Fort Amherst, Kent

Project Overview

Fort Amherst Heritage Trust – the charity responsible for preserving Britain’s largest Napoleonic fortress – set out to reduce running costs and lower the site’s environmental impact, with a clear focus on operational efficiency and long-term cost control.

To address rising energy use across the visitor café and other facilities, a rooftop solar PV system with battery storage was installed on the café building, providing clean, reliable power for both the café and the wider site – reflecting the Trust’s commitment to responsible site management and sustainable operation.

SYSTEM COMPONENTS

1. Solar panels: 45 × DMEGC 450 W (16.65 kWp) all-black bifacial modules – high-efficiency (up to 22.5 %) N-type cells with a discreet appearance.
2. Inverter: GivEnergy 20 kW 3-phase hybrid inverter – enabling real-time energy management, export capability and smart-charging features.
3. Battery storage: – 6 × GivEnergy 3.4 kWh batteries (20.4 kWh) – Storing excess solar energy for evening use and allowing off-peak charging, to reduce grid reliance and overall running costs.
4. Mounting system: Renusol Variosole mounting system – a robust, durable system designed for pitched solar installations – and Genius Speed Flash, for even load distribution without the need for drilling.
5. Pigeon-proofing: Titan Eco’s flagship pigeon proofing system, SolaSkirt® – made from black powder-coated aluminium, for longevity and a seamless integration with the array.

IMPLEMENTATION

1. Assessment & design: Working from Mattwell’s architectural plans, the five individual PV systems were modelled to meet SAP requirements and comply with DNO limits. Array layouts were then developed to optimise orientation, and visual balance, and inverters were selected to ensure consistent performance and regulatory compliance across all properties.
2. System design: The system was modelled to maximise solar generation across the café roof, and the DNO application was submitted for approval.
3. Installation: The Variosole mounting framework was fixed to the tiled roof using Genius Speed Flash – avoiding the need for drilling into the slate tiles. The 45 DMEGC panels were then installed. The GivEnergy hybrid inverter and battery bank were subsequently installed for efficient power distribution across the site.
4. Pigeon-proofing: A full perimeter of SolaSkirt® was fitted around the array, providing protection against nesting birds and completing the system with a clean, uniform finish.
5. Commissioning: Electrical connections were completed to integrate the system with the site. The installation was then fully tested, commissioned and certified in accordance with MCS standards – and the export MPAN was subsequently obtained.

RESULTS

The 20.25 kWp solar PV system generates around 20,100 kWh of clean electricity each year, cutting emissions by approximately 4 tonnes of CO₂. Combined with the 20.4 kWh battery system, it delivers almost 30 % energy self-sufficiency, significantly reducing grid demand across both the café and the wider site – with a projected payback period of less than four years.

By producing and storing its own renewable power, Fort Amherst has strengthened energy resilience, lowered operating costs and enhanced long-term sustainability across its facilities, supporting the continued preservation of this historic site.

Please note: The savings quoted in these case studies are indicative and will vary depending on the size of your system, your annual energy generation, and ongoing electricity costs. Actual savings may differ.