Energy from Waste: Asking the right questions

Energy from Waste: Asking the right questions
17 July 2017

If we don’t ask the right questions, then we will never get what we need - or want!

As a child, I remember being told several pertinent statements by my father when I tried to explain that I wanted to attend a  party at a friend’s house.

“That’s not the question you asked”, he would say. “If you don’t want to hear the answer, then don’t ask the question”. “If you ask the right questions, then you might actually get the answer you are looking for”.

Having recently been invited to deliver a keynote at an Energy from Waste conference in Adelaide I have been asked to help set the scene on understanding where energy from waste sits in a circular economy strategy. I find myself becoming my father and asking the same questions of the industry as it seeks to get bankable Energy from Waste facilities off the ground.

What probably concerns me most, is that the right questions are not always asked. Instead we are quickly drawn into the long-standing debate of whether Energy from Waste is good or bad. Instead policy makers and the waste professionals should be clear on what do we mean by Energy from Waste and where does it fit in addressing some of society’s immediate challenges.

Energy from Waste – Good or Bad?

Like most points of contention there are strong views on either side of the debate and  convincing arguments for both sides.

In my opinion, it comes down to thinking about what questions we ask and making sure we ask the right questions. Is “waste to energy good or bad” is certainly the wrong question!

Instead questions such as “what is the feedstock?” and “what baseload energy source is it replacing?” are far more practical. “How developed are the other systems to target the collection of recyclables more upstream?” is another question that industry needs to be asking. With over 1,000 successfully operational waste to energy facilities across the world, surely it can’t be a bad solution. Instead, it is more about understanding the context in which they operate and the problem they are addressing?

Mass burn incineration is a robust and proven technology operating across the world to manage residual waste which would have otherwise gone to landfill potentially causing even more environmental implications (e.g. generation of methane and production of leachate).  In economies that are otherwise reliant on an energy baseload dominated by energy production from coal, oil or gas with no space for landfill, then Energy from Waste is the best out of a bad set of alternatives.

But that does not mean Energy from Waste across the board is a positive renewable energy solution. With only 35% conversion efficiency, mass burn incineration is primarily a waste management solution (especially in power only mode), and there are more effective ways of generating electricity. If the facility is displacing a renewable baseload such as wind or solar then the case struggles to stack up.   

As a thought, while landfills often get the worse end of the deal, they do offer a flexible solution in some communities where conditions allow. If the waste is not decomposing and releasing emissions into the air or water, then arguably they are simply a storage point for future resource extraction. For example, while my preference would be to eliminate plastics altogether from the material stream, as it is without question that plastics are here to stay at least in the short term. It is better to manage plastic waste by landfill rather than burning it, where it is not recycled. Burning plastic is essentially no better than burning oil.    

As we begin to explore these issues, the suitability of Energy from Waste as opposed to other options starts to focus more around the question “are you trying to solve a waste problem or solve an energy problem?” Saying you are trying to do both is not an informed answer.

If the feedstock is very organic rich, then it makes sense to separate it out for Anaerobic Digestion (and energy production) or composting, although this makes the residual element even more fossil fuel based, especially if removing non-combustible recyclables such as glass and metal. What is then the most appropriate solution to manage the residual waste?

So what is the role of Energy from Waste in a Circular Economy?

I often hear comments of how Waste to Energy has a key role to play in a circular economy, which I tend to struggle with; not least because energy from waste is a linear and not a circular solution. In most, if not all of the numerous diagrams on what the circular economy represents, residual waste that goes to landfill or incineration (operating in power only or CHP mode) is regarded as ‘leakage’.

The same is not of course true for the bio-economy and energy generated from biofuels and renewable feedstocks, or energy from Anaerobic Digestion processed from food waste from separate kerbside collections.

If we stick with the word ‘leakage’ for a moment, then, in its purist sense, waste to energy does not have a role in the circular economy in the long term. Like any leak, you seek to fix it and stop it as soon as possible.

It is also worth remembering at this point that we don’t generate residual waste. Residual waste is a by-product and therefore a failure in the rest of the resource management system. Shouldn’t we be seeking to reduce or eliminate thermal treatment capacity rather than increasing it? Given the Guaranteed Minimum Tonnage (GMT) demands on facilities to remain financial viability over the life of their contracts, if not careful Energy from Waste facilities could quite simply compete with the objectives of a circular economy, either directly or indirectly in pursuit of more sustainable options higher up the waste hierarchy. Let’s be honest, if the circular economy succeeds, we won’t need mass burn combined heat and power or refuse derived fuel plants and  there would be no waste to manage.           

In reality, the total elimination of waste is unlikely, and we will need to manage residual waste in its original form or as a processed fuel for a long time to come. But the rationale for these facilities is different depending on location and the environment in which they operate. For example, the rationale for CHP in Sweden is very different to CHP in Australia. The debate then quickly moves into what solution and why. Energy from Waste is almost the last option on the waste hierarchy (and some would argue it should be at the bottom!). Therefore, having the right Energy from Waste solution that is in harmony with its local surroundings and requirements and not prohibitive to future initiatives within the procuring authority area (and neighbouring areas) to manage waste is critical.       

So what are the right questions to ask?

Without going around in a circle, this depends on the answer you are trying to achieve. But there are many questions that should be asked when considering Energy from Waste. The opportunities or implications of any investment decisions are likely to go well beyond the problems of today. They will have implications on what is done far out into the future, where we may then be trying to address waste and environmental problems that we don’t yet know exist. Some of these typical questions could include:

  • What is the composition of the waste you are burning?
  • What baseload energy source is the Energy from Waste facility replacing?
  • What is the purpose of the proposed facility (i.e. to meet the needs of an energy strategy or a waste disposal solution)?
  • Is the solution robust enough to manage variations in feedstock composition as upstream policy measures are implemented?
  • Is their security of supply over the duration of the facility even if waste volumes are reduced?
  • How does a solution compliment rather than compete with upstream policy?
  • Are their suitable co-locations, clear site ownership, informed stakeholders, suitable funding support?
  • How can a staged approach be taken using smaller, incremental facilities given the uncertainty of future waste volumes?

The list of questions goes on. Let’s start to ask the right questions and have the right debate to inform the right holistic solutions; and let’s move away from is “Energy from Waste good or bad?”. There is no simple answer - what was the question again?

All ‘comments’ are mine and mine alone. If you would like to get in touch or share your opinions, then email me on I will be in Australia from 24th July to 4th August and would be happy to discuss this conundrum with  you. I am presenting at the Unpacking Energy from Waste conference on Monday 31st July at the Crowne Plaza, Adelaide.

Darren is an Associate Director for Ricardo Energy & Environment’s Resource Efficiency and Waste Management Practice, and is a Member of the Chartered Institution of Wastes Management. He has over 18 years of waste sector strategy, service design, waste technology and communications experience, both in the UK and overseas.