Energy Recovery

After giving a general outlook on Waste-to-Energy (WtE) in Europe, this article will present some good practice examples showing how in particular the treatment of residual waste in WtE plants fits into European resource efficiency strategy.

by Dr. Ella Stengler (CEWEP Confederation of European Waste to Energy Plants)

Outlook on WtE in Europe

Instead of being landfilled, the residual household and similar industrial and commercial waste that is not suitable for recycling is treated in WtE plants. It is a hygienic method of treating waste and reducing its volume by about 90%. At the same time the energy contained in the waste is recovered in the form of steam, heat or electricity depending on local demand. These basic facts show the important two fold role of WtE in waste management and energy systems.

In 2012, 456 WtE plants across Europe (EU28 + Norway and Switzerland) recovered energy, and prevented about 79 million tonnes of residual waste from being landfilled. About 50% of the energy produced by WtE plants comes from biodegradable biomass [1], providing low-carbon input into the energy system. This also helps to achieve the European Union’s (EU) policy for renewable energy sources to cover 20% of the whole energy consumption by 2020. The energy available from the amount of waste thermally treated in WtE plants in 2012 represents 32 billion kWh of electricity and 79 billion kWh heat. This is enough to supply 14 million inhabitants with low-carbon electricity and 14 million inhabitants with low-carbon heat. This en ergy is locally available and reduces import of fossil fuels. Furthermore, between 8 and 44 million tonnes of fossil fuels (gas, oil, hard coal and lignite) can be substituted annually, which would otherwise emit 22-43 million tonnes of CO2.

Providing affordable local energy

Supplying citizens and industry with cost-effective and reliable local energy is an important aspect with regard to Europe’s growth, security of energy supply as well as energy and climate goals, which are in the focus of the European Energy Union. This kind of energy is generated by WtE plants from waste that is not good enough for recycling.

In some European cities WtE plants cover 50% and more of the local heat demand - at a very cost-effective price. In Europe, recovered energy from waste for District Heating systems represents 50 TWh per year, i.e. around 10% of the total heat delivered through District Heating systems. Studies suggest that the potential for using heat from waste equals to 200 TWh per year by 2050, which means there are considerable opportunities for further development.

Furthermore, it is expected that DHC (District Heating and Cooling) will function as the backbone of smart cities. DHC will be used as infrastructure to provide efficient exchange and redistribution of energy, including better use of local resources like waste.

Transition from individual heating based on fossil fuels to a combination of more efficient, renewable and competitive energy supplies, incl. WtE, will improve air quality significantly.

Considering that in 2012 the EU 28 imported 106 billion m3 of natural gas from Russia (Eurostat), it is worth noting that the energy content of the waste treated by WtE plants in the EU equals to 19% of Russian gas imports (2012). And in 2020 it could reach even 33% of Russian gas imports, if non-recyclable waste is diverted from landfills to efficient WtE plants.

Energy efficiency in practice – WtE plants as suppliers of heat and steam

In many European cities WtE plants are connected to the local district heating networks providing low cost and sustainable energy. For example, in Paris, Brescia, Copenhagen and Malmö sustainable energy from waste covers more than 50% of heat demand [2].

In Europe, recovered energy from waste for district heating systems represents 50 TWh per year, i.e. around 10% of the total heat delivered through district heating systems. The Study Heat Roadmap Europe 2050 [3] suggests that the potential for using heat from waste equals to 200 TWh per year by 2050.

Residual waste represents a local, cost effective, secure and sustainable energy source which is already used in some District Heating and Cooling (DHC) systems across Europe, allowing them to deliver affordable energy and reducing primary energy consumption.

About 60% of the WtE plants across Europe are Combines Heat and Power (CHP), providing electricity through a steam turbine and then recovering heat with high efficiency for both district heating and steam supply to neighboring industries. Recovered energy from waste for DH systems represents 50 TWh per year, i.e. around 10% of the total heat delivered through DH systems.

A good example of the synergy between WtE and district heating can be found in Denmark. Since the oil crisis in the 1970’s great efforts have been made in Denmark to establish large district heating transmission networks in order to reduce the dependence on oil. WtE is a part of this policy as waste is a locally sourced fuel that, in addition to reducing the use of fossil fuels, contributes to increasing fuel independence.
One of the world’s largest district heating networks is the Copenhagen network that stretches more than 50 km from east to west. Three WtE plants supply heat to the same network and more than 50% of the total district heating in the Greater Copenhagen area is generated by waste.

The following two examples are coming from the Netherlands, where in 2013 almost 12% of all sustainable energy produced in the country was generated by WtE plants.

The supply of heat and steam by Twnece Hengelo WtE plant to local industry and local district heating systems won a 2013 Global District Energy Award in the category "Modernisation of existing networks”. The WtE plant of Twence, supplies steam to AkzoNobel’s salt-production plant via 1.5 km steam pipeline. Thanks to this pipeline, which delivers around 800.000 tonnes of steam per year AktoNobel managed to reduce their consumption of natural gas by 80 million cubic meters per year. Another pipeline connects the WtE plant to the local DH system of the city of Eschede and supplies around 180 GWh of heat which equals the heat consumption of 13.000 households. This allows the saving of natural gas of about 22.5 million cubic meters per year.

The AVR Rozenburg WtE plant supplies steam to industry located in the area of Rotterdam harbor and heat to the DH of Rotterdam. The WtE plant supplied in 2013 416 GWh of process steam to several industrial plants via an above-ground steam pipeline. The current DH system  - South Branch, length of 26 km, supplied in 2013, 416 GwH of heat for 50.000 households in Rotterdam. In 2015 a new DH pipeline – North Branch, length of 16 km, will aupply on a yearly basis around 972 GWh of heat to the city of Rotterdam, providing sustainable heat for 95.000 households.

The last example of the efficient use of resources comes from the north of Italy.

The A2A Brescia WtE plant delivers both electricity and heat through DH system, satisfying the energy needs of one third of the inhabitants of the city of Brescia. In 2013, the WtE plant supplied 561 GWh of electricity and 805 GWh of heat for district heating. This represents fossil fuel savings of about 150.000 toe (tonnes of oil equivalent) and avoid 400.000 tonnes of CO2-emissions. It is worth noting that in the city of Brescia the WtE plant delivers 68% of the local district heating demand.

The examples presented above demonstrated well the general trend in the WtE sector – strong focus on achieving high energy efficiency and providing substantial results for the local industry and communities.


References:

1. European Commission, Directive 2009/28/EC on energy from renewable sources, www.eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32009L0028&from=EN (16.12.2014).

2. CEWEP, ESWET, EHP, DHC+, Warmth from Waste: A Win-Win Synergy, April 2014, www.cewep.eu/information/energyclimate/warmthfromwaste/1115.Warmth_from_Waste_A_Win-Win_Synergy.html (16.12.2014).

3. Heat Roadmap Europe 2050 (Second pre-study for the EU27), May 2013, http:// [...]

 

 


published: , 12|1990
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