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A biomass boiler is a direct replacement for a conventional gas, oil or LPG boiler. It can be used to heat water, steam or thermal oil to be used in a heating system or in a process. They run on wood derived fuel which is normally either wood pellet or wood chip, although log is a fairly common fuel as well.


Fuel is stored in a hopper (except for log systems) and transported from the hopper to the boiler by suction, screw auger, or conveyor. It is ignited automatically and the boiler controls the rate of fuel feed according to the heat demand.


As the fuel is combusted, the heat passes through a heat exchanger which transfers the heat to the water within the system. Often efficiencies in excess of 90% are achieved during this process. The boiler control automates the oxygen levels and temperatures to achieve the highest possible efficiencies.


• Care Homes

• Hotels

• Country Houses

• Dairy Farms

• District Heating systems


• Domestic Houses

• Schools

• Factories

• Leisure Centres

• Holiday Parks

• Swimming pools

• Offices

• Council Offices












The Renewable Heat Incentive (RHI) is a UK Government scheme set up to encourage uptake of renewable heat technologies amongst householders, communities and businesses through financial incentives. It is the first of its kind in the world and the UK Government expects the RHI to contribute towards the 2020 ambition of 12% of heating coming from renewable sources. The scheme is administered by OFGEM.


Eligible applicants join a tariff that corresponds to their biomass heating capacity. Once registered onto the tariff it is fixed for 20 years but will increase by RPI each year. In other words, the tariff can go up, but not down once you are registered on it. The tariff will pay out for every kWh of heat produced and recorded on the heat meter.


As more and more applicants are accepted onto the scheme, the tariff will drop, but only for new applicants. This means that once you are on the tariff, you are secure for 20 years, but delaying your decision to go ahead with a biomass installation could cost you if the tariff drops in that time. The tariff is reviewed every quarter.


The RHI for homeowners is based on the deemed heat use of your home. This figure is calculated by an energy assessor and shown on your Energy Performance Certificate (EPC) as a value in kWh for space heating and hot water. These two figures are added together (providing that your biomass system is configured to provide heating and hot water), and the tariff is applied to that total figure.


In other words if your space heating requirement is 50,000 kWh and your hot water requirement is 3,000 kWh then the

combination of the two (53,000 kWh) is multiplied by the current tariff rate, e.g:


Deemed heat use: 53,000 kWh

Example tariff: 10.98p (correct as of 16 Jan 2015)

RHI income: £5,819.40 per annum


This amount is paid to you every year divided into 4 equal quarterly payments, for a total duration of 7 years. The tariff will benefit from any increase in RPI, but will not decrease once you are accepted onto the scheme.

How Does This Work? Check Out Our Videos  


Generate Green offer Wood Chip, Wood Pellet and Log boilers. Which fuel is right for you depends on a number of factors such as:

• Local availability of fuel

• Storage space

• Automation requirements

• Delivery access

• Budget

Probably the most important factor when deciding on a fuel type is quality. If you are using your own wood supply such as felled logs, or home made woodchip, then it is essential that you check the quality of the fuel before using it as otherwise it may reduce the life of your boiler or cause problems with the fuel feed system.


Wood pellets are the most consistent and popular fuel type. They are manufactured to a required standard (EN / EN Plus) which means that you know that the pellets will have been tested to ensure the right moisture content, consistency and therefore calorific value (the amount of energy released by a given quantity of fuel). Wood pellets are the most compact fuel type, requiring less storage and therefore deliveries are not as frequent. Pellet boilers have a high degree of automation requiring very little if any interaction on a day to day basis. Fuel feed is normally achieved by a suction (vacuum) system through to the boiler.


Wood chip has the least calorific value of the fuel types and also requires a much larger storage space. It is however quite cheap compared to wood pellets, so if you have the space to store it then it can be a very cost effective fuel.


Estates with their own wood supply

sometimes choose to produce their

own wood chip. Wood chip needs to

be dried down to the right moisture

content (typically 25%) to use in most boilers, but there are some boilers that can be used with ‘wet chip’ which has a typical moisture content of 50%.


Again similarly to wood pellet, fuel feed systems are can automated requiring little or no interaction. Fuel is typically fed by means of an auger and a rotary or hydraulic ram mechanism.


A very manual process which due to

the nature of how log boilers work,

it also requires a great deal more

infrastructure than a pellet or wood chip boiler. You should only consider log if you have your own consistent supply of good quality seasoned logs (ideally 1-2 years). Burning off-cuts and waste wood is unlikely to produce enough heat to be effective.


Logs have to be manually cut and

stacked into the boiler on a daily basis. Some customers choose to have a pellet module attached to their log boiler as a backup, but this system should be run on log the majority of the time.




One of our trained surveyors will visit to discuss your needs and to survey the site and system requirements. They will make a boiler recommendation based on your needs, fuel availability and space. They will talk you through the entire process, discuss how the equipment works, provide an indication of price and explain the RHI in detail.



Following our site survey we will send you a full proposal detailing the exact equipment, costs, scheme of works and any exceptions. It will also have our terms and conditions attached and payment terms. Once you are happy with the proposal, simply sign and return it to us and we book you in for installation.


If you require finance, be that personal, asset or corporate loan, then ask to speak to one of our Business Managers who would be happy to talk you through the options and arrange for a quotation to be sent to you.



We understand that you require as little disruption as possible during installation. We work closely with you to ensure that any interruption is kept to a minimum and the work is completed in the shortest possible time.



Our design team will prepare a full design specification of your system, and schematics for connection onto your existing heating system. Our designs will be presented to you so that you have a full understanding of the scope of




We commence any preparatory engineering work as quickly as practicable such as laying concrete bases or installing an underground heat main. Once complete, your biomass boiler will be delivered, located and installed to the highest quality standard. We pride ourselves on the quality of our work, and our installation teams are polite, courteous and respectful.



We show you how to operate and conduct occasional checks on your new biomass system. We also show you how to take meter readings (if required) for the Renewable heat Incentive.



We complete your RHI application to OFGEM for you, and show you how to submit readings online for RHI payments.



Along with our standard warranty package, we offer ongoing maintenance and servicing packages to ensure that your biomass system performs efficiently well into the future.

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