A lot of us do not think about where electricity comes from, all most people know is that it’s readily available to them. The electricity that we use today is most likely generated by burning fossil fuels such as coal, oil, and natural gas – all of which emits harmful gases that contributes to climate change.
Renewable energy such as solar is now more affordable than ever and is being used to produce electricity for a wide variety of residential and commercial uses. The sun is a promising source of energy. Electricity produced from sunlight will be a key part of our journey toward sustainable energy in the future. As much as solar was expensive in the past, scientists have come up with a good and reliable way of harnessing energy from the Sun. Solar power comes in two forms; thermal and photovoltaic.
Thermal Solar Energy
This is the most basic form of energy whereby sunlight is concentrated and converted into heat. Mirrors are one of the main components of the solar thermal system. They reflect sunlight onto a receiver containing a heat-transfer fluid, which is warmed up by the sun. In other words, solar thermal technologies capture the heat energy from the sun and use it for heating and/or the production of electricity. The heat powers a generator that produces electricity, which is thereafter used in powering industries and homes. It’s similar to the way fossil fuel-burning power plants work except the steam is produced by the collected heat rather than from the combustion of fossil fuels.
Photovoltaic (PV) Solar Power
One the other hand, PV converts sunlight directly into electricity. These solar panels are longer lasting and efficiently convert energy from the sun to electricity. Solar energy is produced when sunlight strikes solar panels, which then turn solar power into usable electricity. Solar energy is captured through solar panels and converted to solar electricity using photovoltaic (PV) technology (”photovoltaic” means electricity from light — photo = light, voltaic = electricity). This possible thanks to the photovoltaic effect. Although we cannot see the photovoltaic effect with our own eyes, we can look more closely at the solar panels where this process takes place. In short, this effect takes place when photons (tiny electromagnetic particles) of light are absorbed by a specific material, which in turn releases electrons from atoms. Released electrons are then available to do the electrical work, such as powering a light bulb. This photovoltaic transformation is the way solar energy is generated.
Using PV technology is a much more popular form of solar power. Solar panels contain photovoltaic cells made from silicon, which is found in abundance on the surface of the earth, that transform incoming sunlight into electricity rather than heat. The cells are then wired together forming solar panels, which are subsequently wired to a circuit. When the sunlight hits these silicon cells, these panels generate electric current, which is connected to an external load and powers it. A single solar cell is not enough to produce sufficient electricity, therefore multiple cells are connected to each other to form an array of cells called solar panels.
This is a basic framework model for producing electricity and number of panels can be connected to produce the desired electrical output. PV cells are generally easier to maintain and require no maintenance. They produce no greenhouse gas emissions and are environmentally friendly. Solar-powered cells do not produce any noise, unlike wind turbines or hydropower stations. The more sun that strikes your solar panels, the more electricity generated from solar panels. Therefore, it is important to consider factors like shade and cloud coverage when designing a solar energy system.
3 Factors That Impact Solar Electricity Production
Households should consider these factors before the installation of their residential solar systems.
Shaded solar panels won’t produce the same amount of energy as those in direct sunlight. If your roof gets shade off by tall trees or building, solar may not be your best choice. Ideally solar panels should be located such that there will never be shadows on them because a shadow on even a small part of the panel can have a surprisingly large effect on the output. The cells within a panel are normally all wired in series and the shaded cells affect the current flow of the whole panel.
Solar energy production varies day-by-day depending on the weather. A cloudy day will not be as productive as a sunny one. But it’s important to focus on the year-round picture. Photovoltaic panels are actually designed to use direct or indirect sunlight to generate electricity. This means that they will still perform even if sunlight is partially blocked by clouds. However, if the density of cloud coverage is high, they might only produce 10-25% of their rated capacity.
Solar panels can benefit from a good tilting. The direction your home is facing and even your roof’s pitch, have a significant effect on how well a residential solar system works. Ideally, solar panels should be at the same angle as the latitude where they’re mounted. Pitches between 30 degrees to 45 degrees usually work well in most scenarios.