Iterating towards a tailored neighbourhood retrofit solution in partnership with Northern PowerGrid
Place based decarbonisation needs to happen at scale. But as 3Ci’s research has demonstrated, the sums of money involved are eye watering.
Treating each property in an area as an individual unit to be optimised is unlikely to result in the most cost-effective set of interventions. Instead, examining options at a neighbourhood scale will allow for a more efficient use of resources, as well as supporting better planning for local low voltage network reinforcement – that is, ensuring the right infrastructure is in place to supply the necessary grid power to the neighbourhood.
Newcastle City Council (NCC) is developing a Low Carbon Neighbourhood model to discover how to achieve this aim. The project looks initially at a low rise mixed-tenure residential neighbourhood of 228 homes, with 156 being council owned (and managed by Your Homes Newcastle). As the pilot evolves, a generalisable process is being developed for replication elsewhere as well as providing a springboard for unlocking additional inward investment to the city.
Challenge – balancing specificity with a need to scale
To date, attempts at establishing neighbourhood scale guidance for residential decarbonisation have struggled to provide sufficiently accurate and complete recommendations. A lack of accurate data alongside challenges getting all relevant stakeholders to collaborate have hampered efforts to move from theoretical estimations to the more fully fleshed out details necessary to provide the confidence to invest.
Examples of complexities to be resolved include:
- Differences in the characteristics of housing typologies (eg flats, townhouses, terraces) and age imply different solutions in terms of fabric insulation, heating, renewable generation etc
- Older properties in particular often lack detailed floorplans and BIM data needed to design the best interventions
- Power and heat demand varies significantly by time of day, with implications for the optimal solution design
- Mixed tenure neighbourhoods exacerbate the complexity of achieving agreement between residents
- Distribution Network Operators (DNOs) have their own regulatory compliance requirements which aren’t always considered alongside local authority priorities
Solution – building a robust techno-economic model from ground up
Newcastle City Council are in the process of building a replicable model for neighbourhood scale decarbonisation.
The first pilot neighbourhood, St Paul’s Place, was selected because:
- ‘Fabric’ retrofit improvements were already in place allowing better optimisation of heating systems
- Gas boilers in the social housing units were nearing the end of their service life; an ideal opportunity for change
Working closely in partnership with Northern Powergrid (NPg), NCC initially pooled available neighbourhood level data including NPg low voltage network data, calculations on roof solar potential and housing stock data to establish a baseline set of characteristics.
Next, a selection of buildings from the neighbourhood were chosen (to be representative of the diversity of housing stock) and more detailed surveys were carried out:
- An exterior 3D laser scan using a drone
- An interior laser scan using Matterport technology
These enabled the creation of a more de tailed BIM model of each property and provided the basis for an energy retrofit assessment to (and beyond) PAS 2035 standard.
Approximate models are being ‘cloned’ across the whole estate to enable exploration of the best combination of low carbon technologies to ‘de-gasify’ heating supply (for example communal air or ground source heatpumps), as well as incorporating local renewable electricity supply and storage.
NCC have fortnightly calls with NPg to align their activities and ensure that the implications of design choices are considered in the context of local network reinforcement and flexibility requirements – this is about a full city-wide approach and one that can be replicated by all local authorities in their licenced area. The aim is to model energy demand and usage on a half hourly basis to help understand the distribution network load implications and potential role for solar photovoltaic, battery installation and smart dynamic optimisation.
Once complete, NCC expect to be able to identify the best local combination of technologies and build out the financing model which will enable deployment (likely a combination of grant and investment), but the goal is to use this level of modelling to de-risk projects, move away from grant funds and attract investment.
Impact – social housing as a market maker
While the pilot is still ongoing, NCC anticipate the outcome of this work to provide the confidence to invest in the right mix of low carbon technologies in St Paul’s Place. With >150 properties owned by the council in the neighbourhood, and over 25K across the city, they provide sufficient scale to help ‘make a market’.
The robust nature of the survey work will provide confidence to landlords and owner occupiers to invest in the upgrades, and there is potential for NPg to join an investment ‘alliance’ here given the potential reinforcement savings and flexibility gains the scheme could unlock.
What next? – legal and commercial arrangements
As NCC zero in on the most feasible technical options for the first Low Carbon Neighbourhood, they will work on which are the most feasible, and how to deliver them, both in terms of financing and legal / contractual terms (including any potential need to modify tenancy agreements).
Fortuitously, Ofgem has recently awarded funding to NPg to develop a ‘community DSO’ (distribution system operator – ie the more active future of DNOs) model. This 5 year project aims to deliver a proof of concept for a new replicable local energy market framework – perhaps the solution to the financing of Newcastle’s LCNs.
Find out more
 Targeted to be complete by end of 2023