Be.SHARE: an innovative heating and cooling network for the Brussels North District

Be.SHARE is a project for a low-temperature district heating and cooling network that is comprised of local and decarbonised energy production units harnessesing geothermal energy in public spaces (energy recovered from the ground beneath our parks and streets) along with riothermal energy (energy recovered from our sewage water). This system efficiently supplies heat and cooling to a diverse range of users in the district.

Be.SHARE is one of the 20 winning projects of the European Urban Initiative's (EUI) third call for proposals focusing on energy transition and urban innovation.

The Be.SHARE project is spearheaded by Brussels Environment on behalf of the Brussels-Capital Region and in partnership with the intermunicipal companies Vivaqua and Sibelga, the private company Karno, the Vrije Universiteit Brussel (VUB) and the non-profit organisation Convivence-Samenleven.

The project will receive almost 5 million euros in funding from the European Union.

What makes the European EUI programme unique is that it facilitates knowledge transfer to other European cities. The Be.SHARE project aims to share the expertise and innovations developed in the Brussels Region with all interested partners and stakeholders, including these 3 European cities:

• Manresa in Spain
• Leeuwaerden in the Netherlands
• Jablonec nad Nisou in the Czech Republic

The first question to ask is: cheaper compared to what? Compared to fossil fuels, whose prices can fluctuate and skyrocket, as is currently the case? Undoubtedly.

A district heating network powered by local, carbon-free sources can, in any case, offer

• an affordable price;
• price stability thanks to energy self-sufficiency (reliable);
• clean energy.

The price of heating is subject to the social tariff. Those eligible for this tariff will be able to pay the same price for their heating as they do for gas or heating oil (this applies to social housing tenants at Foyer Laekenois). For other users, the aim is to be competitive with the price of fossil fuels and more cost-effective than an individual heat pump. As for the cost of distribution (in the case of a network: upkeep, maintenance, provision for replacement), the aim is also to be comparable to current gas network charges or the maintenance costs of an oil-fired boiler. The benefit of pooling resources allows individual costs to be reduced. Furthermore, there is no longer any need to compare ourselves with gas, a fossil fuel that emits carbon, from which we have agreed to phase out gradually. In this regard, over the coming years, the federal government has planned a tax shift involving the gradual reduction, starting on 1 April 2026, of taxes on electricity transferred to gas, and the introduction in 2028 of ETS2, which shifts the cost of CO₂ emissions (carbon tax) on fossil fuels used for domestic heating and transport (with the revenue going towards a European Social Fund designed to support households during the transition).

The Northern District offers fertile ground; it is a very dense area in terms of both urban development and energy. To ensure its decarbonisation, we need to look beyond individual solutions within each building. The creation of a local energy network that harnesses local, carbon-free energy sources in the public domain is an innovative and promising solution.

Furthermore, the Northern District is particularly interesting as it comprises various types of buildings and uses, ranging from offices to housing. This system facilitates direct energy exchanges based on complementary needs: at certain times of the day or year, for example, the network will enable surplus heat from an overheated glass-fronted office tower to be captured and stored, so it can be made available to homes requiring heating at the end of the day. In the same vein, the same equipment can be used on the same day at different times: for example, in the morning and evening by the homes, and during the day by the offices.

No, using sewer heat recovery does not mean that the heating will smell of sewage.

Although sewer heat recovery recovers heat from wastewater, there is no contact between this water and the building’s heating system. The technology relies on completely sealed heat exchangers installed within the sewer network. These devices capture only the heat, without ever mixing the wastewater with the water circulating in the heating system.

In practical terms, it works much like a radiator or a fridge: heat is transferred through a wall, but the fluids remain separate. Only thermal energy is recovered – not the water, not the smells, and not the bacteria.

Inside the buildings, the heating system is entirely conventional. The water circulating through the system is clean, just as in any traditional heating system. For occupants, there is no difference in terms of comfort: no smells, no nuisance, and no health risks.

Riothermy is therefore a safe, discreet and efficient solution that makes use of existing local energy and reduces the use of fossil fuels, without impacting users’ quality of life.