Do you want chips with that?
Sales of biomass boilers are soaring. Yet, the technology needs careful consideration if you are to reap the rewards of lower fuel bills and carbon savings. Mark Northcott, managing director at Remeha Commercial, gives some pointers to a successful installation.
Biomass boilers are in favour. This is not surprising given the outstanding carbon savings on offer from biomass, reduced fuel bills due to the relatively low price of woodchip and pellets and the tempting carrots on offer from the forthcoming Renewable Heat Incentive (RHI). Yet, despite these benefits, biomass boiler installations are not without their pitfalls and they will not be the perfect solution for all applications.
The RHI will certainly encourage consideration of this tried and tested technology. While the legislation is still to be enacted in parliament, the proposed tariffs have been announced. Any local authority is going to be tempted by the offer of a sum up to 7.9 p/kWh of heat generated. Even without this incentive, Remeha has found that biomass installations using woodchips or pellets will achieve rapid payback on investment. The Carbon Trust has produced case study evidence that shows paybacks ranging from just 2.9 years through to 4.7 years due to the lower costs for wood over other fuels. Payback times will fall once the tariffs offered by the RHI kick in.
Biomass boilers are outstanding performers in terms of reducing carbon emissions. Burning wood simply releases the CO2 that was absorbed during the tree’s growth, keeping the level of carbon at an equilibrium when those trees are regrown. Using solid biomass for heating typically gives reductions in carbon emissions of around 90% in comparison to using fossil fuel heating systems. The Carbon Trust reports that CO2 emissions for woodchip biomass range from 10-23 kg CO2/MWh. This compares with 263-302 kgCO2/MWh for natural gas.
Availability should not be an issue for most applications but it needs consideration as sourcing fuels can be difficult in certain areas of the UK. The Forestry Commission estimates that an additional 2 million tonnes of wood could be harvested from currently under-managed UK woodlands by 2020, representing half of the available, currently unharvested, material in English woodlands. The Carbon Trust states that sufficient UK woodfuel resources exist to supply a large number of new biomass heating systems.
Fuel storage and delivery needs to be considered also. Fuel can be stored in dedicated storage facilities (either above or below ground), in integrated facilities within existing buildings, or in removable storage containers. If there is no readily-available local supply, haulage costs could prove prohibitive.
A biomass boiler is best suited to being operated relatively continuously (between around 30% and 100% of its rated output). This means that a fossil fuel system is often specified in addition to the biomass boiler to manage peak loads. Biomass boilers are considerably larger in volume than an equivalently rated fossil-fuel plant due to the combustion characteristics of solid, organic materials. Buildings where the heating system is used for long periods during the year, such as swimming pools, hospitals etc offer conditions more suited to biomass boilers than general occupancy buildings such as offices, for example.
Periodic removal of ash and cleaning of heat exchanger surfaces will be no different to the operation and maintenance (O&M) requirements of other solid fuel systems. Look for a manufacturer that offers automated de-ashing and heat exchanger cleaning mechanisms. Even with the best equipment, biomass systems do require more looking after than oil or gas-fired systems. For a typical biomass installation, the time needed for on-site staff may be around 0.5 to 1.5 days per month but this can come down with experience.
Certainly, biomass has a bright future. Remeha is well versed in all aspects of supplying biomass boilers, often in conjunction with our eco-friendly, low NOx commercial gas boiler ranges. Whatever your requirements, Remeha has the perfect solution to match.
The chips are up at Ringmer Community College
Where better to learn about sustainability than at school? Award-winning eco-college Ringmer Community College has updated its heating system by installing a state-of-the-art, 450kW Remeha-Gilles biomass boiler.
Fuelled by wood chips, the biomass boiler runs alongside a 200 kW gas boiler. Consideration has been given to fuel storage, with two containers situated in a purpose-built area next to the boiler. The containers last approximately two weeks and can be taken out and restocked.
So what advice would Stephen Green at Ringmer Community College in East Sussex give other schools and colleges looking to invest in biomass technology?
Fuel – investigate how to source your woodchip or pellet before installing your boiler. Make sure it is easy to source and that your supply is good quality, reliable, sustainable and local – that way you avoid incurring huge haulage costs.
Choose the correct boiler – we have found the Remeha-Gilles boiler to be an extremely sophisticated and effective boiler operating at outstanding efficiency levels.
Identify the support offered by the boiler manufacturer/installer – they need to guarantee adequate support in your area. We received back-up from Remeha along the way and our installers are operating the boiler alongside us for the first year making it a learning curve for us all.
The wood chip fuelled boiler is playing an important part in helping Ringmer Community College reach its target of reducing its carbon input by 300 tonnes and its energy usage by 15 per cent this year. However, biomass is currently just slightly more expensive to run at present than a gas boiler. This is due to the artificially-subsided rate of gas available to us, which is fixed by the LA. These rates are now due for reassessment, after which we anticipate that our fuel price will be on a par with gas or lower – and that’s not taking into account the RHI tariff payments.
The major investment for a school or college is installing the biomass boiler, although as the demand grows the costs will come down and become more competitive. One thing’s for sure, we certainly haven’t looked back.
Related Industry News