South African wind farm yield predictions, which represent key inputs for the calculation of a project’s revenue and for the valuation of a potential investment, are as accurate as those from other established wind markets in Europe and North America, a new study shows.
Conducted by Lloyd’s Register, the analysis is based on data provided by six of the eight facilities constructed following the first bid window of South Africa’s Renewable Energy Independent Power Producer Procurement Programme (REIPPPP).
The wind farms have a combined capacity of 562 MW and the information assessed represents some 850-turbine years of data.
Lloyd’s Register energy resource services technical lead David Pullinger tells Engineering News Online the assessment was undertaken in an effort to assess the accuracy of yield forecasts made by it and other consultancies ahead of the projects in 2012.
Such assessments are conducted regularly in Europe and North America in an effort to narrow discrepancies between forecasts and actual results, as well as to improve forecasting techniques.
The study found that wind resource assessments used for the first bid window on average over-predicted the energy yield by 4.9%, which was in line with international benchmarks.
The results were presented at the WindAc Africa 2018, which took place in Cape Town ahead of the Windaba conference and exhibition.
Using the latest techniques, Lloyd’s Register found that wind resource assessments provided more accurate estimates with a remaining bias of only 1.4% across the sites studied.
Pullinger says accurate forecasting will become increasingly important as the tariffs bid by wind independent power producers fall and as competition under the REIPPPP increases.
The next bid window is expected to open before the end of the year and after the finalization of the Integrate Resource Plan (IRP).
The draft IRP 2018, which recently closed for public comment, allows for the installation of 11 442 MW of wind energy by 2030, which would represent 15.1% of South Africa’s overall electricity mix.
To date, South Africa has procured over 3 360 MW of wind capacity since the first REIPPPP bid window in 2011.