How Do Solar Panels Work?

Elite Energy News

How Do Solar Panels Work?

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Solar panels work by converting daylight into electricity using photovoltaic (PV) cells. When sunlight hits these cells, it energises the electrons inside them and creates an electrical current. That current is converted into usable power through an inverter, and from there it can power your home, charge a battery for use in the evening, or be exported to the grid and earn you money through the Smart Export Guarantee.

Our guide covers how solar panels work for homes, what they're made of, how inverters and batteries fit into the system, how efficient modern panels are, and what that means for your electricity bills.

If you're looking to install solar panels in your home, you can get a free quote or try our solar panel price calculator to get an estimate based on your property.

How Do Solar Panels Generate Electricity?

Solar panels generate electricity through a process called the photovoltaic effect. Each panel contains cells made from silicon that react when exposed to light, producing an electrical current that can be converted into power for your home. Here's how that process works.

Step 1 – Sunlight Hits the Panels

Solar panels are made up of photovoltaic (PV) cells, each containing layers of silicon semiconductor material. When daylight reaches these cells, tiny particles of light energy called photons are absorbed by the silicon. This is what starts the entire process, and it works with any daylight, not just direct sunshine. A panel on a cloudy day in the UK is still absorbing photons and generating electricity, just at a lower output.

Step 2 – The Photovoltaic Effect Creates a Current

When photons are absorbed, they knock electrons loose from the silicon atoms. The cell is designed with a positive layer and a negative layer, which creates an electric field across the cell. This field pushes the freed electrons in one direction, creating a flow of electrical current. One cell produces a small amount of power, but a typical residential panel contains 60–72 cells wired together, which is what generates a usable output. A modern 465W panel, for example, produces 465 watts of power under standard test conditions.

Step 3 – DC Electricity is Produced

The electrical current produced by the cells is direct current (DC). This is a one-directional flow of electricity – useful, but not compatible with your home's electrical system, which runs on alternating current (AC). The DC output is fed from the panels down to the inverter.

Step 4 – The Inverter Converts DC to AC

The inverter is the bridge between your panels and your home. It takes the DC electricity and converts it into AC at 230 volts, the standard UK household supply. Without the inverter, the electricity your panels generate couldn't power a single appliance.

Step 5 – AC Electricity Powers Your Home

Once converted, the AC electricity flows into your consumer unit (fuse box) and is distributed around your home. Any electricity you generate but aren't using at that moment can either be stored in a battery for later or exported to the grid, where you're paid for it through the Smart Export Guarantee.

How Do Solar Panels Work for Your Home?

Here's how a solar panel system works across a typical day in your home.

Daytime

Your panels generate electricity whenever there's daylight. Any appliances running during this time are powered by solar first, reducing what you draw from the grid. This is called self-consumption, and it's where the biggest savings come from, because every kWh you use from your panels is a kWh you don't pay for at the current rate of around 24p.

Excess Generation

On brighter days, particularly when you're out or not running many appliances, your panels will produce more than your home needs. If you have a battery, this surplus charges automatically. If you don't, or the battery is full, the excess is exported to the grid and you're paid for it through the Smart Export Guarantee. Export rates vary by supplier, with some tariffs paying up to 32p per kWh.

Evening

Once daylight fades and your panels stop generating, your home switches to battery power if you have one. The energy stored during the day is discharged to power your home through the evening. A typical 6 kWh battery can store enough to cover most of an evening's usage.

Overnight

When your battery is depleted, or if you don't have one, your home draws from the grid as normal. You only pay for the grid electricity you actually use. Some homeowners on time-of-use tariffs also use cheaper overnight rates to top up their battery, ready for the next day's peak hours.

What Is a Solar Inverter?

The inverter sits between your solar panels and your home's electrical system. Its job is to convert the DC electricity your panels produce into AC electricity, which is the type of power your home runs on. Every appliance in your house uses AC, so without an inverter, the electricity your panels generate has nowhere to go.

The inverter is usually installed indoors, often in a garage, utility room, or near the consumer unit (fuse box). It receives DC electricity from the panels via cabling that runs down from the roof, converts it to AC, and feeds it into your consumer unit for distribution around your home. It also monitors system performance, tracking how much electricity your panels are generating in real time.

Inverters typically last around 10 years and cost £500–£1,000 to replace. The panels themselves last 25+ years, so you can expect to replace the inverter once during the system's lifetime.

Inverter Types

Standard Inverter

Standard inverters handle the DC to AC conversion for solar-only systems. They're suitable if you don't plan to add battery storage.

Hybrid Inverters

Hybrid inverters do the same job but also manage the flow of electricity to and from a battery. They decide when to charge the battery, when to discharge it, and when to export surplus to the grid.

How Do Solar Batteries Work?

A solar battery stores the excess electricity your panels generate during the day so you can use it later, typically in the evening and overnight when your panels aren't producing.

Without a battery, any electricity you generate but don't use immediately is exported to the grid. You're paid for this through the Smart Export Guarantee, but export rates are significantly lower than what you'd pay to buy that same electricity back later. A typical export rate is around 15p/kWh, while the current import rate is around 24p/kWh. So every kWh you store and use yourself saves you more than every kWh you export.

The battery is connected to your inverter (a hybrid inverter is required for battery systems) and charges automatically when your panels are producing more than your home is using. Once the sun goes down or your usage increases, the battery discharges to power your home before you need to draw from the grid.

Most domestic batteries have a capacity of 5–10 kWh. A 6 kWh battery, which is included in most of our solar packages, can store enough electricity to power a typical home through the evening. Adding a battery increases the proportion of solar energy you use yourself from around 50% to 75% or more, which directly improves your annual savings and shortens your payback period.

When not included as part of a solar installation, batteries start from around £2,000. If you already have solar panels but no battery, we also offer standalone battery installation for existing systems.

What Are Solar Panels Made Of?

A solar panel is made up of several layers, each with a specific role in protecting the cells and maximising electricity output.

The Cells

The core of every solar panel is the photovoltaic cell, made from silicon, a semiconductor material. When light hits the silicon, it causes electrons to move, creating an electrical current. A typical residential panel contains 60–72 of these cells wired together to produce a usable output.

The Layers

Each cell sits between a sheet of tempered glass on the front, which protects the cells while allowing light to pass through, and a polymer backing sheet on the rear. An anti-reflective coating is applied to the glass surface to help the cells absorb as much light as possible rather than reflecting it away.

The Frame

An aluminium frame surrounds the panel, providing structural support and allowing it to be securely mounted to your roof. The frame also protects the edges of the glass and backing from weather damage over the panel's 25+ year lifespan.

Types of Solar Panel

There are three main types of solar panel used in residential installations.

Monocrystalline panels are made from a single crystal of silicon. They offer the highest efficiency (typically 18–23%) and have a sleek, dark appearance. This is the most common type for UK homes and the type we install at Elite Energy, our 465W all-black panels are monocrystalline.

Polycrystalline panels are made from multiple silicon crystals melted together. They're slightly less efficient (typically 15–18%) with a blue, speckled appearance. Less common now as monocrystalline prices have come down.

Thin film panels are made by depositing a thin layer of photovoltaic material onto a surface. They're flexible and lightweight but lower in efficiency. Rarely used for residential rooftop installations.

How Efficient Are Solar Panels?

Solar panel efficiency refers to the percentage of sunlight a panel converts into usable electricity. Most residential panels on the UK market today operate between 15–23% efficiency. The higher the efficiency, the more electricity each panel produces from the same amount of roof space.

The panels we install are 465W all-black monocrystalline modules tested to 23% efficiency, placing them at the top end of the residential range.

Does Roof Direction Matter?

South-facing roofs at around 30–35° pitch produce the most electricity. East or west-facing roofs still generate well but may produce around 10–15% less annually. North-facing roofs are generally not recommended for solar. Shading from trees, chimneys, or neighbouring buildings can also reduce output.

During a free solar survey, we assess your roof's orientation, pitch, and any shading to confirm expected performance before you commit.

Do Solar Panels Work on Cloudy Days?

Yes. Solar panels generate electricity from daylight, not direct sunshine. On an overcast day, panels still receive diffused light through the cloud cover and continue producing electricity, typically at around 10–25% of their peak output.

Ready to Start Generating Your Own Electricity?

Find out which system is right for your home, what it will cost, and what savings you can expect. Every quote starts with a free solar survey, and if you qualify for ECO4 funding, we handle the full application.

We're also currently offering a free air source heat pump with any solar PV and battery installation.*

Get Your Free Quote Try Our Solar Price Calculator

FAQs About How Solar Panels Work

Do solar panels work in winter?

Yes. Daylight hours are shorter so total generation is lower, but panels still produce electricity on cold, bright days. In winter, generation drops to around 30-50 kWh, in comparison to a 110-120 kWh average in summer.

Can I use solar electricity at night?

Only if you have a battery. During the day, excess solar energy charges the battery. In the evening and overnight, the battery discharges to power your home. Without a battery, your home draws from the grid at night.

What is the photovoltaic effect?

It's the process by which solar cells convert light into electricity. When photons from sunlight hit the silicon inside a PV cell, they knock electrons loose, creating a flow of electrical current. This is the fundamental science behind how every solar panel works.

How long do solar panels last?

Most panels are warranted for 25 years and continue generating beyond that. Manufacturers typically guarantee 80–85% of original performance after 25 years. The inverter usually needs replacing once, after around 10 years, at a cost of £500–£1,000. For a full breakdown of installation and ongoing costs, see our solar panel cost guide.

Do solar panels need direct sunlight to work?

No. Solar panels generate electricity from daylight, not direct sunshine. Output is lower on overcast days but doesn't stop.

How many solar panels does a house need?

It depends on your electricity usage and available roof space. A typical 2-bed home may need 6 panels, while a 4–5 bed home may need 16 or more. For a detailed breakdown, see our guide on how many solar panels can I fit on my roof.

What happens during a power cut?

Most standard solar and battery systems shut down during a power cut for safety reasons. However, power cut protection can be added to your system either during installation or afterwards, allowing your battery to keep essential circuits running during an outage.

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