Understand How Energy-from-Waste Works
Energy-from-Waste (EfW), or Waste-to-Energy (WTE) is a process that takes post-recycled municipal solid waste – including plain old household rubbish – and burns it at a high temperature to reduce its weight and volume, and to produce heat and/or electricity.
1. Municipal waste is delivered to our facilities and stored in a bunker.
2. The waste is transferred to a combustion chamber where self-sustaining combustion is maintained at extremely high temperatures. We maintain a negative pressure in the building around the tipping and bunker area and use this air in the combustion process to control odour.
3. The heat from the combustion process boils water.
4. & 5. The steam from the boiling water is used directly or, more frequently, the steam drives a turbine that generates electricity.
6. Electricity is distributed to the local grid.
7. Ash from combustion is processed to extract metal for recycling and to produce a secondary aggregate which is used in construction projects.
8. All gases are collected, filtered and cleaned before being emitted into the atmosphere. We manage gas from the combustion process with state-of-the-art air pollution control technology that is monitored to ensure it complies with rigorous air quality standards. Small quantities of residue arise from the air pollution control process and are sent for specialist treatment / landfill.
9. We control emissions of particulate matter primarily through a baghouse (fabric filter).
10. We monitor other pollutants and operating parameters to ensure compliance with permit conditions.
Using EfW technology will mean there will be:
- Less reliance upon landfill: this will preserve land and natural resources. EfW also helps to meet targets set in the Landfill Directive. EfW is a residual treatment (material that is not recycled or composted) and is not intended to replace recycling and composting schemes.
- Less dependence on imported fuels: 36% of the UK’s energy supply in 2011 was imported. For every tonne of waste processed in an EfW facility, we avoid the need to import over one barrel of oil or mine one third of a tonne of coal.
- Net Greenhouse Gas (GHG) Reduction: for every tonne of waste processed in an EfW facility, over 460kg of GHG is avoided.
- A sustainable source of renewable energy that can operate all year round: solar panels and wind turbines rely on certain weather conditions to operate, but EfW plants can run 24/7 throughout the year, producing energy classified as largely renewable.