The Littlebury Energy Project is dedicated to helping the village understand its energy use and find ways to reduce it. The project’s overall goal is to transition the village from fossil fuels to renewable energy sources to decarbonise the community.
We held a community meeting on Wednesday, 25 September 2024 to present progress on the Littlebury community energy feasibility study. More than 50 people attended to hear Bioregional and Equans present progress on their analysis of heating options for the village.
Our consultants are still working on finalising the report of the feasibility study and we will upload the documents here as they become available. The following are available:
Q & A
Below are the questions that were raised at the meeting. We will upload a full Q&A soon
Technical
- If this system provides heating, does it also require additional systems to provide hot water, or does it heat hot water tanks in the house? Does this require additional plumbing systems?
No other systems will be required to provide the domestic hot water. Typically, a Heat interface Unit would be installed which is a similar size to a combi-boiler. It will contain two heat exchangers, with each serving the space heating/radiator and hot water circuits. Variations in design maybe required around this depending upon the existing infrastructure setup but the intent will be to minimise alterations as much as possible. - If I am considering replacing my old boiler soon, would you suggest going for an individual ASHP or should I wait for a community solution?
This is an early stage feasibility study, and therefore a substantial amount of additional feasibility & design development still needs to be carried out alongside planning, consenting and landownership activities so a communal solution is highly unlikely to happen in the short term. Some properties, under the hybrid solution will be more suitable for a decentralised (e.g. individual ASHP) solution – with the centralised network focusing more on properties around the central village core, as opposed to those which are on the outer boundaries and perhaps are of more modern construction (and therefore more suitable for a decentralised approach). It is therefore difficult to give a direct answer to this question since it is property specific. - How reliable have central energy centres proven to be? Downtime?
The energy centre in Swaffham Prior has experienced zero downtime since it went live. A crucial element of the design was to ensure there is sufficient ‘heat resilience’ at all times, particularly if one or more of the heat pumps were to be off-line for maintenance, for example. As such, there are ground-source, air-source and electric boilers all contribute to the network, all of which are capable of delivering interim heat individually should there be issues in the process. Although, the brief for this study does not comprise design, we have envisaged in our conceptual hybrid solution that there will be built-in heat resilience, with the thermal stores also able to meet heat demands for a time on their own if in the unlikely event, all heat sources were offline. - How feasible is it for older (and leaky) houses to tap into the community energy option?
Due to the mix of age, construction type and thermal performance of the properties in Littlebury, it is highly unlikely that a low temperature centralised solution would be feasible given that this would require multiple interventions in properties to ensure that radiators, pipework and other ancillaries are all compatible with the low delivery temperature from the network. Therefore, it is envisaged that the network will operate at higher flow/return temperatures to minimise the need for costly and dirsuptive interventions. A property with poor thermal performance will still be able to connect to the network, it will just draw more heat from it – but at the same temperature as a property with better insulation / draughtproofing etc. Subsequent improvements to thermal performance will contribute to reducing the amount of heat required in the long-run, beneficial to operation of the network overall, and are to be encouraged – but not essential to confirm feasibility of connection. - Is it correct to say a high temperature heat pump requires less in the way of household modifications (eg new radiators) but costs more to run?
Broadly speaking yes – see answer above for context, a heat pump will require more electricity if it is supplying heat at say 70C compared to say 55C. However, a key element of the centralised part of the village solution would be the integration of renewable electricty generation by way of a solar PV farm. We have modelled different size of PV farms and assessed (at high level) the feasibility of implementing one close to Littlebury so that this could have a behind the meter connection to the energy centre and therefore supply ‘free’ electricity to drive the heat sources. A decentralised (individual ASHP) approach would not benefit from this but the homeowner could potentially have solar panels installed on their roof to offset their heat pumps electricity cost in much the same way. - What’s the obsolescence risk with the proposed approaches?
All the heating solutions available – whether fossil fuel or decarbonised will have an operational lifecycle, approaching which the asset owner will need to consider replacement. The communal heating solution is no different and in our modelling we have allowed for lifecycle replacement (REPEX) costs in our analysis. Typically heat network pipes can last for 40-50 yrs at least so the risk here is very low. Heat pumps and electric boilers etc will all need replacement after about 20yrs which is typically equivalent to oil/LPG/gas boilers. If a more efficient solution is commercially available at life replacement – the communal heating solution will allow this to be integrated and the efficiency benefit absorbed. Overall the risk of ‘obsolence’ is very low beyond expected lifecycle replacement periods as outlined. Decentralised solutions have similar lifetimes and again his has been considered in our techno-economic modelling - What are the benefits of a heat network vs individual ASHPs in old leaky/hard to insulate houses?
See answers 4 and 5 above. The network is likely to be designed to operate at high delivery temperatures to account for the mix of thermal performance in all connected properties, and therefore similar levels of thermal comfort would be felt as currently. Usually properties would buy heat at the same rate, which typically will be substantially less than an individual domestic property electricity tariff. So a leaky/hard to insulate property would just require more heat from the network – but this would be same amount of heat it would require if it were to be heated individually by an ASHP rather than being on the network. The key will be whether the rooftop solar as part of a decentralised (individual) solution could offset as much electricity use of the heat pump as the centralised solution – and therefore provide a comparable ‘cost of heat’ rather than whether or not the property is hard-to-insulate. The internal works required would typically be limited to the installation of a heat interface unit to integrate with the existing heating/hot water circuits. Individual ASHP installations may require more modfication/intervention and internal disruption such as radiator upgrades to satisfy the individual ASHP operating temperatures.
Technical (Financial)
- How are the financials structured for a community system to allow for 10/15yr replacement of core technology.
Yes. We have developed a comprehensive techno-economic assessment model (TEA) for the centralised, decentralised and hybrid options considered. As part of this, a detailed projection of inflation factors, energy tariffs, sale of heat etc are considered alongside a detailed cost build-up. This estimates (as accurately as possible at this high level feasibility stage), lifecycle replacement of major plant equipement, such as heat pump replacement (REPEX), operational cost (OPEX) and energy (ENEX) costs to ensure these are adequately accounted for. In the decentralised TEA, business-as-usual boiler/electric heater replacement is also allowed for. It should be remembered that this is a high-level assessment and not property-specific so there is likely to be variances/errors, the intention would be to build on these and refine during more detailed feasibility/design development. - Does the final detailed study lay out a clear recommendation for the village including likely costs and funding solutions?
Yes. The report will set out a final recommendation and this will be developed further into a seperate ‘Executive summary’ document. More detailed appendices with most of the technical detail/figures etc will also be included in our submission for circulation via the Littlebury working group. - What are the funding options for the community energy centre?
Where appropriate we have considered and factored in potential funding for the centralised/communal heating scheme. The UK government has said that it sees heat networks as being a key contributor to achieving net zero targets and decarbonisation and has various schemes in operation. The key one for a rural heat network such as this is likely to be the Green Heat Network Fund. We have some experience of the application process, eligible costs, appraisal metrics and potential funding levels available under this scheme and have, where appropriate factored this into our TEA. - How would the central infrastructure be funded and how much will it cost for individual households to connect?
See answer to 10 above. Our brief at this stage has been focused on identifying the best technical solution(s) and a core component of this is the economic viability. As this is a high level feasbility study the brief does not extend to detailing a fully financed cost package or confirming the the actual cost to individual households. We have used estimates based on previous projects and experience to determine likely cost of connection and installation for the centralised, decentralised, and hybrid solutions. - Any estimate on the cost of removal of existing boilers and more importantly tanks?
Based on our experience of other projects including Swaffham Prior, we have made estimates of these costs where relevant and included within the high level TEAs (techno-economic assessment models). - Do we have any info from Swaffam Prior regards the total cost of building out the community system AND the costs to consumers versus what it replaced.
Yes – this has been accounted for within the TEAs as appropriate.
General Project
- How engaged were Audley End Estate?
The team met with Audley End Estate to engage their interest in the feasibility study. There were no commitments made between parties, but they understand the overall scope and potential interactions the estate will have with any plans going forward. - What are the timescales for a community solution?
A heat network solution will likely take multiple years to deliver, best practice guides indicate 18 months to continue feasibility and put in place financial structures, then approximately two years to complete detailed design and installation (see graphic below referenced in report, p.82) - What is uptake on Swaffham Prior project – and when could people start signing up?
The system was designed to heat 300 homes, they expect 75% of customers to be onboard within five years. The LEP project team will collect names of residents who are interested in exploring the opportunity. Supporting the project in this way sends a positive signal to grant funds and potential project finance companies. However, “sign ups”to the scheme will not be open until the financial understandings of the project are more fully developed. This will likely take another 6-18 months. - Aren’t oil fired boilers currently set to be banned in 2035 at the same time as gas?
Yes, NEW oil boilers are set to be banned in 2035. - What form will the feasibility study be published in and how do we get hold of it?
The study will be available on the project website as a downloadable document. There will also be an executive summary to capture the main findings from the study. - Will we get a copy of these slides? See the download links above.
- Any more cake? Yes. Cliff Parisi has just brought in some freshly baked Bakewell Tarts!
