This response from NESO was to our question about the Modification Applications being awarded for data centre demand in the UK. It was initially turned down and we appealed. The text of the appeal is below:

Appeal from APRS 24 March 2025

Thank you for the email relating to FOI-25-294 which I received yesterday.   

I would like you to review this request because I disagree with your conclusions that the first question is too difficult to answer.

You say “NESO classifies and records modification applications (‘Mod Apps’) as either ‘Demand’ or ‘Generation & Demand’. There is currently no further categorisation of Mod Apps within our operational datasets.”

However we are aware that BESS operators need to apply for a Mod App to switch from their 100% import, 100% export connection to a Final Demand connection to enable them to operate a Data Centre from that connection. There is a huge difference between a connection for a BESS which does not consume any energy (apart from inefficiencies in conversion between different forms of energy which is presumably negligible in the big scheme of things) and a data centre, which actually consumes the electricity – and runs on 80-85% of maximum connection 24 hours a day 7 days a week. We believe that NESO needs to be in possession of this information to enable them to manage their connections demand.

So we believe that if you don’t already hold this information, it should be a major operational priority for you to have access to this information.  And so we would like you to review the request as it, not only is in the public interest, but it is in the interests of NESO yourselves to know this information. It would be useful to have confirmation that NESO do not differentiate between import connections that are for battery storage and import connections which are for high demand customers like data centres. Because that is the conclusion that I have drawn from the answer that you sent, which is obviously quite concerning. 

At the very least I would like to know the information for Scotland. We believe that there will be a maximum of 15-20 situations where those with a BESS connection in Scotland have applied for a Mod App to convert to a final demand connection.

If you could please carry out an internal review of the handling of my request.

I understand that you should respond to me within 20 working days, as outlined in the Information Commissioner’s guidance:

“The Information Commissioner’s Office recommends that public authorities carry out internal reviews within 20 working days. Under Environmental Information Regulations there is a legal requirement that internal reviews must be carried out as soon as possible and within 40 working days.”

Thanks,

Kat Jones