You’re bound to have heard about this before. Solar energy is everywhere—in the news, on your neighbor’s roof and integrated in new technologies. With all the talk around renewable energy, chances are that you know or have heard of someone who’s installed solar panels at home to generate “clean energy.”
But how do solar panels work? Where does the electricity come from? And how do you actually manage to save money in this process? We break all this down so you know exactly what you’re talking about the next time your solar-savvy colleagues come around.
Is solar energy just a hype? By now, the answer is a clear “no.” Since 2008, there’s been a 39-fold growth in solar generation in the United States. With solar having experienced hockey-stick growth over the years, some things are for sure:
1. The adoption of solar panels can only grow. With the amount of R&D (research and development) put into the innovation of solar technology, homeowners have been experiencing a steady drop in pricing for the past decade. The technology isn’t just available for early adopters; it’s been proven and is available for the mass market.
2. Renewable energy is not just a fad. Air quality and the environment are suffering from all-time high levels of air pollution due to the generation of energy via fossil fuels.
3. Incentives are in place now (for certain regions), but they won’t be here forever. Already this year, the Trump administration has introduced a new solar tariff that can impact the price of solar panels in the new future.
Whether you’re contemplating installing solar panels on your property or looking to understand the conversation on renewable energy, you’re wondering: “how do solar panels work?” You’ve come to the right place.
What’s in a solar panel?
You’re likely to have encountered solar energy in action before, whether it’s in basic tools (like solar-powered calculators) or camping gear (such as solar lanterns or backpacks). Although these are useful applications, extrapolating this technology to power your home can reduce your carbon footprint. So, what is a solar panel actually made out of?
Before we get started, it’s important that we explain a few technical terms behind electricity:
AC (alternating current): an electrical charge that alternates direction. Because AC travels more effectively through longer distances, outlets in your home and office are AC.
DC (direct current): an electric charge that consistently flows in one direction. Most of your home electronics and batteries are powered with DC.
Photovoltaic (PV) effect: a phenomenon that occurs when light hits a certain material and electricity is generated.
A solar panel is made up of a number of solar cells, which each contain a layer of silicon. Silicon is a material that executes the PV effect, in that it can absorb sunlight and convert it into electricity.
On an atomic level, what happens is that the sunlight hitting the silicon triggers electrons to stir into motion. That motion creates a flow of electric current, which is DC. But wait, you remember reading above that homes operate on AC. How do we get from DC to AC?
How do solar panels power my home?
Depending on how much space you have on your rooftop, your energy consumption needs and other factors, you’ll need a number of solar panels. A group of solar panels is called a solar array. Here, we will break down the different parts of a solar system and how it’s all connected to your home.
Besides the solar array, a full solar system requires what’s called balance-of-system (BOS) components. This includes the wiring, switches and other parts that ensure the safe transmission of electricity for usage (or storage). Found on every solar panel is a part called the solar inverter, which is responsible for converting the DC electricity generated by that solar panel into AC.
This electricity can now flow to your home’s electrical panel, from where it is distributed to the power outlets, cooling/heating systems, lighting and other usages around your home.
1. A solar array on your roof or ground-mounted onto a part of your property contains a number of solar panels, which are made up of individual solar cells.
2. These solar cells are the ones that absorb solar energy and convert it into DC electricity.
3. A solar inverter on each solar panel converts DC to AC.
4. The AC energy is transmitted to your home’s electrical panel.
5. Your home’s electrical panel distributes that energy to where it is needed.
Everyone’s energy needs are different (and you can get an idea of how much energy a given appliance needs with this calculator), so some people might generate more electricity than they need to consume. Where does that excess electricity go? Or what if there’s a rainy week—will you “run out” of electricity?
Now that you know exactly how do solar panels work, let’s take a look at what happens to surplus electricity.
What happens if I produce more solar energy than I can use?
As solar power generation relies on the availability of sunlight, it makes sense that most of the production of electricity happens during daytime. The amount of electricity that is generated by solar panels per day (known as peak sun hours) is also dependent on a number of other factors, such as:
The geographical location of the solar panels:
Is the home closer to the southern U.S. states or higher up north in Canada? Homes closer to the equator often see more sunlight.
The time of year:
Is it winter or is it summer? Seasons play a part in how much sunlight gets absorbed on a daily basis.
The time of day:
Is it midday or is it late afternoon? Sunlight is the strongest around noon, which is when your solar panels will be able to generate more energy directly.