Waste to Energy

Waste-to-Energy in a Circular Economy: Friend or Foe?

technology, reuse, process, resource, reproduction, concept, recycle, protection, production, recycling, circular economy, nature, sustainability
© Miha Creative/stock.adobe.com

Circular economy – it seems to be the buzzword of the moment, circling across all industries. But what does it actually entail? According to the United Nations Industrial Development Organization (UNIDO), in a circular economy “materials for new products come from old products. As much as possible, everything is reused, re-manufactured or, as a last resort, recycled back into a raw material or used as a source of energy.”
It’s a way of looking at things differently. Instead of taking raw materials from the environment, turning them into products that ultimately end up back there, it’s much more about taking the waste from the end of the supply chain and putting it back in at the beginning. One could also say that it’s simply about being more thoughtful with the resources we have.
A circular economy is based on three principles: eliminate waste and pollution, circulate products and materials, and regenerate nature. It’s clear where waste management comes in here. Various stakeholders are already discussing strategies, implementing new rules and driving innovations. But one particular sector of the industry has a hard time selling its role to the public: waste-to-energy.

Emissions in focus

It may have started back in the 1960s and 1970s, when toxic dioxin emissions from waste-to-energy plants quite rightfully caused a scandal. “But since then, not only has the technology evolved, there are also very strict regulations implemented, especially in the European Union,” explains Johnny Stuen, technical director at the Waste-to-Energy Agency in the city of Oslo, Norway, and chair of the Energy Recovery working group of the International Solid Waste Association (ISWA). “Now the dioxin contribution of waste-to-energy amounts to 0.15% of all industrial emissions,” says Ella Stengler, managing director of the Confederation of European Waste-to-Energy Plants (CEWEP).
“Yes, the technology is good, but many locations are not measured. So, I would not recommend eating chicken eggs close to an incinerator,” retorts Janek Vähk, Climate, Energy and Air Pollution Programme Coordinator of NGO Zero Waste Europe, adding: “Waste-to-energy is a strategy to manage residual waste but the current incineration approach is no longer fit for circularity. The goal is to achieve net zero but the incinerators only add to the emissions.” Or as Piotr Barczak, Senior Policy Officer for Waste at the European Environmental Bureau (EEB), stated in a recent online discussion organised by the European Suppliers of Waste-to-Energy Technology (ESWET): “We are in the middle of a climate crisis. There is no margin left to build new CO2 emitters.”
So, what about the emissions of incinerators? Ella Stengler advocates a more holistic view. “Utilising waste as a resource helps to replace fossil fuels, such as coal, gas and oil. Moreover, the biogenic components included in the waste are considered carbon neutral. The energy created is used as electricity, heat and/or steam.” Also, waste-to-energy helps reduce methane emissions from landfills, which are even more harmful to the climate than CO2. “If you look at the life cycle, waste-to-energy is already carbon neutral.”

If you take a life cycle approach, waste-to-energy is already carbon neutral.
Ella Stengler, CEWEP

Divert waste from landfill

One of the major goals of the European Union in order to get to a more sustainable future is to reduce landfills to a minimum. The target for all EU members is to achieve a 10% landfill rate by 2035. “Waste-to-energy is an alternative to landfill and a final sink for waste that is not recyclable or reusable, thus fulfilling a hygienic task,” explains Johnny Stuen. “Landfills are dangerous places, whereas waste-to-energy in the EU is strictly regulated.” Hazardous waste that needs immediate safe treatment as well as waste that cannot be recycled because of contamination or composition may find its way into a waste-to-energy plant.
“Some countries depend heavily on landfills and it should not be the first thing. But our goal is to get better at sorting, drive up the recycling rates and put everything that cannot be recycled in sanitary landfill. Of course, we aim to minimise landfill but it is preferable to incineration,” argues Janek Vähk.
One point on which both sides agree is that no recyclable waste should end up in an incinerator. The problem: too many recyclables end up in the residual waste and too much recyclable waste is not recycled as yet. “I strongly advocate efficient source separation. This is essential for quality recycling. When we have to deal with mixed waste it’s already too late,” says Ella Stengler. Stuen agrees: “Waste-to-energy is not the solution by itself. Good sorting systems are essential. And we need a lot more sorting technology so no recyclable waste ends up in an incinerator.” A harmonised collection system might be helpful, according to Janek Vähk, “because it is very confusing what to put in what bin.”
“Waste-to-energy plants don’t have an influence on what they get to burn. Therefore, legislation is needed. They cannot reduce the waste by themselves,” says CEWEP’s Ella Stengler. But of course, just because selective collection is compulsory in the EU, this doesn’t mean that it is homogeneous throughout its territory.
A concern expressed by the EU and NGOs alike is related to the design of the plants. Driving up recycling rates – and in the best case scenario, recycling innovation especially for plastics – will result in a smaller amount of residual waste and therefore less material that may end up in an incinerator. “Should we significantly reduce waste generation, the waste-to-energy plants are flexible and can reduce their volume. But I wouldn’t shut them down just yet,” says Ella Stengler, also pointing to the change in waste that will be delivered to waste-to-energy plants in the future. “We will have less fossils in waste-to-energy thanks to better source separation. So more biogenic input and less fossil fuels will really make an impact.”
Another aspect Stengler stresses is independent heat production: “Europe is highly dependent on fossil fuels. Waste-to-energy can supply energy and so on a local level replace other energy sources and thus make us a little less dependent on other countries.”

Waste-to-energy is a strategy to manage residual waste but the current incineration approach is no longer fit for circularity.
Janek Vähk, Zero Waste Europe

Hindrance for recycling rates?

Another point made by opponents of waste-to-energy is that it hinders the increase of recycling. As for example Australia turns to waste-to-energy to deal with its recycling crisis, energy recovery projects seem to be favoured over the funding of recycling sites. “Some countries are excessively building incinerators. But that leads to conflicting targets. How do you reach 65% recycling and 10% landfill?” argues ZWE’s Janek Vähk. So, it is often seen as the easy way out. But it is not what stakeholders propagate.
“The countries with the highest waste-to-energy rates are also those with the highest recycling rates. It is a sign of a good waste management system,” says Johnny Stuen, pointing at data from Eurostat. This shows that in 2019, the leading country for recycling was Germany, with 67% of municipal waste either recycled or composted and 33% treated in a waste-to-energy plant (see graphic). Malta, with a 9% recycling or composting rate, is also 92% reliant on landfill.
However, a 2018 study by Italian scientists argues that in regions in a transitional phase (i.e. where separate waste collection is still not optimised), it is advisable to avoid the construction of thermochemical plants until separate waste collection has reached high and stable levels of efficiency.

Graphik Municipal Waste Treatment

Municipal Waste Treatment 2019. EU 27 plus Switzerland, Norway and the UK.

- © EU

Production of electricity not enough

Most experts agree that in order to play a sustainable role in a circular economy, waste-to-energy plants must not rely on electric-only production. Co- or better yet tri-generations seem preferable. In order to fulfil this role, the area where a new plant is built has to be considered carefully. If it is too remote from population centres and industry, the heat and steam it produces can hardly be used. Ella Stengler agrees: “Ideally a waste-to-energy plant is situated close to a potential client. There are already some very good examples where incinerators and industry work hand in hand.” (see Prime Examples)
Energy-intensive industries such as cement factories very often rely on waste-to-energy – but not only to use the energy from the plants. The bottom ash is a source for material recovery.
“Bottom ash is non-toxic so it can be used in various ways. You can take out the metals and recycle them. They have a much better climate footprint than virgin material,” explains Johny Stuen. The minerals from the bottom ash can be used in construction. “One third of the mineral part in Europe is used in standard land reclaiming such as roads and houses. It’s also used in the production of cement instead of sand and gravel.”
Nevertheless, the market for secondary raw materials is still in its infancy. CEWEP’s Ella Stengler is convinced that: “We need a stronger secondary raw material market. For that we need more incentives.”

The fly ash produced during combustion is another facet. “It’s toxic and must be treated as hazardous waste in special landfills. It contains zinc, lead, antimony and copper. But there are projects that work on treating the fly ash so that it can be reused,” Johnny Stuen explains.
Another area driving innovation is carbon capture and storage (CCS) and carbon capture and utilisation (CCU) (see debate in WMW 3/2021, p. 36-37). There are various pilot projects in the EU collecting data, as Fabio Poretti, Technical and Scientific Officer at CEWEP, explained at the ISWA conference last October. “In Oslo they are working on a feasibility study.”

Prime Examples

The ETS discussion

The EU Emissions Trade System (ETS) is currently being revised. Some, like Zero Waste Europe, advocate that waste-to-energy plants be included in the EU ETS, arguing it would encourage waste prevention and recycling, and generate climate and employment benefits. “A recent study concluded that the additional cost of incineration can act as an incentive for waste prevention and recycling, which will then become less costly than incineration,” Janek Vähk explains. “Furthermore, increasing recycling would create 7,000 extra jobs. Waste-to-energy doesn’t create that many jobs.”
Ella Stengler agrees that every sector has to make a contribution. “But to include waste-to-energy in the EU ETS is not the right way,” she says. “Landfilling is not integrated and is a lot cheaper than waste-to-energy. This causes counterproductive effects. We need to see the waste sector as a whole, not just the incinerators.” Waste-to-energy plants are part of an integrated waste management system, according to Stengler, whereas ETS is a market mechanism. “It should not be applied to the waste sector, which aims to reduce the impact of waste on the environment as much as possible. Denmark, Sweden and Lithuania have put waste-to-energy under the EU ETS but so far, a lot of money has been spent but no CO2 emissions saved.”

Landfills are dangerous places, whereas waste-to-energy in the EU is strictly regulated.
Johnny Stuen, Agency for Waste Mangement, Oslo

Better communication

Looking at all the discussions, one thing seems clear: waste-to-energy has a communications problem. “We need to do some myth-busting. Transparency is essential,” says Johnny Stuen. “We have to show people what comes in and what goes out of a waste-to-energy plant. Of course, there will always be opposition. But I’m convinced that it is so much better than landfill. Maybe we won’t need it forever. But as long as we have to get rid of non-recyclable waste, it is the safest option.” Ella Stengler agrees: “In an ideal world, there would be zero residual waste. But unfortunately, we do not live in an ideal world. And as long as there is residual waste, waste-to-energy is an important pillar to deal with it.”

One thing everyone can agree on is that we absolutely must produce less waste.