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How Do Biomass Boilers Work & Are They Worth The Investment?

what is a biomass boiler

Biomass boilers offer an alternative way to generate heat and warm your home.

They’re known as being more environmentally friendly than traditional gas and oil boilers because they’re classed as a renewable form of energy.

But what is a biomass boiler exactly and how do these type of organic boilers work?

What is a biomass boiler?

Simply put, a biomass boiler is an eco friendly heating system that uses organic materials to create heat.

This can include wood chips, wooden logs, biomass pellets, blocks and other forms. This biomass is used to then power a hot water boiler.

Biomass boilers are becoming more popular because they are a renewable source of energy and seen as being more eco friendly. If you’re interested in being more eco at home, check out this blog on easy ways to go green at home.

How do biomass boilers work?

A biomass boiler burn natural sources of fuel to generate heat.

This happens by feeding the biomass fuel, such as wood pellets and logs, into the combustion chamber where it is burned into heat energy.

The energy generated from the combustion is used to heat water in the boiler, which is then circulated around the property to provide warmth. Just like other forms of central heating do.

As biomass is a renewable resource, biomass boilers are considered to be more sustainable than traditional gas or oil boilers.

When choosing a biomass boiler, it is important to select one that has been designed and manufactured to the highest standards to ensure optimum performance and safety.

new era biomass boiler

What do biomass boilers run on?

Biomass boilers are similar to traditional oil and gas-fired boilers in that they can be used to generate electricity or to heat buildings.

The main difference between biomass boilers and traditional boilers is that biomass boilers use renewable resources instead of fossil fuels.

Biomass boilers can run on:

  • Wood
  • Wood-based pellets
  • Biomass logs
  • Biomass pellets

Wood is the main source of biomass fuel. As you know wood and other biomass fuels are organic materials that are considered renewable because they can be replenished relatively quickly, depending on the type.

For example, trees can be replanted after they are harvested for fuel and sustainably forest management ensures stocks are not wiped out. In contrast, fossil fuels, such as coal and oil, take millions of years to form.

The wood used in biomass boilers often comes in the form of wood-based pellets. These pellets are small and compact. They are made by compressing wood waste, which can include sawdust, wood chips or even wood shavings.

The resulting pellets are then dried and often treated with a binder to improve their durability. Although adding a synthetic binder does make them considerably less environmentally friendly.

Are biomass boilers energy efficient?

Biomass boilers can convert up to 95% of the wood they use into heat or electricity. However, a more realistic efficiency rating is 70-80%.

Pellets typically have a high energy density and low moisture content, making them an ideal fuel for biomass boilers.

In addition, wood pellets can be easily stored and transported, making them a convenient option for those looking for an alternative to traditional fossil fuels.

What are the benefits of a biomass boiler?

biomass boiler outdoors
Source: Richard Webb

There are plenty of positives that come with a biomass boiler.

Here are 5 main benefits of biomass boilers:

1. Low running costs

Depending on the price of the fuel, the running costs for biomass boilers tend to be around £750 per year. This is roughly the same as a gas boiler.

This depends on the size of the home it’s heating.

Biomass boilers are also eligible for government grants, which can further reduce the cost of installation. From April 2022, the government’s Boiler Upgrade Scheme comes into play.

2. Off-grid power

A bit like a big version of a wood-burning stove, biomass boilers are standalone units and don’t need to be connected to any national grid.

For this reason, they’re great for off-grid places and can provide your home with a reliable source of heat.

3. Energy efficient

Biomass boilers can have efficiency ratings of 97% at the higher end, meaning almost all the fuel is being converted to heat with little waste.

As an average though, biomass boiler efficiency will sit around 70-77% in the real world, as shown in this government study. For example, this is similar to multifuel log burners but lower than electric-based heaters, such as electric fires.

For this reason, biomass boilers may offer a sustainable and efficient way to generate heat and power.

4. Environmental benefits

Contrasting to other heating systems, biomass boilers produce less emissions than oil boilers but more than heat pumps.

However, biomass boilers offset their carbon emissions by absorbing carbon dioxide from the atmosphere as the biomass fuel grows. This process is called carbon sequestration which you can read about in the Eco Glossary.

You can read more on are biomass boilers environmentally friendly here.

5. Fuel is quick to regenerate

all fuels used in biomass boilers are quick to regenerate. Unlike oil or coal which take millions of years to form, biomass can be replenished in a matter of weeks, months or a few years. This makes biomass a much more sustainable option for generating energy.

What are the disadvantages?

There are a few disadvantages that come with biomass boiler systems for you and the environment.

The big drawback of biomass boilers is that they have a large up-front cost. Compared to a traditional gas boiler, you’re looking at least double the costs, if not quite a bit more (explained further on the section below).

Biomass boilers also require regular maintenance and may need to be replaced more frequently than other types of boilers. As a result, biomass boilers may not be the best option for homeowners who are looking for a low-maintenance, long-term solution.

They may not be as environmentally friendly as you’d expect. Unlike electrical energy produced from renewable resources, biomass combustion comes with greenhouse gas emissions and are responsible for millions of tonnes of emissions in the UK each year. As well as contributing to local air pollution, 82% of the wood fuel is shipped in from the likes of US and Canada.

Another potential issue is that biomass boilers tend to be large and bulky. This can make them difficult to install in small homes or apartments.

How much do biomass boilers cost?

The kicker is that biomass boilers are one of the most initially expensive home heating options on the market.

The price for a small domestic biomass boiler will start from £6,000. If you’re considering manually adding biomass and fuel to the boiler, expect to pay between £6,000 – £12,000.

For an automatically fed biomass boiler, you’re likely to be talking of costs between £10,000 and £20,000 for the boiler, installation and delivery.

You may be able to access grants, such as with the Boiler Upgrade Scheme which is running until 2025. This is mainly aimed at air or ground source heat pumps but you may be able to qualify with a biomass boiler too.

Wrap up on biomass boilers

I hope you know have a much better idea of what a biomass boiler is and how they work.

Biomass boiler technology has come a long way in recent years. They are now more efficient than ever before and have the potential to significantly reduce our reliance on fossil fuels, as well as your carbon emissions.

However, they’re still a significant source of greenhouse gas emissions and air pollution. They’re also expensive to install and require regular maintenance in order to function efficiently over the long term.

This being said – they will move energy generation away from more harmful fossil fuels and may provide a good option in certain circumstances.

Overall, biomass boilers offer both advantages and disadvantages. The decision of whether or not to install one should be based on a careful evaluation of your specific needs and circumstances.

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Ben & Murphy Peaks Mam Tor

Ben is the Creator and Editor of Tiny Eco Home Life. I write and publish information about more sustainable, environmentally friendly living in and around the home.

Alongside this website, I love spending time in the natural world, living a simple life and spending time with my young family (Murphy the dog!) I round up my thoughts and recent blogs on the Eco Life Newsletter.