Clichy-Batignolles : Eco-District Energy SolutionsPublished on 09.30.2019
5 min read
Development of the Clichy-Batignolles eco-district in northwest Paris began in the early 2010s, and the last of the buildings are scheduled for delivery in 2020. Over a period of 10 years, city planners have created a mixed-used development combining offices, housing, stores, public facilities and green spaces built to the highest energy and environmental standards.
© AFP PHOTO / Kenzo TRIBOUILLARD - View of the Clichy-Batignolles district from the solar-panel-covered roof of one of the new buildings
Situated between the ring road, Porte de Clichy and the Batignolles neighborhood, the eco-district offers a large supply of office space, including a number of private office buildings (140,000 sq.m) overlooking the Saint Lazare railway tracks and two public structures (120,000 sq.m) housing the new courthouse (Palais de justice) and the Paris police headquarters (formerly located at “Quai des Orfèvres”). Home to an array of shops and services (over 30,000 sq.m), the district also comprises 3,400 housing units (half of which are designated for low-income households) that will eventually accommodate 7,500 new residents in Paris’s17tharrondissement.
Economy of Resources, the No.1 Priority
The eco-district’s goal is to ensure that 85% of its heating and domestic hot water is supplied by sources, primarily geothermal. To achieve this, it is necessary for the buildings to be properly insulated. Paris City Hall has established a 15 kWh/sq.m/year heating limit for Clichy-Batignolles based on an indoor temperature of 18°C. It’s a very strict standard, considering that a Parisian building with poor insulation, like many red brick structures on the outskirts of the city built during the two world wars, can consume up to 10 times more energy. Moreover, many people are accustomed to setting the thermostats of their homes and offices above 18°C.
The eco-district will be supplied by heat drawn from the 600-meter-deep Albien , which flows for about 80,000 square kilometers beneath the Paris Basin. Once used intensively for various industrial and artisanal applications, the aquifer is now carefully controlled since it’s the city’s emergency drinking water reserve. There are five wells within Paris proper. When municipal water service operator Eau de Paris drilled a sixth well, it was decided to use it to create an open-to-recycle system, also known as a doublet earth coupling. A second well was therefore drilled roughly 600 meters from the Eau de Paris extraction well so the used water could be injected back into the ground.
In an open-to-recycle system, heat from hot water pumped from the ground is extracted and used to heat buildings. The used water is then returned to the aquifer. In the case of Clichy-Batignolles (see diagram below), the water collected from the Albien aquifer has a temperature of about 30°C. Heat pumps are used to raise the water temperature to 65°C for the production of domestic hot water or to a slightly lower 50-65°C for district heating purposes.
A series of heat exchangers connected to the district heating network, which is run by (CPCU)1, provide additional heat if necessary. One of the difficulties associated with a geothermal system is that it provides a steady supply of heat, whereas demand varies greatly depending on fluctuations in outside temperature.
The water is pumped through small heat exchangers and the extracted heat is transferred to the building’s heating system. The used water is then pumped back to the geothermal reservoir at a temperature of 12-13°C. All of the water is thus returned to the aquifer without any change in quality.
The heat exchange station was built 10 meters below the Earth’s surface in order to protect the environment and save space, since the price per square meter in the French capital is very high.
Solar Photovoltaic Electricity
Clichy-Batignolles is also committed to producing energy from 35,000 sq.m of solar panels installed on building rooftops and facades. The goal is to generate 4,500 MWh per year, or 1,000 times the average
consumption of a French household.
Rounding out its green credentials, the new urban area has developed many leafy areas (the centrally located Martin Luther King Park has 14 access points) and a road network adapted to eco-friendly mobility solutions (bicycles, scooters) and public modes of transportation. Thanks to an innovative trash disposal system, there are no longer any garbage trucks maneuvering the streets. Rubbish placed in containers at the foot of the buildings is automatically removed by an underground pneumatic system.
The CoRDEES (Co-Responsibility in District Energy Efficiency & Sustainability) Digital Project
An original energy management initiative has been launched with the aim of monitoring how much energy the eco-district’s inhabitants consume. Smart-E is a digital platform managed by Mines Paris-Tech as part of the EU-sponsored CoRDEES2 program. Every hour, the platform collects and analyzes energy data from buildings according to type of equipment (heating, lighting, kitchen appliances, washing machines, consoles, computers, TVs, etc.). A simulation is then carried out at the community level. The model will help residents develop eco-friendly attitudes and enable operators to better align heat and electricity production with demand.
Researchers at Mines Paris-Tech plan to apply this method to other districts, especially old Parisian neighborhoods undergoing renovation.
- Compagnie Parisienne de Chauffage Urbain. CPCU manages the heating network of the greater Paris area and is Europe’s seventh largest operator. It supplies heat to one and a half million Parisians via a 510-kilometer network. In 2017, CPCU’s was more than 50% renewable and recovered energy (mainly household waste together with wood), 30% natural gas and 16% . Geothermal energy still accounts for less than 1% of the total.
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