About Powerstar – Voltage Optimisation System

The Powerstar range of energy saving technologies are researched, designed and manufactured at the EMSc (UK) Ltd headquarters in Sheffield. The company has been in operation since 2001 and is at the forefront of technological advances in energy management. We are constantly evaluating new ideas and researching new technologies. This emphasis on research and design had lead to the growth of the company and has allowed new products and technologies to be brought to market.

As all of our products are manufactured in house we are able to offer a fully supported, engineered solution to your site not just an off the shelf product. With over 150 years of combined experience in design and manufacturing our team of professional project engineers will oversee a project from order to completion and beyond.

BSI 9001              BSI 14001

All our systems are manufactured to quality assurance ISO9001:2008 and environmental standard ISO 14001 and all our components are traceable. Our HV range of distribution transformers exceed the 2021 EU Eco Design Specifications and have done so since their launch in 2012. All of our installation teams are NICEIC registered and have undertaken a thorough competency verification procedure. We are also holders of the SAFE contractor accreditation.


Our support does not end after the Powerstar installation, we offer a full savings analysis and verification service. The measurement and verification procedure carried out is thorough, methodical and in-line with recognised measurement frameworks such as IPMVP. The service provided to clients has been commended as a sound and accurate procedure by independent auditors and verification specialists.

If required, we can also work closely with clients to make sure Powerstar installations are future proofed as a result of any planned expansions or operational changes in the business which may affect loading of the current Powerstar system. In these situations we work with clients to look at the most effective way to ensure we continue to provide maximum savings, which includes advising of potential upgrades to larger systems, the inclusion of additional features or retrofitting to alternative systems in the Powerstar range.

Our Technologies

Powerstar Virtue LogoOur latest product, launched in February 2015, is Powerstar Virtue which is an innovative energy storage system. Powerstar Virtue utilises the induced negative power generated by Powerstar voltage optimisation to charge a storage medium. Fully designed and manufactured in the UK, the system allows companies to save and store electricity locally and switch to this stored supply at any time. Renewable technologies can be integrated with Powerstar Virtue to ensure maximum cost benefit.

Powerstar hv maxPowerstar HV MAX is an energy efficient low-loss amorphous core distribution transformer with integrated variable voltage optimisation technology which allows for an 11,000V input and a regulated 380V (or user defined) output. Suitable for sites that have an inefficient HV/LV transformer on site with high load losses and high voltage profiles, Powerstar HV MAX provides savings by reducing the losses in both load and non-load states with additional savings provided by regulating and stabilising the LV voltage output.

If you do not own your HV distribution transformer you can still benefit from the savings offered by our LV PowerstarMAXvoltage optimisation systems.

Powerstar MAX is and electronic-dynamic voltage optimisation system that is ideal for sites with a high, volatile voltage profile, high night loads, and sites with critical equipment that depend on a stable incoming voltage. The electronic voltage optimisation system supplies voltage at a constant level regardless of the incoming voltage profile.

PowerstarThe Powerstar range of fixed voltage optimisation systems provide a set level reduction across a predefined tap range. The optimised voltage will match the incoming voltage profile, albeit reduced by a set amount. This system is ideal for sites with a high but stable incoming voltage profile.


Watch our short animated videos for an overview of how voltage optimisation and energy storage work

Voltage optimisation works to tackle this over voltage by optimising the incoming power supply so that it matches the requirements of on-site equipment and in turn reduces electricity consumption, energy costs and carbon emissions. Watch the video below for more details.

The Powerstar Virtue energy storage system, uses the unique, patented Powerstar voltage optimisation technology and harnesses the induced negative power feedback to the supply, to charge a storage medium.
In essence, the savings achieved from the voltage optimisation system are diverted into the energy storage system to be used at a time most beneficial to the electricity user.




    October 2016: Powering energy savings in South Africa

      Powerstar South Africa, a distributor for market leading energy storage and voltage optimisation brand Powerstar, is currently saving Pick n Pay, South Africa’s second largest supermarket chain store on average over 8% in electricity costs across two of its stores. The company, which is enjoying its largest period of growth since entering the market