Heating Network – City of Antwerp

February 11, 2019

 

Client: Stad Antwerpen
Period: August 2016 – December 2016


Work

At the request of the City of Antwerp, 3E conducted a study – supported by the expertise of Ingenium and Fieldfisher – on the feasibility of a heating network in the vicinity of Antwerp Town Hall.

A heating network is an excellent way to achieve sustainability in listed historic buildings and historic city centres. However, reducing the energy demand, which is the first step of the Trias Energetica, is because of the nature of those buildings only partly achievable. Procedures such as thermal insulation and solar shading are indeed often in conflict with the preservation of heritage value. The use of renewable energy (i.e. solar thermal systems, PV and biomass) on or near historic buildings is for the same reason also often problematic. Therefore, linking the heating network to a renewable heat generation project seems the best solution to push historic buildings towards climate neutrality.

The heat demand has been calculated based on two scales. The first scale is called the “core area” and has been determined by the heat demand of 4 government buildings: Stadhuis, Vleeshuis, DIVA and Het Steen. The second scale covers the heat demand of the core area plus of the adjacent Woonhaven social housing units. It is the “expansion area”. In addition to determining the heat demand, an inventory of the options available for green heating has been drawn up. The local potential of solar energy, biomass, geothermal energy, sewage waste energy and energy obtained from the Schelde were namely studied.

Next to that, several options were investigated for the establishment of a possible future connection to, for instance, the city heating network from the South powered by residual heat from ISVAG. According to our study, this latter connection has a high potential for CO2-reduction. Based on the long list of concepts and in mutual consultation, 6 scenarios were retained, the biggest differences being the way heat is generated. For each type of heat generation, 2 different scales were again considered, namely the “core area” and the “expansion area” (respectively ‘kern’ and ‘uitbreiding’ in the graphic below).

All the scenarios guarantee a reduction of CO2 emissions in the long term. Compared to the current situation (i.e. individual combustion installations using natural gas), using gas would for example allow a reduction of 20-30% of the CO2 emissions, whereas using energy from the Shelde could reduce it to 50% or even 75% if the CO2 emissions from electricity purchased e.g. for the heat pumps is not taken into account (in case of green electricity).

In other words, the social benefits of the suggested heating networks are undoubtedly highly valuable. However, the financial feasibility of those projects is less obvious. With the applied set of parameters, none of the project proposals reaches an IRR of 5%. Even though the energy potential of the Scheld looked very promising in the inventory stage, it is not financially feasible with a one-time subsidy.