As part of the UK's energy transition, all owners of generating sites in Great Britain are required to ensure that their installations are compliant with Loss of Mains protection regulations. The changes are critical to supporting a robust and reliable electricity network and non-compliance will be subject to enforcement action.
Check if you need to upgrade
Use our self-serve tool or contact your DNO to confirm what action is needed.
Make any changes
If needed, make any necessary upgrades if your equipment is not compliant with Loss of Mains protection settings.
Submit a compliance declaration and evidence - Our ALoMCP portal is set up to help you do this. Our user guide can also offer advice.
The transition is mandatory for all G59 generation sites and everyone is required to comply before 01 September 2022.
Generator owners without compliant assets must act now to make the necessary changes, or face enforcement action
You will be supporting your community and the wider initiatives that are helping us to meet the UK’s zero-carbon targets.
Your upgrades will make your equipment more efficient and improve the resilience of the grid too.
This programme is led by National Grid ESO, the Energy Networks Association, Distribution Network Operators (DNOs) and Independent Distribution Network Operators (IDNOs). Together we are working to build grid resilience and drive the mission to zero-carbon.
Is funding available?
Funding applications for the Accelerated Loss of Mains Change Programme are now closed.
What do I do if my equipment is already compliant?
If your equipment is already compliant, please let us know by submitting a declaration on the ALoMCP portal. It’s important you do this so we know you’ve checked your set up and to avoid us contacting you unnecessarily.
How do I know if I need to make changes to my equipment?
Use our self-serve tool to check if you need to upgrade your equipment. The tool will also provide clear next steps if you do need to make any changes and helps you to start your funding request.
Do I need to take an action if I have generation but I have not yet heard from my DNO about the changes?
It is your responsibility as a generator owner/operator to ensure that your equipment is compliant. If you haven’t heard from your DNO or any other organisation about the changes then you still need to check your equipment and take an action to make a change if it is not compliant. If it is compliant then please declare this with your DNO via the ALoMCP portal, or by getting in touch with them directly.
What are the benefits of these changes?
By becoming compliant you will make your generation more reliable. This will mean it is less likely to trip off, ensuring more consistent generation and a steadier income stream.
More widely, by becoming compliant you will help strengthen the electricity network – this will help deliver cost savings to consumers and it will also embed the network with more resilience, meaning that more renewable electricity can be brought online, helping us meet the UK’s low carbon ambitions.
How can I identify if my inverter or relay is already compliant?
You can quickly check if your equipment is compliant using our knowledge base. This provides an alphabetical list of manufacturers with guidance on whether their equipment is compliant or not.
How do I complete the mandatory settings changes?
You can enlist the support of a contractor, who can assess your equipment and make the changes on behalf of you, or your organisation. The ENA has a directory of self-declared competent contractors who can support you with this, or your DNO can direct you to its list of recognised contractors.
A recognised contractor is one who is “recognised” by the DNO for having appropriate experience and skills to undertake the work of the programme without direct scrutiny by the DNO. This enables a recognised contractor to plan site works independent of the need to arrange a suitable time/date for the DNO to witness the works.
Do I need to use a contractor?
No – there is no compulsion to use a contractor, recognised or not. You can complete the settings changes yourself, if you have the sufficient technical knowledge to do so. Or, your own contractors or site management teams can complete the settings changes.
When is the deadline for compliance?
Your equipment must be compliant by 1 September 2022. This means that your compliance declaration and all evidence of compliance must be submitted via the ENA ALoMCP portal by midnight on 31 August 2022.
Do I need to change my domestic generator?
This programme does not apply to domestic and similar generation that has been connected under EREC G83. It only applies to generation connected before 1 February 2018 or 1 July 2018 for inverters in accordance with EREC G59.
If I have already made changes, do I need to make more?
If you find that your equipment is already compliant you must still inform your DNO to ensure that your assets are registered correctly. This scheme supports electricity generation owners in achieving compliance to the Distribution Code requirements in EREC G59.
What are the setting changes required in the updated EREC G59?
All generators that are connected to the distribution networks in Great Britain have Loss of Mains protection, one of the many protection requirements on the electricity system.
This applies to generating plants that run in long-term parallel with the distribution network and are within the scope of EREC G59, regardless of the type of generator, such as PV, wind or gas. Loss of Mains is designed to check if a generator is still connected to the supply network. Updated EREC G59 requirements must be implemented by generation owners by 1 September 2022.
Where LoM is provided by vector shift, it must be removed and/or replaced with Rate of Change of Frequency Protection (RoCoF). RoCoF is the rate at which frequency changes and is used to detect the absence of the connection to the system and disconnects the site if that RoCoF exceeds a specific value. The RoCoF setting requirement has been changed to 1 Hz/s with a definite time delay of 500 milliseconds. It will mean National Grid ESO will be able to operate the grid more efficiently.
Most of the costs incurred in managing the LoM risk on the electricity transmission system are to limit the RoCoF to below 0.125Hz/s. Currently NGESO is limiting the RoCoF to below 0.125Hz/s so that generators with RoCoF protection are not inadvertently tripped. The costs are significant and are paid for by all of us through our electricity bills. These costs could be reduced if RoCoF above 0.125Hz/s was allowed. To achieve this, we need to change the RoCoF settings at all sites where RoCoF protection has an existing setting of 0.5Hz/s or less.