The Complete Guide to Renewable Energy Sources
Switching to renewable energy can help reduce your energy bills and cut your carbon footprint at the same time. Read on to discover the many different ways green and sustainable energy is generated in the UK.
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What is renewable energy?
In any debate about climate change, the discussion inevitably turns to renewable energy and how we can cut down on fossil fuels. But where exactly is this renewable energy sourced from and how does the UK compare to other countries in the race to net-zero emissions?
Ever since the industrial revolution, we’ve depended on carbon dioxide-emitting fossil fuels such as coal and oil to keep the world spinning. From heating our homes to powering our cars, we’ve relied on burning fossil fuels to such an extent that our need for gas and electricity is contributing to the current climate emergency, with record temperatures and rising sea levels.
Also known as sustainable or green energy, renewable energy sources such as solar and wind can be consistently replenished, though of course, their availability depends on both the time of day and weather.
With rising capacity and falling costs to utilise and retain wind power and solar energy, renewables are playing a larger role in our energy mix than ever before.
What is the UK target for renewable energy by 2050?In June 2019, the UK became the first G7 country to set a legally binding net-zero emissions target, aiming to reduce all greenhouse gas emissions by 100% (compared to 1990 levels) by the year 2050.
Renewable energy sources
Currently, around 85% of energy consumed worldwide comes from fossil fuels. What is the other 15% made up of and what are we doing to make that mix more in favour of renewables?
There are five main renewable resources we use to produce energy in the UK: wind power, solar energy, geothermal, hydroelectric and biomass. In this guide, we’ll take a look at each of these in more detail.
Is nuclear energy renewable?
Although nuclear energy generation emits almost no carbon emissions, the uranium used to produce it is non-renewable. Nuclear energy also produces radioactive waste, which can be highly toxic to humans and animals.
However, unlike wind and solar, nuclear energy doesn’t rely on the weather and so looks like it will be around at least long enough to play its role in helping the UK reach its net-zero targets.
1. Wind power
One of the cheapest and most abundant renewable energy sources is wind power. Turbines as tall as skyscrapers are placed in areas with high winds, which turn blades to feed an electricity generator to produce renewable energy.
Wind power is one of the fastest developing electricity sources, particularly in the United Kingdom. In 2019 wind energy contributed to 20% of all electricity produced in the UK, a huge increase over recent years, while in August 2020, blustery weather led to a record level of wind generation - with roughly 60% of Britain’s power demand being met by wind turbines.
However, although it provides us with a cheap alternative to fossil fuels, wind speed and direction is variable, so it would be very difficult to rely solely on wind for our electricity grid.
In addition, although the UK is well placed geographically for wind levels, a large proportion of the rest of the world is not, meaning it wouldn’t necessarily be possible to replicate our own infrastructure and successes everywhere.
As we can’t rely on the wind to produce renewable energy in all places 100% of the time, other electricity sources compensate for those areas that experience low wind levels.
One of the increasingly popular solutions to this issue is locating wind farms offshore. Placing them offshore has the benefit of more reliable, high wind levels; however, it is also considerably more expensive to install and maintain.
The largest on-shore wind farm currently in operation in the United Kingdom is Whitelee Wind Farm and is located just over 9 miles outside of Glasgow. It is owned and operated by Scottish Power, which has developed this 215 turbine farm with a capacity of 539 megawatts (539,000 kW).
This means that if the farm was to work at its full capacity, in one hour, it would have the means to power over 761,000 households in real-time or around 174 for a full year.
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2. Solar energy
Humans have been harnessing the power of the sun for thousands of years, using its heat to grow crops and keep warm.
Solar energy is the conversion of this sunlight into electrical energy. This is carried out using solar panels, increasingly found on the top of people’s houses and in large open spaces in order to take in the optimal amount of sunlight.
At any given moment the earth receives roughly 173,000 terawatts (173 trillion kW) from the sun, which is 10,000 times more energy than the whole world uses. This means if we were to be able to harvest just 0.01% of the sunlight we receive on earth, we’d be able to power the whole world using only solar power.
Although it may sound like a perfect renewable energy source, there are a few reasons why this is not the case as of yet:
- The equipment used to produce electricity through solar power can be extremely expensive, meaning profit-focused energy suppliers highly prioritise production cost as opposed to sustainability.
- Darkness is the arch-nemesis of solar power, meaning combative, energy storage measures would need to be put in place to balance output in lightless hours. This is an added cost almost as much as the panelling, which again, is off-putting to many companies and residential homeowners.
- Especially in the UK, where sunlight is sometimes at a premium, production would is not as reliable and constant as it could be in many other countries. That said, even on cloudy days, solar panels will pick up a considerable, yet reduced, amount of renewable energy.
- Even with the advancement in solar panel technology, today’s panels still only convert roughly 20% of the sunlight they take in, which on a large scale would need to have more impressive numbers to attract the big players in the production business.
Solar panels present an extremely beneficial and exciting prospect to those homeowners who have the money to spend on the initial investment.
Not only can you create your own electricity free of charge, reducing or eliminating electricity bills, but if you’re creating renewable energy in excess of your usage, you’re able to sell your leftovers back to the electricity companies for a nice little fee.
However, considering the average household consumes around 2,900 kWh per year, you’d need a 4kW solar panel system, requiring an approximate roof space of 28 square metres, to produce enough electricity for your household needs. This could cost you between £6,000-8,000!
As mentioned before, this is an investment that requires considerable amounts of time to see any return. For example, on a 4kW system, you can expect to see around £2,100 profit over 20 years. Not to mention the 40 tonnes of C02 emissions you’d save over 25 years.
In the UK, despite being a little sun-deprived from time to time, we have managed to take advantage of what we do have.
The largest solar farm currently in operation in the UK is in Bournemouth, southern England. It’s called Chapel Lane Solar Farm and covers around 310 acres, roughly 175 football pitches. At full capacity, it can generate 51.3 megawatts (51,300 kW), which is enough to power around 60,000 households.
The solar power revolution shows no signs of slowing down, with plans for another large-scale solar farm recently receiving the green light. The Cleve Hill Solar Park in Kent is set to overtake Chapel Lane as the largest solar plant and is expected to provide enough clean electricity to power over 91,000 UK homes when it opens in 2022.
Another type of renewable energy is geothermal energy. Geothermal energy refers to electricity generated by the heating up of areas of water deep beneath the surface of the earth.
You may have seen hot springs or geysers. These are created by water heated up by the earth’s crust, causing it to project through the surface. Geothermal energy uses this action to generate electricity in a variety of methods, such as powering small turbines with the steam collected.
Geothermal energy contributes very little to the UK electricity mix. However, the United States of America is a relatively large producer of geothermal, generating over 6 times the amount that we do. According to the US Department of Energy, geothermal energy already powers around 60% of the northern Californian coast.
That said, it still only accounts for less than 1% of the electricity mix in the United States as a whole. A 2012 report in The Guardian claimed that geothermal energy had the potential to fuel around a fifth of the UK’s electricity demands; however, as of yet, we have not seen any great advances on this claim.
As such, much of the geothermal potential in the country is not yet accessible. However, there are a few sites scattered around the country that have been heavily invested in throughout recent years.
One of the most notable is the Eden Project in Cornwall. Compared to more advanced renewables on this list, such as wind energy, the output of geothermal is very low. The Eden Project plant has a capacity of 3-4 megawatts (3,000 - 4,000 kW), which, working to its full capacity, could power a maximum of around 5,650 houses in real-time per hour.
Hydroelectric, also known as hydropower or hydro energy, refers to the conversion of natural water current into electricity. This renewable energy source uses large areas of water in a variety of methods to power underwater turbines and generators.
Like wind energy, this is a completely renewable and reliable source of electricity generation. Due to the water cycle, this form of generation is extremely sustainable and can be controlled in a way that proves most efficient.
New technology has also made hydroelectric generation even more environmentally friendly by creating fish-friendly stations, preventing local wildlife from feeling the potential negative effects of the generation process.
Hydroelectric generation relies heavily on geographical circumstances. In the UK we are blessed with a rich variety of terrain, but many countries are not so lucky.
Hydroelectric energy represents around 2% of the UK’s electricity mix, which is still relatively low given its potential and popularity worldwide. Countries that are extremely invested in hydroelectric generation include the United States, Canada, Brazil and China, each of which uses this form of production for a large percentage of their renewable efforts.
The largest capacity hydroelectric power station in the UK is Dinorwig Power Station, near Snowdonia national park in Gwynedd, northern Wales. However, despite its 1.8 gigawatts (1,800,000kW) capacity, which has the potential to power over 2,540,000 households at full capacity, it is only used for pump-storage. This means that renewable energy is stored to be released during high-demand periods in order to balance the grid.
The largest traditional hydroelectric plant in the UK is Sloy, located on the west bank of Loch Lomond in Scotland. This has a potential output of 160 megawatts (160,000 kW), much lower than the capabilities of the Dinorwig Power Station.
Biomass is a great first step towards a solution for the depleting natural gas resources worldwide. It is a form of gas, used in the same manner as the gas we use every day, created using the breakdown of organic matter.
In the UK, around 15 million tonnes of food are thrown away each year, 2 million of which are made up of organic elements such as potato skins and fruit peelings.
This, along with other organic matter, such as livestock manure, decomposes naturally and produces large amounts of methane, a greenhouse gas that is 25 times more potent than CO2. This is taken by biomethane plants and turned into usable gas that can be pumped into the grid.
The Veolia biogas plant in Northallerton, North Yorkshire has been generating biomethane gas for a number of years. It is estimated to be able to fuel around 3,000 local homes and businesses using solely renewable energy sources, showing that biogas does have the potential to progress and have a large effect.
This concept is still at an early stage and has not made a considerable impact as of yet. However, according to the Renewable Energy Association, biomethane has the potential to meet around 20% of the UK’s gas demands eventually.
Renewable energy jobs
With the move towards net-zero emissions by 2050, the renewable energy industry is a rapidly growing and innovative sector. As such, there are a wealth of ‘green collar’ career opportunities for those interested in the renewables and clean energy industry.
Some examples of renewable energy jobs are:
- Renewable Energy Consultant
- Sustainable Construction Manager
- Renewable Installation Contractor
- Solar Project Manager
- Wind Farm Site Manager
- Renewable Energy Sales Representative
How can I cut down on fossil fuels?
Continuing to generate energy mostly through fossil fuels is clearly not sustainable, but unfortunately, for the time being, it is an integral part of our energy mix. As such, we should try everything in our powers to reduce the damaging effects this is having on our planet.
One easy way you can help is by switching to a renewable energy supplier. Many providers offer ‘green’ tariffs, with electricity generated from sustainable sources. To learn more and find some of the best deals, visit our guide to renewable energy providers.