Saving energy through voltage optimisation

20-Aug-2014

Exploring the opportunities for the NHS to save money and reduce carbon emissions through the use of voltage optimisation technology

With rising energy prices and a requirement to meet carbon emissions targets, healthcare estates old and new should be investing in technologies that will drive sustainability. In this feature we focus on the impact of voltage optimisation

It\'s not easy to make savings, but with voltage optimisation it is possible to claw at least some money back that could be used to good effect

Despite efforts by NHS trusts across the UK to reduce their carbon emissions, there is still a way to go to meet tough government targets, which demand an 80% reduction by 2050.

Some of this shortfall is because the average incoming low-voltage electricity supply in the UK is 242V, significantly above the optimal 220V rating of modern electrical equipment. Though this excess energy cannot be used productively, it is still factored into an organisation’s energy bill. However, through the implementation of a voltage optimisation (VO) system, this supply and demand imbalance is addressed, making electrical loads draw less power and enabling trusts to reduce carbon emissions and electricity costs.

Consider the options

There are two main variations of VO systems on the market – fixed and electronic-dynamic, more commonly referred to as ‘variable’.

Duncan Agnew, VO consultant at EMSc (UK), which manufactures the Powerstar range, explains: “A building that has a stable incoming voltage supply, but one that is still over and above the optimum rating for electrical devices, requires a fixed VO system, which drops the incoming voltage by a set amount and matches the optimum voltage profile of the site.

EMSc managing director, Dr Alex Mardapittas, with the Powerstar technology

EMSc managing director, Dr Alex Mardapittas, with the Powerstar technology

“Should a building have an unstable voltage supply, high night loading, or secure critical data, then a system that uses electronic-dynamic VO technology will be required as it can systematically manage the peaks and troughs and ensure the voltage is supplied at a constant, stable level.”

The impact will vary depending on the building and the type of installation, but generally voltage optimisers will deliver between 12%-15% savings, though the most-efficient systems have achieved savings up to 26%.

Agnew said: “It\'s not easy to make savings, but with voltage optimisation it is possible to claw at least some money back that could be used to good effect.”

EMSc UK installed its Powerstar VO technology at the Scott Clinic in Rainhill, Merseyside. As a result of the deployment, annual savings of 51,573kWh are predicted, reducing energy bills by £5,466.76.

Expert advice

Mark O’Grady of NHS facilities management company, MITIE Engineering (North), said: “As the UK faces worsening power quality issues, voltage optimisation is emerging as one of the most-secure technologies for NHS sites to adopt as part of their sustainability strategies.”

Voltage optimisation is not an off-the-shelf solution. Buildings differ in requirements and a site-specific survey should be carried out, along with ongoing consultation to determine the perfect VO installation and to ensure maximum savings

VO units from powerPerfector were installed at Carlton Court Hospital in Suffolk, Cirencester Hospital in Gloucestershire, and at Julian Hospital in Norwich. Analysis revealed average reductions in kWh consumption of 11.6%, 8-10%, and 16.8% respectively.

Spokesman, James Buchanan, advises: “Each site is different and it is essential that a site survey is undertaken prior to recommending installation. However, in our experience, hospital buildings do generally present an excellent opportunity due to the nature of the electrical loads.”

Agnew added: “Voltage optimisation is not an off-the-shelf solution. Buildings differ in requirements and a site-specific survey should be carried out, along with ongoing consultation to determine the perfect VO installation and to ensure maximum savings.”

Companies