DISTRICT ENERGY IN CITIES

PARIS CASE STUDY

OVERVIEW
Paris is a densely populated, energy intensive city that is making real progress and commitments to reduce its impact on the
environment. In 2004 the territory emitted 25 million tCO2eq and in 2009 a reduction by 2% has been noted. The city is now looking
to increase efforts post-financial crisis to bring emissions down to 18.8 million tCO2eq by 2020, a targeted reduction of 25% on 2004
levels. District energy has played an important role in Paris historically in reducing coal consumption and today is expanding to
connect social housing, improve energy efficiency and increase the renewables share. From now and into the future, district energy
will play an important role in carbon reduction commitments, through the reduction of primary energy use and as an enabler of
large scale renewable energy systems inputting into district energy networks.

MW thermal of MW Electric of electricity MW of Cool MWh of Heat MWh of Cool Kilometres of heat Kilometres of cool
heat production production from DES Production production per year production per year network network
connected to a DES connected CHP connected to a DES on DES on DES
> 2000 MWth 250 MWel 330 MW 5,500 GWh 412 GWh 475 km 71 km

*Values for CPCU district heating network and Climespace district cooling network only

Paris is a densely populated city with 21,900 inhabitants/km2 many of which are housed in multi-storey flats and apartments. Paris has a large
commercial sector with high energy demands that are often spatially integrated with residential housing. The density of Paris’ population does create
opportunities for district heating, cooling, gas and electricity: from the level of a block of flats having collective heating to a large district heating network
serving half a million people. Paris also has a relatively large amount of social housing with 1 in 5 people in social housing and a higher proportion in some
suburbs. Social housing is easier to connect to district heating networks as it is often controlled by the city, with investments in upgrading heating
systems made by the city as well.
1
Structure of energy market
The city of Paris currently produces only 3% Electricity, gas, heating and cooling distribution other district heating companies that operate
of its own energy requirements, while the networks are granted concessions by the city under concession in Paris but CPCU does
surrounding region of Ile de France produces of Paris and controlled through concession have many competitors heating buildings not
11%. The City of Paris is the granting authority contracts. The city is obligated to provide connected to CPCU’s network (e.g. gas boilers,
for the public distribution of energy in the concessions to ErDF (French Electricity electric heaters, heat pumps etc.). CPCU is
Paris area and grants concession contracts Distribution Networks) and GrDF (French Gas responsible for approximately one third of the
for electricity, gas, heating and cooling supply. Distribution Networks) for electricity and total heating supply in the city, making CPCU
Cities in France legally own all the underground gas network management and maintenance. the largest district heating network in France.
networks that run through them (including For heating and cooling networks no such Cooling supply and district cooling network
electricity, water, telecommunications, heat, obligation exists. The Paris Urban Heating maintenance is provided in a similar concession
cool). Cities can manage and maintain these Company (CPCU) is 33% owned by the City of model by Climespace, a subsidiary of GDF Suez
pipes, as the City of Paris does for the water Paris and under a concession contract both (see section on Climespace, page 7)
network, or instead they can grant concessions distributes hot water or steam and maintains
to public or private parties to manage and and manages the district heating pipes
maintain these networks. throughout the city (see page 5). There are no

District Energy Strategy of Paris

The current main district energy objective written into Paris have produced two Climate Action Plans in 2007 and 2012 that set out the city’s
the concession contract of CPCU and in the city’s Climate energy and environmental strategy including specific targets and the pathways towards
Action Plans is to increase renewables and recovered achieving these targets. Between these two Paris Climate Action Plans the broad strategy
heat in the energy mix and to develop the district energy and targets of Paris did not change although the pathways to achieving these targets were
networks to new areas. These actions will be vital for updated. The city recognised that in order to catalyse city-wide development towards
Paris to meet its commitment to a 75% reduction in CO2 these targets the city authority would need to be more ambitious and fast-acting in
emissions by 2050. The territory emitted 25 million tCO2eq reducing its own greenhouse gas emissions, and consequently developed more ambitious
in 2004 meaning that projected emissions in 2050 should targets for the city authority to achieve in its buildings and operations. The broad energy
be 6.25 million tCO2eq. and environmental targets in Paris are:

TARGET TYPE PUBLIC BUILDINGS, PUBLIC TRANSPORT CITY OF PARIS 2020 CITY OF PARIS 2050
AND PUBLIC LIGHTING 2020
Greenhouse gas 30% reduction compared to 2004 levels 25% reduction compared to 2004 levels 75% reduction compared to 2004 levels
emissions
Energy consumption 30% reduction compared to 2004 levels 25% reduction compared to 2004 levels Unspecified
Renewable or recovered 30% of energy mix 25% of energy mix Unspecified
energy use

Both Paris Climate Action Plans included measures and targets for the district heating sector that were adjusted over time, such as targets for the
proportion of heat from renewable or recovered energy sources. 2
 2007 PARIS CLIMATE ACTION PLAN

The 2007 Paris Climate Action Plan accelerated district energy development in four key areas:

TARGETS STUDIES
The 2007 Paris Climate Action Plan set out The 2007 Paris Climate Action Plan called for The 2007 Paris Climate Action Plan led to the direct
the targets for the city seen on page 2 and a detailed study on the potential of geother- development of:
also focused on district energy by request- mal energy to be completed and if necessary
ing that the CPCU move to 60% renewable or
• a geothermal well in the Claude Bernard urban
for boreholes to be drilled. If the potential development zone (also called Paris Nord Est –
recovered energy by 2012 in order to receive
was significant then a geothermal energy see Box 5, page 9);
the reduced VAT rate set out in the National
Housing Commitment Act of 5.5%. For 2020, development plan would be produced. In
• extension of 10km of district heating in the
CPCU’s target was to increase the share of addition to this geothermal development
north-east of the city; and
renewable or recovered energy to 75%. This is plan, wind and solar plans would also be
in the context of the Waste Prevention Plan of created. The 2007 Paris Climate Action Plan • significantly large arrays of solar PV (6300m2
Paris which is seeking to reduce the amount also announced the ongoing development across two large arrays).
of waste incineration in the city (which in of a study providing details of the 96,000
2013 provided 39% of the heat for the district residences in Paris, including wall thickness,
heating network). As such, higher shares of age, solar gains, building materials and an
other renewable or recovered energy sources expected analysis of each building’s thermal
will be required to meet the targets. performance. These studies were designed
to help identify the optimal areas for energy
REGULATIONS effi­ciency improvements, and could be used
2007
The 2007 Paris Climate Action Plan called by CPCU to direct network development and
for revisions to regulations relating to the highlight inefficiencies in the CPCU network.
co-ownership of buildings to allow them to PARIS CLIMATE
have easier access to a local heating network. PROTECTION PLAN
Furthermore, while compulsory connection DENSITY BONUSES Plan to combat global warming

of buildings to the district heat network New constructions are able to have a 20%
was already possible in urban development higher ‘land-use coefficient’ if they meet high
zones (see page 4) the 2007 Paris Climate efficiency standards or are developed with

25% le

ases
Action Plan indicated the willingness of

eg
sg
renewable energy production facilities. reenhous

s
Paris to apply stricter efficiency regulations
more generally that could make connection planclimat.paris.fr

compulsory outside of these zones.

2012 PARIS CLIMATE ACTION PLAN

The 2012 Paris Climate Action Plan took LE PLAN
CLIMAT
ÉNERGIE
stock of what had been achieved since the DE PARIS

2007 Paris Climate Action Plan and reiterat-

ed Paris’ commitments to the majority of the
targets set out in the 2007 Paris Climate Ac- ActuAlisAtion
tion Plan. The development of the CPCU heat plan 2012
network to be heated by 60% renewable or climat
recovered energy by 2012 was not realised
énerGie
and so the ambition of this target was re-
duced. The CPCU are now targeting heat
de paris
adOpté par le cOnseil de paris
du 11 décembre 2012
networks having 50% renewables or recov-
ered energy by 2015 and 60% renewable or
recovered energy by 2020. Grandes OrientatiOns

The 2012 Paris Climate Action Plan also fo-

cused efforts on urban development zones
with specific energy policies being applied to
these areas to encourage renewable energy
and energy efficiency and to increase con-
nections to district energy (see page 4).

The 2012 Paris Climate Action Plan also high-

lighted the city’s recognition of heat recov-
ery from systems such as sewage and the
metro as high potential to be explored along
with geothermal in specific urban develop-
ment zones such as Clichy-Batignolles and
the existing geothermal development in
Paris Nord Est (see Box 5). The Plan indicated
that geothermal production would double in
the city over the period 2012-2022.
3
Planning for district energy
Paris uses its land-use planning and city-zoning to promote district energy, as well as energy efficiency, in specific, high-potential areas of the city. In
addition, the city is helping catalyse efforts to expand and interconnect district heating systems in and around the city.

URBAN DEVELOPMENT ZONES DISTRICT HEATING MASTER PLAN

The urban development zones are being used to test The City of Paris has control over district energy through the concession
technologies and policies that will help the city meet long-term contracts that are in place for the heating and cooling networks. In July
energy and environmental targets. These development zones 2012, the city authorities included a requirement for the creation of a
have special regulations and are required to try to connect to ‘heating master plan’ in addendum number 10 of the heating network
district heating if possible. Occasionally, the city of Paris pays for concession contract for all new developments. This heating master plan
the extension of the district heating network to a new zone in will be drafted together with neighbouring authorities and may seek to
order to ensure connections. This is achieved by the city providing interconnect some of the heating networks in the wider metropolitan
a direct, low-interest loan to CPCU for the development of this area and also to pool investment for heat production facilities.
extension. The city creates specific clauses in building developers’ Interconnection of networks can increase efficiency by pooling demand
planning permission that requires connection to district heating and maximising baseload across multiple networks. Pooling investment
or cooling. Paris is now studying the possibility to have new zones is not a new idea in Paris, the city has already pooled investment with
with mandatory connections when the energy mix of the district neighbouring cities to interconnect other networks with CPCU.
heating is more than 50% renewable or recovered energy. This
mandatory connection will be written in a coming city planning For the future, with the creation of the Metropolis of Grand Paris, which
document and will also focus studies on the potential for local will include Paris and 123 surrounding cities totalling 7 million inhabitants,
energy production within these new zones, as well as connection there will be a significant opportunity to further interconnect networks
to the CPCU district heating and Climespace district cooling and maximise regional resources. This may be through the creation of a
networks. Two urban development zones are described below: global pool of investment, for the whole Metropolis of Grand Paris region,
Bruneseau Urban Development Zone (see Box 3) and Paris Nord specifically focused on increasing the share of renewables in the heat
Est (see Box 5) supply and to interconnect networks.

CPCU – Ninety years of district heating

The Paris Urban Heating Company (CPCU) serves 16 towns in
BEST PRACTICE the Paris metropolitan area, including the city of Paris, with hot
Paris uses its partial ownership of CPCU and the concession water and steam. The heat from CPCU is mostly used for space
contract to: set a maximum heat tariff, set a special low heating and hot water in buildings, although steam is sometimes
tariff for social housing residents, and require development used in industrial processes. Box 1 shows the progression of
of renewable and recovered energy in the heat network. CPCU from 1927 to the modern day.
4
 HISTORICAL DEVELOPMENT OF THE PARIS URBAN HEATING
BOX 1 COMPANY (CPCU)
• 1927: The City of Paris creates a concession • 1939: The network has expanded across • 2015: Today CPCU is 33% owned by the
for the delivery of steam through a the centre of Paris to be 13.5km long and City of Paris, 64% by Cofely and 2% is traded
district heat network to national and has 190 clients including many major public publicly. The network serves the equivalent
public buildings. CPCU, a private company, and administrative buildings such as the of 500,000 households and distributed
starts developing district heating under a Louvre, Hotel de Ville and Palais Royal and 5.5TWh of heat in 2013 through its 475km
concession contract. District heating was many department stores, libraries and of network.
seen as the solution to improving the city’s hotels.
air quality as the majority of heating was
from decentralised coal and wood. District • 1949: After World War 2 the City of Paris
heating would also help to reduce the risk purchases 33% of CPCU making CPCU
of fire and the need for thousands of fuel a public-private joint venture. The city
deliveries through the city’s centre. bought this share to help the post-war
reconstruction of the network and to
• 1930: CPCU activities begin with providing help connect new social housing being
heat for a factory and pre-heating trains in developed in the reconstruction.
Gare de Lyon station. Twenty neighbouring
buildings then connect to the network in • 1966: The network has expanded through
order to benefit from uninterrupted and existing metro lines and pipes and now is
secure heat. 120km serving 1700 clients.

These sources of heat can be seen in Figure 1 showing CPCU’s

PEAK REDUCTION WITH HOT WATER LOOPS heat network in Paris. Three of the fuel oil boilers are within dense
The network consists mostly of a steam network with individual heat areas of Paris and so CPCU is one of the few remaining industrial
exchangers at each delivery point but also includes nineteen ‘Hot companies based in the city and must meet strict emissions
Water Loops’ that distribute hot water through small neighbourhoods standards. The three waste incinerators owned by Syctom are
or developments and have heat delivered to them via a heat exchanger fully equipped to reduce air emissions significantly below legal
with the main steam network. Steam was used since 1927 as this thresholds.
was the technology available at the time. Today when new areas
are developed, ‘Hot Water Loops’ are preferred due to the higher
distribution efficiency of distributing hot water (distribution efficiency FIGURE 1:
is approximately 95% in the ‘Hot Water Loops’). Furthermore, as hot Network map of CPCU showing heat production plants
water can store heat better than steam, the ‘Hot Water Loops’ can
reduce peak demand on the steam network, reducing the carbon
intensity of heat (which at peak demand is normally provided by fossil
fuel boilers).

CPCU CURRENT ENERGY MIX

CPCU has a wide range of different heat sources that deliver steam
into the district heat network, the relative proportions of these can be
seen in Figure 2. The baseload heat production comes from 3 waste
incinerators that provide 39% of heat to the network and combined
reduce the carbon emissions of heat by 800,000tCO2. These waste
incinerators are not owned by CPCU but are owned by Syctom, the
waste agency of Metropolitan Paris. CPCU purchases steam from
these three waste incinerators which have a combined thermal
capacity of 397MWth.
Source: CPCU, 2015

CPCU also owns two gas combined heat and power (CHP) plants, each
with an electrical capacity of 125MWel that produce 1TWh of electricity
per year (approximately 160,000 households*) for the local distribution
network. Gas and coal boilers also provide significant amounts of heat
with a combined thermal capacity of 982 MWth. and five fuel oil boilers
provide peaking demand for the network. In total, a thermal capacity
of 4GWth is connecting to CPCU’s network. CPCU owned Heat Plant CPCU network

CPCU owned Combined Heat and Power (CHP) plant

*
Assuming average French household consumes 6343kWh of electricity per CPCU owned Geothermal production plant

year (average for year 2010). Source: World Energy Council, 2014 SYCTOM owned Waste incinerator
5
 CPCU FUTURE ENERGY MIX
The future energy mix of CPCU’s district heating construction begins. The Paris Nord Est urban FIGURE 2:
network is driven by the city’s energy strategy development zone (described in Box 5) will deliver CPCU’s current and future energy mix
through the city’s part ownership role in CPCU enough geothermal heat by 2016 to meet 1% of
and through the concession contract. By the end CPCU production. FUEL 1%
of 2015, CPCU will have reached a 50% renewable BIOFUEL 2%
GEOTHERMAL 1%
energy share allowing it to reduce VAT from 20% to CPCU is looking to create large biomass plants %
5.5% under the National Hous­ing Commitment Act S 10 WA
near the city with a thermal power of 200MWth
MAS S
(2010) which is estimated to save approximately so that biomass can provide 10% of the fuel mix. O L 12
%
WA
UE

TE
BI
F ST
€35 million a year. By 2016, CP­CU’s energy mix will

24%
However challenges for CPCU include addressing

INC
E
have increased to a 53% renewable or recovered

IN

INE
air quality issues and finding good quality biomass

%
COAL BOILERS

CIN
4
energy share and by 2020 this will be 60%.

BOILERS 2

R AT I O N 4 0 %
for the plant. 2013

E R AT I O N 3 9 %
Paris also has a good geothermal resource which If the CPCU achieves the 2020 target of 60% 2016

OA L
is particularly useful for district heating purposes renewable or recovered energy then the net

C
although accessing this resource can be difficult reduction in greenhouse gas emissions could

GA
SB

GA
in such a dense city. Paris is a growing city with OIL %

S
be around 350,000 tCO2eq. In addition, the CPCU ERS 25
A N D GAS C H P

BO
IL
new housing developments on the periphery will have lowered primary energy consumption, ER
SA %
ND G
taking over previously industrial land such as the insulated Paris from fossil fuel energy price AS CHP 30
19th arrondisement. Such new developments are increases, closed-the-loop on waste production
significantly easier to implement district energy in in the region and also helped reduce fuel poverty.
as pipes and networks can be considered before Source: CPCU, 2015

CPCU CONNECTIONS CPCU BUSINESS MODEL

The CPCU meets the equivalent heat demand of 500,000 households and CPCU has operated under a concession from the city of Paris since 1927. CPCU
this includes 100% of hospitals, 50% of social housing and 50% of publicly was originally a private company until the city of Paris bought a 33% share to
owned buildings. The client base of CPCU comprises of 28% private residential make it a public-private joint venture (see Box 1 on historical development of
buildings, 17% social housing with the remaining being businesses and public CPCU). This model has enabled Paris to maintain a high degree of control over
buildings. The city authority has used its assets to provide anchor loads to network development and over heat tariffs, for example 4 of the 10 directors
the CPCU which increases the load certainty on the network. The city also on CPCU’s Board of Directors are nominated by the city of Paris. The conces-
benefits from heat with a high share of renewables, which is critical to the city sion contract specifies a maximum heat tariff that the CPCU can charge. This
meeting its renewables targets for public buildings (30% renewable energy maximum heat tariff is indexed by the proportion of renewable energy sourc-
share by 2020). Through the city’s 33% stake in CPCU, the city has directed es used to encourage CPCU to switch to renewables. The business model also
the district heat company to focus on connecting social housing projects. The allows CPCU to benefit from the expertise of the private sector, Cofely. Cofely
city also uses its ownership to require a special low tariff for all those in social are able to leverage their international expertise and large balance sheet to
housing, ensuring that affordable heat is provided. CPCU is also targeting to improve and invest in CPCU’s networks. CPCU delivers significant returns to
reduce the energy consumption of its users with a ‘heat demand reduction the city with estimated annual benefits to the city of €19.5 million, an annual
plan’. This includes the installation of individual meters, development of build- dividend for the city of €2 million and an annual concession fee of €7 million.
ing insulation and heat leakage reductions in the distribution network. An overview of the CPCU’s business model can be seen in Figure 3.

FIGURE 3. Business model of CPCU: A split asset concession model with public/private concessionaire

Power Grid Municipality / Regulator

Government (Paris)

Concession Tariff Tariff

1 TWh Electricity Agreement approval methodology
7 million euro Reporting
per year sales
per year
19.5 million euros
calculated benefit
CHP and to city per year
Waste-to-
energy* District Heat
Gas, Heat Heat
Network (owned by End
Biomass,
sales city, operated by sales users
Waste etc.
CPCU) Building
HOB 5.5 TWh Asso­c iation 100% Hospitals
CPCU (public/private) per year
50% Social Housing
50% of Public
Buildings
Debt Service Debt Equity Return on lnvestment
2 million euro dividend to City

Shareholders
Lenders *The waste-to-energy plants are owned
33% City of Paris
by regional agency 6
64% Cofely
Climespace – The largest district cooling network
in Europe
Paris has a large cooling network that operates
under a concession model from the city of
District cooling has been operated by
Climespace in Paris under a concession since
BEST PRACTICE
Paris, called Climespace. This network is the 1991. The district cooling network is extremely Climespace uses the basement
largest district cooling network in Europe and innovative and was the first cooling network in
and roofs of existing buildings,
operates in the centre of Paris. Isolated other Europe and today it is the largest. The network
networks include two district cooling networks replaces air conditioning and chillers for many underground connections to the
in La Défense, a large business district in the offices, shops and hotels as well as some of the River Seine and runs 60% of the
west of Paris, operated by IDEX and Dalkia (see most famous buildings in Paris, such as the network through the city’s sewage
page 10 for more information on the cooling of Louvre, by pumping cold water around the city.
La Défense). system to minimise costs of network
development and impact on the city.

THE CLIMESPACE NETWORK FIGURE 4: Network map of Climespace showing extent of network and production sites

Climespace’s district cooling network is over

71 km long with the majority of the network
in the centre of the city and two, separate
smaller networks exist in the North East and
South West of Paris as shown in Figure 4. The
scale, and rapid growth, of the district cooling
network in Paris has been achieved, in part,
by running 60% of the network through the
existing sewage system. In a dense city such
as Paris this significantly lowers the costs and
disruption of network development as roads
do not always have to be dug up in order to
expand the network. When roads do have to
be dug up in Paris it is the responsibility of the
city authorities to coordinate and reduce this
disruption and the city may coordinate with
other utilities such as ErDF to ensure that
roadworks can occur at the same time. The
network is expanded based on new demand
with a large consumer identified and the
network expanded to meet this consumer and
to connect other consumers along the new
pipe’s route.
The network flows cold water through energy
transfer stations that often sit in the basement
of buildings and contain a heat exchanger to
cool the building’s internal centralised cooling
system. These energy transfer stations
have different capacities dependent on the
estimated maximum demand of the building
and take up only a small amount of space (20
square-meters) compared to the building’s Source: Climespace, 2015
previous electric chillers and cooling towers.

CLIMESPACE PRODUCTION
Climespace’s network has nine cold water production sites (from five use of this ‘free cooling’ and uses these three production sites as the
in 2007) with 330MW of cool capacity delivering 412 GWh per year of baseload supply of the network, meeting 75% of the network’s cooling
cooling. The district cooling network makes use of the city’s free cooling’ demand over a year enabling the district cooling network to use 35%
through three production sites that take cold water from the Seine less electricity than normal centralised cooling in buildings. The other
River to provide cool. These sites use this cold water to pre-cool water production sites on the network help meet peak periods of cool demand
before it enters electric chillers. In this way electricity consumption of and are highly-efficient electric chillers with cooling towers.
the electric chillers is much lower, improving costs, energy efficiency
and CO2 emissions. The three production sites connected to the Seine The supply temperature of the network is approximately 4°C and the
are the largest production sites on the network, totalling 148MW. The return temperature can be up to 14°C. The network also has three
control room of the district cooling network works to maximise the cold water storage sites that can instantly provide more power to the
network and also can shift the electricity demand of production sites.
7
 BOX 2 DEVELOPED UNDERGROUND AND IN BUILDINGS

• Climespace’s network and production sites are almost entirely example, the Philharmonie de Paris building was constructed in
underground. This is an economically efficient solution in such coordination with Climespace so that an electric chiller and cold
a dense city. The three production sites connected to the Seine storage was installed during building construction as well as a
are entirely underground and do not need require cooling towers cooling tower. The space is rented by Climespace and the network
as warmer water is pumped into the Seine. The other production developed will be interconnected in the future to the Paris Nord
plants on the network rent underground space from existing Est development (see Box 5).
buildings and have cooling towers on top of the building. For

FIGURE 5: Climespace clients by capacity connected DISTRICT COOLING DEMAND

• Climespace has more than 570 clients with an equivalent demand of
5 million m 2 of office cooled and is steadily growing the network by
connecting 25-30 new clients per year (approximately 14MW of cool
capacity). Clients that are connected already have centralised cooling
systems and are normally replacing individual stand-alone chillers
and cooling towers or undergoing large building renovations.

• The network serves mostly offices, commercial and public buildings

including the Louvre museum and the Forum des Halles as well as
many restaurants, hotels and shops. Customers connect for many
reasons including: the significant space saving, the ability to use the
roof space (as no cooling towers are needed), improved environmental
Source: Climespace, 2015

credentials for the building, the need to replace existing equipment

and the long-term cost saving of district cooling. Climespace has a
range of customers with varied needs for cooling even during winter.
Large server rooms in banks, as well as storage areas in museums
and concert halls all have a significant demand for cool throughout
the year.

• Climespace does not connect to residential users in Paris as the

Housing Shops
cooling season for residential customers is too short, approximately
Mixed Financial two months, and the cooling demand is too low as many Parisians
institutions
Concert halls, museums leave the city for holidays. Some urban development zones in the
Hotels, and restaurants Offices city are focused on residential development and Climespace does
not connect to these, however, Bruneseau (see Box 3) and Paris Nord
Est (see Box 5) are two urban development zones that have led to
significant expansion of Climespace’s activities.

BOX 3 BRUNESEAU URBAN DEVELOPMENT ZONE

• This new Bruneseau development in on the left bank as the district cooling pipe as demand increases. The first phase is
the east of Paris, on the left bank, was across the Seine would not be wide enough already in place and Climespace rents a
developed close to Climespace’s existing to serve the Bruneseau development 2000 square-metre underground space
and separate, Bercy network, which has and additional cooling capacity would be from the library.
a 44MW production facility cooled by required on the left bank in Summer.
the river Seine on the right bank (see • As such, the development of the
figure 4). The city of Paris approached • Climespace has approached the national Bruneseau Urban Development Zone was
Climespace to consider connecting to the public library (Bibliotheque National de the catalyst for Climespace to continue
new Bruneseau development in order to France) on the left bank, to develop a expanding the Bercy network on the
improve the environmental credentials of production facility based on electric left bank, which required a large new
the new development. This connection chillers and cooling towers in the library. development to justify creating a new left
with Climespace would require the This will be developed in three phases bank, production facility.
development of a new production facility with electric chillers added in parallel

8
 BUSINESS MODEL ENVIRONMENTAL BENEFITS
Climespace is 100% owned by the GDF Suez Group through its affiliate Cofely. The In comparison with an equivalent pool of stand-alone
city does not financially support Climespace and investments are financed only by units, the district cooling network is better economically,
Climespace with the original equity for Climespace provided by the GDF Suez Group. environmentally and aesthetically as shown in Box 4.
Climespace allows users to save space as buildings no
Climespace operates under a 30-year concession contract from the city of Paris longer need individual air conditioning units or chillers and
which ends in 2021 and will be renegotiated then. This concession contract specifies the network benefits from reduced land costs by having
tariffs that Climespace can charge to its customers. These tariffs vary dependent many plants and, all the network’s pipes, underground.
on time-of-use and also the size of the energy transfer station that a building The use of highly efficient chillers and free cooling from
requires. Climespace has 124 employees and provides an annual revenue to the city of the Seine allows the dramatic reduction of electricity
approximately €1 million per year with an annual turnover of €74 million. consumption and CO 2 emissions.

MULTIPLE BENEFITS OF CLIMESPACE*

BOX 4 *Compared to an equivalent pool of stand-alone cooling units

• 50% improvement in energy efficiency • 65% less water consumed • In combination with other wet cooling
systems, Climespace, reduces the urban
• 50% less CO 2 emissions • 90% less refrigerant emissions heat island effect in a heatwave by 1-2°C.

• 80% less chemical products used • 35% less electricity consumed

Many clients connect to Climespace because this improves the building energy label making it easier to sell or rent offices and other commercial
buildings. These energy labels include LEED, HQE and BREEAM * and account for full system efficiency rather than just efficiency of the building
envelope, a key best practise for the development of district energy.

*
LEED: Leadership in Energy and Environmental Design. HQE: Haute Qualité Environnementale. BREEAM: Building Research Establishment Environmental
Assessment Methodology

CLAUDE BERNARD URBAN DEVELOPMENT

BOX 5 ZONE (PARIS NORD EST)
• The Claude Bernard Urban Development Zone is a new certificate (see section on Building Efficiency page 11). In this way
development in the North-East of Paris comprising of 12,000 flats the Climate Action Plan has directly led to the innovative scheme
and 1 million m 2 which will be partially supplied with renewable being developed in Claude Bernard.
heat and cool from a new geothermal well developed at the same
time as the new development. The project will extract 60°C water • A new company Géométropole was created in December 2013 that
from a geothermal well bored into the Dogger aquifer at 1600- is 44% owned by CPCU, 22% owned by Climespace and 34% by the
1700 meters deep and return water into another borehole. This public financial institution: Caisse des Dépôts et Consignations.
hot water will be used to meet some of the heat demand for the This company will supply heat to CPCU’s network in the Claude
development and in summer will be used to produce cooling for the Bernard development and cold water to Climespace’s network in
development through absorption chillers. the development.

• The 2007 Paris Climate Action Plan called for a detailed study on • This project is estimated to cost €15 million and will have one-tenth
the potential of geothermal energy in Paris to be completed and if of the CO 2 emissions compared to normal gas heating. The heat
necessary for boreholes to be drilled. The 2007 Paris Climate Action production capacity of the plant will be 11MW. The estimated cost
Plan also specified the Urban Development Zone of Claude Bernard is €21 million for the construction of the geothermal plant and
to meet specific requirements in relation to energy including 20% €32 million for the geothermal wells and to the deployment of the
lower energy consumption levels than existing thermal regulations district heating network.
an effort to become energy self-sufficient, to use at least 25%
renewable energy and to aim for the BBC Effinergie Rénovation

9
Cooling the La Défense Business District
La Défense is a large business district to the west of Paris, located on indirectly cools the equivalent of 1 million square-metres of office and
the adjoining cities of Puteaux, Courbevoie and Nanterre, cities that have hotel space through interconnections to 2 adjacent networks (see Figure
formed with their Department Council a Joint Association - SICUDEF 7). SUC has a cooling capacity of 85MW providing 80,000MWh of cold
- responsible for their district cooling networks. Business districts water per year.
typically have extremely high and dense cooling demands making them
The SUC network uses the ‘free cool’ of the river Seine through a river
ideal for district cooling development, which is best achieved during
connection to provide a large proportion of the cold water. Electric
periods of construction in the business district. The SUC (Société Urbaine
chillers are able to provide cool during periods of peak demand. The SUC
de Climatisation) network in La Defense operates under concession from
network does not use cooling towers freeing space on roof tops in the
SICUDEF, this concession zone is shown in Figure 6. SUC is owned by
district for other uses.
Dalkia and serves 70 high rises through 6km of network and directly or

FIGURE 6: SUC network concession zone

Source: Dalkia
FIGURE 7: SUC network in La Défense

Source: Dalkia

10
 Building Efficiency and District Energy
Paris has large amount of older housing stock, which can present chal- Paris is a city that requires heating, cooling and hot water. The demand
lenges in renovating them or improving thermal efficiency or connect- for cooling and hot water varies significantly by building type, however,
ing then to district heating networks. Like many cities Paris will need to the demand for heat is more constant (see Figure 8). To put the energy
focus on both new and old build housing stock in order to meet carbon levels in perspective the BBC Effinergie Rénovation certificate (a national
targets. Development of district energy in new and existing buildings will building certificate for energy efficiency) requires that primary energy
enable Paris to lower its exposure to energy prices unilaterally and also consumption for new construction must be less than 104kWh/m2 /year
to improve its carbon emissions. in the Ile-de-France region while average buildings in Paris consume
275kWh/m2 /year.

FIGURE 8: Energy consumption by building type in Paris

450 Source: Mairie de Paris, 2012

400

350

300

250 Cooling

200
Specific uses of electricity
150 (lighting, IT, etc.)
Hot water, cooking and other
100

50 Heating

0
Cafés, Residential Health Education Sport, Offices Shops Transport
Hotels, facilities Culture, buildings
Restaurants Leisure

In 2010 the city of Paris launched a arrondisement (i.e. buildings built between programme, piloted in one area of the city,
government-subsidised housing programme 1940 and 1981). These buildings already has proved extremely successful and is now
(OPATB) to improve the thermal performance had a high proportion of collective heating being deployed throughout Paris.
of buildings. The first goal of this programme (56%) and the programme catalysed the
was to retrofit poorly insulated buildings by creation of co-owners’ associations to It is extremely important that as well as
installing new insulations (building façades, seek to reduce the energy demand on such assessing district heating, cities improve
roofs), removing oil boilers, and installing collective heating systems, which sometimes the efficiency of buildings. By improving
double glazed window. Where possible the involved connecting collective heating to efficiency through building design and
programme also sought to switch heat the district heat network. Within two and a district heating, cities can reduce energy
from electricity or natural gas to district half years of the programme, 151 co-owned consumption at least cost. The Pompidou
heating. The city of Paris paid 100% of the properties had carried out an energy audit, centre in Paris is a strong example of how
thermal diagnosis and provided double the 38 co-owned properties had undertaken a building efficiency and district energy can
national incentives for these renovations. works project and 28 (2,236 housing units) compliment each other.
Initially the programme focused on very had already voted to approve work for a 8
energy intensive buildings in the 13th GWh/year saving under the OPATB. This

11
 THE POMPIDOU CENTRE RENOVATION AND EFFICIENCY PROJECT
The Pompidou Centre, Paris.
Photo: Dalkia

The Pompidou Centre is Europe’s largest modern Through the modernisation process, the Pompidou Centre needed to replace 13 roof
art gallery with close to 4 million visitors per year. mounted air units that ejected heat from the building. Rather than simply replacing these,
Built in 1977 the building has been undergoing a Dalkia developed an energy efficient alternative of 13 air-to-air roof mounted heat pump
modernisation process of its heating and cooling units that optimise the Pompidou Centre’s heat and cool consumption and reduce the
facilities of the Pompidou Centre’s 100,000 square- in house chillers’ operation and production. In winter, or when it is necessary to raise the
metres. Dalkia have been a partner from the early temperature to 21°C in the Pompidou Centre, the air-to-air heat pumps provide heat by
construction phase of the Pompidou Centre and removing heat from the outside air. In summer or when the temperature of the rooms should
have since been in charge of the operation and be lowered to 23°C, the heat pumps work in reverse to remove heat from inside the building.
maintenance of the whole building air conditioning The modernisation process was phased over a 41 month period to prevent damage risk to
systems (temperature and humidity controls) with the exhibitions’ artefacts and maintain full public access and work was completed in April
heat being provided by the CPCU district heating 2015. The full installation being now completed, monitoring of the delivered savings will be
network and cold being produced by the Pompidou conducted over the coming months.
Centre’s chillers.

New air-to-air
heat pumps on the roof of Centre Pompidou.
Photo: Dalkia

The operation of the new equipment is pro- This significant reduction in energy consumption as well
jected to reduce by 25% the energy demand as other environmental benefits during development,
for heating and cooling in the Pompidou such as the reduction of chemicals in water treatment and
Centre including a 28% reduction in heat legionella prevention and the reduction of water effluents.
demand from CPCU and a 34% reduction are contributing to the building achieving the required HEQ
in electricity consumption by the electric (Haute Qualité Environnementale) building standards.
chillers. 12
 REFERENCES
Climespace (2015). Available from: http://www.climespace.fr/
CPCU (2015). Available from: http://www.cpcu.fr/
DRIEA IF (2013) Situation de l’Île­d e­France au regard des principaux indicateurs de développement durable. Available from: http://www.driea.ile-de-
france.developpement-durable.gouv.fr/IMG/pdf/Brochure_CS_IDDT_DRIEA_avril_2013_cle0b14f8.pdf
Mairie de Paris (2007) Paris Climate Protection Plan. Paris
Mairie de Paris (2012) Plan Climat Énergie de Paris. Paris
UNEP (2015). District Energy in Cities: Unlocking the potential of energy efficiency and renewable energy. Paris. Available from: unep.org/energy/des
World Energy Council (2014). Enerdata. Available from: www.worldenergy.org/data/

Author: Lily Riahi Research Assistant: Ben Hickman Contributors: Yann Francoise, Dalkia, Climespace,
CPCU, Veolia, ENGIE

For further information on authorship, contributors, interviewees, survey respondents and reviewers please see UNEP’s District Energy in Cities
publication. UNEP would like to thank the City of Paris, CPCU, Climespace and Dalkia for their assistance in the development of this case study.

For more information, contact:

Djaheezah Subratty Lily Riahi

Head Policy Unit, Energy, Climate, & Technology Branch Advisor, Policy Unit, Energy, Climate, & Technology Branch
djaheezah.subratty@unep.org lily.riahi@unep.org

www.unep.org/energy/des
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