Accelerated Loss of Mains Change Programme

The Accelerated Loss of Mains Change Programme (ALOMCP) is an industry-wide project that is taking place across Great Britain (not Northern Ireland). It is being run by the National Grid and Network Operators (DNOs). After some delay, it is now open for applications.

The purpose of the programme is to update Loss of Mains (LoM) protection for renewable electricity generators with a view to reducing the risk of needless tripping. The approach taken to achieve this aim is to relax the RoCoF limits (rate-of-change-of-frequency) on the grid.

Details of the programme are outlined below but what is important to note is that Locogen can carry out the works and process all the paperwork with no cost to you.

All you need to do is email and we’ll send you two documents to complete. We’ll then register your site for grant funding, schedule the work with you and record the neccessary changes as required by the  National Grid.

Background to the ALOMCP

Distributed generation, such as renewable generators like wind turbines, hydro schemes and solar PV needs to be fitted with Loss of Mains protection. This has usually been provided by RoCoF or Vector Shift (VS) relays. These technologies are intended to prevent the formation of power islands and they should not operate in the case of faults that do not cause islanding. However, RoCoF relays were programmed to trip when sensing rates of change of frequency as low as 0.125 Hzs-1 and both these and VS relays have been found to trip in response to transmission faults that do not cause islanding. This can then exacerbate problems and lead to Low Frequency Demand Disconnection and unnecessary loss of demand.

With 50,000 distributed generation sites supplying 15GW, this situation presents a significant risk to the security of supply. The current practice of managing risk by limiting the largest losses and increasing inertia in the system, meanwhile, is costly; over £100 million in 2018. These costs are ultimately borne by consumers.

The accelerated loss of mains change programme will affect G59 connected renewable energy generators connected before February 2018, which have their loss of mains protection provided by either VS relays or RoCoF relays with settings more sensitive than required by the Distribution Code. It is proposed that RoCoF relays be adjusted to 1Hzs-1 with a definite time delay of 500ms and VS relays be removed where used as loss of mains protection. These changes should be made as soon as possible and no later than April 2022. The Energy Networks Association has more details here.


Grant funding available

In order to encourage rapid compliance with the accelerated loss of mains change programme, generators will be paid for making these changes. These payments will be fixed-rate sums, rather than tailored to individual circumstances. The rates paid for the work are as follows:

  • £1,500 where only a settings change or disablement is required. For sites that have additional protection devices that require work, an additional £500 is given for each device on top of the additional £1,500 for the first device.
  • £4,000 where a physical change in relay is required.

It should be noted that these payments are made on a ‘first-come, first-served’ basis and the funding is set to decrease from March 2022 onwards, so we strongly recommend that you act now. 

It should also be noted that this is the first in a three-stage process for ensuring compliance. The second stage is an unfunded requirement to comply and the third stage is enforcement, with fines for non-compliance.

Clearly, then, it is the generation owner’s best interest to act quickly and secure the funding available. Indeed, the Energy Networks Association (ENA) advice is that: “applying early maximises the opportunity of being accepted.”

The ALOMCP process

An online portal for funding applications are available on the websites of all Distribution Network Operators, Independent Distribution Network Operators, National Grid Electricity System Operator, and Energy Networks Association.

Locogen will upload the following information in support of your application:

  • Capacity
  • Generation type
  • Existing Loss of Mains (LoM) relay type and setting
  • Relevant Network Operator
  • Lead time for change
  • MPAN

What to do now

If you have not yet received an email from us, please drop us a line at with your contact details. We will then send you a Letter of Authority, which allows us to carry out the work. We’ll then gather all the information required for your application, upload to the programme portal and then schedule and carry out the works.

Please remember that the funding is allocated on a first-come-first-served basis, so it makes sense to act now.

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