The central issue for determination related to the interpretation of National Policy Statement EN-3 insofar as it relates to overplanting (i.e. the situation where the installed capacity of the facility is larger than the generator’s grid connection agreement). The solar farm had a maximum generating capacity of 49.9MW(AC) but proposed the installation of an indicative number of panels with a total capacity of 78.54MW(DC). The overplanting was to account for three factors:

a) the difference between a solar panel’s nameplate capacity and real operating conditions in the field;

b) the degradation of panels over time; and

c) the maximization of energy exported to the grid.

The Claimant’s primary ground was that overplanting for any reason other than to account for panel degradation was not countenanced by, and gave rise to conflict with national policy in EN-3. The First and Second Defendants argued that EN-3 did not prohibit overplanting for reasons other than panel degradation.

In a judgment that will have important implications for the solar industry, Eyre J rejected all 6 grounds of challenge. He found that the Inspector was correct to conclude that overplanting which went beyond that necessary to address module degradation was not inconsistent with EN-3; provided the overplanting was justified and account was taken of the full effects of the development (including overplanting), there was no separate requirement to consider whether the overplanting was reasonable; and that the potential loss of energy as a consequence of clipping was not an obviously material consideration which the Inspector was required to take into account.

A copy of the judgment can be found here.

Annabel Graham Paul and Stephanie Bruce-Smith acted for the Claimant.

Hereward Phillpot KC and Isabella Tafur, instructed by Burges Salmon LLP, acted for the Second Defendant developer.