Energy recovery
From skip to socket: how leftover waste becomes electricity
Not everything can be recycled. What's left after sorting is baled as fuel and used to generate electricity instead of going to landfill.
Even after careful sorting, some of what arrives in a skip can't be recycled: mixed scraps of plastic, textiles, dirty paper and other odds and ends. Years ago that went to landfill. Today we bale it as fuel, and it is used to generate electricity.
What is refuse derived fuel?
Refuse derived fuel, or RDF, is the burnable part of waste that is left once the recyclable materials have been taken out. At our facilities it is baled and wrapped so it can be transported cleanly, then sent to waste-to-energy plants.
How it becomes electricity
- The fuel is burned in a furnace at high temperature under tightly controlled conditions.
- The heat turns water into steam.
- The steam drives a turbine, which generates electricity for the grid. Some plants also supply the leftover heat to nearby buildings.
- The gases are cleaned before release, metals are recovered from the ash, and much of the ash is reused as aggregate.
How much power does it make?
More than most people expect. According to Tolvik Consulting's annual review, energy from waste plants in the UK processed about 16.8 million tonnes of waste in 2024 and exported around 10,000 GWh of electricity, roughly 3.6% of the UK's net power generation.
Why not just landfill it?
Waste is managed in an order of preference known as the waste hierarchy: prevent it, reuse it, recycle it, recover energy from it, and only then dispose of it. Energy recovery sits above landfill because the waste does something useful, and because rotting waste in landfill gives off methane, a powerful greenhouse gas.
Recycling still comes first, which is why we sort every load before anything is baled as fuel. Our aim is to send nothing to landfill at all: see what happens to the waste in your skip.