Wind Turbine Efficiency: How Has It Improved Over Time?

Topic: Read Time: 7 mins
Landowner type:
Independent landowners | Institutional landowners
Energy: Onshore wind
Back to Blog

Have you been wondering how wind turbine efficiency has changed over the years? If you want to learn all about how electricity generation from wind power has altered, stay with us! In this in-depth article, we’ll uncover the major changes to the construction of wind turbines since 1987.

You might be well-versed in the importance of wind energy to the UK’s electricity profile But have you ever thought about wind turbine efficiency and just how impressive energy production can be?

Believe it or not, between 2009 and 2020, electricity generation from wind power has risen by 715%. And with 2020 being called the “greenest year on record” by the National Grid, it’s clear that our approach to renewable energy is improving hugely.

So, how have we managed to increase our generation capacity this significantly in just 10 years? And what does the future look like for wind power in the UK? This deep dive will cover everything from how wind turbines work to the tweaks that have made turbines way more efficient over the years.

Now, let’s get to it.

How Do Wind Turbines Work? 

If we’re looking at things simply, wind turbines have a special rotor that turns when the wind hits the blades.  This movement then turns a generator that produces electricity and sends energy to the grid. The effectiveness of a wind turbine depends largely on where it’s based. For example, you’re far more likely to get a decent amount of energy in a high-wind area than somewhere with virtually stagnant air.

And in case you were wondering, offshore wind turbines are typically larger and experience higher wind speeds than onshore turbines.

How Efficient Are Wind Turbines?

Wind turbines over farm

Before we discuss improvements to wind turbines over the years, you might be wondering how efficient wind energy is in general.

Although no turbine will ever be 100% efficient, it’s said that they’re between 20-50% efficient depending on the time of year. During peak wind times, you’ll get an efficiency rating of around 50%. When wind levels are lower, this drops to around 20%. But as wind turbines produce electricity for around 80% of the year (on average!), they’re certainly a reliable source of renewable energy for the UK.

Why is Wind Energy So Important?

If you’re wondering why wind energy is becoming so popular, then let us fill you in. Not only is it an incredibly clean energy source, but strong winds are abundant in the UK and don’t cause any air pollution. In the coming years, it’s hoped that we can reduce carbon emissions by transitioning over to a fully-renewable energy model.

But wind energy is also crucial for helping the country meet its net-zero obligations by 2050. Although we’ve come a decent way in decreasing our emissions since 1990, there’s still a long road ahead.

As of 2023, the UK has 11,000 wind turbines installed onshore and offshore. This boasts an impressive installed capacity of 28 gigawatts (which is nothing to scoff at!). Plus, the UK’s shallow continental shelf means that the seas around our coasts are very well-suited to offshore wind turbines too.

Although constructing new turbines requires a decent upfront investment from developers, the potential returns (both environmental and financial!) are worth the effort.

Looking at Wind Turbine Efficiency Over Time

If we look at the history of renewable energy, we can see that the first wind turbines were installed on UK land back in July 1987. This 3.7 MW turbine was tucked away in Orkney and was the first installation to provide clean energy to British homes.

Over the years, turbines have gradually gotten a lot bigger.

In 2018, a large 260-metre-tall turbine was revealed by GE Renewable Energy and was designed to provide enough energy for 16,000 European homes. And onshore?  Well, in 2017 we were graced with a 4.8MW turbine with a mammoth 158-metre rotor and tip heights of up to 240 metres!

What Changes Have Been Made to Wind Turbines to Improve Efficiency?

Hub height

The hub height is a huge factor that has increased wind turbine efficiency over the years.

The average height of a wind turbine has increased a whopping 66% since early turbines were installed in 1998.  The average turbine in the US is approximately 94 metres as of 2021, with UK turbines hitting around 74 meters according to RenewableUK. But it’s possible that modern UK turbines could reach US standards if planning permission guidelines are loosened.

Generally, the higher a turbine tower is, the more energy it can capture as wind speeds typically increase with altitude. Plus, higher hubs face less resistance with obstacles on the ground which leads to above-average wind shear.  This is otherwise known as the change in wind speed with altitude.

Rotor diameter

a technician servicing a wind turbine

Another major factor that contributes to wind turbine efficiency is rotor diameter. This refers to the overall width of the circle created by the turbines when the blades spin. As time has gone on, longer blades have been used for almost every turbine.

These can capture significantly more wind than smaller blades, resulting in a greater percentage of wind energy harvested per turbine. It’s believed that the average rotor diameter worldwide has increased around 6 times in the last 30 years. And in terms of average size, we’re looking at increases from around 20 metres to 129 metres! Talk about progress.

Better materials

Over the years, the materials used to construct turbines have also improved significantly. Most modern turbines are constructed with glass and carbon fibre composite materials which are generally lighter and more efficient than previous iterations.

Don’t worry though – they’re still incredibly strong.

Depending on the location, you might also find parts of onshore and offshore turbines constructed from aluminium and wood. To make things even more appealing (and environmentally friendly), between 84% and 90% of a wind turbine’s materials are recyclable.

With better materials generally comes improved functioning and a longer lifespan. The result? Greater wind turbine efficiency.

Photo showing a wind turbine

Better predictive maintenance

Although every wind turbine requires scheduled maintenance, improvements to sensors mean that operators can more easily predict major faults and failures. While previous turbines relied on condition monitoring and failures in generators and bearings, modern technology is way ahead of the game.

Not only do new-age turbines feature fluid sensors, but they also boast vibration sensors to detect gearbox failures before they happen.

A Final Word

The future of wind energy is looking more positive than ever before.

With the Conservative government finally warming to the idea of onshore turbines and planning permission rules set to soften – there’s no telling how much clean energy we may produce in a few years.

Now, the massive technological improvements to turbines in the last few decades mean that further changes will be minimal for several years. But there’s truly no saying what the future might hold.

With the government’s date for net-zero limits edging ever closer, we’ll need to dial up our wind efforts significantly to replace our current reliance on oil and gas. And is the UK population willing to champion renewables? Well, we’ll just have to wait and see.


Over the years, we’ve been asked by several different clients about wind farm trends and just how reliable wind energy can be. Here are some of the questions we have been asked (and their answers, of course).

What percentage of UK electricity is generated by wind turbines?

According to the National Grid, wind energy makes up 26.8% of the UK’s total electricity production in 2022.

What is the trend in wind power in the UK?

As the UK has a target to increase offshore wind capacity to 50GW by 2030, it’s a good sign that more turbines are going to pop up offshore. There has been resistance to building onshore turbines for several years. But it’s said that planning permission will be eased in the coming years to assist with net-zero limits.

How loud is a wind turbine?

People often argue that wind turbines are eyesores and can be too noisy. Regular background noise tends to register at around 40-45 decibels, and the average fridge operates at 40 decibels or so. It’s said that sound pressure levels for wind turbines are around 38 decibels, which means that most noise from turbines won’t be heard.

In very rural areas you might hear a very quiet buzz – but even then you’d strain to hear it. As wind turbines become more efficient and develop over time, they may get even quieter! Plus, it’s worth remembering that turbines always need to be placed a minimum distance from the edge of any home.

How long do wind turbines last?

An average wind turbine is designed to last between 20 and 25 years, but it will likely need maintenance over time. For this reason, it will take a few years (at least!) to get a decent return on your initial investment. But it’s entirely possible to extend planning permission through repowering if you want to benefit from your site for longer.

There you have it: an ultimate overview of wind turbine efficiency that should help you understand the current market!

If you want to learn more about the efficiency of your site or have any questions regarding a wind farm extension, get in touch. Our expert team will be more than happy to help.

The Ultimate Guide to Wind Farm Extensions

Download the free ebook

The Ultimate Guide to Wind Farm Extensions