Data centres are now writing grid rules, from PJM's backstop to Spain's hours

Victoria Shinder01 October 2026, 07:112 min read

Two decisions this week, on two continents, show regulators turning data-centre demand from a forecast into a rulebook. They start from the same fact, large new loads arriving faster than supply, and reach for different levers.

PJM: buy the capacity, then argue about the bill. The largest US grid operator planned a reliability backstop procurement after its last two capacity auctions fell short of reserve targets, largely because of data-centre forecasts. FERC approved it only in part on 29 September, flagging cost allocation, exit rules for transmission owners and collateral for load-serving entities, and PJM postponed the auction that was due to open the next day. Its chair called the last-minute filing a mess with billion-dollar consequences for consumers. The open question is who pays for capacity bought because of a specific kind of customer. Source: https://www.utilitydive.com/news/pjm-delays-backstop-procurement-ferc-data-center/831751

Spain: make the load bring its own clean supply. A draft royal decree would tie grid access for data centres of 1 MW and above to matching 80% of consumption with renewable output in each hour, from plants commissioned no more than 18 months before the site opens. Shortfalls would bring surcharges of up to 500% on network charges and, after five bad years, possible loss of grid access. A developer writing in Energy-Storage.news argues the hourly test makes batteries effectively mandatory. Source: https://www.energy-storage.news/spain-is-making-batteries-a-licensing-condition-for-data-centres-and-nobody-noticed

The difference is where the cost lands. PJM's route socialises procurement first and settles allocation later, which is exactly what FERC sent back. Spain's route puts the obligation on the connecting customer from the start, at the cost of a stricter and more complex compliance regime. Both are trying to answer the same question: should a new load that drives system cost carry that cost directly?

What to watch. In PJM, whether a revised filing assigns more of the backstop cost to the customers whose demand created it, which PJM itself now says it wants. In Spain, whether the 80% hourly target and the penalties survive into the final decree. If they do, other European countries struggling with data-centre connection queues will have a template.