Types of renewable energy

A guide to renewable energy types

The UK is aiming to get at least 15% of its energy from renewable sources by 2020. This means that we’ll all start to use more wind, solar, hydro, biomass, tidal and wave energy in the near future. Don’t want to wait until 2020 to do your bit for the environment?  Lots of providers (including us) offer Green tariffs that help you reduce your carbon footprint.

Depiction of a wind turning blade that uses wind energy to generate power

Wind energy

Electricity is generated by land or sea based wind-powered turbines. Wind energy electricity production is picking up, and according to latest government figures, onshore wind generated 25% of renewable energy, with offshore contributing another 20% in 2016.

Considerations

Offshore arrays (wind turbines) produce more electricity because they tend to rotate at higher, more consistent speeds than onshore ones. They can produce a significantly greater amount of electricity with a higher wind speed of only a few miles per hour. The downside? They’re more expensive to develop. Onshore ones are cheaper to build, but tend to be unpopular with local communities. 

Solar energy

Although it may seem like sunny days are in short supply, the UK actually gets about 13% of its electricity from solar energy. In fact, nearly half a million UK homes have solar panels. Solar panels work by getting particles of light to knock electrons free from atoms, which then creates a flow of electricity.

Depiction of the sun shining on a solar panel to generate electricity from solar energy

Considerations

Roof panels on private homes are the biggest source of solar energy for the UK. However, more and more solar panels are being fitted on offices, schools, churches, farms and train stations. The government has incentivised homeowners with generous feed-in tariffs for generating electricity for the National Grid, but with these tariffs due to end in 2019, the number of people getting solar panels fitted will probably drop over the next few years.

However, new technologies - like household batteries – mean that people can start making AND using their own electricity instead. Also, solar panels are becoming more efficient and the price of solar panels and batteries continues to drop. Hopefully, these new advances in solar panel technology will slow the decline and help solar energy become a cheaper, cleaner source of energy.

Depiction of hydro energy which uses water to turn turbines to generate hydroelectric energy

Hydro energy

In hydroelectric energy schemes, reservoir or river water powers turbines that drive electricity generators. Hydroelectric accounted for 6% of renewable energy generation in 2016.

Considerations

It’s unlikely we’ll see hydro grow in the UK to the scale it did in the 1950s and 1960s. There are some environmental concerns and the most appropriate sites for these schemes have already been taken. 

However, small-scale hydro resources, such as watermills and weirs, producing less than 5 megawatts, are still likely to play a part in our energy mix. All schemes need to get environmental permits, planning consent and connection to the local electricity network.

Biomass energy

Biomass energy comes from living or recently living organisms – mostly plants. When burned in a power plant, biomass generates electricity. Also, biomethane, a naturally occurring gas produced from organic matter, can be fed into the gas Grid. Biomass was the source of most of the country’s renewable energy in 2016 (36%).

The most common biomass fuels are:

  • wood
  • crops
  • waste from households and businesses
  • sewage sludge – forming sewage gas
Depiction of biomass energy which is a popular form of renewable energy

Considerations

Some environmentalists aren’t too keen on biomass energy – the process emits some carbon and the plants are not necessarily renewable. However, energy from biomass fuels can make significant greenhouse gas emission savings when compared to fossil fuels.

A depiction of tidal and wave energy which is a renewable energy source

Tidal and wave energy

Tidal stream energy is generated when water passes through waterwheels powering turbines. It can also be made with barrages, forming tidal reservoirs – with water let out via underwater tunnels containing turbine generators.

According to the government, tidal stream and wave energy has the potential to meet up to a fifth of the UK’s current electricity demand. 

With wave energy, equipment is put on the sea’s surface. It captures the energy produced by the waves’ movements and converts this into electrical power.

Considerations

The UK has the potential to be a world leader for wave and tidal stream technologies because it has many tidal estuaries and long-standing expertise in marine oil and gas exploration.

However, the problem is funding. Tidal energy is still undeveloped because the level of public money needed can’t be justified, and it’s unpopular with some environmentalists. Wave energy also failed to win support because tests in Cornwall and Orkney have proved too costly.