When a refrigeration failure at NHS Drayton Surgery led to the loss of temperature-sensitive vaccines, it exposed something broader: energy was essential to day-to-day operations yet was not actively managed. A solar and battery storage system, designed around the surgery's actual demand, was the fix. NHS Drayton Surgery solar and battery storage was the fix, designed around the surgery's actual demand.
At the same time, rising electricity prices were increasing operational pressure. The surgery was paying 42p/kWh on a legacy meter arrangement that restricted tariff access and obscured the true shape of its demand. The requirement was not simply to reduce spend, but to introduce a more controlled and reliable approach to energy across the site.
Taking Control: Tariff and Metering
Vester Energy was engaged as the surgery’s energy broker, with an initial focus on establishing control. Correcting the meter class and securing an immediate tariff revision reduced the unit rate from 42p/kWh to 27p/kWh, saving over £7,000 at a stroke. The meter was then upgraded to smart half-hourly settlement, giving the surgery accurate visibility of how and when energy was being consumed, and unlocking access to time-of-use tariffs essential to the next phase.
This foundation mattered. It ensured that any future investment would be based on measured demand rather than assumptions. Twelve months of half-hourly data showed precisely how much solar generation the site could utilise.
Designing NHS Drayton Surgery Solar and Battery Storage
Green Shield Group designed and delivered a system sized to their operating demand. The solution combined a 23.66 kWp solar PV system with 28.21 kWh of battery storage. The battery stores excess daytime generation for later use, discharges during high-cost peak periods, and charges from the grid overnight when electricity is cheapest. Tariff, solar, and storage operate as an integrated system rather than independent decisions.
The project was delivered on a turnkey basis within a live healthcare environment, integrating with existing infrastructure while minimising disruption to clinical activity.
“Vester and Green Shield Group helped us take control of our energy. We’re on track to save over £18,000 in the first year, which we’ve been able to put back into service provision.”
– Daniel Ferrett, Surgery Manager
The financial outcome is substantial. Electricity costs have fallen from £22,566 to £6,694 per year, a reduction of more than 70%. That saving breaks down into three elements: tariff optimisation £7,553, solar generation £6,677, and battery storage £1,641. Combined with gas supplier optimisation, part of the same advisory engagement, the surgery is saving over £18,000 per year across its total energy spend. The solar system alone is forecast to pay back within 7.3 years, with cumulative benefits projected at over £174,000 across a 25-year asset life.
The impact is operational as much as financial. Critical services such as refrigeration are better protected. Energy is no longer a passive overhead.
A Sustainable Model for Primary Care
For other NHS primary care sites, the project demonstrates a clear and repeatable approach. Establish control through data and tariff alignment. Design generation and storage around actual demand. Deliver within the real-world constraints of a healthcare environment. Drayton Surgery cut electricity costs by 70%, saved £18,000 in year one, and reinvested every penny directly into patient care.
