Households to provide flexibility in Balancing Mechanism for first time

For the first time, households will provide flexibility through the Balancing Mechanism to help match supply and demand on the power grid as part of a new trial launched by the Electricity System Operator (ESO).

Participants in the trial include customers with smart electric vehicle chargers, which will adapt their charging schedules in response to instructions sent from the ESO.

The ESO said the first flexibility providers will be revealed shortly and more are expected join in the coming months.

The trial, which is being launched through the Power Responsive programme and will run until April 2024, is part of a wider project to make operational metering standards for the Balancing Mechanism more proportional for small-scale assets.

The current standards require that assets must be metered with an accuracy of plus or minus 1% and a resolution of three decimal places. Readings must be taken once per second with a latency of less than five seconds. These standards also apply to sub-assets within a Balancing Mechanism Unit.

Explaining the importance of these standards, the ESO said large margins of error can create “poor situational awareness” for its control engineers, “leading to inconsistent dispatching.”

“It also leads to demand forecasting errors which results in more actions needing to be taken in the control room to manage the uncertainty, increasing balancing costs for all.”

For participants in the trial, the ESO is relaxing these standards for sub-assets with a capacity of less than 100kW that are part of aggregated units.

The accuracy requirement will be loosened to +/- 2.5% to align with both the Code of Practice 11 (CoP11) within the Balancing and Settlement Code (BSC) and the Measurement Instrument Regulations. The required resolution will change to 1kW, while the refresh rate will remain once per second for aggregate units but once every ten seconds for sub-assets.

The trial will be open to up to 50MW of flexible capacity and up to 10MW from each provider.

As well as establishing whether small-scale assets can meet the necessary requirements and provide the relevant data to compete in a range of ESO markets going forward, the trial will also explore how the ESO’s processes and systems will need to be adapted to accommodate these assets.

Earlier this year, Flexitricity co-founder and chief strategy officer Alastair Martin told Utility Week that overlapping metering standards were hampering the ability of behind-the-meter assets, including smart EV chargers, to participate in flexibility services. He said assets that comply with CoP11 should be allowed to participate in almost all flexibility markets.

Commenting on the new trial, Martin said the standard that is being relaxed is “actually a relatively new standard,” which was introduced shortly after Flexitricity entered the Balancing Mechanism.

“They were obviously thinking about what might be present in the Balancing Mechanism in the future and thought they’ve just got to put something down that is a standard for everyone to work to.” He said Flexitricity challenged the standard “as soon as we read it”.

Martin said metering requirements, whether for operations or settlement, should be “commensurate with the size of the asset delivering the service”. He said the new standard did not adhere to this principle, instead applying the metering requirements necessary for large-scale power stations “all the way down to the bottom”.

By contrast, Martin said CoP11, which was developed by Elexon, sets less stringent requirements for smaller assets. “There’s no way that this trial, if done properly, can report anything other than the standards in CoP11 are fine,” he remarked.

Importantly, Martin says the operational metering requirements for small-scale assets set out in CoP11 align with the equivalent requirements for settlement: “That means, and this is absolutely crucial, you can use the same meter for settlement purposes that you use for operational purposes. As long as you read it fast enough and the control room can see it in real time, it can serve two purposes.”

He said this will be essential for making household participation in the Balancing Mechanism economically viable.

Martin also hopes that the trial will help to address the issue of aggregated units being skipped over in the merit order in favour of larger individual assets.

“The issues around skip rates are all to do with control room systems and there is a project that’s aiming to deal with that – the Open Balancing platform,” he explained. “There’s a lot going on there – a lot of code is being written, a lot of things are being worked out. I’m hoping that is the thing that fundamentally makes a difference to the skip rate.

“But when you’ve got a trial, you’ve got a period of visibility of a particular technology class, maybe that might result in more dispatch of these resources whilst they’re doing the trial, and that would be no bad thing.”

Unsurprisingly, Martin said Flexibility is planning to participate in the trial.