Energy from waste
This section covers energy from waste (EfW) technologies and the processes used for heat or electricity generation, or sometimes both.
- Why use energy from waste?
- Cost and funding
- Project timescales
- How and where energy from waste works
- Practical issues
- Case studies
- Links to further information
Why use energy from waste?
- It has a key role to play in the hierarchy of waste treatment.
- It often produces a secondary fuel and by-products are produced which can then be used commercially.
- It deals with waste streams that cannot be minimised, recycled or otherwise dealt with. This type of waste will always exist no matter how successful waste reduction schemes are.
- It reduces the waste sent to landfill site. This avoids landfill tax and penalties for exceeding limits on landfill and failing to provide alternative waste disposal methods.
- It reduces emissions of the powerful greenhouse gas methane by reducing landfill.
Cost and funding
The cost of producing energy from waste is complex and depends on many factors. According to figures prepared by WRAP in 2008 capital costs can be expected to vary from:
- £7,747 per kWth installed capacity for incineration to
- £8,750 per kWth for anaerobic digestion.
The ‘Cost and Funding for EfW' page provides more detailed information about costs, payback periods and funding mechanisms.
Timescales for delivering projects vary widely, but on average are likely to be in the region of three to five years. Several factors will influence the timescales including the:
- size of the plant will determine which type of planning consent is required.
- type of plant will determine if Environmental Impact Assessment (EIA) and Environmental Permitting are required and the length of public consultations needed.
- type of fuel required and the ability to secure supply contracts.
- need for any additional infrastructure, for example, a heat network.
How and where energy from waste works
Energy from waste produces energy directly through combustion, or produces a combustible fuel through a chemical process. Secondary by-products are often produced which have additional uses. For example, the ash from incineration is used in construction materials.
There are two categories of energy generation: incineration; and mechanical or biological treatment (MBT). These different technologies regularly work in conjunction with one another. The diagrams below show how both technologies work to produce electricity, heat, biogas and fertiliser.
The fuel for these technologies comes from all types of waste, except inert waste.
- wood residues
- crop wastes, including straw
- animal waste, including manure, sewage sludge and poultry litter
- municipal solid waste
- landfill gas
- commercial waste.
The processes for producing energy from waste and information about identifying opportunities for these technologies is available on the examples of 'How energy from waste works' page.
There are practical issues to consider for different scales and applications of energy from waste. See ‘Practical issues for EfW' for more information. This includes information on the planning permission needed for these projects.
Here are some examples of how some councils are already using energy from waste:
Links to further information
‘Planning for waste management facilities: A research study' (2004) - on the Department of Communities and Local Government website
Energy from Waste - on the Environment Agency website
31 January 2011