
Infrastructure Planning Blog
11. An Offshore Wind DCO, Planning and Infrastructure Bill updates and grid reforms
Today's entry looks at the decision to grant development consent for the Mona Offshore Wind project, amendments proposed to the Planning and Infrastructure Bill, and a consultation on electricity networks.
Wake me up*
The Secretary of State granted development consent for the Mona Offshore Windfarm. There are quite a few interesting points to note from this decision.
First, one of the heated issues related to ‘wake effects’ (which is where wind turbines create a "wake" of reduced wind speed and increased turbulence downstream). The particular issue was that these effects would lead to a wake loss of 0.83% and 1.67% for each eight of Orsted’s eight wind farms, causing an additional wake loss of approximately 1.38% compared with the baseline across Ørsted assets as a whole.
For context, paragraph 2.8.197 of EN-3 sets out that “Where a potential offshore wind farm is proposed close to existing operational offshore infrastructure, or has the potential to affect activities for which a licence has been issued by government, the applicant should undertake an assessment of the potential effects of the proposed development on such existing or permitted infrastructure or activities.”
The promoter did not carry out such an assessment on the basis that Orsted’s wind farms could not reasonably be considered to be ‘close to’ the its assets as they would be located at least 30km from the proposed array area and that the reference to ‘licences’ rather than ‘consents’ does not apply to authorisations.
The Secretary of State, who clearly had the freshest bowl of Weetabix on the morning of the decision letter, was plainly frustrated by this stating that “the Applicant has taken a consistent entrenched position... the Applicant’s position is unhelpful and overly legalistic and [the SoS] is unable to agree with any of the arguments put forward in support of that position”.
To drive the point home, the Secretary of State (presumably whilst singing ‘Jumper’ by Third Eye Blind) goes on to say that he is “particularly disappointed to see that the Applicant was expressly asked to provide a wake assessment by the ExA, but instead of complying with that reasonable request, refused to do so for the same legalistic reasons. This is an issue that should and could have been properly addressed during the examination by reasonable parties acting collaboratively, rather than adopting entrenched positions.”
In their view, an assessment should have been carried out and “a project is unarguably “close” enough to be relevant if it is accepted that there is a direct physical impact on that project” and given the “clear finding that the Applicant’s approach to this issue has not been consistent with NPS policy, nor helpful to good project planning, the Secretary of State concludes that effects on other offshore infrastructure and activities should be ascribed moderate negative weight in the planning balance”.
The Secretary of State relied on an assessment prepared by Orsted’s consultants and introduced a Requirement to the DCO securing a wake effects plan. In other words, you have all been warned.
Second, the decision letter records a debate from yester years on construction hours which, in this case, was decided against the developer. Even though communities along specific sections of the route would experience construction impacts over an extended timeframe and potentially delay the development, the Secretary of State sided with more restricted weekend working hours. On the other hand, the promoter did manage to convince the Secretary of State not to require horizontal directional drilling (contrary to the recommendation of the Examining Authority) in particular locations.
Third, this project is another example of the “enhanced duty” relating to national landscapes being considered. Please do read Blog 3 for our views on that duty. In this case, the promoter secured a fund of over £2m for further measures. This does nothing else but underline the fact that the duty is operating as a stealth tax on development.
Fourth, the Secretary of State has removed a DCO provision relating to inconsistent and overlapping planning permissions on the basis that it ‘is not considered necessary and creates potential ambiguity’. Those provisions, by the way, are now precedented and can be found in the Lower Thames Crossing and Luton Airport Development Consent Orders. These provisions ensure that enforcement action is not taken against either the beneficiary of a planning permission or the undertaker (of a DCO) where an inconsistency arises following the Supreme Court’s decision in the Hillside Parks case (on which, see below) but this particular DCO won’t have the benefit of them.
The final thing to note is that this decision was made 12 days early! Hurrah! On that, it would be very tempting to see the improvements in time frames at the post-application phase and cheer. This is certainly positive, but without looking at the entire period from pre-application to consent, I don’t think we should cheer too loudly. Risk aversion in the regime is a serious issue which causes promoters simply to lift and shift time from post-application to pre-application, and that is no doubt part of the reason why no one has formally elected to take the “fast-track” route.
(*depending on your age, you can take this to be a reference to Wham!, or Evanescence, or if you’re a bit edgy in Autumnal months, Green Day).
Lording it over us
The Planning and Infrastructure Bill has made its way to the House of Lords. There are a few amendments which may raise some eyebrows (e.g., see page 6, where an amendment is proposed to force a National Policy Statement for abattoirs) but there are a few from Lord Banner KC that I think are quite neat.
The first relates to a new ‘principle of proportionality’. The purpose of this amendment is to require that planning functions are exercised so that ‘the nature and extent of information and evidence required to inform the determination of any permission, consent, or other approval within the scope of the Planning Acts [including the Planning Act 2008] shall be proportionate to the issues requiring determination, having regard to decisions already made (whether in the plan-making or development control context) and the extent to which those issues will or can be made subject to future regulation”. To be clear, I support this and it should be adopted – but I’m not sure the entities who it is targeted at really think they are doing anything that is different from this.
This comes back to the point that proportionality is as much an outcome of institutional cultures and practices, as it is legislation. Changing the former is difficult, but my sense is that the strong signals like the Mona decision letter on wake effects are better signals to tell various parties to stop (or do) something are more effective at driving cultural changes. The power to give specific directions on how an entity interprets a duty is, in my mind, a stronger way to deal with this.
That doesn’t mean legislation isn’t a potential answer, but simply that its not the whole answer. Last week we covered an extension of the EIA regime grounded in chicken manure, and before that we had the Supreme Court’s Finch judgment – in my view, it should be Parliament’s role to reverse the effect of those judgments given they add arms and legs to EIA, separately from the more general principle of proportionality suggested and the Secretary of State occasionally rebuking applications in decision letters.
Lord Banner has also proposed an amendment relating to the Supreme Court’s judgment in Hillside Parks. As a reminder, that case holds that, unless there is an express provision otherwise, where development has taken place under one permission, whether a later planning permission may lawfully be implemented depends upon whether it remains physically possible to carry out the development authorised by the second permission in light of what has already been done under the first permission.
The proposed amendment sets out that ‘where there is more than one planning permission which relates to some or all of the same land, the lawfulness of both past and future development carried out pursuant to one of those planning permissions shall be unaffected by the carrying out of development pursuant to another of those planning permissions, except to the extent expressly stated in any of those permissions’ – this is the sum effect of the precedented provisions in the LTC and Luton Airport DCOs highlighted above, but only for the TCPA regime. Given the Mona decision, in my view, it is necessary to enact a form of Lord Banner KC’s amendment.
Grid(un)lock
The Government has published a new consultation on electricity network infrastructure. Key points to note:
- There is a recommendation to change the NSIP thresholds to remove 132kv wooden polls, and also increase the threshold of 2km to 10km (and, on the latter further clarity will be provided about how to calculate the km length).
- Increasing the permitted development right for substations so they cover 45 cubic meters (up from the current 29 cubic meters).
- Various procedural changes to the "necessary wayleaves" process, and significantly changing the standard term of a wayleave from 15 to 40 years.
- Extending the ability to acquire access rights to cover adjacent land and also extending the ability to obtain these powers to Transmission Owners.
We'll be digesting these further in due course so don't forget, you can sign up to the Infrastructure Planning Blog by using the sign up link directly below!
This publication is intended for general guidance and represents our understanding of the relevant law and practice as at July 2025. Specific advice should be sought for specific cases. For more information see our terms & conditions.
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