Energy from Waste – the good and the bad
Back in the early 1990’s, someone pointed out to me that at the end of the day, all waste is either buried or burned. I often reflect on this. Most recently when the BBC reported that waste incineration was now our dirtiest (most polluting) form of generating power. I wondered what we would do with our waste if this option didn’t exist. In the UK we have around 60 energy from waste (EfW) sites accepting about 16 million tonnes of waste in 2023 (Environmental Services Association). It contributes just over 3% of our total energy in the UK (BBC).
Why has this been called out as the dirtiest form of energy?
It probably is! Now that coal is no longer used to produce energy and our other energy sources include, wind, solar, anaerobic digestion, natural gas and nuclear. I confess that the cynic in me cannot get away from the fact that the proceeding news item was about the push for nuclear energy, but that’s for another day. But let’s put this into context. The main purpose of EfW is to provide one of the solutions for dealing with the roughly 125 million tonnes of waste we generate each year. As an alternative to landfilling. In doing so, the calorific value of that feedstock is converted into power and heat.
“Disposing of household-like residual waste in landfill, which is a mixture of biogenic and fossil-based materials, releases methane – a powerful greenhouse gas (GHG). An independent report produced by consulting engineers Fichtner, in 2021, estimated that the net GHG emissions of sending one tonne of typical residual waste to landfill is 432.7 kgCO2e. By comparison, Fichtner estimated that the net GHG emissions of sending one tonne of residual waste to conventional EfW is 230.9 kgCO2e. It is therefore estimated that EfW saves approximately 200kg CO2e for every tonne of waste treated compared with landfill. (Ref: ESA Statement on Energy from Waste).
What is the most sustainable solution?
In 1975 the European Union’s Waste Framework Directive came up with the concept of the waste hierarchy. Where, in order of most (1) to least sustainable (5) options were presented as an upside-down pyramid. In order these are:
- Prevention: Reducing the amount of waste generated.
- Reuse: Giving products a second life before they become waste.
- Recycling: Reprocessing waste materials into new products.
- Recovery: Recovering energy from waste, such as through incineration.
- Disposal: Safely disposing of waste to landfill
Clearly, not having the waste in the first place is the most sustainable solution. As no resources or energy are consumed from the outset. But if we have to have stuff. Then we have a responsibility for slowing down its inevitable end of life emissions to air, land or water, by reusing and recycling time and time again. But only so much recycling can be done and there will be the inevitable waste from the recycling process.
EfW has a place
It extracts the remaining energy, releasing GHG and leaving behind ash to be landfilled. It’s a delicate balance of conserving the energy. This follows Albert Eistein’s Law of Conservation which states “energy cannot be created or destroyed, but can only be converted from one form to another”.
In the 50 years since this concept was used, we have seen the increased use of recycling banks, and kerbside collection. Landfill tax has been increased year on year and biodegradable waste is diverted to composting, AD, or EfW. There are laws that make producers of packaging, batteries, electronic and electrical items, and tyres, pay for collection and recycling. There’s tax on single use plastic. Such rules have led to reduced material use, improved recyclability, innovative re-manufacturing of products and waste materials, leading to reduced carbon emissions.
Every household and every business has the power to make decisions about their waste. So if you are not a fan of EfW, look for ways to eliminate, reuse or recycle your waste.
Useful Links:
https://www.bbc.co.uk/news/articles/cp3wxgje5pwo
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