Shedding light on solar farm capacity

Michele Vas analyses the recent Galloway v Durham County Council case which was principally concerned with the issue of whether the planning permission approved a solar farm with a capacity of 50MW or more.

This raised concerns about the lawfulness of the planning permission, as it questioned whether the authorised scheme could only be consented through the Development Consent Order (DCO) regime instead of a regular planning permission.

The claimant in the case (a local resident) raised concern with the land area covered by the planning permission, on the basis it approved a solar farm with a larger footprint than was necessary.  It questioned whether the planning permission allowed for a very large number of and area for solar panels that could only have a capacity under 50MW if the panels were considerably below the power of conventionally used and available panels.

The court quashed the planning permission citing that when the Council made its decision, it lacked access to and did not consider the information on the 50MW capacity contained in the Draft EN-3 (now adopted). This information  included the distinction between what the court labelled the “Combined-Panels Method” (i.e. combined capacity of the installed solar panels measured in DC) or the “Combined Inverters Method” (i.e. counting and aggregating the capacity of installed inverters which is measured in AC).  The latter now being the preferred method for measuring the capacity of solar farms in adopted NPS EN-3.

The parties did not identify or address this information, it was only uncovered during the court hearing, the Council did not have the benefit of this information when determining the application which was material to its consideration.

It is important to note that the quashing of the planning permission is fact specific, indeed this was noted by Fordham J himself who stated:

 ” .. on the very particular facts of this individual case, there was in my judgement a public law unreasonableness in not addressing whether the grant of Planning Permission was “approving more panels over a larger area than were required” for a 50MW solar farm …“

There are however some practical key takeaways from the judgment:

• Making information available as part of a planning application which explains a developers approach to measuring capacity, including methods of measurement and the total area or percentage ground cover. This will be particularly important where the land area proposed is significantly larger than the industry standard.
• For new applications, developers should be assessing capacity on the “Combined-Inverters Method”.
• Overplanting is accepted as a means to address panel degradation and maximise the grid connection across the lifetime of the solar farm site, with the judgment suggesting that  reasonableness of the allowance for overplanting should be considered in the context of the solar farm proposed.
• A level of flexibility and adaptability is acknowledged in the planning process for solar farms, provided they comply with the approved plans and relevant planning policies. Care should be taken to ensure that planning conditions make allowance for that flexibility, for example the condition in this case which required “strict accordance” with the approved plans, cut across other conditions which arguably allowed for future flexibility through the submission of further details.
• The wider social, environmental and economic benefits of the solar farm development were considered significant in determining its acceptability.

The judgment emphasises the need for transparency, evidenced explanations and compliance with statutory requirements in solar farm developments. Providing comprehensive details as part of the planning application process is crucial to understanding the developer’s approach to capacity measurements in larger-scale projects, and allowing councils to make informed decisions.

Michele Vas is a Partner at Dentons. This article first appeared on the firm's UK Planning Law Blog.