Prison reforms energy-wasting operation
The electrical consumption for mechanical services at Her Majesty’s Prison Edinburgh has been reduced by nearly 27% following the implementation of a Trend controls survey. The associated reduction in overall site consumption was 11%. The savings amount to many thousands of pounds, and the return on investment (ROI) for all works, including replacing outdated and obsolete plant was very favourable and fell well within the defined requirements of the Scottish Prison Service (SPS).
The mechanical control panel is directly responsible for the prison’s AHUs, pumps, fans and associated equipment — which can represent over 40% of the electricity consumption of a prison.
SPS has a defined energy-management strategy and has worked closely with Trend for nearly 20 years. This relationship currently includes the operation of a framework service contract for BEMS maintenance.
Ronnie Macdonald, energy and engineering services manager at SPS, explains, ‘We have comprehensive BEMSs installed at all of our main establishments, which over the years had been set up by a number of different system integrators, all with their own ideas about user interface configuration, control strategies and the most appropriate technology. We identified that through greater consistency in relation to technologies, strategies and staff interaction, we could realise significant operational and energy efficiencies. We therefore decided to call Trend in to see what could be done.’
Prior to the survey proposed by Stuart Lonie, Trend’s business-development manager, a set of objectives was agreed on. They included identifying hardware and cabling that had reached the end of its service life, as well as devices that had become obsolete or increasingly difficult to service.
The brief included identifying viable enhancements to the BEMS that could improve energy efficiency through hardware and software upgrades.
The findings also needed to outline a schedule of priced upgrades and replacements.
HMP Edinburgh now operates its heating and ventilation systems under a demand-led strategy. These systems are operated at part load by default, with output increased automatically as required.
Ventilation rates, for example, are set at 80% of capacity by default, and automatically increased to 100%, depending on CO2 levels in extracted air.
Ronnie Macdonald concludes, ‘It was always my belief that we could get far more out of our BEMS. The Trend controls survey was the real turning point in enabling us to go back to basics, clearly assess what was possible and identify which activities could provide the best results. I’m delighted with what’s been achieved, and we will use this experience to roll out similar programmes across other SPS sites.’