How a Solar Panel Works Under Cloudy Skies
Understanding how a solar panel works is one of the first steps toward seeing why solar power has become one of the fastest-growing renewable energy sources in the world.
One of the most common forms of clean energy is solar energy. It has become more popular in recent years, with solar panels appearing on rooftops around the world.
Much of their appeal is due to the fact that they don't have any moving parts that would eventually have to be replaced. Here’s a brief look at the seemingly mysterious process by which these panels convert the sun’s energy into electricity.
Why Understanding How a Solar Panel Works Helps You Save More
At their core, modern solar panels are based on the photovoltaic effect: the ability of certain semiconductor materials to generate electricity when exposed to sunlight or other electromagnetic radiation.
This is the principle behind all PV solar panels and PV cells in use today — from small solar energy technologies powering individual devices to large solar array installations powering entire buildings.
To find out how modern battery technology fits into this high-tech energy future, read our strategic guide to residential energy storage to save more!
Photovoltaic Cells
A solar panel is essentially a collection of several cells, called photovoltaic (PV) cells. While smaller items like solar-powered radios and calculators typically require a single cell to generate the power they need, a car or house would require several thousand.
A solar cell contains several components, beginning with the two layers of silicon that make up most of the cell. The cell also contains metal plates by which electrons are guided into the home's wiring as electricity. To close the circuit, electrons then have to flow back into the cell through its metal backing.
Additionally, each cell is covered with an anti-reflective coating to ensure that the sunlight isn’t reflected away, depriving the cell of the photons it needs to initiate the process.
Each solar panel is made up of many of these PV cells, wired together into an electrical circuit. The glass casing protects the cells from weather while still allowing enough sunlight — including diffused light on overcast days — to pass through and reach the semiconductor material below.
This is why most solar panels continue generating power even under cloud cover, though output is reduced compared to direct sunlight.
To see how today's systems handle cloud cover, read our article about
Related article: How Solar Works When It's Not Sunny
Silicon Layers
Although silicon is strong enough for use in a PV cell, it’s not a very good conductor. To compensate for this, manufacturers add trace amounts of phosphorus and boron to the two layers.
With the added phosphorus, the top layer contains more negatively charged particles (electrons) than it normally would. To balance things out, the bottom layer with boron contains fewer electrons than it normally would.
This deliberate imbalance between the negatively charged and positively charged layers is what makes the photovoltaic cell function.
Silicon is the dominant semiconductor material used across the solar industry because it is abundant, durable, and well understood — though PV technologies continue to evolve as private companies and researchers develop new materials and more cost-effective manufacturing processes.
If you're curious about the inventors and early breakthroughs that paved the way for these modern marvels, check out The History of Solar Energy!
Establishing an Electric Field
An electric field is then needed to generate electricity. The positive and negative charges in an electric field attract each other the same way the opposite poles of two magnets do. The field is created when the two silicon layers in a cell are brought together.
Extra electrons from the top layer quickly move into the bottom layer near the junction where the two layers meet. With the added electrons, the bottom layer then becomes negatively charged, while the top layer becomes positively charged. At this point, all that is needed is sunlight.
This built-in electric field is the engine of how solar power works — it acts as a one-way gate, directing loose electrons in a consistent direction to create an electrical current rather than letting them scatter randomly.
To get a better handle on the underlying science of photovoltaic cells and current flow, read our guide on How Solar Panels Actually Work!
Without it, even abundant solar radiation striking the cell would produce no usable electric current.
Generating Electricity
When sunlight reaches the cell, photons begin knocking electrons loose from both silicon layers. These loose electrons are then pushed out of the junction area by the electric field and onto the metal plates. As long as there is sunlight hitting the cell, the process will repeat itself, generating more clean energy.
This continuous cycle — sunlight hits the PV cells, electrons flow, electrical current is produced — is what makes solar panels generate electricity reliably day after day with no fuel and no moving parts.
PV panels perform best under direct sunlight, but they still produce electricity from diffused light, meaning solar energy produced on a cloudy day is still real and usable energy.
Related article: How Solar Saves for Rainy Days
The rated capacity of a panel refers to the amount of electricity it can generate under ideal test conditions, though real-world energy production depends on factors such as solar radiation levels, panel orientation, and shading.
Powering a House or Building
From the metal plates, the electrons flow as electricity to an inverter in the house or building. This is necessary to convert the direct current (DC) from the cell into the alternating current (AC) required by most appliances.
Modern solar inverters often include maximum power point tracking technology, which continuously adjusts the operating point of the solar array to extract as much usable electrical current as possible throughout the day as light conditions change.
This helps solar energy systems maintain strong energy production even as conditions shift between direct sunlight and diffused light.
Related article: PECO Residential Solar Power Rebate: How TerraSol Energies Makes Going Solar Easy
While the electricity generated by one cell doesn’t amount to very much, it accumulates when multiple solar panels are involved, with many conductive wires drawing loose electrons away from the metal plates.
Lost electrons eventually find their way back to the negative plate, where they will take part in the process again, creating more solar energy.
When solar panels convert sunlight into more electricity than a home or building uses at a given moment, that surplus energy — or surplus power — can be fed back into the grid through net metering, earning credits against future energy bills.
Alternatively, solar energy systems paired with battery storage can hold onto that excess for use at night or during outages. Either way, installing solar reduces dependence on the grid, lowers your carbon footprint, and makes renewable energy a practical everyday reality.
Related article: The End of the Tax Incentive Is Not the End of Residential Solar in PA
It's also worth noting that solar thermal panels are a different category from PV panels — they operate on a different principle, using the sun's energy to produce hot water rather than generating electricity.
Most solar panels installed on homes today are PV solar panels, but solar thermal systems are also an option for hot water heating, and some homeowners combine both for maximum energy coverage.
TerraSol Energies has been helping homeowners and businesses across Pennsylvania, New Jersey, and Delaware install solar panels since 2009 — handling everything from design and permitting to installation and ongoing support.
Our certified team will assess your property, size your solar array correctly, and make sure your solar energy systems are built to deliver maximum energy production for decades to come.
Contact us today at 888.873.9995 or request a custom solar proposal. Take the first step toward understanding not just how a solar panel works, but how it can work for you.
Frequently Asked Questions
How do solar panels work step by step?
First, the solar panels absorb sunlight and convert it into direct current (DC) electricity. Second, an inverter changes this DC power into alternating current (AC) electricity. Finally, this AC electricity flows into your home's electrical panel to power your appliances.
Do solar panels work in the rain?
Yes, but at a reduced capacity. Heavy clouds lower their energy output to about 10% to 25% of normal. However, rain is actually beneficial because it washes away dust and debris, keeping the panels highly efficient once the sun comes back out.
Can I run AC with a solar panel?
Yes, you can run an air conditioner on solar power. However, because AC units draw a massive surge of electricity, you need a properly sized solar array combined with either a grid connection or a robust battery system to handle the heavy load.
