This assessment has determined that P50 annual energy yield expectations should be revised to a level approximately 9.4% below pre‐construction forecasts (892 GWh per annum vs 985 GWh per annum). This revision is due to a number of factors associated with energy yield prediction. In particular, resulting from the limitations with industry modelling tools when applied to a site of this complexity and scale, using modern large rotor turbines.
Energy yield modelling techniques are continuing to evolve to improve the accuracy of prediction, informed by research and analysis by wind industry participants and experts. Trustpower has undertaken a comprehensive analysis in conjunction with independent engineering advisors to better understand the factors contributing to this revision and will apply these learnings, along with advances in modelling techniques, to future developments.
Trustpower expects that lower wind production at Snowtown Stage 2 would reduce FY17 EBITDAF by approximately A$8.5 million in a year of average wind. Trustpower also expects a reduction in the valuation of the Snowtown Stage 2 generation assets of between A$60‐70 million. This reduction would be applied against the Group’s revaluation reserves. Snowtown Stage 2 generation assets were revalued upwards by A$315 million as at 31 March 2015 following an independent valuation of the Group’s generation assets.
Trustpower remains pleased with its investment in Snowtown Stage 2 and the value created for shareholders from this project.