ESO: Solar power that never sleeps

A solar farm in East Sussex has become the first of its kind to provide a night time reactive power voltage support service to National Grid ESO. Reactive power services are a key part of smoothing out voltage fluctuations to ensure a safe and secure electricity system. During the trial, the solar plant, operated by Lightsource BP, helped keep voltage within the correct range even when the sun wasn’t shining.

It took a small adaptation of the project’s technology to allow it to help keep the lights even once the sun has set. Inverters, normally used to convert solar energy into electric current, were tweaked to help adapt grid electricity to keep it at the right voltage. For example, if there are high winds at night, the solar farm inverter could prevent the voltage from rising too high or, on a still night, it could prevent voltage from falling too low.

The trial illustrates the role solar power could play in helping to balance the grid through dynamic voltage control, something which has traditionally be handled by gas or wind generators. “The success of this trial clearly demonstrates very clearly that innovation is key in addressing the future growth of the energy sector. With electricity demand increasing so rapidly, we have to be in a constant state of evolution in order to solve the problems of the future,” explains Kareen Boutonnat, Lightsource BP Chief Operating Officer.

It follows three years of testing and development and forms part of National Grid ESO and UK Power Networks Power Potential project that is looking at how to absorb more distributed energy resources, primarily renewables onto the grid. It is hoped that the project could save UK energy customers over £400m by 2050 and provide an additional 4GW of power capacity to the South East of England.

“As we move towards our 2025 ambition of being able to operate the GB electricity system carbon free we are seeing more renewable generation come online – such as wind and solar – which in turn requires finding new ways of managing system characteristics like voltage. This innovative trial, which forms part of our Power Potential project, is an exciting first step,” explains Dr. Biljana Stojkovska, National Grid Electricity System Operator, Power Potential Project lead.