Disposing of waste simply by incineration used to have a poor reputation with the public – it was the bad guy of waste management. Today, because of advanced techniques such as gasification, and strict emissions control, generating renewable energy from material that cannot be recycled (that is, destined for landfill) is seen as a responsible approach and a key component of renewable energy.
Changing perceptions about energy recovery from waste are partly being driven by the government objective of meeting 15 per cent the UK’s energy needs from renewable sources by 2020. It is anticipated that eight technologies will help achieve this. Five relate to renewable electricity, (offshore wind; onshore wind; hydro; solar; and biomass) and three to renewable heat and fuels (transport fuel; heat pumps; and biomass). The UK Renewable Energy Roadmap, Update 2013 reported overall renewable energy production at 4.2 per cent for 2012, up from 3.8 per cent in 2011. Renewable electricity was up 24 per cent, with its poor relation, heat and fuels, up 7 per cent. So we are on track, but there is still some way to go.
In the UK’s Renewable Energy Roadmap, the contribution of biomass for both electricity and heat is expected to be around 18 per cent of the total renewable target. This biomass comes from virgin material (wood, straw and crops from the UK and overseas), waste wood, household “black bag” waste, and commercial and industrial waste. The waste part of the biomass component, after recycling, will include some food and organic waste, film plastics, paper and card that is not recyclable and miscellaneous combustibles. The waste used as feedstock for energy from Waste (EfW) facilities is called refuse derived fuel (RDF). Anyone who has seen this material coming out of a modern waste processing facility would recognise that all the recyclable material has been effectively removed.
Ironically, while the UK is trying to increase renewable energy production we currently export around 1.5 million tonnes a year of RDF to Europe because the UK’s EfW infrastructure is not yet in place. These exports could produce enough renewable electricity to power 400,000 households. Similarly, there is around 4.5 million tonnes a year of waste wood feedstock available from construction and demolition, old kitchens, office and household furniture, etc, with various levels of contamination, paints, glues and resins. So there is plenty of fuel to be working on.
However, even allowing for government incentives, there is a pressing need for more EfW infrastructure. Building EfW facilities requires specialist skills and advanced technical competencies. MWH has been working in this area in Europe for nearly a decade and recently won the contract to build the Birmingham Bio Power gasification project in Tyseley, Birmingham. This 10.3MWe project is a good example of EfW by gasification. It will form part of the redevelopment of an existing industrial site and will use waste wood feedstock from a local business. The £47.8 million plant is the first of its kind in the UK to use the Canadian Nexterra gasification technology and it received £18.2 million from the Green Investment bank as part of the overall funding mix.
Key focus areas for MWH are smaller to medium size schemes of 5 to 25MWe. This is because this market segment covers many industrial businesses and the private developer market as part of a more distributed, and therefore local, energy network of facilities. Equally important, there is a serious appetite from investors for such sized projects. EfW is inherently more complex than other renewable technologies because of feedstock arrangements, technology selection, permitting and the funder’s requirements.
The main contractor has to understand and integrate component technologies to provide a fully working facility with guaranteed performance levels to support investment assumptions and financial risk modelling. They requires financial gravitas and a demonstrable project delivery capability. On the Birmingham scheme, in addition to design and construction of the facility, MWH will also operate and maintain the plant. This total service provision gives real security to many developers.