How solar panels work: Quick guide with stages and schemes

03 Feb 2022
9 min
Beginner

Andrey GorichenskiAuthor

The solar industry in the US is expected to grow by 400% in the next decade: from 20 GWs of solar power that are installed annually, we’ll move to 80 GWs per year in 2030. Since solar is going to be a hot topic for a long time, here’s a quick guide on the basics of it. Read the article, and when one of your friends or colleagues asks “How do solar panels work?”, you’ll be the first to answer.

Solar energy gets to your home appliances just in 3 steps

The Sun sleeps at night, so do solar panels

It’s only logical: how does a solar panel work when there is no sunlight? If the moon is bright, it can be strong enough to cause the photovoltaic effect to occur, but you can’t expect too much power from it. Maybe it will be enough to power the lamp on your nightstand but hardly any more than this.

This is the reason why in an off-grid system – when you aren’t connected to the grid – it is mandatory to have energy storage. With batteries, you can run any appliance in your house at night powering it with the energy you collected during the day.

Cloudy weather brings solar production down by 20-40%

Some believe that panels become absolutely powerless when the sun is blocked by a small cloud. In reality, it is not so. Of course, when irradiance levels drop, it affects how a solar panel works. While clouds do block some of the solar radiation that is visible to the eye, other types of radiation can still go through and successfully land on panels.

Solar panels get less sunlight in the winter

Solar panels produce 50% less energy in June than in December

Strange as it may seem, cold and sunny weather is best for solar panels. How they work depends on the temperature of the modules: when they heat up, the production drops. The problem with winter is that there is naturally less sunlight, so your system is going to produce around 50% less energy than in the summer.

Snow is a blessing and a curse for solar panels. On one hand, it reflects the sun's radiation on your panels. In other words, snow raises the albedo of a surface and you get more solar energy in winter months. On the other hand, snow heaps block sunlight and hinder energy production.

Clearing panels from the snow with a shovel is not recommended – you might damage the modules. Wait patiently, and the heap is going to slide off the roof on its own. Solar panels heat up while working so they might the snow and even clean themselves in the process.

Benefits of solar panels outweigh disadvantages

So what are the reasons behind solar panels being so popular today? Advantages of solar panels include:

• Green energy for sustainable development. The world tries hard to decrease greenhouse emissions. Solar energy is one of the biggest hopes of humanity to stop global warming as solar panels don't release harmful gasses into the environment.
• Reliable source of energy in all circumstances. Panels work all day long and aren’t afraid of harsh weather or natural disasters. They don’t need fuel, they make no smell or sound and their lifespan exceeds 25 years.
• Smart long-term investment that offsets your energy expenses. On average, solar panels allow you to decrease your monthly electricity bill by $100. In some cases, you stop paying for energy at all. In the US, solar panels generally pay for themselves in 6-8 years, depending on the area. Everything after that is profit. What is more, a solar system increases the value of your property and prolongs the lifespan of your roof.

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It’s a lot, as you can see. What are the possible cons? When it comes to disadvantages of solar panels, you could probably mention:

• Legal constraints. There is no single federal policy about the status of solar panels and prescriptions for their installation. In some states, like Florida, it is perfectly legal to install panels without any papers. In other areas, you would need a solar permit. Find out how easy it is to go solar in your state here.
• Installation and dismantling. Solar panels take some time to be installed and it’s difficult to remove them once the setup is complete. If you decide to move out, it’s more reasonable to sell the house with the solar system instead of detaching the panels from the roof and trying to install them in a new place.
• The upfront costs might seem quite high. A small 5 kW solar system in the US may cost over $13,000. However, some states have special programs and incentives that allow you to decrease your expenses. Of course, you should make use of the Federal Solar Tax Credit program that currently allows you to return 30% of installation costs.

Why may solar panels not work? Leave it to the experts

In situations where your panels don’t produce any power, PV modules themselves are rarely at fault. Reliable manufacturers test every module before shipping. Even if the module was damaged during transportation, its performance may decrease, but the ability to produce electricity shouldn’t disappear completely. That is why under no circumstances should you try to dismantle a solar panel to see what’s inside – you’ll just end up with a broken module.