How Solar Panels Work: A Plain-English Guide
Solar panels convert sunlight into electricity you can use in your home. The UK gets enough sunlight to generate 80–100% of a typical household's electricity needs. Here's how the technology works, what the jargon means, and why over 1,500,000+ UK homes have already made the switch.
Quick Answer
Solar panels convert sunlight into electricity using photovoltaic cells. Sunlight knocks electrons free in silicon cells, generating DC electricity. An inverter converts this to 230V AC for your home. Panels work on daylight, not direct sunshine, so they generate power even on cloudy UK days.
Last updated March 2026
Fact-checked by John Rooney, Solar Energy Editor. Editorial policy
What is solar power?
Solar power is electricity generated from sunlight. It's one of the most abundant energy sources on Earth. The sun delivers more energy to the planet in one hour than humanity uses in an entire year. Solar power systems capture this energy using photovoltaic (PV) cells and convert it into usable electricity for homes and businesses.
“More solar energy reaches the Earth's surface in one hour than is consumed by all human activities in a year. The challenge has been to capture it efficiently and affordably — and that challenge has now largely been met.”
What is solar energy?
Solar energy is the radiant light and heat from the sun. It can be harnessed in two main ways: solar PV (photovoltaic panels that generate electricity) and solar thermal (panels that heat water). In the UK, when people talk about "solar panels" they almost always mean solar PV, the type that generates electricity and qualifies for MCS certification.
Is solar energy renewable?
Yes. Solar energy is a fully renewable energy source. The sun will continue to produce energy for approximately 5 billion more years. Unlike fossil fuels (oil, gas, coal), solar energy produces no greenhouse gases during operation. A typical UK home solar system offsets around 1.2 tonnes of CO₂ per year.
What is solar PV?
Solar PV (photovoltaics) is the technology that converts sunlight directly into electricity. A solar PV system consists of panels on your roof, an inverter that converts the electricity from DC to AC, and optionally a battery to store excess energy. Solar PV is the type of solar system eligible for support under the Smart Export Guarantee (SEG).
What does PV stand for in solar?
PV stands for photovoltaic. The word comes from "photo" (light) and "voltaic" (electricity). A photovoltaic cell converts photons from sunlight into an electric voltage, literally turning light into electricity. When you see "solar PV" it means solar panels that generate electricity, as opposed to solar thermal panels that heat water.
What type of energy is used by a solar panel?
Solar panels use electromagnetic radiation from the sun, specifically visible light and some infrared and ultraviolet light. The photovoltaic cells in the panel absorb photons (particles of light) and convert them into direct current (DC) electricity. An inverter then converts this to alternating current (AC) that powers your home's appliances. Panels work on cloudy days too because they need light, not direct sunshine.
What do solar panels do?
Solar panels generate electricity from sunlight that you can use to power your home. They sit on your roof and produce free electricity during daylight hours. Any electricity you don't use is either stored in a battery or exported to the grid for a SEG payment of 3–15p/kWh. A typical 4.4 kWp system (10 panels) generates around 3,900 kWh per year, enough to cover 80–100% of an average UK household's electricity needs.
What are solar panels?
Solar panels are flat, rectangular devices that convert sunlight into electricity. Each panel is made up of 60–72 photovoltaic cells (typically silicon-based) wired together. Modern panels used in the UK are around 1.7m × 1.1m and produce 420–460 watts each. They are mounted on roof brackets at the same angle as your roof and connected to an inverter inside your home.
How do solar panels work?
Solar panels work through the photovoltaic effect:
Sunlight hits the panel
Photons from sunlight strike the silicon cells in the panel, knocking electrons free from their atoms.
DC electricity is generated
The freed electrons flow through the cell as direct current (DC) electricity. Each cell produces about 0.5 volts, and cells are wired in series to produce higher voltages.
Inverter converts DC to AC
Your inverter converts the DC electricity into alternating current (AC) at 230V, the type your home appliances use.
Electricity powers your home
The AC electricity flows to your consumer unit (fuse board) and is used by whatever's switched on: lights, fridge, washing machine, EV charger.
Surplus is exported or stored
Any electricity you don't use is either stored in a battery (if you have one) or exported to the grid. Your supplier pays you 3–15p/kWh for exports under the SEG.
How does solar energy work?
Solar energy works by capturing sunlight and converting it into usable electricity. In a home solar PV system, panels on your roof absorb light, generate DC electricity, and an inverter converts it to AC power for your home. The system is connected to the national grid, so when your panels produce more than you need, the excess flows to the grid. When the sun goes down, you draw from the grid as normal (or from a battery if you have one). The entire process is automatic with no moving parts.
Will solar panels work in winter in the UK?
Yes, solar panels work in winter in the UK. While output is lower than in summer due to shorter days and lower sun angles, panels still generate meaningful electricity from October to March. A typical 4.4 kWp system produces around 25–30% of its annual output during winter months. Panels actually perform slightly more efficiently in cold temperatures, and modern N-type TOPCon cells have improved low-light performance compared to older technology.
Monthly generation pattern
Peak output is May–August (60–70% of annual total). December and January are the lowest months, but panels still produce 5–8% of the annual total. Spring and autumn are surprisingly productive; March and September often match each other. A battery helps maximise winter self-consumption by storing daytime generation for evening use.
What does SOC mean in solar?
SOC stands for State of Charge. It refers to the current charge level of your solar battery, expressed as a percentage. For example, SOC 80% means your battery is 80% full. Most solar battery apps (Huawei FusionSolar, Tesla app, etc.) display SOC so you can see how much stored energy you have available. It's the solar equivalent of the battery percentage on your phone.
Typical SOC settings
- Minimum SOC (10–20%): The lowest your battery will discharge to. Keeps a reserve for unexpected usage.
- Backup SOC (20–30%): Some systems let you hold a reserve for power outages.
- 100% SOC: Fully charged. Once full, excess solar is exported to the grid.
Frequently Asked Questions About Solar Energy
What is solar power?
Solar power is electricity generated from sunlight using photovoltaic (PV) panels. It is one of the most abundant energy sources on Earth and produces no greenhouse gases during operation.
What is solar energy?
Solar energy is the radiant light and heat from the sun. In the UK, it is harnessed primarily through solar PV panels that generate electricity for homes and businesses.
Is solar energy renewable?
Yes. Solar energy is fully renewable. The sun will produce energy for approximately 5 billion more years. Unlike fossil fuels, solar produces no carbon emissions during operation.
What is solar PV?
Solar PV (photovoltaics) is the technology that converts sunlight directly into electricity. A solar PV system includes roof-mounted panels, an inverter, and optionally a battery. It is the type of solar eligible for support under the Smart Export Guarantee (SEG).
What does PV stand for in solar?
PV stands for photovoltaic, from 'photo' (light) and 'voltaic' (electricity). A photovoltaic cell converts photons from sunlight into electric voltage, literally turning light into electricity.
What type of energy is used by a solar panel?
Solar panels use electromagnetic radiation from the sun, primarily visible light. Photovoltaic cells absorb photons and convert them into direct current (DC) electricity, which an inverter converts to AC for your home.
What do solar panels do?
Solar panels generate electricity from sunlight. They sit on your roof and produce free electricity during daylight hours. Surplus electricity is stored in a battery or exported to the grid for a SEG payment of 3–15p/kWh.
What are solar panels?
Solar panels are flat, rectangular devices made up of photovoltaic cells (typically silicon-based) that convert sunlight into electricity. Modern panels used in the UK produce 420–460 watts each and measure approximately 1.7m × 1.1m.
How do solar panels work?
Sunlight hits the silicon cells in a solar panel, knocking electrons free and generating DC electricity. An inverter converts this to 230V AC power for your home. Any surplus is exported to the grid or stored in a battery.
How does solar energy work?
Panels on your roof absorb sunlight and generate DC electricity. An inverter converts it to AC for your home. When panels produce more than you use, excess goes to the grid. When the sun is down, you draw from the grid or a battery. The process is fully automatic.
Can solar panels heat radiators?
Not directly. Solar PV panels generate electricity, not heat. However, you can use the electricity from your panels to run an electric boiler, a heat pump, or an immersion heater, which in turn heats your radiators and hot water. Many UK homes pair solar PV with a heat pump for highly efficient heating. If you want panels that directly heat water, you'd need solar thermal panels, but these are not eligible for SEG payments.
What does SOC mean in solar?
SOC stands for State of Charge: the current charge level of your solar battery expressed as a percentage. For example, SOC 80% means your battery is 80% full. Most solar monitoring apps display SOC in real time.
Related Guides
Sources
- MCS — Microgeneration Certification Scheme — mcscertified.com
- Energy Saving Trust — Solar Panels Guide — energysavingtrust.org.uk
- Ofgem — Smart Export Guarantee (SEG) — ofgem.gov.uk
John Rooney is the founder of Solar Info and has been covering the UK solar energy market since 2023. He fact-checks all content against official MCS and Ofgem data and maintains relationships with MCS-certified installers across the UK.
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