Introduction
In 2025, St. Leonard's Care Home, part of B&M Care Homes, took a major step towards lower running costs and lower carbon emissions by installing a roof mounted solar PV system with Spirit Energy. The system includes 155 solar panels and is expected to generate 62,849 kWh of clean electricity each year. Here is what was designed, how it is set up, and what the numbers look like.
The Solar System Design
Our work with St. Leonard's focused on designing a system that fits the roof and matches the care home’s steady daytime demand. The final design is a 70.53 kWp roof mounted solar PV array made up of 155 Trina 455W panels, with an active PV cell area of approximately 310 m². The panels are installed on a pitched roof using brackets fixed to the rafters, with over roof mounting frames.
The DC array feeds two inverters:
1 x Solis 30K S5 1 x Solis 40K S5
To forecast performance, we used the standard MCS methodology and included a 5% shading allowance. The system is estimated to generate 62,849 kWh per year. The model assumes 80% of this generation is used directly on site, with the remaining 20% exported. In practical terms, that equates to:
Around 50,279 kWh used on site per year Around 12,570 kWh exported per year.
Installation Highlights
The installation was planned to minimise disruption to an occupied care home. The system is designed around a straightforward rooftop array installation, with key electrical equipment located internally and protected, ready for connection and commissioning once network permission is in place.
St. Leonard's pitched roof suited an over-roof mounting approach, with brackets fixed into the rafters and mounting frames installed above the roof covering. DC cabling is routed from the roof into a top floor riser cupboard, where the two Solis inverters are installed, keeping the main plant tidy and out of the way. MID compliant generation metering is included for accurate measurement and reporting.
Safety was treated as a core requirement throughout, with appropriate working at height controls for roof access and a compliant electrical design including correct isolation, labelling, and monitoring to support safe operation and maintenance over the life of the system.
Financial and Environmental Benefits
St. Leonard’s solar system offers impressive financial returns:
- Annual electricity bill savings of over £13,000.
- An internal rate of return (IRR) of 21%.
- A net present value (NPV) exceeding £240,000.
- A payback period of just six years.
- Over 20 years, the system is projected to achieve a total return on investment (ROI) of 334%.
Environmentally, the system will offset 8,548 kg of CO2 emissions in its first year, supporting carbon reduction targets and helping to future-proof the site against tighter net-zero expectations.
Conclusion
St. Leonard's solar investment demonstrates how care providers can align sustainability with financial prudence. By reducing carbon footprint and electricity bills at the same time, St. Leonard's is taking practical action to lower operating costs while supporting long term environmental goals.
Whether you operate a single care home or manage a wider portfolio, installing solar panels can be a game-changing investment. If your building has suitable roof space and high daytime electricity usage, now could be the perfect time to explore the benefits of going solar.
