City: Lund (SE)

District name: Brunnshög

Project name COOL DH - Cool ways of using low grade Heat Sources from Cooling and Surplus Heat for heating of Energy Efficient Buildings with new Low Temperature District Heating (LTDH)

Project status: Under construction

Project start – end October 2017 – September 2021

Contact: Reto Michael Hummelshoj - RMH@cowi.com Göran Strandberg Goran.Strandberg@kraftringen.se

Size of project area: World’s largest LTDH network

Building structure: Newly built / Existing neighbourhood / Mixed Land use (% or m²/hectare) 100 ha.

Description

The COOL DH project will innovate, demonstrate, evaluate and disseminate technological solutions needed to exploit and utilise sources of very low-grade "waste" heat for heating of energy efficient buildings via Low Temperature District Heating (LTDH) and show how the District Heating (DH) systems can be more resource efficient and more energy efficient. The demonstration covers both new developments and stepwise transition of existing areas with district heating and energy retrofitting of buildings. The COOL DH consortium consists of the utilities and municipalities of the two cities Lund (SE) and Høje-Taastrup (DK) and leading DH energy specialists as well as leading industrial manufacturers.

Goals and ambition

Brunnshög district area will host the research facilities of MAX IV and European Spallation Source, ESS and Science Village Scandinavia. The main objective is to use the surplus heat from these research centers to increase the decarbonisation of the whole district heating network of Lund. In particular the project addresses use of low-grade heat sources by focusing on the huge amounts of low temperature surplus heat that is available from cooling of these facilities. Moreover, the buildings are powered by CO₂ neutral sources as it to a large extend is based on Wind power & Hydro power. The project addresses the use of these low-grade heat to heat buildings with high energy efficiency that can use the energy at very low temperatures i.e. <40oC mean temperature (5th Generation DH) for space heating combined with decentral temperature topping to 45-50oC for the part used for preparation of DHW using renewable energy sources. The houses served are designed to have a primary energy consumption of 40-45 kWh/m² p.a. The project will also show how existing buildings in Lund after energy refurbishment can adopt to LTDH enabling a district by district to convert to LTDH.

Is this project idea replicable in other districts of Europe? Why? Under which conditions?

The solutions demonstrated are generically usable at all sites where low-grade heat is available. The COOL DH concept is demonstrated in relative large scale already, in the initial phase. Moreover, COOL DH has a large built-in replicability potential and the solutions can widely be replicated in North and Central Europe. In Sweden there are 396 DH utilities. They all have areas that can be converted to. Also in Central and Eastern Europe, the potential is significant especially in areas with upcoming new DH systems for low energy settlements and districts with deep energy renovation.

Economic Indicators/expected impact

The new LTDH supply will be tariffed according to actual costs, but is based on experience expected to be 10-25% cheaper in variable cost depending on temperature level. But CAPEX will be higher. The cost of the surplus heat is zero or even (as there is a saved cost of not having to operate a heat sink at the source). The project will be calculated on basis of the present DH market price, from which CAP-EX and O&MEX for the total at the consumers are subtracted. This will define the earned margin. The earned margin will serve the DH users collectively leading to a competitive lower overall cost than for the present DH system, which represents best available solution existing today.

Environmental Indicators/expected impact

The yearly energy saving based on recovery of low grade waste heat is estimated at 10 GWh p.a.; Each 1 MWh used low grade waste heat will save 1 MWh primary energy; used low grade waste heat will marginally save 300 kg CO₂ /MWh; In Lund the share of renewables will be increased from 98% to 100%.

Societal Indicators/expected impact

The project will contribute to reduce costs of heating supply, which means that collective DH supply can reach out further and compete with local supply based on natural gas and heat pumps, especially in areas where buildings are energy renovated or in areas where new energy efficient buildings are constructed. COOL DH will demonstrate secondary effects of efficiency improvement in operation of cooling systems that supply the low-grade heat to the LTDH systems and other quality of life improvements on reduced emissions and tertiary use reducing costs of snow clearance and increasing green season of plants in the science village area.

Overall strategies of city/municipality connected with the project

The municipality has a political goal to reduce its environmental and climate impact substantially. Between the years of 1990 – 2020 Lund will decrease the total amount of GHG emissions by 50 %. In 2050 the GHG emissions should be nearly zero. The municipality has six overarching goal areas where one is to decrease its environmental and climate impact substantially. In this way, the expansion of the city can take place without increasing the GHG emissions and the biomass presently used in the district heating system will be released to replace fossil fuels where this is used today. As in many other Swedish cities, district heating started up in the 1950’s and the district heating system now covers almost the entire city. The main heat production unit is a large scale biofuel based CHP facility. Other important production units are a large scale geothermal system, a heat pump for recovery of heat from sewage water, district cooling heat pumps and other renewable energy sources. Kraftringen has the ambition to be completely free from fossil fuels in all heat production, and the production in Lund is fossil-fuel-free already today. Expansion of the city will call for more nonfossil energy sources to be integrated and used in the system such as low-grade waste heat.

Strategy

The sustainability framework for the municipality of Lund is called Lundaeko. This framework is structured into eight different focus areas: Involvement, sustainable consumption, clean water and clean air, minimizing climate impact, decreasing chemical stress on the environment, sustainable city, climate change adaptation and biological diversity.

Key steps of the process

The different focus areas are taken into account in the yearly planning process of the municipality. The yearly progress is described and evaluated in a sustainability report and is processed in an evaluation with top city management and decisionmakers. Internal and external revues are performed on a regular basis.

How are citizens involved in decision making process?

The development of the area is being implemented by the Lund-owned utility Kraftringen. Lund municipality is one of the main partner and sponsor of the project. Generally the public authorities pay a lot of attention to the citizens acknowledgement about the development of the project’s works through a constant communication activity. Specific tasks of the project focus on the relation with the citizens.

Financing aspects

Soft loans over 50 years are used for building works. The housing companies finance the RES supply for the selected demo blocks. The public utility including 3rd parties finances the part of costs not covered by EC grant. The project will contribute to reduce costs of heating supply, which means that collective DH supply can reach out further and compete with local supply based on natural gas and heat pumps, especially in areas where buildings are energy renovated or in areas where new energy efficient buildings are constructed. The cost savings derive from the low marginal cost of purchasing low-grade energy.

Business model

One task of the project is dedicated to the searching for the most suitable business model including terms for new LTDH tariff promoting energy efficiency, flexibility in supply options and ensure low return temperature, since this is vital for an efficient performance of the waste heat recovery. The business plan looks into new possible price models and contract boundaries, where the utility may own and operate substations including possible heat pump and main pipes in the building, and ensure regular inspections and heat supply at competitive cost.

Regulatory aspects that help the project

The project proposal will be approved by the authorities based on calculation of societal benefits excluding taxes and fees but including value of environmental externalities

Regulatory aspects that hinder the project

The Swedish heating sector, including district heating, is unregulated. Success factors The unregulated sector results in a competitive market. The economic feasibility of this project therefore depends on cost awareness combined with a successful marketing/selling strategy.

Challenges and barriers

The unregulated market means sometimes heavy competition. Establishing district heating infrastructure in a new city development results in planning problems regarding the exact location of the piping network, since the roads haven’t been planned in detail in all parts of the area.

See more examples in '100% Renewable Energy Districts: 2050 Vision'