The location and timing of the provision of Energy Centres on large multi-phase development sites with district heat networks is complex as there are a number of often competing factors: –
- Overall capital cost
- Cash flow
- Operational efficiency & costs (which influences resident energy costs)
- Phasing flexibility
- Matching Energy Centre output to development heat demand
The above factors are best considered at the planning application stage, so as to ensure that all options remain open and the most appropriate strategy is selected. Planning authorities are generally amenable to a balanced strategy as they recognise that it is not always viable to deliver a development with a single Energy Centre.
From a long-term operational and overall capital cost perspective, a single Energy Centre is more favourable than multiple Energy Centres. However, during the initial stages of development, this would be operationally inefficient due to there being a low connected heat load. Furthermore, an Energy Centre sized for many thousands of homes is a costly piece of infrastructure to deliver at the outset of a project. Where development is expected in multiple and separate areas of a site simultaneously, a single Energy Centre would not be able to initially provide heat in a cost-effective way to the remotely developing phases.
These factors can combine to make other strategies most appropriate: –
- Two or three permanent Energy Centres
- Use of temporary plant rooms for the initial phases prior to connection to a permanent Energy Centre.
The particular characteristics of a development will help to define the most appropriate strategy.