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How biomass energy works

Biomass energy might sound complicated, but it’s actually as simple as you can get. Here’s how you can use this cheap, plentiful source of energy to warm up your home.

Biomass energy might sound complicated, but it’s actually as simple as you can get. Here’s how you can use this cheap, plentiful source of energy to warm up your home.

Written by
Sajni Shah
Utilities comparison expert
Last Updated
11 JANUARY 2024
6 min read
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What is biomass energy?

Biomass energy is basically a fancy way of describing wood, animal dung, charcoal and sugarcane. In other words, any naturally occurring material that can be used to create electricity.

Biomass is a catch-all term that describes living things (or at least, things that were living once). It can mean either a plant or animal product. As these are organic materials, they contain energy they’ve absorbed from the sun.

Biomass energy clearly isn’t a new technology – we’ve been using it since we were rubbing sticks together in caves. But it’s been making a comeback in recent years, as we look to find sources of renewable energy.

How does biomass energy work?

Biomass contains stored chemical energy from the sun, and can be burned at power plants or in domestic biomass boilers and wood stoves to produce heat and electricity. It also encompasses biofuels such as diesel.

How does biomass create electricity?

Burning large amounts of biomass heats water, which creates steam. This steam then spins turbines, which run generators to produce electricity.

What are the benefits of biomass energy?

Here are some of the reasons we should consider using biomass energy:

  • Biomass energy is a renewable energy source, so long as there is a sustainably managed supply.
  • Because there’s so much of it around, biomass energy is cheap. That means it can be used all over the world.
  • If we use waste products as energy, it means there's less rubbish going to landfill.
  • You can use biomass energy at home, if you have a biomass boiler or a wood-burning stove.
  • Burning biomass releases fewer nasty chemicals than burning coal.

What are the disadvantages of biomass energy?

Unfortunately, biomass energy isn’t without its downsides. Here are some of them:

  • Burning wood and other organic products still releases CO2, which contributes to climate change.
  • Burning biomass also releases poisonous carbon monoxide into the atmosphere.
  • Chopping down trees is bad for the environment, even when you’re using the wood to create energy.
  • Growing trees and other crops requires lots of land, which could be used for other purposes, such as growing food or building houses.
  • Growing trees – or anything else – on an industrial scale is bad for biodiversity, and could threaten wildlife.

What are biofuels?

As you’ve probably guessed by now, biofuels are fuels made from biomass. Biofuels can be made from vegetable oil, sugar or corn, and come in the form of either a solid, liquid or gas.

The two most common kinds of biofuel are biodiesel and bioethanol. Using biofuels to power cars and buses is not only cheaper, it also gives off less CO2 than other fuels. That means fewer emissions.

Why is biomass energy bad for the environment?

Biomass energy is considered to be carbon neutral. This is because the CO2 the trees absorb as they grow offsets the CO2 the biomass releases when you burn it.

But the maths doesn’t quite work when you’re cutting down trees to make energy. Even if you replace every tree you chop down with a new one, it’ll take a long time for those saplings to absorb all the carbon you’ve already burned.

Is biomass energy a form of renewable energy?

Biomass energy is considered renewable because it’s pretty easy to grow more trees. But burning those trees creates CO2 in the atmosphere, which means it’s not as environmentally friendly as you might hope. There’s always a trade-off, so you have to carefully weigh up the positives and the negatives.

Can I get help with the cost of installing a biomass boiler?

Yes, if you’re keen to power your home with renewable energy, you can apply for a grant of £5,000 towards the cost of installing a biomass boiler. Launched in April 2022, the Boiler Upgrade Scheme (BUS) is a government initiative aimed at encouraging more people to switch to cleaner heating systems like biomass. A biomass boiler works in much the same way as your gas boiler, except it burns natural materials – usually woodchips or logs – to heat up your home.

To be eligible for a £5,000 biomass grant, you’ll need:

  • To be the owner of a property not connected to the gas grid in a rural area of England or Wales
  • A property with an installation capacity up to 45kWth (don’t worry – this covers most homes)
  • A valid energy performance certificate (EPC), with no outstanding recommendations for loft or cavity wall insulation.

It’s also worth noting that the grant can only be used to replace traditional fossil fuel heating systems (gas, oil or electric).

If you live in Scotland, you may be eligible for a Home Energy Loan to help you pay for the installation of a biomass boiler. There’s a maximum loan of £9,000 available and you may be able to claim up to 75% cashback.

If you’re in Northern Ireland, you can find out about grants on the nidirect website.

How does the Boiler Upgrade Scheme work?

To get a new low-carbon boiler fitted, you’ll need to find an MCS-certified installer in your area who is able to carry out the work. This ensures that your boiler installation will be carried out to the correct standards. It’s a good idea to get quotes from more than one installer to make sure you’re getting value for money.

Once you’ve found an installer you’re happy with, they will apply for the grant on your behalf, with the £5,000 saving deducted from your bill.

Energy regulator Ofgem, which is running the scheme, might get in touch with you to carry out checks on the installation.

See more about BUS on GOV.UK.

Is a biomass boiler right for my home?

Before taking the plunge, it’s important to weigh up the pros and cons of biomass boilers, especially as they aren’t cheap to install. Even with a £5,000 grant, the upfront costs can be significant. According to the Energy Saving Trust, it’s likely to cost you around £16,000 to install an automatically fed pellet boiler.

Wood boilers also take up space. They’re larger than their gas or oil equivalents and you’ll need somewhere to store the fuel, preferably close to the road to make fuel delivery easier.

Biomass boilers are best suited to larger homes that take a while to heat up because burning wood is much more economical than gas or oil. They can also increase the value of a property because of their energy efficiency.

The best way to find out whether your home is suited to a biomass boiler is to seek advice from a qualified MCS-certified installer.

How can I be greener? 

There are a few ways you can do your bit to be more environmentally friendly

  • Monitor your energy use 
  • Use a smart meter 
    This will tell you how much energy you’re using in real time, helping you cut down. 
  • Switch energy suppliers  
    Use an energy provider that’s committed to renewables. 
  • Unplug electric devices when you’re not using them 
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