NESO has extended the evidence submission window for Gate 2 grid connection applications until at least mid-August to allow more time for projects to be registered.
The GB system operator said it will provide notice of 10 working days before the window closure, and will not issue the notice before 4 August.
It follows a series of technical issues reported by customers attempting to register schemes since the connections portal was opened for applications on 8 July.
A three-week window closing on 29 July had initially been proposed but NESO has been forced to delay the process as it deals with the problems.
Trade groups have been calling on the organisation in recent days to extend the evidence window to make sure that all companies wanting to register projects for priority status in a major overhaul of the GB connections queue are able to do so without issue.
NESO chief operating officer Kayte O’Neill said: “We appreciate that to date the process of submitting evidence to NESO as part of the connections reform evidence submission window has not been to the standard we hold ourselves to, and we are sorry for the disruption this has caused to our customers.
“We value stakeholder feedback and are taking immediate action to restore confidence, ensuring that the connections reform process supports Great Britain’s energy transition effectively.
“To ensure that customers have an equal and fair access to this process, we are allowing sufficient time to ensure that the portal is delivering as expected.
“We will give 10 working days’ notice before the window closes. This notice will be issued no earlier than 4 August 2025.”
O’Neill added that NESO staff have made “significant progress” on resolving the issues over the past two weeks, and “restoring confidence in the process remains our top priority”.
“To build on the progress we are making against these areas, we have deployed additional resource to resolve outstanding challenges,” she said.
Responding to the intervention, RenewableUK’s director of future electricity systems Barnaby Wharton said: “We welcome NESO’s positive response to the concerns we’ve raised regarding the technical issues affecting its portal.
“In particular, NESO’s agreement to our request to ensure that our members will have ten working days on a stable platform to submit evidence is most welcome.
“This means that it is fulfilling its legal requirement to provide sufficient time for the application process to take place. This period will start no earlier than 4th August.
“We look forward to further details of how our members will be able to amend and save information already submitted, so that they can apply for grid connections for their clean energy projects with confidence.
“We remain committed to working with NESO to support the delivery of connections reform, and we appreciate their swift action in taking steps to address the problems affecting the portal to this point.”