Written by Tom Gill Updated on 1 September 2022 The UK is in the midst of an energy crisis, with soaring bills adding to the ongoing cost of living rises.Climate change is getting worse too, making green energy sources such as wind and solar power more important than ever.So what would the UK look like if it was powered entirely by renewable energy?We've looked at what 100% renewable means, calculated how much space would be needed for clean energy, and put together a breakdown of renewable technologies. What's on this page? 01 What does a ‘100% renewable energy UK’ mean? 02 Renewable energy 03 Transport 04 Home heating 05 Summary What does a ‘100% renewable energy UK’ mean?A 100% renewable UK means a country not using finite energy sources — no natural gas, no oil, and no coal. All of the UK’s energy has to come from renewables.That means solar, wind, and hydropower, as well as geothermal and biomass energy.The government has already committed to reaching net-zero emissions by 2050, which doesn’t necessarily mean a UK powered completely by renewable energy.Instead, it refers to a UK where any emissions are offset by either renewable sources or carbon capture.We’ve imagined what a UK using entirely renewable energy sources could look like instead.100% renewable is more than just the power we use though; it’s also about infrastructure, food, and transport. It’s a complete transformation of how the UK works.One of the challenges facing the UK in reaching 100% renewable energy is our growing population. The government has predicted that by 2041, there’ll be 72 million people living here.That’ll introduce additional strain on the grid, so it’s important the UK manages the introduction of more renewables to accommodate an extra five million or so people. Renewable energyThe energy makeup of a 100% renewable UK needs to be diverse enough to meet the demands of a country.That means having enough renewable energy options to turn to when one or the other dips, because it’s an unavoidable fact that they don’t work 24/7.To have enough choices, the UK will need to dedicate more territory than ever before to make sure a grid powered entirely by renewables can cope.The average estimate for energy consumption in a 100% renewable UK is range from 1,500 terawatt hours (tWh).Let’s look at how some of the main renewable energy types could meet some of this demand, and roughly how much space we’d need to allocate to them.Wind powerThe UK generated 75,610 gigawatt hours (gWh) of electricity from onshore and offshore wind in 2020, which is enough to power 8.4 trillion LED bulbs for an hour.That’s 24% of the UK’s total electricity generation for a year, including both renewable and non-renewable energy. The capacity for wind power in the UK is just over 24 gigawatts (gW) and it’s expected to rise to 40 gW by 2030.It’s hoped that the UK’s wind power capacity will increase to 100 gW by 2050 — enough to power 12.6 million homes a day.It’ll continue to be a mix of onshore and offshore wind, with onshore making up the bulk of the UK’s wind generation.The UK can generate around 60,000 gWh year from onshore wind. That’s some way off meeting the 1,500,000 gWh in a 100% renewable UK, so let’s try and make up 1,250,000 gWh with offshore wind, while assuming the remaining 190,000 gWh is generated from other sources.Using the widely recognised three watts per metre figure, it would take roughly 18,030 square miles, which is around 6.2% of the UK’s marine territory.That’s a lot of space to use, so a balance will have to be struck between wind, fishing, conservation zones, and shipping lanes.For onshore wind, our 2023 National Home Energy Survey showed that the UK public is keen — one in two Brits would be happy to live next to an onshore wind farm.Solar powerSolar power capacity in the UK is at 14.6 gW, and will hopefully reach at least 85 gW by 2050 — in line with the Climate Change Committee’s recommendation.The UK used 294.4 tWh of electricity in 2021, with solar contributing around 13 tWh. That’s impressive, but capacity needs to increase we’re going to reach 100% renewable.If we covered almost every roof in the UK with solar panels, and used just 0.5% of land for solar panels, we could generate around 170 tWh.Or, if we just relied on solar farms, it would require roughly 1,930 square miles of land to provide a similar amount of power.Acknowledging advancements in technology is important too. Solar power efficiency is improving all the time, and exciting technology like solar windows could mean the space needed to meet energy demands is actually far less than we’ve predicted.Other solutions include thin-film solar panels, which are less efficient than standard solar panels, but can be installed on more extreme angles and work better in cloudy weather.HydropowerThe UK’s hydropower capacity has grown at a snail’s pace — 1.5% of electricity came from hydro in 2013, and it’s only managed to reach 2.1% by 2022.One of the key reasons behind hydropower’s slow growth is the concern over displacing local communities, so the main focus has been on wave and tidal energy.It’s harder to estimate space here than with wind and solar, because wave and tidal energy technology doesn’t have a standard design yet. With wind and solar, we already know the dimensions needed to generate any amount of power, meaning we know how much space is required.Government estimates say wave and tidal energy could provide up to 20% of the UK’s energy needs.Even if we could reach 20% of current energy needs with hydropower, capacity would still have to be expanded significantly in a 100% renewable UK.Want to learn more about hydropower in the UK? Check out our page: What’s The Potential of Hydropower in the UK?BiomassBecause biomass power plants and boilers emit a significant amount of greenhouse gases, there’s a debate about whether biomass belongs in the renewable category.Ideally in a 100% renewable UK, we’d provide all of our energy needs from clean renewables, such as solar, wind, and hydro power.Biomass fuels, or bioenergy, can still play a part when they’re handled properly though. That means ensuring 100% of the carbon emissions from burning biomass is absorbed and stored. Transport Buses and trainsFully electric buses and trains are key to a 100% renewable UK — and we’re already making good progress.London introduced its first fleet of all-electric buses less than six years ago. Now, the capital boasts 650 zero-emission buses and plans to convert the entire fleet by 2034.Coventry is on track to become the first city in the UK to have an entirely electric bus fleet, with 300 vehicles expected on the streets by 2025.38% of trains are electric too now, though the freight industry has a lot of room to improve — just 8.5% of freight locomotives are electric. Electric vehiclesA robust and reliable charging network is essential to a 100% renewable future, but right now, the infrastructure is not good enough.The Eco Experts has investigated why so many EV chargers are broken, and found that 5.2% of the UK’s public EV chargers weren’t working. If this were 5.2% of petrol stations, that would mean 450 stations unable to provide fuel.This is a big issue when it comes to switching the UK to electric vehicles, which must happen if the country is to become 100% renewable.There are already worrying signs. The government announced in 2021 that the number of chargers on UK roads would reach one million by 2030. To hit that target, 145,000 chargers would need to be installed every year.It only gets worse when you look at projected sales for electric vehicles. To meet the current level of demand, the UK would need to install 507 EV chargers every day until 2035. Home heating Heat pumpsHeat pumps are one of the most exciting alternatives to traditional heating systems, because they don't use gas, oil, or other polluting fuels.Instead, they use either air — in the case of air source heat pumps — or the ambient warmth of the soil in your garden, in the case of ground source heat pumps. They’re powered by electricity, so right now they’re expensive to run.The price of electricity will go down when the UK becomes 100% renewable though, so heat pumps will become much more affordable. Hydrogen boilersThe UK produces just 10 megawatts of energy with low-carbon hydrogen, which is far below what's needed in a 100% renewable UK.And unfortunately, low-carbon hydrogen is exactly that: low carbon. It's neither entirely green nor carbon neutral, because emissions are still released into the atmosphere.The government has been criticised for its hydrogen strategy because of this fact, as it defines low carbon as anything under the pollution levels of typical fossil fuels.It’s also expensive to produce green hydrogen, which is carried out via electrolysis — the process of separating hydrogen from water.For each kilogram of green hydrogen, it costs £3–£5, which is a lot more expensive than the more polluting grey hydrogen — £1.27 per kilogram.Read about what’s stopping the UK’s hydrogen revolution for more information. SummaryIt’s clear that a 100% renewable UK is a challenging target, but it’s absolutely one we must hit if the worst effects of climate change are to be avoided.It’d also mean the UK becoming completely energy independent, so there’d be no more panicking about interruptions to gas supplies, or wars that cause dramatic oil-price fluctuations for us. Written by: Tom Gill Writer Tom joined The Eco Experts over a year ago and has since covered the carbon footprint of the Roman Empire, profiled the world’s largest solar farms, and investigated what a 100% renewable UK would look like. Tom has a particular interest in the global energy market and how it works, including the ongoing semiconductor shortage, the future of hydrogen, and Cornwall's growing lithium industry.