How Solar Panels Work: Solar Power Science Explained

Interested in making the switch to solar energy, but not sure how solar panels work? Understanding household renewable energy systems can make it easier to find the best solar panels for your home.

Many homeowners are going solar to help lessen dependence on traditional utility companies and slash monthly electric bills. In addition to these cost savings, switching to a home solar system means minimizing your environmental footprint. Between the financial advantages and the improved ecological stewardship, solar energy can seem like a no-brainer.

Let’s dive into the science behind solar and how solar panels work to power homes.


How Do Solar Panels Work?

When you buy solar panels, your installer will position several panels on the roof of your home in what’s called a solar array. The specific number of solar panels you require depends on several factors, including the size and position of your roof, the amount of sunlight your home receives, and the type of solar panels you select.

Solar panels use photovoltaic cells, or PV cells, to absorb light from the sun. (More on the photovoltaic effect in just a moment.) When sunlight hits the panels, they generate a direct current, or DC electricity. However, homes require alternating current, or AC electricity.

A device called a solar inverter is a key part of the solar energy system, as it converts the electric current from DC to AC. The AC power then circulates through your household electrical panel and is distributed as needed to your different systems, appliances and outlets.

Here’s a quick, step-by-step summary of how solar panels work to power your home:

  1. Photovoltaic cells absorb sunlight, then turn it into DC energy.
  2. An inverter turns the DC energy into AC energy, which is what your household electrical system requires.
  3. Electricity is distributed throughout your home, powering outlets and appliances.
  4. Any excess or leftover electricity that is produced is fed into a battery bank or back to your local power grid.

The Science of Solar Panels

While there are a few types of solar panels to choose from, most household systems work in roughly the same way. There is usually a layer of silicon cells surrounded by a metal frame and a glass case. There are also wires throughout the panel, allowing the free flow of electricity.

You may (or may not) remember from your high school science classes that silicon is a non-metal with conductive properties. In other words, it is able to absorb light and then turn it into electricity. How it works is simple: when light hits the silicon cells, electrons are set into motion, producing an electrical current. This electricity generation process is known as the photovoltaic effect, and it is one of the core principles of solar technology.

More About the Photovoltaic Effect

Let’s dig into the photovoltaic effect a little deeper. This principle was first discovered way back in 1839 and is generally associated with semiconductor materials. The photovoltaic effect simply describes the property by which these materials can generate electricity any time they are exposed to sunlight.

Here’s a step-by-step summary that explains how solar panels work by employing the photovoltaic effect:

  1. Sunlight hits the solar panel, which has two layers of silicon, an n-type layer that sits on top of a p-type layer.
  2. The sun’s energy knocks an electron from its bond in the upper n-type layer, creating both a freely roaming electron and a positively charged “hole” where the electron was previously bonded.
  3. The hole travels down to the p-type layer, and the free electron travels through conductive wires to an inverter.
  4. The inverter transforms the solar electricity from DC to AC so that it can be used in your home.
  5. The electricity flows throughout your home to power systems, appliances and outlets.
  6. The free electron eventually flows through the house and back to the p-type layer of the panel, where it fills a positively charged hole and closes the loop needed to maintain the flow of electricity.

How Solar Panels Work With Your Power Grid or Battery Bank

We mentioned earlier that any excess electricity generated by a solar panel is fed back into a power grid or can be stored in a solar battery. What are these, exactly, and how do solar panels work with each component?

If your home is connected to the electrical grid (and most homes are), then it comes with a utility meter. This meter allows your utility company to measure how much energy you are consuming. During solar panel installation, your solar system will typically be connected to the utility meter. Thus, the meter assesses and measures your home’s solar energy production.

Many solar homes produce more energy than they consume. In this case, you can either send your excess energy back to the electrical grid (through a process called net metering), or you can purchase a battery to store your energy for future use.

  • Power grid: When you feed energy back into your power grid, you can receive credits from your utility company to save even more money on your monthly bills and help offset the cost of solar panels.
  • Battery bank: The best solar batteries have a high capacity so that you can store enough excess energy to power your home during power outages and on cloudy days.

Additional Components of Your Home Solar System

Now that you understand the most important components of your home solar system, there are a couple more items to consider that affect how solar panels work in terms of efficiency.

We mentioned above that most solar panels come with a glass casing. This helps protect the silicon solar cells and ensures the longevity and durability of your home solar system. Beneath that glass case, there may also be some insulating materials, which protect your equipment from humidity as well as from heat dissipation. This insulation is crucial because it allows the solar panel system to work optimally.

A lot of solar panels are coated in anti-reflective materials as well. This is so that they can absorb as much of the sun’s light as possible. Again, this is an important way to keep your home solar system working smoothly and efficiently.

A final note for homeowners who are interested in solar energy: As you select your solar panels, you will generally have a choice between monocrystalline and polycrystalline. Monocrystalline panels are made using a single silicon crystal. They tend to be the most efficient solar panels, though they can also be pricier. Polycrystalline solar panels are made up of multiple crystal fragments and usually cost less.

Getting Started With Solar Energy

Now that you know how solar panels work, you may feel ready to get going with a home solar system. The first step is identifying the top solar companies in your area and calling an installer to find out if solar panels are worth it for your home. Your installer will conduct an assessment based on the size of your home, the surface area of your roof, the amount of sunlight you get and more. It will furnish some guidance as to how many solar panels you need and which type of panel is the best bet.

Getting a home solar system can be a great way to save money on your monthly utility costs while demonstrating a real commitment to environmental stewardship.