CE Delft conducted an exploration on behalf of the municipality of Zaandstad, examining the options for making the Krommenie district natural gas-free. The study aims to support the municipality in identifying a preferred direction for the local energy transition. It was carried out in collaboration with housing corporation Parteon, heat company HVC, and grid operator Liander.
Three natural gas-free heating technologies were investigated and compared. The first is the electric air-source heat pump, an individual solution that extracts heat from outdoor air and uses electricity to bring it to a suitable temperature (30-55 °C). The second is the medium-temperature heat network (MT heat network), a collective system that distributes hot water through underground pipes to multiple homes (55-70 °C), potentially sourced from geothermal energy. The third is the low-temperature heat network (LT heat network), also a collective system but operating at lower supply temperatures (30-55 °C), using sources such as aquathermal energy or underground thermal energy storage (UTES).
All three technologies were assessed against five themes and sixteen criteria: sustainability, costs, feasibility, reliability, and scalability. The MT heat network performs best in most neighborhoods. Its main advantages include relatively low costs for residents, as less insulation is required, energy taxes are lower, and it is less sensitive to price fluctuations. It also requires less indoor space and places less strain on the electricity grid. A key precondition is the availability of a suitable heat source, for which geothermal energy is considered the most promising option, though further research into its feasibility and associated costs is still needed.
The air-source heat pump is the most sustainable of the three options and also offers the ability to cool homes, which is an increasingly relevant benefit given warmer summers. Monthly energy costs are often lower than what residents currently pay, and the technology can be scaled up relatively quickly. However, drawbacks include high upfront investment costs for homeowners (especially for insulation), the indoor space it requires, and its significant demand on the electricity grid, which is not always able to meet this demand. Grid operator Liander is working to expand capacity, but this is a lengthy process.
The LT heat network scores lowest overall. Costs for residents are the highest among the three options, though it does offer cooling capabilities and requires less indoor space than a heat pump. It scores well on sustainability.
The municipality is advised to engage in dialogue with residents, businesses, and other stakeholders to collectively determine how the different themes should be weighted. A key consideration in this process is ensuring that the energy transition and its associated costs are distributed fairly.