Energy Project Case Study:
New Housing Development,
Hertmonceux
Project Background
The Strawberry Field development consists of 17 new homes planned for the Herstmonceux Community Land Trust (HCLT). The homes have been designed to achieve an Energy Performance Certificate (EPC) rating A.
The developer had already proposed a design for solar power and renewable heating. BHESCo were engaged to explore alternative options for heat and power that would deliver long-term affordability and security of supply for residents.
Project Development
BHESCo reviewed the proposed development’s architectural plans to identify opportunities for improving energy performance and sustainability. The original design featured individual air source heat pumps and 7 – 8 rooftop solar panels per home. BHESCo proposed an alternative heating option consisting of a shared ground source heat pump system (GSHP) with communal solar PV, operated under an ‘Energy Club’ model. This design maximised on-site renewable electricity use and reduced heating and hot water costs.
Baseline energy demand was assessed using SAP (Standard Assessment Procedure) calculations from the M&E consultant. BHESCo then estimated annual carbon emissions using grid electricity intensity and calculated energy and CO₂ savings from the proposed renewable systems.
BHESCo Recommendations
- Solar batteries to store excess energy and optimise energy use during peak times.
- An alternative energy plan that includes additional solar panels and a ground source heat pump system.
- Proposed a shared solar energy system to maximise efficiency and reduce costs.
- Proposal for BHESCo to finance and manage the renewable energy systems, providing billing services through an “Energy Club” model.
These recommendations are expected to deliver significant long-term cost savings and support the development’s goal of achieving an EPC rating of A for each property.
Options recommended by BHESCo
Project Funding
The project could be financed through a blend of grant funding, community investment, and establishment of an ‘Energy Club’ model. The three funding options that are most feasible include:
Option A: £422,150 total / £24,832 per property
Option B: £670,244 total / £39,426 per property
BHESCo Analysis & Recommendations
BHESCo provided a summary report describing the strengths and weaknesses of each option. The following table summarises the key features and benefits.
BHESCO’s proposal & system description
A total of 246 × 430W solar panels will be installed across rooftops and a ground-mounted solar array, delivering a combined capacity of 105.8 kWp.
This system is designed to exceed the total annual energy demand of the development, supporting carbon reduction and long-term energy savings.
Each block will have high-efficiency ground source heat pumps installed in downstairs service cupboards, drawing heat from a shared ground loop.
This system offers superior efficiency in cold weather, a longer lifespan, and removes the need for complex in-loft installations.
An efficient heat distribution system will be implemented in all homes, fully compatible with the low-flow temperatures of heat pumps. This approach enhances indoor comfort while supporting reduced energy use.
Expected project outcomes
Improved Heating Efficiency
GSHPs to deliver a seasonal COP of 4.3, offering higher efficiency than ASHPs.
This leads to an estimated 5% reduction in electricity use for heating and hot water across the site.
Significant Energy Bill Savings
Households save £947 annually on energy bills vs. gas boiler baseline.
Development imports 4,057 kWh less electricity per year than ASHP baseline.
Solar PV generation exceeds total site electricity demand, providing revenue opportunities from export.
Carbon Negative Performance
Each home will reduce CO₂ emissions by 1.9 tonnes per year, resulting in a carbon-negative outcome of -0.3 tonnes per home (as properties generate more clean energy than they consume).
Total CO₂ savings across all 17 homes: 32.3 tonnes annually.
Microgrid & Energy Club Model
A shared solar energy system and bulk supply meter allow for local energy sharing through BHESCo’s Energy Club.
This setup reduces grid dependency, boosts solar utilisation, and streamlines billing and management.
Per household impact
Impact for the whole development (17 Homes)
Impact summary of potential improvements
Next steps for your development
If you are interested in partnering with BHESCo to support the design of a cost-effective low-carbon heat and power system for your development, please leave your details below and a member of our Projects Team will get back to you soon.