Data centers and battery storage are the two markets that have swollen RTE's connection queues the most in recent years. They are usually analysed separately. Yet they compete for the same resource, transmission capacity, and they share a trait: much of what sits in the queue will never be built.
TWO QUEUES FILLING AT ONCE
| Data centers | Battery storage | |
|---|---|---|
| Capacity in the queue | Close to 18 GW reserved for around 80 projects (May 2026) | Around 14 GW in RTE queues (end-2025) |
| Projects actually committed | A fraction, as RTE reforms its rules | Around 1.2 GW of identified projects by 2030 |
| Main constraints | Connection, transformers, permits, acceptance | Connection, transformers, permits, acceptance |
Sources: RTE (data centers); Live As One 209, French BESS market snapshot, September 2026, based notably on RTE data (batteries). Figures should be read as orders of magnitude.
Together, the two markets account for over 30 GW of requests, one reason RTE is revising its allocation rules and moving away from pure first-come, first-served.
WHAT THE COMPETITION CHANGES
Paper projects will be filtered out. Financial commitments, maturity criteria, pre-identified sites: across Europe, grid operators are separating projects that will be built from those holding capacity. See European queue reform.
Equipment is shared. Transformers and connection equipment are ordered by both markets, as well as by networks and industry. Whoever secures delivery slots first moves ahead.
Territories compare. The same area may see both a data center and a storage project. Residents' concerns add up, and acceptance is prepared the same way.
YET THEY COMPLEMENT EACH OTHER
A battery installed behind the meter on a data center site can shave peaks, offer flexibility to the grid and secure supply. That is increasingly valuable: grid operators are testing flexible connections that get customers connected sooner in exchange for occasional limits, and the upcoming EU data centre rating will show whether a site offers grid flexibility. See the EU A–G rating.
WHAT DEVELOPERS AND LENDERS SHOULD CHECK
The grid operator's works schedule, and how reliable it is
Delivery slots for transformers and equipment
Permit status and local context
Flexibility or phased connection options
See how we support battery storage projects and our lender due diligence.
FREQUENTLY ASKED QUESTIONS
Do data centers and batteries compete for grid connection in France?
Yes: both compete for RTE transmission capacity. Together they account for over 30 GW of requests, much of which will never be built.
Can a battery be installed on a data center site?
Yes. Behind the meter, it can shave peaks, provide grid flexibility and secure supply, an asset grid operators increasingly value.