Is there a future for biomass boilers?

Dec 31, 2011 | Heat Transfer

As businesses are targeted to reduce their carbon output by at least 2% year on year, so more and more should be turning to renewable sources of fuel such as biomass to generate energy. Tony Green, sales and marketing director of Byworth Boilers, assesses the current situation

We may have seen a change in government but it is clear if the UK is to meet its commitment to reducing CO2 emissions in the next decade and beyond then the coalition’s policy on renewable energy needs to remain as firm as ever.

Equally, as businesses are targeted to reduce their carbon output by at least 2% year on year, so more and more should be turning to renewable sources of fuel such as biomass to generate energy. But are they?

Certainly the technology is in place within Europe and like most forward looking industries the UK boiler industry is keen to react positively and encourage the use of UK manufactured boiler plant that can convert biomass fuels into both steam and hot water.

Defining biomass

Biomass fuels generate energy by burning readily available renewable sources such as food crop residues, certain grassy plants, wood and animal matters. These sources may include:

• Wheat, oats, barley and oilseed cake waste after harvesting;

• Willow, poplar and miscanthus grassy residues;

• Forestry trimmings, wood processing and straw waste.

Wood products such as chip and pellets remain the most commonly used biomass fuels and are readily available all over Britain. In Europe, particularly in Scandinavian countries with their vast expanse of forests, wood chip is the preferred fuel.

In the UK, which is currently a developing market for biomass boilers, both wood chip and wood pellets are the main biomass resources.

Industrial biomass boilers

While acceptance of domestic and light commercial biomass boilers is on the increase, a number of factors stand in the way of the development of their industrial counterparts.

Compared to conventional industrial boilers the biomass equivalent takes up considerably more space in the boiler house.

This is mainly due to the extra fuel handling equipment and sophisticated filter system that is required. For example, the stoker that replaces the burner is much larger as is the hopper needed to store the material. Currently in the UK wood pellets are the ­preferred fuel option as they have a relatively low moisture content (approximately 10%).

Chip contains higher levels of moisture (approximately 30-50%) which can cause problems in handling/feeding equipment.

Pelleting however makes pellets far more expensive – in the region of £130 per tonne compared to £50 per tonne for chip. Pellets also work out at approximately 30% more than the price of or gas. Increased maintenance costs also enter the equation. A biomass boiler with a stoker has more mechanical parts which inevitably leads to additional time and expense spent on upkeep.

The additional equipment needed inevitably impacts on manufacturing costs which in turn affects the purchase price of the boiler. A biomass boiler is around double the cost of a standard steam or hot water unit.

Until industrial biomass boilers become more commonplace and manufacturing techniques evolve, this difference is likely to remain.

Given that in recent years emission levels on conventional boilers have reduced dramatically and the fact that few large biomass boilers are actually out there working day in and day out, very little comparable data is available although initial results are encouraging. The Environmental Agency is being extremely cautious on the subject. It is no wonder therefore, without proven data on emissions savings, industry is sitting on the fence.

Government incentives

Without doubt Government incentives will be key to the future of industrial biomass boilers. The Government has just announced the much anticipated renewable heat incentive (RHI) tariffs which will reduce running costs by providing rebates for energy users from 1.9-7.6 pence per kWh depending on the thermal output of the customer’s plant.

The tariffs will be available over 20 years with annual adjustments for inflation and commence once the scheme has Parliamentary approval. Installations commissioned after 15 July 2009 could be eligible. Hopefully this new incentive could prove to be the game changer the industry has been waiting for.

Are industrial biomass boilers the future? Despite all the difficulties Byworth Boilers is seeing an increase in enquiries and new biomass boilers are being commissioned. Basically the answer lies with the Government and the subsidies they make available.

In today’s economical climate and with all the noises currently emanating from Westminster on cost-cutting, viability looks to be some way down the line. In days gone by before coal, oil and gas, wood was the main fuel source. Perhaps we have now come full circle. Certainly, if we are to avoid serious environmental consequences we need to be considering different alternatives and biomass is definitely one of those options.