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Powering the 21st Century Jan/Feb 2016
Issue 1
How renewables
are revitalizing
district heating
What’s in store for
the global gas engine
market
Award-winning
decentralized
energy projects
Inside Germany’s
benchmark
cogeneration plant
District heating
TIMES ARE
CHANGING
FOR DISTRICT
HEATING
As recently as a few years ago, politicians in the Netherlands saw district
heating as old-fashioned – but it is gaining in popularity as it enables the
distribution of both renewables and surplus heat,
writes Klaas de Jong
T
heating grid. Illustrative of the change is the northern city
of Groningen, the European capital of natural gas, which
will start this year with a heating grid for at least 11,000
houses. Deep geothermal heat from well at the Zernike
university campus will be the main heat source.
New initiatives
The Dutch government’s new policy towards district
heating did not come as a total surprise. Several new
initiatives across the country showed in practice that
district heating is a feasible and sustainable alternative to
the so-dominant Dutch gas infrastructure.
The eye-catchers are activities in the cities of
Rotterdam and Amsterdam. The growth of district heating
in these cities is an inspiration for the rest of the country.
The province of South Holland is developing a provincial
grid with connections between the cities of Rotterdam,
The Hague, Schiedam, Delft, Leiden and Dordrecht
and the horticulture areas Westland and B-triangle. In
2015, Amsterdam followed by founding a coalition for a
metropolitan heating grid.
In the eastern part of the Netherlands, the cities of
Arnhem and Nijmegen are realising an inter-city district
Gas-fired cogeneration or renewables
Large power stations have traditionally been the main
source for district heating. The existence of district
heating in the big cities of Rotterdam, Amsterdam,
Utrecht and The Hague was due to the presence of gasfired power plants, and a coal-fired power plant owned
by RWE Essent which supplied the cities of Tilburg and
Breda. In several new urban areas, district heating has
been implemented with combined heat and power (CHP)
units as the main heat producers.
The big price difference between coal and natural gas
and the growth of renewable electricity (mainly imported
from Germany) dramatically changed the electricity market
in the Netherlands. Existing gas-fired power plants and
CHP plants drastically reduced their operating hours in
order to minimize financial losses. At NUON’s (Vattenfall)
new high efficiency gas-fired cogeneration plant in Diemen,
a large heat storage tank was installed in 2015 to enable
heat delivery for up to 48 hours without running the gas
turbines. Heat storage is necessary for flexible operation on
the electricity market without losing heat.
However, in general, gas-fired cogeneration is in big
trouble in the Netherlands. There is no governmental
support, and Dutch politicians accept the loss of efficiency
due to a reduction in operating hours or even mothballing
of cogeneration plants and CHP units. Their only interest
seems to be in renewable energy.
For district heating, however, renewable energy was
not bad news in the end. In 2012 the Dutch government
decided to support renewable heat. Just as for renewable
imes are changing in the Netherlands. Henk
Kamp, the Dutch minister of the Department
of Economic Affairs, limited the production of
natural gas in Groningen to 27 billion cubic
metres in 2016. That is only half the production of the
top year, 2013. Earthquakes in the Groningen area were
the reason for these restrictions. At the same time, Kamp
presented a vision for heating in which he suggested that
natural gas grids could be replaced by district heating
grids – a remarkable change of policy.
A few years ago Dutch politicians regarded district
heating as old-fashioned, but nowadays it is becoming
popular because it enables the distribution of both
renewable and surplus heat. In 2008 Warmtenetwerk, the
Dutch association for district heating, was founded. This
association, now with 200 Dutch and Flemish members,
plays an important role in the changing image of district
heating.
Reprinted from the January/February 2016 edition of DECENTRALIZED ENERGY
Copyright 2016 by PennWell Corporation
Rotterdam’s ‘vertical city’ complex
Credit: Ossip van Duivenbode
District heating
The 850-metre transport pipeline to drilling in Rotterdam
Credit: Leen van Blois/V S Hanab
electricity, producers of heat receive a fee per unit of energy. This
programme, called SDE+, proved to be very successful. It resulted in
several new district heating schemes, but also in a changeover from
cogeneration to renewable heat sources on existing grids.
SDE+ operates on the basis of competition per unit of energy. By
doing so, the government hopes to achieve the maximum amount of
renewable energy production for the lowest costs. As renewable heat
is much cheaper than renewable electricity, since 2012 the main part
of the SDE+ budget has gone to heat generation.
Waste-to-energy is now the main heat supplier
Rotterdam and Enschede recently changed from gas-fired
cogeneration to waste incineration plants. In the cities of Amsterdam,
Alkmaar, Nijmegen and Arnhem the heating grids are being extended
on a large scale thanks to the availability of heat from waste-toenergy plants.
The old city of Dordrecht decided a few years ago to realize a
district heating grid for some 10,000 houses in existing city areas. The
main reason for this decision was the availability of heat at the HVC
waste-to-energy plant.
The heat from a waste-to-energy plant is regarded as 50%
renewable according to EU regulations. This is important because the
Netherlands has promised to achieve a 14% share of renewables in
its total energy consumption by 2020, but in 2015 it was still only less
than 5%. The Dutch government has therefore strongly increased its
support for renewable heat – and this support is a key factor for the
development of new heating grids.
The owners of the waste incinerator are happy with the
developments in district heating. The generation of electricity is not
very profitable. In the night hours the price of electricity is extremely
low nowadays. Selling heat makes sense, while in the past plant
owners focused on maximum power production.
Several new grids thanks to deep geothermal
In 2007, tomato grower Rick van den Bosch had the guts to drill
first for deep geothermal heat in the Netherlands. His well proved
successful, and others followed. At the start of 2016 there are more
than a dozen deep wells in operation.
Up to now, all the owners of geothermal wells have been
agricultural companies with large greenhouses. The thermal power
of the deep wells (two to three km deep) even makes it attractive for
the big horticultural companies to distribute heat to other consumers.
This has resulted in eight new heating grids in horticultural areas.
The largest project is Agriport A7, which features a double well with a
total capacity of 26 MWth and a grid that connects eight greenhouse
companies to the wells.
The horticulturist Ammerlaan in the village of Pijnacker came
up with the idea of selling heat from his well to homes and public
buildings. After connecting a school building, the municipal
swimming pool and some offices to his well, Ammerlaan starts this
year with heat delivery to some 500 apartments. Ammerlaan not only
grows and sells plants, but is now an operator of a heating grid and
sends bills to consumers for heat!
Groningen will be the first city to incorporate deep geothermal
District heating
Meerhoven wood-fired cogeneration plant, Eindhoven
Credit: Peter de Kong
heat on a large scale in an urban area. An earlier project in The Hague
failed due to the financial crisis.
In 2015 the Dutch government rewarded four initiatives for deep
geothermal heat with financial support. The expectation is that,
in 2016, there will be new applicants in the SDE+ for geothermal
projects.
Bio-heat
The share of biomass in the fuel for waste-to-energy plants is 50% in
Europe. But apart from this, waste wood has also become a source of
energy for district heating.
Thanks to governmental support for renewable energy, there are
now several district heating plants delivering bio-heat generated by
wood boilers, and cogeneration plants fuelled by wood or biogas.
The new De Purmer plant in the city of Purmerend is the largest in
the Netherlands. The plant was commissioned in 2015 and utilises
wood chips from the Forestry Commission (Staatsbosbeheer). The
total heating capacity of the installed wood boilers is 44 MWth. The
De Purmer heating plant is owned by the municipality of Purmerend,
which also owns the district heating grid. Purmerend has the highest
market penetration for district heat of all Dutch cities, with the grid
connected to 70% of the buildings.
The municipality of Eindhoven is also a front-runner in the field of
biofuel-based district heat. The city council is now building its third
wood-fired cogeneration plant at the site of a former Philips factory.
The decision to build new plants is due to the successful operation of
the first plant. This wood-fired cogeneration plant, which produces
1 MWe and 5.6 MWth for the Meerhoven housing area, operates for
around 8400 hours per year and produces quite nice financial results.
Bio-based heat enables the development of small-scale heating
grids as well. Examples include a grid for 300 houses in the city
of Zwolle, a grid for the village of Marum and an industrial area in
Hengelo with an Eaton factory as its main customer. In these projects,
wood-fired boilers are the main heat source. A peculiar example is the
new Polderwijk housing area in Zeewolde, which features a heating
grid for 1200 houses. A dairy farmer supplies the heat from a CHP
system running on biogas, which is transported through a pipeline
from the farm to the plant at the Polderwijk.
Masters in horizontal drilling
Dutch contractors have showcased their skills in some ambitious
district heating projects.
The heat transport pipe from the AVR waste-to-energy plant at the
isle of Rozenburg to the centre of Rotterdam was probably the most
challenging. The route is 25 km in length and crosses several large
waterways, railways and important motorways. To overcome these
obstacles, contractor Visser & Smit Hanab applied the technique of
horizontal directional drilling.
The longest drilling was in the heart of the town. In order to cross
the Katendrecht area without digging, the contractor realized a
1500-metre drilling with a depth of up to 40 metres. Two pipe sections
of 850 metres and two of 650 metres were transported by tug over the
river and welded together at the drilling site for this unique operation.
The pipeline was commissioned in 2014. Heat transport company
Warmtebedrijf Rotterdam invested €100 million in the project.
Shareholders are the city of Rotterdam and E.ON.
The pipeline between NUON’s new 435 MW gas-fired cogeneration
plant in Diemen and Almere was also a unique project. At 8.5 km, the
length of the route from Diemen to Amsterdam is not as impressive as
the pipeline in Rotterdam, but Almere is a new town in the Flevoland
polder.
In addition, the pipes had to be laid at the bottom of the former
Zuiderzee, now Lake Ijssel. Contractor A Hak developed new
techniques to lay the large pipes 1.5 metres under the bottom of the
lake. The dykes had to be crossed by means of horizontal directional
drilling. Dykes are important for Almere as this town is in a polder,
which is two to five metres below sea level.
In autumn 2016 a large project will be ready in Amsterdam. The
northern part of the city will then be connected to the AEB wasteto-energy-plant in the port area south of the IJ. This water will be
crossed by means of horizontal drilling. The route of the pipeline is
16 km. While the equivalent of 66,000 houses in Amsterdam are
already connected to a heating grid, the city’s target is connection of
230,000 homes by 2040.
Regulations and policy
Tariffs for heat are based on the principle that the costs for a
household with district heat should not be higher than the costs
of an individual condensing gas boiler. This simple principle was
the basis for the Dutch heat law, which protects heat consumers
with a connection of less than 100 kW heating capacity. For larger
customers, the heat price is free.
The price of natural gas is rather high for households due to energy
taxes, while for large gas consumers such as industry, hospitals and
greenhouses the taxes are very low. The development of heating grids
in greenhouse areas, and of some steam grids in industrial areas,
indicates that there are chances in these market segments.
In his heating vision in 2015, Minister Kamp said he aims to
introduce a new heat law. He said the new law is needed to speed up
the development of district heating. He also initiated a study for new
market models for district heat. These models will be available in the
spring of this year.
Klaas de Jong is Chief Editor of Warmtenetwerk Magazine
www.warmtenetwerk.nl