Photo: DTU

Waste imports detrimental to climate in the long term

Energi
A new DTU analysis indicates that in the long term, Danish CHP plants should be exclusively sized for Danish waste volumes.

Even though imported waste for incineration has become good business for Danish CHP plants, this should not be a future focus area for Denmark, says Marie Münster, Professor, DTU Management Engineering.

Together with PhD student Amalia Rosa Pizarro Alonso, she has just completed a comprehensive analysis in close collaboration with Ciprian Cimpan, postdoc from the University of Southern Denmark, examining whether it will continue to be feasible economically and beneficial to the climate to import waste.

“We examined thousands of scenarios and life cycle analyses involving multiple variables, such as alternative waste treatment, transport, waste quality and different energy systems. And the conclusion is that in the long term, the climate footprint does not justify importing combustible waste to Denmark, even though it may still be economically profitable,” states Marie.

Waste imports benefit climate today
She explains that right now, importing makes good sense. This is because foreign waste equals cheaper district heating, as the capacity of large CHP plants is fully utilized. Currently, several Danish plants actually have problems obtaining enough waste from Danes to utilize their capacity.

“At the moment, this is also beneficial to the climate, as many large plants would otherwise burn fossil fuels to meet their power demand. Furthermore, the originating countries for the imports predominantly process their waste in a less climate-friendly way,” explains Marie.

"In the long term, the climate footprint does not justify importing combustible waste to Denmark"
Professor Marie Münster, DTU Management Engineering

Future focus on smaller plants
However, according to the researchers’ analysis, a breaking point will be reached in about ten years when the climate no longer benefits from importing waste for energy conversion, because our energy sources are becoming better and cleaner.

“Although our analysis shows that importing will continue to be profitable, the long-term focus should be on constructing plants that are sized for Danish waste volumes. Because in just ten years, waste imports will only benefit the climate in very few cases,” says Marie.

An example is if the waste would otherwise be deposited in an old-fashioned landfill, lying around and emitting gases, or if it is incinerated exclusively for electricity generation, repressing cleaner energy sources.

In addition, the analysis points to waste volumes in Denmark not changing.

“Historically, the waste volumes are closely connected with the economic development, and if we look at the Ministry of Finance projections, the same volumes will be available for incineration, after sorting for recycling, in 2035 as in 2014,” explains Marie.

Analyses

The links to the analyses show only abstracts. Interested parties may contact Professor Münster directly for the full text.


The climate footprint of imports of combustible waste in systems with high shares of district heating and variable renewable energy. Pizarro Alonso, Amalia Rosa; Cimpan, Ciprian; Münster, Marie. In Waste Management, 2018.


The economic value of imports of combustible waste in systems with high shares of district heating and variable renewable energy. Pizarro Alonso, Amalia Rosa; Cimpan, Ciprian; Ljunggren Söderman, Maria; Ravn, Hans V.; Münster, Marie. In Waste Management, 2018.