Solar panels provide clean, abundant energy from the Sun.
The creation of electricity from solar panels is remarkable as it happens with no moving parts to wear out, no fuel needed to be consumed, and zero pollutants created. For a solar panel to work, sunlight is all that is needed — a natural clean and renewable energy source.
Solar panels work by converting the energy in sunlight to electricity, which happens inside photovoltaic (PV) panels when they are exposed to sunlight. Sunlight has a tremendous amount of energy and even at the solar panel efficiency of less than 30% that is commercially viable today there is plenty of energy in sunlight to completely meet the energy needs of our planet.
What’s most interesting about how a solar panels works is how different the process is from other means of generating electricity.
Traditional Ways of Making Electricity
It seems surprising, but most of our the electricity generated even today is still stuck in the age of steam. This is a technology that dates back hundreds of years, and which relies on heating and boiling water to create steam to turn a turbine. The main difference between conventional power plants today is what fuel we are burning to boil the water. Today, coal and natural gas, both polluting nonrenewable resources, are most common. Even space age nuclear power splits the atom to release heat used to boil water. All of these methods create pollution and naturally use and pollute an astonishing amount of water.
Traditional power plants, like this nuclear facility, create pollution and harm water quality. (Credit: Wim van 't Einde/Unsplash)
Making electricity from solar panels is different as it is the only commercially viable way of making electricity without any moving parts.
How a Solar Panel Works
Solar panels make electricity using what’s called the photovoltaic effect. The discovery of this process dates back to the early 1800s, the age of steam, when scientists discovered they could generate a weak electric current when sunlight hit specially coated plates. The discovery was interesting but not useable for many decades.
Solar panel technology got a huge boost from another technological leap — the space race. We needed an energy source in space for satellites and space stations, and coal-fired power plants were highly impractical for this. Solar panels today are similar in concept, though much refined, to those created in the 1950s
In fact, some of the earliest solar panels are still producing electricity at the National Renewable Energy Laboratory in Colorado. But how do they work?
The Solar Sandwich
Solar panels are made from two different layers of semiconductors with a non-conducting layer in the middle, which looks something like a sandwich. The layers are constructed so that when sunlight hits the panel electrons flow between them. Moving electrons are what makes up electricity, meaning the solar panel sandwich creates electricity with no moving parts, no fuel needed, and nothing emitted (so no pollution).
An easy way to think about this solar sandwich is to imagine a solar panel with three layers. The top and bottom “bread” layers are both semiconductors, and the middle filling is a nonconductive material.
The “solar sandwich” produces energy that is fed through an inverter to provide AC power to your home.
In the top layer of semiconductor “bread” energy from the sun knocks electrons loose. These negatively-charged electrons want to go to the positively-charged bottom layer, but they’re blocked by the middle nonconducting layer. So, they have to go the long way around, through wires that create a solar circuit. These moving electrons create electricity, which we can harness to power lights, computers, cars, and more. Remarkably, once the electrons have made the loop they return to the solar panel so the panel does not lose anything in the process and is not used up. In this way a solar panel can work for many decades producing clean energy without needing any routine maintenance.
Solar panels make electricity in the form of Direct Current or DC power. We use Alternating Current or AC power in our homes and buildings, so the DC power needs to be turned into AC through the real brains of a solar installation, the inverter. Solar inverters come in different sizes and configurations (for example, larger string inverters and smaller micro inverters) depending on the size of the solar installation. In either case the inverter takes the DC power and turns it into the AC power we need, syncing to the AC power profile of the utility grid. The solar inverter is what connects the solar panels to the electrical system in a building, and ensures that we can use all of the electricity we’re generating from the sun.
For a quote on installing solar panels on your home or business, contact Cromwell Solar today!