How do solar panels work? Solar power explained

Solar panels may seem complicated—we'll make it simple.

You probably already know that solar panels use the sun's energy to generate clean, usable electricity. But have you ever wondered how they actually do it?

At a high level, solar panels are made up of solar cells, which absorb sunlight. They use this sunlight to create direct current (DC) electricity through a process called "the photovoltaic effect." Because most appliances don't use DC electricity, devices called inverters then convert it to alternating current (AC) electricity—the form that your home can use. This is the electricity that ultimately saves you money on electric bills.

Don't worry—we're not here to overwhelm you with the nitty-gritty details. But if you want to understand how solar panels create electricity a bit more, we'll explain what you should know.

Key takeaways

• Solar cells are typically made from a material called silicon, which generates electricity through a process known as the photovoltaic effect.
• Solar inverters convert DC electricity into AC electricity, the electrical current appliances run on when plugged into a standard wall socket.
• Other types of solar technology include solar hot water and concentrated solar power. They both use the sun's energy but work differently than traditional solar panels.

Solar energy and photons

Solar energy is the light and heat that come from the sun. To understand how it's produced, let's start with the smallest form of solar energy: the photon.

Photons are waves and particles created in the sun's core through a process called nuclear fusion. The sun's core is a whopping 27 million degrees Fahrenheit. This extreme temperature and pressure causes hydrogen atoms to collide and fuse, creating helium. The reaction releases massive amounts of energy in the form of photons.

This process is constant. Over 500 million tons of hydrogen atoms are converted into helium every second, resulting in photons that generate solar energy here on Earth.

How solar panels generate electricity

In a nutshell, solar panels generate electricity when photons (those particles of sunlight we just discussed) hit solar cells. The process is called the photovoltaic effect.

1. Solar cells have two layers of silicon. Each one is specially treated, or "doped," with phosphorus and boron to create the positive and negative sides of the solar cell, respectively. When photons hit the solar cells, they create an electric field at the junction between the layers.
2. This electric field knocks electrons loose from the atoms in solar cells, setting them in motion.
3. The electrons flow through the solar cell and out of the junction, generating an electrical current.
4. Metal plates on each side of the solar cells capture the electrical current and transfer it to connecting wires.
5. The electrical current flows through the wires to a solar inverter, which converts it to usable electricity for your home.

Alternatives to silicon solar cells

While silicon is the most common semiconductor used in solar panels, alternative options exist.

• Thin-film solar cells are a broad category of solar cells made from lightweight and often flexible materials.
• Organic solar cells are a type of thin-film cell that use carbon-based materials as semiconductors.
• Perovskite solar cells are a third type of thin-film solar cells built out of perovskites, a class of man-made materials with a unique crystallographic structure that makes them highly efficient at converting sunlight into electricity.

What are solar panels made of?

A typical solar module includes a few essential parts:

• Solar cells: These do the heavy lifting, absorbing sunlight and generating electricity.
• Glass casing: Provides durability and protects the solar cells from the elements.
• Insulation layer and back sheet: Protect against heat buildup and humidity inside the panel.
• Anti-reflective coating: Maximizes sunlight absorption.
• Wiring: Regulates electricity transfer to your inverter.

How do solar panels generate electricity for your home?

Generating an electric current is the first step in the process of a solar panel’s working, but the process doesn't end there. Here's how a solar array creates a complete, usable electricity system for your home:

1. Solar cells absorb sunlight and generate direct current (DC) electricity.
2. Solar inverters convert DC electricity to alternating current (AC) electricity.
3. Electricity flows through your home, powering your devices.
4. If you have a grid-tied system, excess electricity can flow to the grid or be stored in a home battery.

What types of solar technology exist?

We've mainly focused on photovoltaic (PV) solar because it's the technology most homes and businesses use. But two other types of solar technology are worth knowing about:

Solar hot water heater

Solar hot water systems use sunlight to heat water for your home—no electricity needed.

Concentrated solar power

Concentrated solar power (CSP) uses mirrors to focus sunlight onto a single point, generating intense heat that drives a steam turbine to produce electricity.