Ene 04 - Low and Zero Carbon Technologies

District heating systems – fuel mix - KBCN0885

Where the feasibility study is considering connection to a district heating system and this burns a mixture of fuels, only the proportion of output generated from second generation bio-fuels (or waste incineration that complies with BREEAM requirements) can be considered for this issue. For instance, a system burning a 25/75 mix of compliant biofuel vs fossil fuel can only count 25% of its output towards a meaningful reduction in CO2 emissions (where relevant to the BREEAM scheme) against the baseline building. As fuel mixes may vary over time, at least one year or more of historical information must be provided to balance out any seasonal variations. Where the system is new or proposed, robust evidence must be provided of the anticipated fuel mix. The fuel mix must be calculated based on the energy content of the input fuels in kWh.

19/12/2017 Wording clarified

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Feasibility study – comparison with connection to existing LZCs - KBCN0563

In carrying out a feasibility study (covering all the areas required as stated in the manual) the primary intent is to demonstrate to a reasonable level of certainty that the chosen LZC is the most appropriate of all those available. Some of the options (for example community heating/cooling schemes) may not allow for a simple like for like comparison but a comparison can be made overall across many factors. For example in a community heating scheme the life cycle costing estimate might need to be simply the cost of using and maintaining the system for the measuring period, if upfront costs and payback period information is not available. Similarly for an existing community scheme, planning would not be a barrier but land use and noise impacts could be compared. The feasibility study must include a comparison of all criteria and for it to show that each has been factored into the final option being made. While some options may provide information in different formats and differing levels of detail making direct comparisons not straightforward, a comparison can still be made and this should aim to be as comprehensive and representative as possible. This will serve to demonstrate with reasonable certainty that the chosen option is the most appropriate. 

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LCC – LZC energy sources discounted - KBCN0606

When sufficient information can be provided to justify that LZC energy sources are not appropriate for the development, the LCC analysis, for those LZC sources, do not need to be included in the feasibility study. The feasibility study (covering all the areas required as stated in the manual) intends to demonstrate, to a reasonable level of certainty, that the chosen LZC is the most appropriate of all those available.

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LZC technologies – planning conditions and restrictions - KBCN0535

Where a mandatory planning condition exists (eg to attach to a District Heating Scheme), this will clearly affect the number of options available in a feasibility study. In such cases, compliance can still be achieved where evidence on the planning condition restrictions is provided, and it is clarified how this excludes other technologies from being considered. The feasibility study will still need to be carried out to cover the remaining energy needs of the building (eg Electrical and lighting load in the case of a district heating scheme).  

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LZC technologies – shell only feasibility study - KBCN0409

For a shell only project, compliance may be assessed on the built form only i.e. demonstrating that sufficient space and clearance for the installation of future LZCs has been considered, the built form is suitably sited, and that massing and orientation are optimised for the future systems.

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