Solar Basics
What are solar panels made of?
Photovoltaic solar panels are used for most residential installations. These panels use silicon, a semiconductor, to generate energy. Silicon, also used in computers, is an expensive material responsible for about 60% of the overall cost of a solar electric system.
How do solar panels work?
Solar panels collect solar radiation from the sun and actively convert that energy to electricity. The solar panels are made up of several individual solar cells that function similarly to large semiconductors. When the solar cells are exposed to sunlight, they convert the energy from sunlight into usable electrical energy. The energy generated from photons striking the surface of the solar panel causes electrons to be released, and electric fields in the solar cells pull these free electrons in a directional current. Metal contacts in the solar cell harness the directional current (DC) to generate electricity. This conversion of sunlight to usable electrical energy has been dubbed the Photovoltaic Effect.
Solar Systems
How do homes get the power?
An inverter turns the DC power generated by the sun and the Photovoltaic Effect into alternating current (AC) which is usable energy that powers your home. Solar systems are grid-tied, meaning it is an electricity-generating system that is linked to the normal utility system of a household. In other words, it’s simply an extension of your existing utility supply. Being hooked into the grid allows for net metering which means:
If your solar panels are producing more electrical power than you’re using:
1. That solar-generated energy will be sent back into the grid and can be used by neighbors and others on the grid.
2. The utility company gives you credits for that extra energy: your electric meter will spin backwards, and your monthly electricity bill will be lowered (We’ll talk about this a bit more when we cover net metering below).
On the flip side, if you need more electricity than is being generated by your solar system (say at night time):
1. Electricity will be drawn from the utility grid for you to use, just as it is traditionally done.
2. Your electricity meter runs forward.
Because of net metering, grid-tied system owners receive the full value of the electricity produced by their system. It measures the net difference between the electricity you take from the utility grid and the electricity you feed to it with your own system. Net metering is a consumer-based renewable energy incentive, and policies vary by state.
