Large scale solar power generation backed in revised UK planning policy

The government’s stated aim is to increase the UK’s solar capacity to 70GW by 2035, up from the 14GW of capacity noted in the British energy security strategy published last year, and in its technical annex (59-page / 1.74MB PDF) to its ‘Powering Up Britain’ reports has suggested solar capacity will need to hit 90GW by 2050 to align with wider net zero targets. 

To meet those targets, more solar ‘nationally significant infrastructure projects’ (NSIPs) will need to be approved over the next decade and beyond – only two projects, the Little Crow Solar Park project and the Cleve Hill Solar Park project, have received development consent to date. The latest planning policy proposals published by the government now provide the confidence that prospective solar developers have been seeking.

The solar NSIPs planning regime

NSIPs are subject to a special consenting regime under the Planning Act 2008, where approval for projects is considered and determined by the secretary of state. There are currently six national policy statements (NPS) – one overarching policy and five technology-specific policies – in respect of energy infrastructure that guide decision-making around applications for development consent for energy NSIPs.

The government has recognised, however, that these existing policy statements are out-of-step with subsequent net zero targets it has committed to. In autumn 2021, it embarked on a review of the energy NPSs and proposed amendments to five of the six existing policies – including its overarching energy NPS, EN-1, and EN-3 which applies to renewables NSIPs. It has now published, and opened a further consultation on (19-page / 231KB PDF), draft revised NPSs for the five energy policies subject to the current review – including EN-1 and EN-3.

One of the problems prospective solar farm developers have faced to date is that the existing EN-3 does not refer to solar generation specifically. This has meant that, while utility scale solar projects have been able to be promoted under the NPS for energy infrastructure, developers have had to follow a more protracted route to gaining planning permission: developers have had to rely on the general policy support within EN-1 for their solar projects.

According to the proposed new EN-1, the government envisages solar – together with wind – as accounting for the predominant sources of cheap, clean electricity supply in 2050, when the UK hopes to operate a ‘net zero’ economy, albeit complemented by other energy technologies that are less reliant on weather factors. In this context, the draft revised EN-3 helpfully moves the dial in favour of solar development and provides important clarifications on how issues arising in the context of the development and operation of utility scale solar farms should be factored into planning decision making.

Capacity clarification

The existing solar NSIPs regime applies to projects where the proposed generation capacity is more than 50MW in England – estimated by the government to typically consist of around 100,000 to 150,000 solar panels and cover between 125 to 200 acres – and 350MW in Wales. The government is not proposing to change these limits under the revised regime, despite the proliferation of such utility scale projects.

However, the government does intend to change the way that capacity is calculated. From the point at which the updated regime begins to apply, the capacity of solar projects will be assessed by reference to the maximum combined capacity of the installed inverters and measured in alternating current (AC). To date, capacity has been assessed by reference to the direct current (DC) generated from the solar panels, which feed into the inverters. This change will not apply retrospectively to consented projects.

Project lifetime, repowering and decommissioning

The draft revised EN-3 retains the helpful steer given in the initial 2021 proposed reforms that impacts from solar farms should be considered as temporary, though it does recognise that project developers will take different approaches to determining how the project lifetime should be considered in the consenting process.

In particular, the updated draft recognises that project lifetimes are now more likely to be 40 years and longer and, crucially, that applicants may choose to bring forward consent without specifying a time limit, or with differing time-periods. There is therefore no one size fits all approach, and each project will be able to bring forward and defend its own approach, against the wider commercial background for that project.

Unlike with other renewable energy technologies referred to in EN-3, the government has made clear that it is not yet prepared to provide policy on the ‘repowering’ of solar schemes at the end of their life, given the time period before that is relevant. Repowering is a term which refers to the replacement of generation assets that have deteriorated in their efficiency over time.

It is notable, however, that the policy changes recognise that decommissioning is not necessarily inevitable, stating that it is only “expected” to happen. This likely won’t stop the debates during the examination phase of the planning process about what is meant by the ‘maintenance’ of a project, whether a project is really “temporary”, and local planning authorities seeking to force decommissioning to avoid ‘blight’ on the community.

Site selection

The draft revised EN-3 sets out factors around site selection for solar farms that will play into NSIP planning decisions.

The proposed new policy confirms that development of ground mounted solar arrays is not prohibited on so-called ‘best and most versatile’ (BMV) agricultural land, but that poorer quality land should be preferred for development to higher quality land.

Where solar farms are to be sited on agricultural land, the draft revised EN-3 also states that consideration may be given to whether the proposal allows for continued agricultural use of the land and/or can be co-located with, for example, onshore wind generation or storage facilities.

The draft revised policy has also been strengthened to recommend that field surveys are used, where necessary, to establish how agricultural land envisaged for siting solar farms should be classified and to determine soil types, which will inform how the soil should be managed during the construction, operation, and decommissioning phases of the project.

Public rights of way have also been added to the list of factors influencing site selection and design under the updated draft EN-3. The policy acknowledges the impact proposed developments may have on public rights of way and encourages applicants to ensure continued safe use of such rights of way during construction and operation, where possible, and to maximise any opportunities to enhance and expand the public rights of way network. A link is also drawn between public rights of way and visual impacts, with prospective developers encouraged to minimise visual outlook from existing way routes. The government has further suggested that applicants should set out their plans in an outline public rights of way management plan.

Whilst the additional policy provided in relation to public rights of way acknowledges the potential impacts that large-scale solar development may have on such routes, it is often the case that landowners will agree to permissive paths being created for the operation of the solar farm but not the adoption of public rights of way. The policy will need careful balancing with the desire to reach voluntary land agreements. In practice, it can hopefully provide a useful point of reference for both applicants and local authorities alike when discussing appropriate measures to be taken regarding public rights of way impacts of the proposed development, whilst respecting landowners’ positions.

The section relevant to solar NSIPs in the draft revised EN-3 also refers prospective developers of offshore solar farms to the need to comply with regulatory requirements relating to offshore transmission networks. More details on that are contained in the draft revised EN-5, which is the proposed new NPS for electricity networks infrastructure. The government has also confirmed that the route and type of terrain traversed by the cabling linking an offshore solar project to the grid connection may have an impact on the project’s viability.

Operational noise, community benefits and battery safety

The latest draft revised NPSs do not provide additional clarity on how matters of operational noise, community benefits and battery safety will factor into solar NSIP planning decisions. These are issues that are commonly raised by local residents in relation to solar projects.

The government has echoed what promoters always say – there are sufficient existing protections in the NPSs to address the risk of operational noise, that community benefits are not to be weighed in the planning balance, as is clear from case law too, and that battery safety is adequately protected by health and safety law. Unfortunately, we do not think that this will prevent these issues being raised in the examination phase of the planning process moving forward, particularly around community benefits, given the government’s contrasting messaging on onshore wind – the government has previously consulted on community benefits for communities hosting onshore wind projects and on Thursday published a consultation on community benefits for electricity transmission networks.

Archaeological investigations

The draft revised EN-3 provides useful clarifications on the extent of prospective solar NSIP developers’ obligations to undertake archaeological investigations on proposed sites. This has been the subject of much debate in pre-application processes.

Many local planning authorities have tended to focus on requiring a minimum amount of trenching from developers rather than focus on the sensitivity of the area and the likely absence of effects on heritage sites that will typically stem from solar developments. Such an approach can add significantly to cost and programme to developers.

The draft revised EN-3 states that “the extent of investigative work should be proportionate to the sensitivity of, and extent of proposed ground disturbance in, the associated study area”. This should help to reduce debate on this topic moving forward and enable applicants to take a proportionate evidence-based approach, rather than meet an arbitrary number in respect of on-site trenching.

Co-written by Matthew Fox and Toby Yeates of Pinsent Masons.