Heat networks only become a sustainable route when the transition pathway of the heat source is clear. If a network remains dependent on fossil heat for too long, fossil lock-in can occur: infrastructure is built, but the source mix does not move quickly enough. A credible pathway must show how the network will shift step by step towards sustainable sources.
For the Gelderland built environment, this means that heat networks should not be assessed only on connections and cost. Source strategy, phasing, residual heat, aquathermal energy, geothermal energy and governance all belong in the decision. A clear pathway gives residents and building owners more confidence that connection contributes to climate goals.