National Grid Electricity System Operator (ESO) has integrated a live data feed from 90 wind generators into its control room systems and processes, giving it greater visibility over their ability to increase output.
The ESO said the “power available” signal will enable wind generators to provide balancing services such as frequency response much more regularly than they have up until now.
“Historically our control room had limited visibility of the potential power that intermittent generation – particularly wind – could deliver at any given time and in any given conditions,” said Colm Murphy, electricity market change delivery manager for the ESO.
“The limited visibility was particularly relevant when intermittent generation sites reduced their output to provide frequency response capability or positive reserve. Without accurate visibility of the potential power available from intermittent generators, these generators couldn’t easily participate in real-time frequency response markets, for example.
“The power available signal is essentially a live set of data that goes straight into our control room and gives them that visibility.”
Colm told Utility Week the inability to access accurate, up-to-date information on their available headroom meant wind generators were previously only used “sparingly” to provide frequency response: “Frequency response is a really critical tool. It’s one of the most important things we do. And if you don’t know how much response you’re going to get from a generator, then you don’t have certainty in one of your most important tools.
“It meant that we were using them as often as we could or when they were at their most competitive. There was also a risk because we didn’t have true visibility of what their actual maximum potential could be, we weren’t able to accurately pay wind sites for the headroom they provided on a minute-by-minute basis.
In instances where they were used, Colm said their headroom was calculated in reference to their nameplate capacity – how much power their turbines could technically produce – “but that’s dependent on weather conditions, unlike say a nuclear station or a CCGT”.
“If we don’t know what there actually is given the weather conditions, then how do we know how much response they can provide once they’re de-loaded,” he explained. “They might only provide a fraction of what we expected them to do or they might be able provide much more.
“And then at the end of the day when we come to settle it and pay for it, we would be paying against the nameplate rating maximum output, which they may never be able to get near to because of wind speed and weather conditions.”
Colm said new windfarms have been required to provide the power available signal since 2016 but it is only now that the data has been integrated into their control room operations.
He said a “huge amount” of work has gone into establishing the accuracy of the data and upgrading its control room systems and processes. The ESO worked with Renewable UK and the University of Strathclyde to create a guide for generators on how to provide the data, to what tolerances and how it will be used.
Colm believes there are plenty of older wind generators not currently required to provide the signal that will now be looking to do so in order to take advantage of the commercial opportunities that come with it. The ESO said work is also underway to integrate the power available signal from solar generators.