Is the battery actually reducing grid constraint?
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Europe’s Largest Battery Site Just Went Live – But Is It Delivering on Its Promise?
Last Monday, Europe’s largest battery site went live in Blackhillock, Scotland; a major milestone for the UK’s net zero transition and potentially great news for consumer bills.
Why? Because the site is located in a high-congestion area near several offshore wind farms. Ideally, when there’s excess wind power, the battery should store the surplus instead of forcing turbines to shut down. Zenobē estimates this could save consumers £170 million over 15 years and prevent 2.6 million tonnes of CO₂ from entering the atmosphere. https://www.zenobe.com/news-and-events/ ... ge-launch/
But is that what’s actually happening? Let’s look at the data.
What We’d Expect to See:
On windy days, we’d anticipate a lot of Balancing Mechanism (BM) bid activity, meaning National Grid instructs the battery to charge, easing congestion.
Wht We’re Seeing Instead:
Using Arenko's Nimbus Trade Platform, we tracked the strategy of one of the new Zenobe units (T_BLHLB-2) over two days. The attached plot tells an interesting story:
The battery is participating in Quick Reserve (yellow bars), making capacity available to the BM. It’s also receiving large BM bid instructions (red bars), instructing it to charge—so far, so good.
However…
As the battery fills up, it needs to schedule large discharges (purple bars) to bring its state of charge back down. But because it’s in a congested area, National Grid doesn’t want it to discharge—so it reverses these exports via BM Bids.
For nearly 12 consecutive hours (March 6th, from 5 PM onwards), the BM bids are almost a mirror image of the scheduled exports.
The Result? The battery appears practically idle, yet it’s still earning payments from both Quick Reserve and trading spreads (the difference between wholesale sell prices and BM bid instruction prices).
This means that instead of delivering the expected savings, this setup could actually increase for consumers, as batteries are getting paid for Quick Reserve but not delivering real value to the grid.
So, how do we fix this?
Is this a market design issue? How can National Grid ESO provide the right incentives for battery optimizers to maximize grid benefits?
https://www.linkedin.com/posts/margot-s ... -5id88m0EA
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