The Heart of England NHS Foundation Trust (HEFT) has partnered with renewable energy installer, Ecolution, to install solar PV arrays at Solihull Hospital and Heartlands Hospital in Birmingham.
Both hospitals are benefiting from the electricity generated from their two 250kWp roof-mounted arrays. HEFT identified solar as a means of saving energy, cutting costs and reducing the hospitals’ carbon footprints.
Initially, HEFT requested over 250kWp for each of the hospitals roof but due to the nature of the feed-in tariff degression bands this would have resulted in a drop in FiT levels of 35% so HEFT elected to cap the installs at 250kWp.
Ecolution chose black-framed Hyundai 250W modules, using over 2,000 panels across 28 roofs – all with varying pitch, orientation, height and covering. The installations were completed in les than six months, in time for the hospitals deadline of March 2014.
The arrays are predicted to deliver over £2 million in associated savings and feed-in tariff payments over the next 20 years.
Pete Sellars, director of estates for the NHS, said that he was delighted that the £3 million project did not result in the closure of any wards or disruption to critical services.
A particular challenge that Ecolution faced were the hospitals’ electricity back-up generators. If the solar arrays ever produced more than the electricity load on the generator it would create a back feed into the generator which results in a rise in voltage which would prevent it engaging. The generator would also feed the supply with the PV system causing potential damage to the PV array and generating equipment.
To negate this, Ecolution designed a bespoke solution by connecting a radio frequency module into a relay that provided Ecolution with a radio signal whenever the generator was about to engage.
The PV distribution board contactor then receives a signal to stop sending the electricity supply to the PV system, ensuring that the generators and PV systems do not operate simultaneously.
Before the installation of solar HEFT spent more than £1 million per year on energy, the solar arrays are expected to save it over 10% on its current expenditure – a figure that will only rise if electricity prices rise in the future.
Robert Harley, business development manager for Ecolution commented: “This project was completed in time, on budget and without any complications, despite the high level of technical detail required on this project. Throughout, Ecolution continually listened to the needs and concerns of NHS and MITIE employees and adapted our working practices to accommodate their requirements without moving away from the initial brief that we were given.”