Renewable Energy Facts

In this guide, Pexapark takes a look at some of the most frequently asked questions about renewable resources, as well as some of the most controversial. We will help you separate the facts from fake news when it comes to wind and solar energy.

In the olden days, disagreements could last for weeks. Want to know who played in goal for France at Euro ’96? We couldn’t just whip out our phones and Google it. We had to rely on brains – and woe betide you if your friend remembered different.

We have rounded up 30 common questions about wind and solar energy that range from the sensible to the frankly ridiculous, and give you answers. This will help you wow your colleagues without a phone in sight.

So, let’s crack on. Oh, and it was Bernard Lama!

Interesting facts about wind energy

 “I know more about wind than you do.”

So said Donald Trump during his first presidential debate with Joe Biden in October. But do you want to know more than Trump? These 15 answers will help. Enjoy!

Who invented wind turbines?

Windmills have been around for centuries but the first known wind turbine to produce electricity was built in Scotland in 1887 by Professor James Blyth, in his garden. He was followed by US inventor Charles Brush in 1888; and, in 1891, Denmark’s Poul la Cour developed the first wind turbine that produced a steady flow of electricity.

Do wind turbines work?

 Yes, there are now 651GW of wind turbines installed worldwide, and wind represents 5.3% of global electricity production and 2.2% of all energy. Turbines work and firms are getting smarter at managing when the wind isn’t blowing. Even an average-sized turbine (2.5MW-3MW) can produce enough power for 1,500 EU homes each year.

What are wind turbines made of?

Mainly steel (71-79% of total mass); fibreglass, resin, or plastic (11-16%); iron or cast iron (5-17%); copper (1%); and aluminium (0-2%). But this mix will change as turbine makers find ways to make machines bigger, cheaper and more recyclable.

How big are wind turbines?

 The world’s largest offshore turbines are as tall as skyscrapers: GE’s Haliade-X is due to be 245 metres tall, which is almost as high as the Eiffel Tower. Onshore wind turbines are far smaller, averaging 142 metres, but that’s still 1.5 times taller than the Statue of Liberty.

How long do wind turbines last?

 Typically 20-25 years but, with continuous investment in innovation, we’re beginning to see some that are effective after 30+ years.

Can wind turbines be recycled?

Yes, 90% of a turbine can currently be recycled, and companies are working hard on the other 10%. The most problematic parts to recycle are blades, which are made of fibreglass that is difficult to split into its different parts: plastics and glass fibres.

Why do wind turbines have three blades?

Inventors have experimented with various designs over the years and learned that using three blades is the most efficient way to generate electricity by increasing the speed of blade rotation. But there are two-bladed, vertical axis and other designs out there, as well as other wackier ideas like putting multiple rotors on one tower.

Why are wind turbines white?

First, because it looks nicer and blends into the natural environment. Nobody wants to look at a wind turbine that’s coloured like a clown’s trousers! But second, the white helps deflect UV rays away from the inner components and stops them overheating.

Do wind turbines use oil?

Yes, gear oil is used in lubricating gearboxes, and grease is used on the main rotor shaft’s bearing, yaw bearing, pitch drive gears, blade bearing and generator bearing. But they don’t burn oil. If they did then they wouldn’t exactly be green, would they?

How fast do wind turbines spin?

It depends how windy it is! On average, a turbine completes 10-20 revolutions per minute, which means that the blade tips move at 120mph. At maximum speeds, the blade tips move at 180mph.

How many birds do wind turbines kill?

Far less than cats, buildings, cars and power lines. The US Fish & Wildlife Service has estimated that turbines could kill 140,000-500,000 birds a year, which sounds a lot but is tiny compared to the millions that die in collisions with vehicles or buildings; and the billions killed by cats. Even so, wind companies are trialling technology that can make turbines safer for our winged pals – including painting one blade black.

Are wind turbines loud?

No. The closest that wind turbines are placed to homes is around 300 metres and, at that level, General Electric says it would have a sound pressure level of 43 decibels. That’s around the level of an air conditioner or refrigerator, and would be lost in the ambient background noise. Owners also have to comply with strict regulations.

Do wind turbines cause cancer?

This is a claim that’s come directly from former Trump, but with no evidence to back it up. Every reputable study has shown that wind turbines don’t affect human health.

Do wind turbines lower property value?

Currently, there is no evidence that wind farms damage the values of nearby homes. In fact, the studies we’ve seen show widespread support for wind: a study in the UK in May 2020 showed 77% support for onshore wind, for example. There are people who don’t want to live near turbines, so they won’t be back for a second viewing.

Do wind turbines slow down the rotation of the Earth?

Yes. If we install a few more onshore wind turbines then the Earth will stop spinning and then turn the other way. We’re joking of course! No, wind turbines don’t slow the rotation of the Earth. Wind happens when air flows from areas of high pressure to low pressure. Turbines couldn’t affect the 1,000mph rotation of the Earth’s surface.

Interesting facts about solar energy

The prolific inventor Thomas Edison said in an interview in 1910 that he’d “put [his] money on the sun and solar energy” – and the industry has come a long way in the 110 years since then. But what do you need to know about solar? Here goes…

Who invented solar panels?

The discovery of solar panel technology pre-dates Edison’s quote. In 1839, French physicist Edmond Becquerel discovered photovoltaics while experimenting with a cell made of metal electrodes. In 1876, William Grylls Adam and Richard Evans Day applied this photovoltaic principle and found that they could generate electricity when certain metals are exposed to light. And, in 1883, American inventor Charles Fritz made the first solar cell, which is the technology used in solar panels.

Do solar panels work?

Yes. Solar panels work by allowing particles of light, or protons, to knock electrons free from atoms and produce a flow of electricity. There is now over 580GW of solar power installed globally, and solar represents 2.7% of global electricity production or 1.1% of all energy. It has also been called the “cheapest electricity in history”.

Could solar energy power the whole world?

In theory, yes. For example, the designers of a project called Desertec in 2014 said they could generate all of the world’s electricity needs in a small area of the Sahara Desert. However, the obstacles to this include lack of political will, and the technical challenge of moving electricity from where it is produced to where it is needed.

What are solar panels made of?

Most are made of silicon because it’s abundantly available. It’s the main component in the sand on a beach, making it the second most available element on earth.

How big are solar panels?

Typical solar panels on a house measure around 165cm by 100cm, and solar panels on commercial buildings are longer. In solar farms, panels tend to be larger at about 300cm each.

How long do solar panels last?

Most last around 25-30 years each, but solar panel makers are constantly improving the technology so that number is likely to rise.

Do solar panels only work in sunny regions?

You need the sun to make them work, but solar is a viable electricity source even in countries that aren’t traditionally warm and sunny. For example, the World Bank’s Global Solar Atlas shows the solar potential of over 200 countries worldwide.

Do solar panels need to be cleaned?

Yes. The rain can clean solar panels in some climates but, in very dry places, there can be dirt of bird droppings that need to be removed by hand.

Can solar panels be recycled?

Yes, 95% of silicon solar panels can be reused, and all external metal parts can be re-moulded for cell frames.

Do solar panels work on cloudy days?

Yes. They won’t work as efficiently but, as long as light particles are still travelling through the clouds, the panels will work. They don’t just need clear cloudless days.

Do solar panels work in winter?

Yes. They will likely produce less energy than in summer because there are fewer daylight hours but, like other electronics, the cold weather may help them to work more efficiently.

Do solar panels work at night?

No. That’s a step too far! But pairing solar panels with storage technology enables you to save up electricity that you could use to power your building at night.

Do solar panels cause cancer?

 Some people are concerned that solar energy systems could emit electromagnetic fields that could cancer. Thankfully, they don’t. These systems don’t emit EM fields and, even if they did, there’s no scientific proof of a link between them and cancer.

Do solar panels work better nearer the sun?

They can do. Solar panels can work better if they are higher, but not because they are nearer the sun. Rather, it’s because they are less likely to be shaded by other buildings or trees. But putting them higher also makes them more difficult to clean, which would affect their efficiency.

Do solar panels suck energy out of the sun?

They don’t. Solar panels can’t take more energy than the sun was going to produce anyway. But this isn’t purely the reserve of satire. In 2015, one US town rejected a plan for a solar farm on the basis of public complaints, which included fears that it would drain the sun’s power and stop photosynthesis. The mind boggles.


There you have it! Hopefully you will now sleep safer knowing that increasing global wind capacity will not in fact slow the rotation of the world – and that wind and solar are both a lot older than you might think.

If you’d like to find out the answers to more questions on renewables, check out our in-depth guide on renewable resources.  And if you have questions you’d like us to tackle, get in touch.