An Introduction to Biomass

An Introduction to Biomass


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After a brief sidestep into the realm of policy with last week’s Green Deal post, we turn our focus back to renewable technology. This week we are looking at biomass.

Overview

Biomass is biological matter composed of living, or recently living organisms, which can be burned or broken down by anaerobic digestion to produce energy. Examples of biomass include wood, straw, animal waste, agricultural by-products and energy crops like oilseed rape. Domestic biomass boilers usually burn logs or wood pellets, so this post will be focusing mainly on wood biomass.

Historically, heating homes with wood was the norm. Today, the practice is popular in mainland Europe and the USA. Many houses in the UK have a fireplace, although heating an entire house using biomass is less common. With the introduction of the Renewable Heat Incentive (see the policy section below) the popularity of biomass as a potentially cheap and sustainable way of heating the home is expected to increase.

So how sustainable is biomass? Burning wood or straw releases carbon stored in the plant matter over the course of its lifetime. When fossil fuels are burned, they release carbon absorbed over millions of years. The carbon released by burning biomass is converted into new plant material by photosynthesis, negating the release of the stored carbon. However, it is important to note that wood biomass is only sustainable if the forests it comes from are properly managed. There is a limit on the land area available to grow these fuels, meaning that in the future biomass will be one of several renewable energy sources used to heat our homes.

The Upside

  • Biomass is much more environmentally friendly than using coal, oil or gas. Heating the average home using a wood pellet boiler rather than oil would release 10 times less carbon dioxide (CO2) every year.
  • Burning logs or wood pellets is generally cheaper than using oil or electricity. If you can harvest your own wood then it will be even more cost efficient. The Energy Saving Trust estimates that replacing an electric heating system with a biomass one can save roughly £630 per year, with a CO2 saving of 7.5 tonnes per year.
  • Biomass energy sources are renewable, but we must make sure that they are sustainably managed.
  • There are several different types of biomass, so you can choose which one best suits your situation.
  • It is possible to use biomass from local sources. This minimises carbon emissions from transportation, and also supports the local economy. Search for local wood fuel suppliers using Log Pile.
  • It is easy to store wood pellets in your home, even if you live in a small house. To see an example of a wood pellet stove being used to heat a home, watch this video.
CAT’s wood pellet boiler with automated feeder. To the right are our two log boilers.

The Downside

  • Installing a biomass system can mean high initial costs. A simple log stove can cost around £500, with an automated wood pellet boiler costing up to £15,000.
  • Biomass is a low-carbon technology, but it is not carbon neutral. The harvesting, processing and transportation of materials all contributes to CO2 emissions. Wood pellets require more processing than logs, but they have a lower moisture content so they burn more efficiently.
  • It is cheaper to order fuel in bulk, but storing large amounts of  logs can be difficult in smaller homes.

Policy

The 2008 Climate Change Act is a legally binding agreement that the UK will reduce its net carbon emissions by 80% by 2050, compared to emissions in 1990. Government policies like the Green Deal and the Energy Company Obligation are all aimed at reducing the UK’s carbon output and encouraging people to embrace less carbon-positive fuel sources.

The Government’s latest scheme is the Renewable Heat Incentive. This will operate on a system similar to the Feed-in Tariffs for wind and solar energy, with householders who take up the scheme being paid for heating their homes using renewable energy. The domestic RHI has yet to be launched in the UK, although the non-domestic scheme has been in place since November 2011. The domestic RHI is expected to be launched this summer. More information can be found on the Government website.

Preceding the launch of the RHI is the RHIPP scheme (Renewable Heat Incentive Premium Payments), giving householders money towards upgrading their heating systems.

A look inside one of CAT’s log burners

And did you know…

Over the past year CAT has been building a biomass teaching facility, which has just opened. Approved by HETAS – the regulatory body for biomass installers – CAT now offers Biomass for Installers (HETAS H005). Intended for experienced plumbers and engineers who want to expand into the renewable heating market, Biomass for Installers will enable those in the plumbing and heating sector to move in to the renewable energy field.

In Ofgem’s last quarterly report of 2012 it was noted that 90% of installations done as part of the non-domestic RHI were for biomass boilers. With the imminent roll-out of the domestic RHI, the number of skilled biomass installers required can only increase.

More information on biomass can be found on CAT’s info page.