How does solar energy work
Posted by Solar energy guru | Filed under Solar energy facts
People often ask the question of how does solar energy work but they really aren’t asking the correct question. Solar energy is simply the light and heat given off by the sun. Only about half of the actual energy produced by the sun makes it to earth; the other half is reflected back into space by our atmosphere. The solar energy that makes it through the clouds to us is easy to see and feel.
Rather than ask how does solar energy work, most people actually want to know how we get power from solar energy. In other words, they really just want to know how we turn the sun’s heat and light energy into a usable power source. While it can be used in many ways by utilizing and concentrating the heat of the sun, most people are talking about electric power generation.
There are two methods by which solar energy is converted into a usable source of power. Both methods use solar panels to collect the solar energy but one process focuses on the sun’s heat and one process focuses on the sun’s light. When setting up a home to use solar energy for it’s power source, the most efficient home solar setup will utilize both processes.
The first process is called solar thermal. In this process, the answer to the question of how does solar energy work is by harnessing the sun’s heat. This can be done without any external aids in place, such as the sun heating the water in a swimming pool or by the sun heating the stone in a home’s wall. Most often, solar panels are used to capture more of the heat from the solar energy than can be captured without the panels.
Once the solar panels capture the heat, it is then transferred to water which flows through tubes in the panels. These tubes are called solar thermal collectors and they can circulate the heated water through a space. The heated water in turn heats the air in the space, thereby distributing the solar power throughout as heat.
The second process is the photovoltaic process and is usually what people are thinking of when the ask how does solar energy work. Photovoltaic (PV) panels capture the light emitted by the sun and convert this energy into usable electricity. They do this by exciting the electrons in the solar energy which produces direct current (DC) electricity.
Of course, DC electricity isn’t usable for most home needs. The DC electricity must go through a conversion process in a mechanical device known as an inverter to be changed into the typical 120 volt of alternating current (AC) electricity. Some of the energy is lost during the conversion process but the rest is easily stored in deep cycle batteries that can power your home during the evening hours.
The most efficient means of building a completely solar powered home will utilize both processes. Solar thermal power can be gathered without the solar panels in passive heating techniques built into the home’s design that not only gather the heat but also distribute it evenly throughout the home. Using solar panels to focus the thermal energy can heat the home’s water as well as help to distribute the heat more evenly when needed.
The PV panels in the home’s solar array will be busy harnessing the light energy from the sun throughout the day. This energy is converted to usable AC electrical current to power all the appliances and other things that run on electricity. Battery storage allows for the electricity to be available even in bad weather or through the nights.