Carillion's energy savings at Ministry of Defence

24 June 2013

Engineers responsible for maintaining a historic Army barracks in Chepstow - home to 1 Rifles - have set their sights on a 50% cut in energy use in a project that should pay for itself in just over a year

CarillionEnterprise (C-E) is achieving savings at Beachley Barracks as part of the Ministry of Defence's (MOD) energy Spend to Save programme that involves investing in projects throughout the Defence estate to achieve significant reductions in its £1 million a day spend on heat, light and power.

The savings at Beachley are being achieved by the introduction of 12 VSDs on ventilation systems and boilers across the site to regulate the speed, flow of water and air. Kevin Muttitt, energy implementation manager at C-E says: "The VSDs have been introduced as one of seven key energy reduction technologies forming part of our 2012/13 Spend to Save programme of works. We estimate that the savings of over £16,000 pa will see the scheme pay for itself in just under 15 months."

C-E manages the site for the Defence Infrastructure Organisation (DIO), the MOD's property and services provider. It appointed specialists to survey the site and produce a detailed analysis of all the drives that could be controlled. The equipment chosen included Invertek Optidrive HVAC and fan-pump inverters.

A total of 12 inverters were installed on various fan and pump applications with motor frequencies/ speeds typically reduced from 50 hz to between 35 and 40hz, easily meeting the project objectives of a minimum 20% reduction.

Muttitt said: "Installing the inverters provided less mechanical stress on belts and couplings as the inverters offer an inherent soft start and soft stop for the load under control. As an example a 15kw hot water circulation pump running at a load of 14.7kw, 50hz operation, had its frequency reduced to 40hz and the load dropped to 7.4kw, achieving a 50% reduction."

Steve Setterfield, assistant site estate delivery manager said: "The VSDs were installed in Beachley as part of several sustainability initiatives. The work was carried out through the summer months when disruption to heating would be at a minimum. To date there has been no noticeable drop in performance and we're already seeing a reduction in energy use."