How does energy storage work?

The Virtue energy storage system works by harnessing the induced negative power (back EMF) generated by Powerstar voltage optimisation technology to charge a storage medium and integrate it with renewable generation (if available). This ensures that users will always have optimal power at times of need as they have the flexibility to switch to the stored power at any time to suit their requirements.

How does the Virtue energy storage system work?

How does Virtue work


  • The supplied electricity flows into the Powerstar MAX voltage optimisation transformer and is optimised before reaching the load.
  • The load controller will dictate the amount of power required by the facility
  • The excess power is siphoned into the master controller by the induced negative power feedback (back EMF) generated from the Powerstar voltage optimisation system
  • The master controller contains an inverter/charge controller that controls the output of power to the storage medium.
  • It communicates with the Powerstar system to not only charge the batteries efficiently, but ensure any excess current not accepted during charging is diverted in the direction of the supply.
  • Renewable generation can be integrated with the Virtue energy storage system, with the energy generated from renewable sources directed to the same master controller to either power the facility directly or convert it to DC voltage in order to charge the batteries.
  • The master controller can be manually set to discharge the storage medium and disconnect the grid supply at a pre-determined time, in such as way as to have no effect on the load.
  • The master controller will communicate directly with the National Grid and respond to any demands, this will ensure maximum cost benefit from DNO incentivised schemes
  • The discharged energy will flow back into the master controller and be converted to AC, as well as smoothed to provide a stable flow of power to the Powerstar voltage optimisation system.

Effects of energy storage on load

The below charts show a typical load profile for a commercial store.

The green lines indicate low-tariff periods, the yellow lines represents medial tariff periods and the red lines the indicates the high peak tariff periods. Therefore the green shaded block section on the left hand chart illustrates the region that the facility needs to avoid to ensure it does not incur highest costs and inconsistent supply.

HHD profile of a commercial store load without on-site renewable generation

graph before Virtue installationGraph after Virtue installation

The chart on the right hand side illustrates how the Virtue energy storage system can enable the facility to come off-grid through the peak demand period by powering the facility through the energy storage system. The rest of the load profile remains unaltered, because the storage medium was charged using the induced negative power, not power from the grid.

Therefore this facility is not only saving money, but they are also directly reducing kWh usage, both for themselves and for the grid.


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    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