Market News

Why the Accelerated Loss of Mains Change Programme is urgently required

22nd October 2019

A massive blackout on 9 August 2019 left 1.1 million people in the UK without power, created huge travel disruption and led to important questions being asked about the state of the UK’s energy infrastructure. The UK energy minister, Ofgem and the Department for Business, Energy and Industrial Strategy required National Grid ESO (“NGESO”) to undertake an investigation.

The final version of the resulting report was published by NGESO on 6 September 2019. This concluded that the blackout was instigated by the sudden loss of power at the Hornsea One wind farm off the coast of Yorkshire and the Little Barford gas-fired power plant near Cambridge, following a lightning strike on a transmission circuit. On top of this and of particular relevance to the PV industry, various embedded generation totalling approximately 500MW of capacity tripped offline exacerbating the drop-off of power. Whilst Ofgem requires that NGESO holds sufficient back-up power in reserve in case of the unexpected loss of power, the amount that it held in back-up that day – 1GW from a subsea cable that imports electricity from France – was not enough to counteract the sudden loss of 1.7GW that occurred. An automatic shutdown of 5% of total demand was triggered in order to avoid a total shutdown. The biggest question that still remains to be answered is how can another huge power cut like this be averted in the future and what does this mean for renewable generators?

NGESO, which is responsible for the real-time balancing of electricity generation with demand across the network, identifies in its report areas that could be improved and suggests certain measures that could be adopted to achieve this. One such measure singled out is the Accelerated Loss of Mains Change Programme (“ALoMCP”) which is aimed at countering the risk of inadvertent tripping and consists of accelerating the implementation of a modification to the Distribution Code. This programme was initiated by NGESO, Distribution Network Operators and Independent Distribution Network Operators prior to the blackout and has since been approved by Ofgem. The modification to the Distribution Code requires that generators installed prior to February 2018, and those where the generation equipment is not type tested, comply with new setting requirements for the interface protection in accordance with Engineering Recommendation G59. Generators must comply with this by 31 August 2022 and after that point, owners who have not made the changes may be subject to an enforcement programme.

The ALoMCP aims to incentivise generators to bring about the changes required to their interface protections as early on as possible and well ahead of the official 2022 deadline. Provided they meet certain eligibility criteria, generators would be paid to effect the changes required. In order to apply to be considered for these payments, owners will have to submit the details of their generators and the changes they would undertake into a portal that has recently been launched by the Energy Networks Association (“ENA”).

Source: NGESO incident report into 9 August 2019 blackout

Earlier in the year, ENA sent out a request for feedback document regarding the scheme. As asset managers to PV installations with a combined installed capacity of 1.7GWp, QE provided ENA with extensive feedback which largely focused on the procurement methodology and suggested ways to make this fairer. In particular, QE’s position is that all generators that will eventually have to change their settings should be entitled to benefit from the payment scheme whereas the available information stated that “payment will only be made available until it is no longer economic to pay for any further changes”. The basis for what is ‘economic’ depends on what the grid needs in order to operate efficiently, i.e. lowest impact on BSUoS, and QE pointed out that this implies that for those sites for which payment is not economic, the change is not beneficial to the grid. Hence, the change should not be required at all for those sites for which payment is not economic.
Alongside specific feedback regarding the procurement methodology, QE provided comments on the amount of the payments suggested (and set out why higher amounts would be more appropriate, for example, where generators have to be completely shut down to undertake the changes), how the portal could work to allow for efficient information uploads and how communication between generators and the DNOs could be managed in an effective way. QE also required further clarification as to the information that will be required to be submitted as part of the application process, the criteria that will be employed in the decision-making process and practical information regarding the changes that will be required.

The ENA application submissions portal went live on 2 October and QE have been working on the submissions process since then. As part of this process, QE have prepared all necessary submission information per site, evaluated the changes required by the modification to the Distribution Code and have submitted applications for a number of sites. Once notified that any of these applications have been successful, QE will manage the process of effecting the changes required by liaising with specialist subcontractors and then shall follow up to ensure that the generators receive the compensation that they are entitled to.

If you are interested in applying to take part in the Accelerated Loss of Mains Change Programme, please contact us via the enquiries section of our website.


This article is written and edited by Shirine Azzi. She can be contacted at:


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