Biomass is the leading renewable fuel in the EU and with government plans to increase the amount in the UK’s energy mix, for many organisations the fuel provides a good green alternative to grid-fed energy.
Its growth has spurred legislation such as the EU Emissions Trading System and the UK government’s Renewable Heat Incentive. However, for some in the industry biomass removes valuable resources that could otherwise be used in the manufacture of panel products and different engineered solutions. For others the intensive farming and harvesting of ‘green’ wood with its own carbon footprint is seen as a negative impact that would otherwise not exist, despite arguments that it is a carbon neutral form of fuel.
There is an alternative to green or virgin wood though, in the form of pellets derived from waste or ‘life expired’ wood. Dalkia has been at the forefront of waste wood biomass for some years, developing this market alongside other renewable fuels for its customers and establishing a new business division, solely focused on the collection, storage and processing of large quantities of waste wood. This comes from construction sites, local authority waste transfer stations and the packaging and cabinetry industries.
Once it has processed the waste wood into pellets, Dalkia uses the biomass fuel in its own energy centres to produce clean, green energy. It also generates heat and power from biomass for community schemes and individual organisations. Customers benefit from a depth of expertise based on the provision of international energy services across 133,000 sites.
Offering significant benefits over traditional fossil fuels such as gas and oil, biomass is usually available at a lower cost and the technology offers different options, depending on the nature of the site and the pre-existing conditions. Therefore biomass can be used to fuel boilers, or it can be burnt in a combined heat and power plant – where the heat, which would normally be released as steam, is captured and put to use. No one solution suits all sites.
The efficiencies this type of onsite power production offers over standard grid-fed energy are the result of its proximity to the point of demand – less energy is lost in transmission over a much shorter distance – and, of course, the nature of the primary fuel source, which makes this an environmentally-sound option. In addition, it provides the customer with the opportunity to fix energy costs over a longer term, compared with fossil fuels which are subject to market fluctuations.
The benefits of biomass have pushed it into the limelight and in turn this has propelled its use across a whole host of sites that may not be ideal. This leads to frustration, because what is expected is not delivered. Such issues are caused by poor fuel quality, the wrong choice of boiler technology, lack of operation and maintenance and poor integration with a site’s existing energy plant.
A good understanding of the technology and its requirements is vital to ensuring it is properly specified and the desired results can be achieved. The financial savings need to be weighed up against the carbon reductions available and then offset against any incentives that might be available, depending on the organisation.
Site viability is a key consideration and this is where expertise from an energy company in the early planning stages can ensure the right solution is specified and installed, with proper operation and maintenance planned. Site and operations managers at production sites place a lot of expectation on biomass, yet it’s important that the premises lend themselves to the demands this creates, otherwise benefits won’t necessarily outweigh the costs.
The reality is that wood biomass requires space and lots of it. This is because frequent deliveries are needed, often in large articulated vehicles. Customers often overlook the day-today disruption this could cause. Then there is storage to consider – wood pellets need to be stored on site, either in a hopper connected to the energy centre, or very nearby. Access must be available at all times, which is not always possible, given the pressure for car parking and deliveries for core business functions.
Once spatial considerations have been covered it is then necessary to determine if the buildings themselves are suitable for conversion to biomass as the primary energy source. Where there is an existing low temperature hot water heating system, where the existing boilers need replacing or buildings are not connected to the mains gas supply – these are all factors that lend themselves to biomass conversion. However, where there is no existing waterborne heating system, conversion to biomass could be a more costly process.
Despite conversion, many sites retain an existing fossil fuel burner to provide peaking capacity during periods of higher demand and enable the biomass boiler to be specified to meet the base load. This allows the biomass boiler to operate within its modulation range for a greater part of the year, spending more time at a higher output and delivering the greatest efficiency.
With the right advice, many UK sites lend themselves to an onsite biomass energy conversion, but it is important that customers understand the physical requirements, aligned to their own expectations and cost versus carbon reduction targets, to ensure it is the right solution for them.
