Products & Services
Biomas Boilers & Stoves

Householders could be paid hundreds of pounds a year for generating heat by biomass boilers through the RHI.

The tariff levels have been set at 5.14p/kWh. Investing in biomass will mean cleaner energy and cheaper bills.

Biomass heating systems burn wood pellets, chips or logs to provide warmth in a single room or to power central heating and hot water boilers.

A stove burns logs or pellets to heat a single room and may be fitted with a back boiler to provide water heating as well. A boiler burns logs, pellets or chips, and is connected to a central heating and hot water system.

The term ‘biomass’ refers to any biological material that is burnt to generate energy. Modern biomass appliances are clean, controllable, and easy to use. They range from cosy domestic log-burning stoves that keep the heat in the room rather than sending it up the chimney, right through to fully automated, temperature-controlled commercial boiler systems. The most common fuels are wood-derived.

  • potential income through the UK government’s Renewable Heat Incentive (RHI)

  • lower home carbon emissions

  • begin to dramatically lower your fuel bills

How they work, Costs & Savings
  • About Biomass Boilers

    Biomass boilers can be installed wherever there is space to put a boiler (can be in an outhouse) and where the building has a water tank or space to install one.

    Pellet, wood chip or wood burning boilers directly replace gas, oil or LPG boilers, providing hot water for radiators and taps. A biomass boiler can prove to be a particularly good option for householders not on the gas grid, and for organisations and businesses looking to meet environmental obligations.

    Modern biomass boilers are clean, efficient, and completely controllable. Wood pellet boilers have microprocessors controlling the amount of fuel and air being supplied, and can reach 90-95% efficiency. Unlike a fossil fuel boiler, a wood pellet boiler doesn’t waste energy switching itself on and off to regulate the temperature. Instead, it modulates its firing rates to match the building’s energy requirements. Not only does this increase fuel efficiency and cost, it cuts electricity and increases the boiler’s lifetime.

    Smaller pellet boilers have a hopper from which they take the fuel as needed. Larger commercial boilers take fuel in directly from a silo via a suction-based or electrical conveyor system. There is very little ash, because of the high efficiency rates. Ash trays therefore only need to be emptied once every few weeks. Wood burning boilers need to be fed manually.

    Most domestic and small commercial biomass boilers use logs or wood pellets. Larger ones often burn wood chips.

    We can connect a biomass boiler to most plumbing systems.

    Biomass boilers can be combined with other renewable technologies. A good option is to run a biomass boiler during the winter, then use solar thermal panels to heat hot water in the summer.

  • About Biomass Stoves

    Biomass stoves can be installed in any room with a chimney or where a flue can be installed.

    Biomass stoves provide extremely efficient room heating. There are various options, all combining the cosy glow of a warm fire with the efficiency of oil. Waste gases are taken out through a flue and vented externally. Most stoves are designed to burn either logs or wood pellets.

    Radiant heat stoves: The simplest option, burning the fuel in a single combustion chamber and using the heat from the flames to warm.

    Radiant heat stoves with gasification: These work by burning the fuel in one combustion chamber and using the natural down draught to suck the resulting gases down to a second chamber. Here, secondary air is added for a high temperature after burn. These stoves are incredibly efficient, turning up to 93% of the fuel energy into heat for the room. You also get two visible fires to watch and enjoy.

    Convection wood pellet stoves: With these, the heat doesn’t come directly from the flames. Instead, the stove draws cold air in using a fan, warms it via a heat exchanger, and returns it back into the room. These can also be extremely efficient. Note though that the stove is dependent on electricity, because of the fan, so won’t be much use in a power cut.

    The most sophisticated wood pellet stove designs have automated feeders, so all you have to do is fill a hopper every few days. You programme the stove exactly as you would a gas or oil burner, and it stops and starts automatically, taking pellets in as needed. Some models can even be lit by text, so you can be sure the room is warm when you come home.

    Some wood pellet stoves combine convective and radiant heat.

    Pellet or wood burners with back boilers: Back boilers can be added to any of these types of stove (subject to space), so that you can run central heating and hot water. The back boiler can be connected directly to the central heating circuit, but it is usually most efficient to connect it to a dual tank supplying both the hot water and radiator systems. This way, you can store hot water so you don’t need to keep the stove burning all the time.

  • Biomass Fuels

    Most biomass stoves and boilers are designed to work with a specific fuel, though some can take various types. The most common fuels for domestic and small commercial boilers are logs and wood pellets. Larger boilers are often fuelled by wood chips.

    Wood pellets are made from recycled wood waste or sawdust. They are small (typically 6mm in diameter), regularly sized, and easy to handle because they simply flow, like a liquid. They are very dense, with a water content of only around 10-15%.

    Wood chips are simply fine pieces of mechanically chopped wood. They are produced to meet certain specifications for size and moisture content. The bark should be stripped before chipping.

  • Costs & Savings

    Pellet costs depend mainly on the size and method of delivery. If you have room for a large fuel store, you can pay as little as around £190 per tonne for tanker deliveries. Buying by the bag is more expensive. A 10kg bag, delivered, can cost around £11. Logs can be cheaper, depending on local availability. Although the price of wood fuel can vary, it is often cheaper than other heating options.

    Savings in carbon dioxide emissions are very significant up to 15.4 tonnes a year when a wood-fuelled boiler replaces a solid (coal) fired system or electric storage heating. Financial savings are more variable – if you replace an older gas heating system with a wood-burning system you might save up to £70 a year, but if you are replacing an old electric heating system you could save as much as £880 per year.

  • How does burning biomass reduce my carbon footprint?

    As trees grow, they absorb carbon dioxide. Whether the wood is left to rot naturally or burnt, this carbon dioxide is ultimately released back into the atmosphere. This means that wood fuels are carbon neutral, unlike fossil fuels which release additional carbon dioxide (CO2) when burnt.

    Wood pellets help you reduce your carbon footprint more than simple logs, because they are more efficient, using less wood for the same amount of heat.

  • How efficient are biomass burners?

    Biomass burners are at least three times as efficient as an open fire, which sends 75% of the energy it produces straight up the chimney. A biomass stove can be anything between 75% and 95% efficient. Pellet boilers are around 95% efficient comparable to oil-powered systems.

  • How much storage space will I need?

    Pellets take up less space than logs, but more than coal or oil.

    To supply the fuel for a typical domestic biomass central heating system for a year you will need a dry storage space the size of a garden shed. You can of course have more frequent deliveries, but this will add to the cost of running the system. If you are considering just a stove, then you can buy pellets by the bag as and when you need them.

    If you are planning a larger system, you will need space to site a storage silo no further than 15m from the boiler itself. Typical bulk deliveries of wood pellets are three to five tonnes. To store five tonnes you need around 12m2 of dry storage space.

  • How green are wood pellets?

    Wood pellets are generally produced as a by-product of sawmilling, so no energy-intensive processes are needed. They usually contain nothing other than the wood, though some may have petroleum added as a lubricant. You can check this with your local supplier. And once the pellets have been burnt, you can use the mineral-rich ash as fertiliser.

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