Intercommunale Leiedal, Belgium

Overview

Intercommunale Leiedal is a collaborative association of 13 cities and municipalities in the West-Flanders region of Belgium. Home to 310,000 residents, this region forms part of the cross-border Eurometropolis Lille-Kortrijk-Tournai. Currently, the area relies heavily on fossil fuels, with energy consumption increasing by 25% from 2005 to 2017. Despite the rise, CO2 emissions have decreased by 18% during the same period. Local renewable energy production remains limited, accounting for only 8% of the primary energy used. Heating consumes 53% of the region’s energy and is used primarily for residential and tertiary purposes. Heat is harnessed predominantly from natural gas and heating oil, although their shares are decreasing. Sustainable heating options, such as heat pumps and traditional biomass like wood stoves, still make up a small portion of the energy mix.

Leiedal’s pilot project marks a significant advancement in 5th-generation district heating, showcased in the new mixed-use neighbourhood of “De Voerman” in Anzegem. This innovative system harnesses heat and cold from a main drinking water pipe running near the site. The pipe carries a consistent temperature of around 10°C throughout the year. A central heat exchanger extracts thermal energy from the water with a maximum temperature difference (delta T) of 4°C.

The primary loop, from the bypass through the heat exchanger, is supported by a secondary loop—a district heating/cooling network of non-insulated water pipes connecting the heat exchanger to each dwelling and business. Despite the larger diameter required by the low delta T, these pipes help reduce investment costs. Each connected building has an individual heat pump that converts the 10°C water temperature to meet specific heating, cooling, and sanitary warm water needs.

Leiedal is responsible for the development of the concept of the energy community, as well as for the business model, and the installation of the infrastructure. The first houses and buildings are expected to be built from 2026 onwards.

Energy size

The maximal thermal capacity contracted is 230kWth (0,23MW). This is with a delta T of 4°C. With a higher delta T, e.g. up to 8°C, the thermal capacity can be doubled. The annual energy production is estimated at 720MWh/year.

Technologies used

The heat and cold will be extracted from a main drinking water pipe. The system contains the following components:

• A bypass from the drinking water pipe, deviating the drinking water and leading it through:
• A heat exchanger exchanges the heat from the drinking water with the district heating/cooling system. This is installed inside a newly built technical cabin
• The secondary heat/cold grid distributes the heat and the cold on the site. Note: there is no central circulation pump to let the water circulate on-site
• Per dwelling, there will be one heat pump (individual)

Ambition, vision and expected objectives

1. To finetune the concept of “energy broker”, introduced by Leiedal, acting as a process manager to guide the set up of DHC systems involving all stakeholders Leiedal introduced the expertise of “energy broker”, a process manager to guide the set-up of DHC-systems (organise the workflow, building capacity, setting up cooperation agreements, improve cooperation with the different departments of the cities/municipalities, creating a business model for upscaling, etc.).
2. To create an organisational and financial model in which citizens play a role in the ownership and management of a local district heating, via a community energy model and/or energy cooperative.
3. To integrate district heating in local and regional (urban) planning tools and instruments of spatial policy.

Further reading

https://www.leiedal.be/nieuws/drinkwaterleiding-verwarmt-de-voerman-anzegem

https://www.leiedal.be/warmtenet-de-voerman