Case Study
How a Large Hotel Could Reduce Electricity Costs by £27,000–£32,000 a Year
A measured electrical investigation identified substantial savings through better control of existing systems — without compromising guest comfort or replacing serviceable plant.
Challenge
Despite previous investment in energy-saving technology, including voltage optimisation, the hotel continued to carry a substantial electrical base load overnight.
The challenge was to establish which systems were responsible, why they continued operating during lower-demand periods, and where further investment would deliver a worthwhile commercial return.
Investigation
Temporary electrical monitoring was installed across the hotel’s main incoming supply and selected distribution boards. Demand was recorded at 30-second intervals during normal operation, with the main supply monitored for approximately 96 hours.
- Plant-room pumps, Variable Speed Drives and BMS controls
- Kitchen ventilation plant
- Staff and public-area lighting
- Guest-bedroom distribution
- Voltage optimisation and power-factor performance
Measured profiles were compared across occupied and off-peak periods, supported by physical inspection of the relevant engineering systems.
Key Findings
Plant-room demand
The principal opportunity was in the plant room. Pumps appeared suitably sized and serviceable, but the measured profile indicated that the control strategy no longer reflected varying operational demand.
| Date | Off-peak | Peak |
|---|---|---|
| Sat 27 May | 47.2 kW | 54.8 kW |
| Sun 28 May | 31.8 kW | 51.0 kW |
Other findings
Kitchen ventilation. Approximately 70% of the monitored load remained overnight. Programmed control offered an estimated annual saving of £4,000–£7,000.
Staff-area lighting. Fluorescent lighting operated for prolonged periods irrespective of occupancy. LED replacement and occupancy controls offered an estimated saving of approximately £12,000 a year.
Public-area lighting. Existing LED lighting operated through daylight hours despite substantial natural light. Better daylight and time control could save an estimated £2,000–£5,000 annually.
Guest-bedroom block. Demand fell to approximately 0.1 kW off peak and responded correctly to operational demand. No intervention was recommended.
Power factor. Performance remained excellent at 0.98–0.99. No additional power-factor-correction expenditure was justified.
Recommendations
- Recommission the plant-room pump and BMS control strategy.
- Investigate the bypassed Variable Speed Drive and verify sensors and pump settings.
- Introduce seven-day scheduling for kitchen ventilation.
- Replace appropriate staff-area fluorescent fittings with LEDs and occupancy controls.
- Add daylight and time control to public-area decorative lighting.
- Retain the existing bedroom controls and power-factor correction.
- Re-monitor affected systems after implementation to verify savings and performance.
Outcome
The investigation identified a conservative potential saving of £27,000–£32,000 per year, equivalent to an estimated 15–20% reduction in total electricity costs.
The strongest opportunity came from improving how existing plant was controlled. The priority plant-room improvements were expected to cost approximately £4,000–£5,000, with an indicative payback of three to five months.
By measuring individual systems before recommending investment, the hotel received a practical action plan focused on reducing operating costs, protecting guest comfort and avoiding unnecessary capital expenditure.
