Demonstrators

Albertslund, Denmark

The case study of Albertslund is located about fifteen kilometres west of central Copenhagen. Currently, the existing DHN supplies heat to a major portion of the municipality. The DHN was initially built in 1964 and covers around 90% of the municipality’s thermal demand.

 

This network is connected to the Greater Copenhagen DH transmission network, which integrates heat produced by waste incineration, CHP plants and peak-load boilers, and provides most of the heat uses throughout the year, i.e., 100 MW of heat capacity from the transmission company VEKS, supplied at 100-110ᵒC.

 

Additionally to withdrawing energy from the backbone, natural gas and oil boilers are also set up as local reserve sources, accounting for 145 MW of capacity installed, while waste heat from a data centre (0.35 MW approximately, recovered at ~20°C) is also supplied nearly constantly to the DHN by means of a heat pump. Around 270 GWh are distributed along the DHN and 220 GWh are finally supplied to end users yearly.

The project involved two partners: Albertslund Forsyning’s, the municipal utility company that manages the DHN and Artelys who have developed the datamining and optimisation tool.

Albertslund Forsyning’s overall energy efficiency strategy focuses on moving from a 3rd generation, high-temperature (i.e. 85°C) and centralised DHN, to a 4th generation system with lower supply temperature (i.e. 60°C) and a more distributed heat generation. To implement their strategy, a range of activities is foreseen addressing both heat distribution and distributed generation.

 

In the framework of the REWARDHeat project, effort has been placed on lowering the supply temperature to a subnetwork, consisting of around 110 residential houses in Porsager, an area in the South-East of Albertslund.

This has been pursued by:
 

  • Installing a shunt valve to lower the district heating supply temperature from 85°C to 60°C across the entire area. This measure follows an extensive retrofit of most of the district's homes, completed in recent years in collaboration with Albertslund Forsyning.

  • Developing a datamining software (by Artelys) to gather and structure monitoring data from two separated SCADA solutions in place and enable implementing performance optimisation through continuous supply temperature modulation.

  • Exploration of a data-based approach to minimize the network operation costs. In particular, it aims at adapting the operation of the shunt in order to control the return temperature under a certain threshold to prevent maluses and foster bonuses.

 

Gardanne, France

Located in the town of Gardanne, the site is an historic coal-mine, operated between 1989 and 2003 and is the largest mining well in Europe, with 1100 m depth, 10 m diameter, currently filled with water as the rest of the mining complex ensuring the geological stability of the terrain. Through the launched district sized real-estate development project the site aims at becoming the economic hub of the territory with very stringent energy, environmental and social requirements offering 80000 m² of offices, companies, or hotel, aiming thus at becoming the driver for employment and social integration in Gardanne. Additionally, it aims at hosting cultural activities with a sciences museum for improving education, science and innovation. The complex is fed by a thermal and electric smart grid, cooling and heating the «Yvon Morandat Well» district. The network is partially delivered: the network already connects 3 tertiary and commercial customers and 3 more are under construction, with a foreseen total heating demand of about 2,198 MWh/year and a cooling demand of about 1,425 MWh/year.

The main neutral-temperature network is used for both heating and cooling purposes, and operates at a temperature between 7-29°C. The extraction depth is at -950 m and injection happens at -264 m, whilst the whole shaft is equipped with a 1 km long optic fibre for temperature data acquisition. Moreover, the system was initially equipped with a 230 kWp PV plant, which produced energy is self-consumed by the network, thanks to a cascade of installed storage means.

Once completed, the infrastructure should account for a 1,3 km long neutral-temperature network and produce 2.1 GWh/y of heating energy and 1.4 GWh/y of cooling energy.

 

The demonstrator leans on the currently developed neutral-temperature network. The project partners involved are ENERGIE SOLIDAIRE, DALKIA and EDF that collaborate to achieve the following goals:

  • Set up of PV fields combined with different storage solutions (thermal, electric) to reduce electricity consumption from the grid

  • Optimization of RES utilisation and energy balancing across the district heating and cooling network, to foster “energy solidarity”, by integrating production/load forecasts and new optimized operation modes in the automation system

  • Utilization of the water well as a seasonal storage aimed to balance injection/extraction of energy in the mineshaft

  • Design and set up of a permanent exposition on district heating and cooling ,i.e., the “House of Energy”, with dedicated guided tours to explain through visual media, renewable based DHC networks.

Helsingborg, Sweden

This demonstration site is located in the district of Drottninghög in Helsingborg (Sweden) and consists of a newly built, small-size, heating and cooling network supplying energy to four new apartment blocks (5 to 7 floors and 110 apartments), with a total living area of 7,795 m2. The construction has been implemented by Tornet, who are specialized in construction and management of affordable rental properties, with a commitment to energy efficiency, responsible material utilization, and sustainable product choices.

 

The Energy Centre at the core of the small network consists of a thermal substation designed to cover the demands for DHW, SH, and SC. The energy system interfaces with the Helsingborg DHN network. The Energy Centre also integrates a 4-pipes, geothermal HP. The heat pump is used solely for heating, while space cooling is provided through free cooling, heat being extracted from the building via the Air Handling Units and directed to the boreholes.

 

The project involved three partners: INDEPRO, tasked with strategic planning, ARVALLA, overseeing construction management, and EURAC who developed an optimised rule based control for the management of the boreholes field. The project aims to achieve the following objectives:

 

  • Installation of a standardized substation, streamlining construction processes through the deployment of standardized design.

  • Integration of a geothermal heat pump in the substation aimed to minimise the import of energy from the district heating network.

  • Integration of PVT panels, reducing electricity consumption from the grid and charging the boreholes field in summer.

  • Integration of a state-of-the-art smart monitoring and control hardware and software.

  • Assess management strategies aimed to select the most effective way of sourcing heat for the buildings, between the district heating network and the borehole field.

 

La Seyne-sur-Mer, France

The demonstration site located in La Seyne-sur-Mer is a DHC network operated at different temperature levels to accommodate different needs encountered along the expansion. The DHC network is operational since 2008, while DALKIA took over ownership and management starting 2019. The network was extended along the project elaboration and the number of customers raised from 4 to 14 in 2024.

 

The neutral-temperature DHCN initially set up uses seawater as energy source and sink, and allows to cover both heating and cooling needs, as it is operated between 13-24°C, the temperature varying over the year according to the seawater temperature and the extent of heating and cooling, partially loads balancing out over the network. The buildings connected to this network are set up with substations exploiting water-to-water heat pumps to draw or reject thermal energy from/into the network. The networks stemming from the core one are conceived as semi-decentralised ones, as substations integrating large HPs connect the extensions. Depending on the energy uses of the buildings integrated in the subnetworks, those can be operated in heating mode only or provide both heating and cooling.

The project involved two partners: DALKIA, who owns and manages the network, and EDF who developed the advanced control tools and implemented them in DALKIA’s platforms. Overall, the project aimed to improve the energy efficiency of the system through new equipment installation and advanced control strategies integration. Particularly, the following objectives have been pursued:

 

  • Installation of a variable speed pump at the central pumping station in order to reduce flow, raise the temperature difference between supply and return temperature, hence lower electricity consumptions overall.

  • Upgrade of the SCADA system and set up of a reliable 4G communication with the remote substations.

  • Development and deployment of a centralised, advanced supervision and control system based on model predictive based optimisation techniques.

 

Lund, Sweden

The project area Medicon Village is a campus in Lund focused on medical research with more than 2500 employees working for several different companies. E.ON implements an ectogrid™ Low Temperature Heating and Cooling Network to supply Medicon Village and three large apartment blocks.

 

An ectogrid™ consists of traditional building blocks, such as heat pumps, cooling machines, heat exchangers and piping. The innovation of the technology lies in the way these building blocks are combined enabling new hydraulic coupling that achieves an automatic bidirectional capability. Generation is mainly distributed, where excess energy from each building is used internally by heat recovery from the chillers and recovery of chill from the heat pumps, thus lowering the overall energy consumption in each building. The decentralized heat pumps and chillers in each building raise or lower the supplied temperatures to the levels that are specific to the building requirements, avoiding unnecessary energy consumption.

 

Within the REWARDHeat project, a new kind of decentralized generation unit has been developed and tested by e.on. The heat pumps are connected in a novel “transversal” way to simultaneously act as both heat pumps and cooling machines. Both the inlet and outlet temperatures are controlled and steered to optimize the functionality of the grid. This novel substation setup has a significant impact on the potential for the overall system performance optimization. i.e. how the control of several buildings and substations in an ectogrid™ can be coordinated.

Milan, Italy

The demonstration site in Milan is a newly built neutral-temperature district heating and cooling, set up by the utility company A2A. This innovative system, located near the Parco della Resistenza in the southern part of the city, uses groundwater as an energy source. Groundwater is pumped from aquifer monitoring wells beneath the park and distributed to the three buildings involved in the project. Using heat pumps, the energy from the water is harnessed to heat indoor spaces in winter and produce domestic hot water, while in summer it can be used for cooling. This system reduces electricity usage and takes advantage of waste heat produced by the buildings themselves.

Heat from the water wells is distributed at around constant 15°C along the year. A kindergarten (via Giambologna), a municipal centre (via Tibaldi) and a multifamily home (via Balilla) are the first users of the network. While the first two only require space heating and domestic hot water being covered, the municipal centre also requires space cooling in summer.

An interception pit collects water from the primary groundwater channel, supplying it to the network. The main distribution substation has been installed in the technical room of the kindergarten, alongside the heat pump-integrated substation dedicated to that building. Additional dedicated heat pump-integrated substations have been installed at the municipal building and a multifamily residence.

 

In the framework of the REWARDHeat project, the following objectives have been pursued:

  • Design and set up of the groundwater intakes and installation of the new neutral-temperature DHC network

  • Installation of heat pump integrated substations at each of the three buildings

  • Implementation of monitoring and control hardware and software

  • Investigation on contractual models adapted to the local context.

Mölndal, Sweden

The demonstration site in Mölndal features a newly constructed, small-scale, low-temperature district heating and cooling network, developed as the extension of a nearby existing high-temperature district heating. This original network supplies heating to old tertiary and residential buildings and is connected to the Gothenburg backbone. Due to the characteristics of these buildings, the supply temperature is high, at around 80°C, with a limited temperature drop.

To optimize the return temperature to the backbone, the newly built low-temperature section, which serves both newly built tertiary and residential buildings, has been connected to the return line of the existing network via a heating central constructed underground. As such, this new network operates at temperatures below 60°C, which effectively lowers the return temperature to the backbone to below 50°C.

The new heating central is also equipped with geothermal heat pumps that generate heating during periods of low electricity costs, while also enabling space cooling distribution to the tertiary buildings, thus boosting both utility and energy efficiency, by allowing to select the most environmentally friendly and affordable energy vector on an hourly basis. Additionally, since the network’s distributed temperature is insufficient for domestic hot water preparation, booster heat pumps are installed in each building to meet requirements. Meanwhile, space heating and cooling are generated centrally, as described.

 

The main beneficiaries of the project include INDEPRO, responsible for feasibility studies, and ARVALLA, which managed procurement and installation activities. Beyond the primary project partners, other key stakeholders are Husvärden (the property owner) and Mölndal Energy DH along with Krokslätt Energi AB, which serve as the backbone network owner and energy distribution manager respectively.

Palma de Mallorca, Spain

The Parc Bit power plant is a Combined Cooling, Heating, and Power facility that supplies electricity, heating, and chilled water to the Parc Bit Innovation Centre and the University of the Balearic Islands, through a district heating and cooling network. The plant generates hot water using a combination of CHP engines, a biomass boiler, solar thermal panels, and a fuel boiler. To meet cooling demands, the facility employs three conventional electric chillers and two absorption chillers. The absorption chiller and one of the electric chillers use water for cooling and share the same cooling towers, while the remaining electric chiller utilizes ambient air for cooling purposes.

The district heating and cooling network, divided into four sectors for both heat and cold distribution, was constructed starting in 2000. Today, the network serves 25 customers, providing heating, cooling, or both.

The network comprises four branches of pre-insulated steel pipes, each containing two pairs of pipes: one pair for supply and another for return flows of heating and cooling. The total length of the DHC network, measured in a single direction, is approximately 4.6 kilometers.

 

In REWARDHeat, SAMPOL developed a hybrid Digital Twin of the power plant and the DHC network, combining high-fidelity physical models with simplified reduced-order models. This approach enabled the implementation of advanced control strategies designed to minimize fossil natural gas consumption and optimize electricity production during periods of high demand.

Szczecin, Poland

Szczecin’s demonstration site is located on the Łasztownia river island, and constitutes the first case of low temperature, hybrid DHC network in Poland.

 

The network newly set up is developed according to the e.on’s ectogrid™ concept. Typical operation temperatures are in the range of 30-50 ºC at the supply pipe -in summer and winter respectively-, and 25-35 ºC at the return. A Heat Balancing Station connects the new network to the existing high-temperature DH and to adiabatic coolers, allowing to distribute both heating and cooling to the users. Initially, the HBS supplies the Maritime Science Center with a capacity of about 400 kW for heating and 750 kW for cooling. The HBS is designed to cover heating loads for about 3450 kW and cooling loads for 2250 kW, accounting for the foreseen future extension and connection of additional customers. The MSC’s space heating and DHW loads are covered with direct heating in winter. Polyvalent, 4-pipes, water-water chillers cover DHW and space cooling needs in mid- and summer seasons, and reject waste heat into the network. The chillers draw water from the network's return pipe, ensuring the condenser operates within its permitted temperature ranges throughout the year.

 

The objectives pursued during the project by Szczecińska Energetyka Cieplna and e.on are:

 

  • Development and set up of the initial low temperature DHC network backbone.

  • Construction of the Heat Balancing Station and set up of the first customer substation.

  • Implementation of the network management system, aimed to optimize mass flow and temperature in the network based on demand side loads assessment.

 

Topusko, Croatia

The area of Topusko is rich in thermal springs. The concessionaire for the extraction of geothermal hot water is Health Spa Topusko and Top-Terme Lcc, who manage a large healthcare structure including hotels, mud baths and swimming pools.

 

Heating and domestic hot water preparation for all buildings and facilities takes place inside the central thermal station : geothermal water is collected at 62 °C and used to condition technical water to the different temperature levels needed; technical water is then distributes from here to the uses. In addition to distributing geothermal and technical water throughout the healthcare facility, high electricity consumption is also required to operate the wet cooling tower. This demand is particularly pronounced during summer when there is no need for space heating, hence higher temperature water is available after domestic hot water preparation.

 

Within REWARDHeat a complete refurbishment of the central heating station and of the district heating network has been performed, aimed to significantly increase the overall system energy efficiency. The following measures have been implemented:
 

  • All pipelines have been replaced new variable-speed pumps and remotely controlled valves have been set up. This allowed to implement an active control of both mass flows and temperatures set points.
  • The control hardware of the whole system has been renovated by Enisyst, as at project start the system was operated manually.
  • Although buildings substations could not be substituted nor can be controlled actively as they are owned by the building owners, heat meters have been installed also and connected to the central heating station via LoraWAN technology, aimed to monitor space heating delivery and DHW preparation, hence allowing to forecast energy uses.