Project Summary
In partnership with Dorset Council (DC), the South West Net Zero Hub commissioned a consultant to undertake a portfolio-level feasibility assessment of rooftop solar PV across the Council’s leased property estate.
The study evaluated 122 buildings and ranked them across technical, commercial, legal and ESG criteria to identify the most feasible deployment opportunities. The project also developed an Excel-based screening tool to support ongoing decision-making and prioritisation for installation of rooftop solar PV across DC’s leased property estate.
Background
Dorset Council has committed to achieving a carbon-neutral Council by 2035 and net zero across the county by 2045. The study wanted to build on the existing rollout of renewable energy across its direct-owned estate, including a £18.2 million retrofit programme delivering over 13,000 solar panels (4.5MW). This study focused on its leased estate, where delivery is more complex due to tenancy and legal considerations. A shortlist of 122 buildings was assessed using a consistent methodology to identify the most viable opportunities for solar PV deployment covering a range of building types across Dorchester, Weymouth, Swanage, and Shaftesbury.
The feasibility assessment undertaken by Ramboll was based on a combination of Council-provided datasets, spatial mapping tools, and standard analytical software. The primary dataset was supplied by Dorset Council via outputs from Dorset Explorer, which included key information for each of the 122 shortlisted buildings such as location, site description, building type, tenure, and site coding. This data formed the foundation of the portfolio-level analysis.
Our Role
The South West Net Zero Hub commissioned the consultant to undertake the feasibility study and supported project delivery throughout.
Location
Dorset
Technology
Rooftop Solar PV
Financing and Ownership
Dorset Council’s leased estate.
Results
Portfolio-level Feasibility Assessment:
The consultant used mapping and visualisation tools, including Google Earth and Dorset Explorer, to review building locations, rooftop area, orientation, layouts and surrounding site characteristics e.g. level of shading and roof access.
The study identified a clear pipeline of solar PV opportunities, segmented into high, medium, and low priority groups. The top 25–30 sites form a strong core delivery programme. While the next 30-35 sites are lower priority but still offer viable solar PV potential, and should be addressed further along the timeline. The bottom 55 sites were determined as low viability due to varying constraints, and solar PV adoption should be avoided here.
| Installed capacity [MWp] | Annual production [mWh/year] | |
| Top 25-30 sites | 4.53 – 4.63 | 5430 – 5561 |
| Medium 30-35 sites | 4.53 – 4.63 | 5430 – 5561 |
| Bottom 55 sites | 1.33 | 1593 |
Legal Review & Workshop
In addition to this, Ramboll completed a legal review of two undisclosed leases for DC’s leased estate, to assess practical delivery considerations and identify barriers for installing solar PV on the leased assets. Personal information has been redacted for this case study, but here are some of the key considerations:
· Absence or limits of explicit rights to install landlord-owned infrastructure such as solar PV, inverters, etc. So tenant consent would be required via a lease variation or licence.
· Risk of breaching tenant rights from ongoing disruption from noise, structural issues and maintenance. Installation and maintenance must be scheduled to minimise this.
· Unclear or conflicting insurance responsibilities.
· Lack of contractual mechanisms for energy sharing or financial recovery.
Ramboll hosted a workshop to present key findings and recommended actions to the South West Net Zero Hub and Dorset Council.
Benefits
This project provides Dorset Council with a structured pipeline of solar opportunities, supports targeted investment, and establishes a repeatable methodology for future decision-making.
Next Steps
The next phase is to carry out detailed feasibility studies for 10–20 top-ranking sites, engage stakeholders, and refine the screening model as new data becomes available.