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