The use of clean energy to replace our consumption of fossil fuels is a major part of green living. Solar power is one such type of clean energy, and it has become a popular way to power homes and commercial buildings. Solar power is both eco-friendly and cost-effective over the long term, as it is derived directly from the sun’s natural light. But what exactly is solar power and how is it used? In this post, we’ll tackle the definition of solar power.
Definition of Solar Power
Simply put, solar power is energy that comes from the sun. This power is derived from the sun’s rays that reach the Earth, and is then converted into other forms like heat and electric power.
One major benefit of solar power is that it can be renewed and sustained. It’s a power source that can be used by all to produce electric power for a number of purposes. Solar power, along with other clean sources like tidal and wind power, is used more to save money. Google, Microsoft and Apple are among the major companies that invest in clean energy.
Aside from being cheaper than fossil fuels, solar power cuts cost related to damage to nature through extraction, spills and pollution from combustion.
How is Solar Power Produced?
In order to understand the definition of solar power, we need to take a look at how it’s produced. Energy from the sun is converted into electric power, either with photovoltaics (PV), concentrated solar power (CSP), or both.
PV cells convert light into an electric current, and it is the first method that was developed to produce solar power. At first, it was solely used as a source of power for small and medium-sized gadgets. Remember the solar calculator? It was powered by a single solar cell. From there, PV cells were further developed for powering homes through an off-grid rooftop PV system.
On the other hand, CSP uses many lenses or reflectors to collect more power from the sun’s rays. These lenses, mirrors and tracking systems are designed to focus a large area of sunlight into a small beam. The thermal power collected throughout the day is normally applied to oil or molten salts that retain heat. This heat boils water for steam turbines throughout the night.
CSPs were developed in the 1980s. To date, the Ivanpah in the Mojave Desert is the largest solar power plant in the world. It can produce over 392 MW of solar power.
PV Cells and Systems
Let’s dig deeper into the definition of solar power by knowing more about PV cells. These cells are more commonly known as solar cells or solar panels. They are composed of semiconductor substances: 2 sheets of silicon that are split by an electric field.
The design of PV cells capture the photons contained in sunlight. Each cell has an N-layer and P-layer, and both are made of silicon atoms. The N-layer has extra electrons, while the P-layer is missing electrons. Electric power is made when sunlight directs electrons from the P-layer to the N-layer. This creates a circuit back to the P-layer.
The PV system produces direct current (DC) power that depends on how intense sunlight is. For practical use, some systems use inverters to convert to alternating current (AC). Some systems also use multiple cells that are connected inside modules. These modules are wired together to form arrays, then connected to an inverter. This way, it produces power at the desired voltage.
Many homes in developed countries get their power from grid-connected PV systems. These power systems are stand-alone and can provide power at night and at other times of limited sunlight. Some PV systems also come with high-power batteries as backup sources of power.
Concentrated Solar Power
Unlike PV systems that directly convert solar power, CSPs use the heat from sunlight to generate power from steam-driven turbines. There are many ways to do this, and the best known are the parabolic troughs, compact linear Fresnel reflectors, Stirling dishes and solar power towers. In all of these systems, fluid is heated by sunlight and thermal storage can generate enough power for 24 hours.
Parabolic troughs consist of reflectors that focus light onto a receiver that is positioned along the reflector’s focal line. The receiver is a tube right in the middle of the mirror and is filled with a working fluid. The reflector is designed to follow the sun during daylight hours by tracking along a single axis. This CSP is the best land-use type for producing solar power.
Compact linear Fresnel reflectors use many thin mirror strips instead of mirrors to focus sunlight onto the working fluid. They are cheaper, and more reflectors can be placed in the same amount of space. Thus, more sunlight is used. In addition, they can be used in large and more compact plants.
Stirling dishes come with an engine that drives an electric generator. They are more effective in converting and storing solar power. Solar power towers use an array of tracking reflectors to focus sunlight on a central receiver atop a tower. To date, they are the most cost-effective CSP and offers better power storage.
Uses of Solar Power
Solar power is clean energy and can be used to produce power for homes and buildings. It can benefit many types of business and industries. It can fuel a number of devices, from water heaters, furnaces, ovens, to watches and phones.
Learning about the definition of solar power is not enough until we realize its benefits. Solar power can be renewed and we have an endless supply of it. It doesn’t produce greenhouse gas emissions and other forms of pollution. Indeed, solar power is the future of power and soon we’ll see more ways of how to use it.