Market News

Grid Liaison Service: Will a new Best Industry Practice Manual spell real change?

02nd July 2018

QE’s Grid Liaison Service was set up with the aim of improving communication between PV generators and the UK’s DNOs. Recent developments indicate that the GLS and its partners could be about to reach a new, important consensus on best industry practice.

At QE we have always been fully aware of the impact of grid disconnections on our clients’ strategic objectives, having identified these early on, through our asset management work, as one of the major factors impacting PV plant production levels. In fact, according to our data, DNO outages are the single most important cause of production loss affecting PV sites in the UK.

According to our data, DNO outages are the single most important cause of production loss affecting PV sites in the UK.

This led QE to engage experts in grid connections in order to draw on their experience in this field and to undertake a joint exercise in reviewing and classifying two years’ worth of data relating to UK grid related incidents. Transforming this data into KPIs and ratios uncovered specific areas of production losses – key information that could in due course be shared with the DNOs and their respective sub-DNOs. Armed with the results of this study, the GLS, EA Technologies and the STA were able to take the step that followed: Direct engagement with the DNOs.

A major limitation on our clients’ ability to mitigate grid disconnection related losses is the ‘non-firm’ nature of their grid connection agreements. Under these non-firm connection agreements, the DNOs are not obliged to maintain a PV plant’s continuous connection to the grid and can request either constraints on the connection or a complete shutdown of the plant for a number of reasons. The DNOs are however still subject to Ofgem regulation and they do have a duty to act ‘reasonably’. Our ability to demonstrate the degree of these grid related losses accordingly would set the context for what would be construed as ‘reasonable’ behaviour.

Our initial communication to the DNOs included a detailed analysis of production losses arising from grid disconnections including incidents per site, the timing of the incidents, losses of MWh/MWp and other indicators. In the series of meetings that followed, we made it clear that generators were taking this matter very seriously and that we intended to test the DNOs’ reasonableness. Whilst DNO reactions varied from cautious to collaborative, it was clear that all DNOs shared the same concern about appearing to be unreasonable in front of the regulator, Ofgem, or appearing to be below the standard of their peers in terms of dealing with stakeholders such as PV generators.

A dialogue developed due to these interactions and a consensus emerged on certain aspects of the DNO/Generator relationship. In principle, the DNOs agreed that certain changes were required: That DNOs should improve their portals so that notifications of disconnections or required curtailments would be logged correctly and generators would have an opportunity to consider mitigation options; That where grid related incidents result in a certain threshold of production losses being exceeded, the DNOs would be obliged to consider mitigation strategies; That DNOs were to find a way with the generators to share information, without breaching confidentiality, that allowed multiple stakeholders to be aware of, and act on, opportunities for improvements to the grid infrastructure; That DNOs and generators would agree the terms of a Best Industry Practice Manual (‘BIPM’) that would be drafted by the STA, and that would serve as a guide and a point of reference in case of disputes or varying criteria across the country.

The first of these to be put into motion is the BIPM: An STA working group is currently engaged in drafting its scope and content, with the assistance of EA Technologies – chosen as the advisors to support this process due to their proven grid expertise and previous work with the GLS. By the end of January, EA had led a round of meetings with the DNOs, supported by the GLS and the STA, to agree the contents of the BIPM. Encouragingly, some of the DNOs responded very collaboratively and even contributed important ideas to improving relations between the parties, including raising their own awareness of the impact of their decisions, agreeing a common glossary of terms, promoting opportunities to invest in the grid which will lead to various benefits for the generators, facilitating the mitigation of incidents and communicating more effectively with all stakeholders.

We expect that EA will present a final draft of the BIPM for approval very soon and that the STA will be in a position to sign it in the first half of this year on behalf of its members. This would be a landmark achievement in the development of renewables in the UK and we believe that it will lead to significant benefits to all parties.

If you would like to speak to us about this, or any related matter, please contact QE’s Head of Asset Management, Florus den Blanken, via the enquiries section of our website.

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


This webpage uses cookies to improve the user experience.By clicking "Accept" we understand you acknowledge our website's Privacy and Cookies Policy


Please enter your professional email address and full name to access this content

Please enter a valid email address