Power Available: unlocking renewables’ potential to help balance the electricity system


It’s an exciting time for zero carbon electricity in Great Britain. April brought record levels of solar generation, and we’re on an unprecedented coal-free run.  The ESO is committed to enabling zero carbon generators to play a larger role in balancing electricity supply and demand. The Power Available (PA) project is one innovation that hopes to do this.

Today we’ve integrated the PA signal from over 90 renewable generators into our control systems and processes, providing greater visibility to our control room engineers as they balance the system on a second by second basis.

This achievement is the result of collaboration between ESO and the wind industry – supported by RenewableUK – and means the balancing services market for real time frequency response is becoming even more accessible to renewable generators. And while only PA for wind power is being integrated initially, work is underway to make PA for solar available later.

So, what is PA, and why is it good news for the electricity system?

PA is a live data feed available to our control room engineers which tells them what the potential maximum power output of a wind generator is at a given time and in given conditions – and they can compare this to the generator’s current operating output (the difference is often referred to as its ‘headroom’). Our control systems can then accurately calculate the response and reserve capability held on each generator, enabling them to compete with other generation technologies to provide real time response and reserve services.

Through innovations like the PA project our electricity system is becoming smarter, more flexible, and – since wind power is often a cost-effective option when it to comes to real time frequency response – delivers increased value to consumers.

Historically our control room has had limited visibility of the response and reserve potential of intermittent generators, like wind, which make up a growing percentage of installed capacity in Great Britain. With the PA signal in our control room, our engineers have that insight at their fingertips, improving our forecasting ability and supporting our 2025 zero carbon system operability ambition.

Power Available is a significant development for our control room operations, and delivering the project has been challenging at times. Through innovations like the PA project our electricity system is becoming smarter, more flexible, and – since wind power is often a cost-effective option when it to comes to real time frequency response – delivers increased value to consumers.