Electrify your profits

Okay, so it might not be nearly as eye-catching as a sparkling set of new chiller doors, or as smart as new energy-efficient lighting, but for retailers such as Andrew Thornton, of Thornton’s Budgens Belsize Park in London, voltage optimisation has led to some electrifying savings.

Andrew is no stranger to investing in energy efficiency, and has clear cut reasons for doing so. “My motivation for reducing energy is clear: to cut my carbon footprint and save money,” Andrew points out.

He adds: “The store already boasts a wide range of energy efficient measures, from the latest, most efficient chillers with doors, to LED lighting and, most recently, voltage optimisation equipment, which is already achieving impressive results.”

So just what exactly is voltage optimisation, and why do retailers need it?

Let us enlighten you. As of 1995, the nominal European voltage was harmonised at 230V, meaning that all equipment placed on the market within the EU is designed to run at 230V. However, in mainland UK the average voltage supplied from the national grid is 242V, with levels ranging to as much as 253V, depending on local conditions.

This overvoltage means that many businesses and homes are receiving voltage at much higher rates than their equipment needs to perform. It’s a bit like filling an old banger with high-performance fuel, or feeding caviar to your cat.

Overvoltage not only causes a reduction in equipment life span, but also dramatically increases the amount of energy consumed - entirely needlessly.

The problem is compounded by what are known as voltage spikes - unexpected surges and dips in voltage which over time can also damage in-store and back-office equipment such as chillers, CCTV, tills and computers.

The spikes in voltage are caused by jumps and falls in demand on the national grid. When demand on the grid is high, the voltage will fall. Alternately, when demand on the grid falls, the voltage can rise. Other factors such as the increasing use of solar PV and wind micro-generation systems feeding power into the grid can also add to more volatility in the voltage level in the system.

As a result, a growing number of retailers are now investing in voltage optimisation systems, which deliver power to their stores at a reduced voltage of around 216-220V, saving energy, offering protection from spikes, and extending the life of electrical equipment.

Products such as chillers and air-conditioning units, which use motors to run their pumps and fans, particularly benefit from voltage optimisation, as do incandescent lamps and T8 fluorescent lamps.

Energy-saving expert Brian O’Hagan from Ecomonitor believes the savings could be significant for store owners. He says: “By bringing supply voltages to the lower end of the statutory range through optimisation technology, electricity consumption could be reduced by about 10% on average, although savings of up to 20% are possible, dependent on the mix of voltage and equipment.” The company supplies the combined voltage optimisation and energy-management software Eco-system360.

O’Hagan suggests that voltage optimisation would be a “sound and economically viable solution in terms of energy reduction and power surge protection” for stores using about 150,000 kWh units of energy per year (in monetary terms that is about £15,000 a year, excluding any standing charges and VAT).

Stores such as Andrew’s, which uses Ecomonitor’s system, have achieved average energy savings of 10% at sub three-year payback levels.

Prices depend on the size of unit, but typically start at £3,400 for the smaller 60 amp units up to £8,900 for the larger 250 amp units, including installation. As they’re not exactly pretty, units tend to be situated in back office areas. A 250 amp unit measures 500 x 550 x 450mm.

However, as is the case with installing any new energy saving equipment, it is vital that a site survey and voltage logging process are carried out prior to any work so that savings can be accurately measured. •