How do solar panels work?
Solar panels work through a photovoltaic process where radiation energy is absorbed and generates electricity. Sunlight is absorbed by semi conductor cells – normally silicon – and transformed from photo energy (light) into voltaic (electrical current).
When the sun’s radiation hits a silicon atom, a photon of light energy is absorbed, ‘knocking off’ an electron. These released electrons create an electric current.
Photovoltaic cells absorb the sun’s energy and convert it to DC electricity, then an inverter converts DC electricity from your solar modules to AC electricity, which is used by most home appliances. Electricity flows through your home, powering electronic devices and appliances. With a grid tie system,surplus electricity produced by solar panels can be fed to the electric grid.
Additional important parts to solar panels
Aside from their silicon solar cells, pretty much all solar panels use a clear casing for protection of the PV cells. There is a layer of insulation and a protective back sheet. The insulation is important because increases in temperature will lead to decreases in energy output.
Solar panels also have an anti-reflective coating that increases sunlight absorption. Monocrystalline cells are made up of a single silicon crystal, whereas polycrystalline cells are made up of fragments or shards of silicon. Mono formats provide more room for electrons to move around and thus offer a higher efficiency solar technology than polycrystalline, and are more expensive.
Thin film solar panels
Thin film is less bulky than crystalline silicon, and increasingly cheaper to produce. Though it is less efficient, the conductibility is expected to sharply rise as research improves this newer technology.
The main benefits to these type of panels are one thin unit, without any casing or thick wafers. These thin flexible panels can be conveniently molded to surfaces with nearly any shape.
The power coming in is in DC format and needs to be converted to AC power for use in your home. This is what an inverter does. Once the power is converted to alternating current it joins the main electrical system of your home.
Solar electricity is used in the home
If your solar power system is grid tied, the electricity runs through your net meter and powers your appliances without you having to change a thing. If your solar panels don’t produce enough energy to cover all of your electricity needs, you’re still connected to a power company, so you can automatically draw more energy from your utility when you need. What happens if you produce more power than you use?
Leftover solar electricity goes back to the grid
It might seem counter-intuitive to be on the traditional power grid when you have a solar energy system, but being on the power grid allows you to use as much electricity as you need before sending any excess power back to your power company to use. Solar panels generate electricity when the sun is up, but we use electricity at night too, when we’re not producing solar power. That’s why it’s important to stay connected to the power grid or invest in power storage (batteries).
Electricity is measured by the net meter
Net metering is when your local utility company agrees to provide energy credits for any surplus power you produce and add back to the power grid. This meter is similar to the electric meter you probably have now, but it measures power going in two directions instead of just one. In some cases, these energy credits can roll over long-term, and some utilities will even pay you money for the excess power you produce.