Biomass heating

Is Biomass Heating right for you?

If you have access to a supply of sustainable wood fuel, biomass heating could save you a significant amount of money over a year compared to Electricity, Oil or LPG.

What is Biomass Heating?

Biomass heating systems burn wood fuel, such as chips, pellets or logs to provide warmth in a single room or to power central heating and hot water boilers. Biomass boilers can vary in output, from around 8kW, up to megawatt sized energy plants. Because of this biomass can be suitable for any sized application, with a single boiler or multi-boiler plant room heating a single small dwelling up to an apartment block or entire village.

Depending on the size, domestic biomass boilers can be installed in outbuildings or boiler rooms, in much the same way as an oil boiler. There are however, biomass boilers that are suitable for installing within your property, including decorative models that have the appearance of traditional stoves.

A biomass boiler would normally be connected to a buffer tank, which the boiler would heat. Your property would draw from the heat stored in the buffer tank, instead of directly from the boiler. This allows the boiler to run for a longer period of time, while the tank is heated, instead of having to ignite every time there is a demand for heat from the property. This greatly increases efficiency and reduces fuel usage and maintenance costs.

Domestic biomass heating is a great alternative to oil or LPG boilers for properties that are “off grid”, with log and chip boilers being especially well suited to householders who have access to a sustainable fuel supply.

If you would like to discuss which option is best for you, contact us today.

Biomass Wood Chip Heating from Cedar Renewables

Wood chip

Wood chips, can by their nature, vary in quality and suitability for use in biomass boilers. For this reason there are specific standards that define the characteristics of wood chips produced for biomass. These normative specifications define the size of the wood chip:

  • P16 Specification, < 1% > 45mm, (maximum chip length 85mm)
  • P45 Specification, < 1% > 63mm
  • P63 Specification, < 1% > 100mm


And moisture content:

  • M20 < 20% moisture
  • M25 < 25% moisture
  • M30 < 30% moisture
  • M40 < 40% moisture
  • M55 < 55% moisture
  • M65 < 65% moisture


Informative specifications for wood chip include:

  • Net energy content, typically in MJ/Kg or kWh/m3
  • Bulk density, in kg/m3
Biomass Wood Pellet Heating from Cedar Renewables

Wood pellet

Wood pellets have been one of the most common forms of biomass fuel used in biomass boilers. They are cylindrical in shape and made from compressed sawdust, which is often the waste product from the timber industry (e.g. sawmills). Their specification is strictly defined to ensure consistent quality. Biomass fuel has to meet CEN/TC 355 standard Wood pellets for biomass must be;

  • Less than 10% moisture
  • Be 6mm in diameter and less than 30mm long (20% can be up to 45mm)
  • Have a bulk weight of 650kg / m3
  • Ash content, max. 0.5%
  • Dust content, max 2.3%
  • Energy content, 49 kilowatts/kg

Wood pellets are fused by the natural lignin present in dry wood. It strengthens the wood as well as having water proofing properties. The very low moisture content helps consistent combustion efficiency, as during the burning of fuel, any water content must be evaporated before combustion can occur. This process requires energy, and therefore reduces overall system efficiency. Pellets are additionally very dense. Both these qualities make them a good source of energy.

Biomass Wood Logs Heating from Cedar Renewables

Wood logs

Wood logs are probably the least common form of biomass fuel and have a more limited application. Typically, the largest log boilers have outputs of around 60kw, so are suitable for domestic or smaller commercial installations. They require greater user input as they require regular filling, however, if you have access to an approved, sustainable source of seasoned logs, they can be a very cheap way to heat a property. Additionally, combination log and pellet boilers are available which run on wood pellets if there is an interruption in the supply of logs and use wood pellets to light the boiler automatically.

Log boilers work by a process known as wood gasification, whereby wood gas is produced from the logs as they are heated in the boilers firebox and then burned at high efficiency with minimal ash production or flue emissions.

The four processes of Gasification

The four processes of Gasification

Key steps when having Biomass heating installed

When installing a biomass heating system, it is important to ensure that the proposed system meets all the client’s requirements and the heating requirements of the property, especially when installing a system to replace an oil boiler. This is why it’s important to use an experienced MCS accredited installer, such as Cedar Renewables. To make sure of a system that perfectly matches your home and your heating and hot water needs, a we will work to three key stages:

Pre design assessment with Cedar Renewables

1. Pre-design assessment

This stage is to determine which heating system will best suit your property and the feasibility of your preferred system. With years of experience in the renewable heating industry Cedar Renewable will be able to advise you on the most beneficial system for you. If choosing a Biomass Boiler, we will be able to advise you on the best location for all the associated equipment; this is especially important if choosing a woodchip or pellet boiler, as you require enough room for the fuel bunker. We can produce a budgetary estimate, detailing the work required and including different options, where applicable.

Renewable heating design by Cedar Renewables

2. Detailed design

Should a Biomass Boiler prove to be the most advantageous system for you, we will begin the detailed design process. This will include identifying a suitable location for the boiler and other plant equipment, including the fuel bunker, a full heat loss survey to determine the heating and domestic hot water requirements of your property and a heat emitter design to ensure the heat is transferred efficiently into your property. All of this information will be included in our full quotation, along with a performance report detailing the estimated energy savings and Renewable Heat Incentive payments that you could receive.

Renewable heating design by Cedar Renewables

3. Installation

Our team of qualified engineers, led by one or both of our directors will be onsite to carry out the installation. All work will be completed in house, including the fitting out of the plant room, fabrication of the fuel bunker and fuel feed system, installation of buffer tank and connection in to the pre-existing heating system, if required. We can also complete the installation of the underfloor heating and or radiators, depending on which is selected, connection of the heating controls and final commissioning of the system. Upon completion you will be provided with a full handover pack and we can even assist in the application for the RHI.

What is the Renewable Heating Incentive?

The Domestic Renewable Heat Incentive is open to applicants who wish to upgrade to a renewable heating technology in a domestic property that they own.