Wind energy explained

We'll walk you through everything you need to know about wind power here in the UK, from how it's generated to whether you should consider installing a turbine at home.

What is wind energy?

Wind energy is a type of renewable power that captures the natural movement of wind and converts it into electricity. Harnessing wind as a power source has deep roots here in the UK; for thousands of years, we've been using it to propel boat sails across the water and turn windmills to grind wheat into flour. As technology advanced, those traditional windmills have evolved into the sleek, towering turbines that dot our landscapes today.

Modern wind energy relies on wind farms that are made up of dozens, sometimes hundreds or even thousands, of these turbines all working together to generate electricity.

There are two main types of wind farms:

• Onshore wind farms — These are built on the land, typically in open areas like hills or fields where wind flows freely. They're generally cheaper to build and maintain, and the UK has plenty of them, especially across Scotland, Wales, and other rural regions.

• Offshore wind farms — These are built out at sea, where winds tend to be stronger and capture wind more consistently. While they're more expensive to build, thanks to the challenges of working in a marine environment, they can generate a lot more electricity and avoid some of the aesthetic concerns associated with onshore turbines.

How does wind energy work?

Wind energy relies on wind farms made up of multiple turbines that have been installed in open spaces, like on hills or out at sea. It's thanks to these specific conditions that Scotland has become such a hotspot for wind power, with around 70% of the country's electricity now coming from onshore wind alone.

But where exactly does wind energy come from?

It all starts with the sun. As the sun's heat warms the air, it causes it to rise. Cooler air then rushes in to fill the gap, creating the movement we know as 'wind'. Wind energy captures this kinetic energy using turbine blades, which spin as the wind passes through them. This spinning motion is then converted into electricity that powers our homes and businesses.

You can learn more about where electricity comes from here.

How do wind turbines generate electricity?

Wind turbines are specifically designed to maximise the amount of energy they can capture. They're fitted with sensors that constantly monitor wind direction, with an in-built mechanism that lets the turbine rotate so that it's always facing into the wind.

The turbine blades themselves have a slightly tapered shape that lets them catch any air movement, even during low wind. As the blades turn, they rotate a shaft connected to a gearbox inside the turbine. This first shaft spins quite slowly, but the gearbox uses it to drive a second, much faster shaft located deeper within the turbine.

This second shaft is connected to a generator that contains magnets that spin rapidly past coils of copper wire. As the magnets whizz past the wire, they cause electricity to flow through it, converting the kinetic energy from the wind into electrical energy. This electricity then travels through a series of cables down the turbine tower and into the National Grid, where it's distributed to homes and businesses across the country.

Types of wind turbines

There are two main types of industrial turbine design, each working in slightly different ways to capture wind energy. These are:

• Horizontal axis turbines (HAWTs) — These are the turbines you're most likely already familiar with. Their blades look like giant propellers spinning around a horizontal axis. These tend to be the go-to designs because they're the most efficient at converting wind into electricity.

• Vertical axis turbines (VAWTs) — These have blades that slightly resemble a kitchen whisk, rotating around a vertical axis. They're more compact than horizontal turbines and can catch wind from any direction, but they tend to be less efficient overall.

Here's how the two compare:

Is wind power renewable?

Wind power is completely renewable, and it plays a vital role in our journey towards Net Zero — the target of balancing the amount of greenhouse gases we create with how much we remove from the atmosphere.

As long as the sun exists, we'll always have wind, which, in turn, means we'll always be able to use wind turbines. These convert wind into electricity without burning fossil fuels, which means they don't release harmful pollutants into the atmosphere. This makes wind power a clean, sustainable way to meet our energy needs now and in the future.

Alongside other forms of renewable energy, like tidal turbines and solar panels, wind power is one of the most reliable, natural sources available.

Wind energy advantages and disadvantages

Wind energy offers a wide range of benefits, but like any technology, it also has some drawbacks worth considering. Let's take a look at both sides.

Advantages

Some of the main pros of wind energy include:

• Unlimited and renewable — Wind is an infinite resource; we'll never run out of it, making it a sustainable long-term energy solution.

• Zero carbon emissions — Wind power generates electricity without producing harmful greenhouse gases, making it one of the cleanest energy sources available.

• Cost-effective over time — Once turbines are installed, the electricity they produce is cheap to generate, with minimal ongoing fuel costs.

• Job opportunities — The wind energy industry supports thousands of jobs across manufacturing, installation, and maintenance sectors.

• Land-sharing potential — Wind farms can be built on non-arable land (which can't be used for growing crops), and the space between turbines can usually house grazing livestock.

Disadvantages

Some of the cons of using wind energy are:

• Dependent on wind conditions — When there's no wind, turbines don't generate any electricity. The amount of power produced also depends on wind speed, which can be unpredictable and vary throughout the day.

• Requires backup power — When wind speeds are too low, alternative power sources or battery storage are needed to maintain a consistent electricity supply.

• Wildlife impact — Wind farms can pose risks to birds and bats that nest in or fly through the area, as the fast-moving blades can be difficult to avoid.

• Aesthetic concerns — Some people feel that wind farms spoil the landscape, including obstructing scenic views of the countryside or coastline.

• High upfront investment — Building a wind farm takes a big initial investment for manufacturing, putting the infrastructure in place, and installing the turbines.

• Limited lifespan and maintenance costs — Each turbine typically lasts around 20–25 years and needs regular maintenance. Recycling turbine blades at the end of their life can also be difficult.

• Weather vulnerabilities — Extreme weather conditions, like ice forming on blades during cold, wet weather, can reduce the efficiency or even damage the turbines.

What happens to excess wind energy?

Sometimes, a wind turbine might be too efficient and generate more energy than necessary. When wind turbines generate more electricity than we need, there are several ways to handle the surplus.

The excess energy can be stored in large batteries for later use, making sure we have power available when the wind speed drops. The surplus can also be sent to neighbouring countries through electricity interconnectors: underwater cables that link the UK's grid to other nations. In some cases, excess wind energy is also used to pump water uphill through hydro dams, which continue generating additional electricity by releasing the water at high speeds through a series of motors.

If none of these options are available, the wind farms might be manually slowed down or temporarily shut off until more energy is required or the National Grid is equipped to handle the supply.

Are wind turbines available for homes in the UK?

Yes, domestic wind turbines are also available for homeowners who want to generate their own electricity. They come in two main types:

• Pole-mounted turbines — These are free-standing structures that work best in large, open spaces with good exposure to the wind. They can generate around 6 kilowatts (kW) of electricity, meaning they're ideal for powering an entire household.

• Building-mounted turbines — These are smaller units that can be installed on the roof or wall of your house or an outbuilding. These typically generate around 2kW of electricity, enough to cover a decent chunk of your home's energy needs.

It's worth noting that building-mounted turbines can only be fitted on detached houses or outbuildings. If you live in a semi-detached property, you'll need to opt for a pole-mounted turbine instead.

How much do wind turbines cost to install?

The cost of installing a domestic turbine varies depending on the size and type you choose. Building-mounted turbines are cheaper to install than pole-mounted ones, but they're also smaller and less efficient at generating electricity.

Generally, you can expect costs to range from around £7,000 for a small building-mounted system up to £70,000 for larger installations. A typical 6kW pole-mounted system, including equipment and installation, costs approximately £31,000.

While these upfront costs might seem steep, larger turbines generate more electricity, which means they'll offset your initial investment more quickly than smaller models. A larger upfront investment can actually lead to better long-term returns through reduced energy costs.

How much can I save with a wind turbine?

The savings you'll see depend largely on your turbine's location and its ability to capture wind. A well-positioned 6kW turbine could save you around £700 per year on your energy bills in Great Britain, or approximately £550 in Northern Ireland.

You could also earn additional income through the Smart Export Guarantee, which pays you for any excess electricity your turbine generates that you send back to the National Grid. This scheme is only available in Great Britain, but if you're in Northern Ireland, it's worth speaking to your energy supplier to see if they offer a similar energy-return scheme.

Do I need planning permission to get a wind turbine?

Whether you need planning permission for your domestic turbine depends on the type you're installing and where it's going.

Building-mounted turbines on detached houses or outbuildings usually don't need planning permission if they meet specific criteria, such as being a reasonable distance away from neighbouring houses and complying with Microgeneration Certification Scheme (MCS) standards for noise levels.

Similarly, pole-mounted turbines in your garden also typically don't need planning permission if they meet certain requirements, like the blades being at least 5 metres above ground level and the turbine being at least a distance equal to its total height plus 10% away from your property boundary.

You can find more information on building requirements on the GOV.UK site. If your turbine installation doesn't meet all of the criteria, or you're unsure, it's best to check with your local council to avoid running into any problems.

Shop energy deals at UW

Wind power is becoming increasingly important in creating a cleaner, more sustainable future for the UK. Whether it's through large-scale wind farms or domestic turbines, using the power of the wind helps reduce our reliance on fossil fuels and could even cut energy costs.

Find out how UW can help you save on your gas and electricity bills with our competitive energy deals, including fixed-rate plans. You can also explore our single-fuel electricity or gas tariffs. Plus, the more services you bundle with us, the more you'll save on your overall costs.