where you can use solar power

Solar energy can be used in all types of equipment, home appliances or other situations where the conventional energy used. However, as we stated earlier, solar power produced through the panels is direct current or DC. This would, therefore, need to be converted to AC or alternating current to make it adaptable to domestic/commercial use. Solar energy is also widely used for heating during a winter season. Through a process known as convection, warm air can be circulated throughout the home to keep the residents warm.
While solar energy can significantly reduce your dependence on the utility companies and even help you save on your monthly energy expenditure, remember that you may not be able to disengage the utility companies entirely. In future, as companies like TESLA in the U.S. relentlessly engage in developing energy storage technologies, you may be able to store energy for several days from your solar installation. When that happens, you can switch to solar power for all your energy needs.