Increasing onshore wind energy by 2.5% for 3E

Client Challenge

Renewable energy specialist, 3E, wanted to add a further wind farm to its portfolio. Our client’s new plan was to build a 50 MW onshore wind facility, Shevchenko, on the coast of the Caspian Sea, near the town of Aktau, Kazakhstan.

3E asked us to help optimise the site’s potential, maximising the return on investment. Turbine choice and layout were critical considerations. Making the wrong decisions here would result in the wind farm not achieving the best possible returns and, later on, potentially operational problems. High levels of turbulence-induced fatigue, for example, could result in future mechanical turbine failures. 3E also needed a bankable yield assessment that the company and project stakeholders could trust. This assessment calculates energy production across a project's lifetime and provides an accompanying confidence level for that prediction. The document was critical to the project’s development stage, informing investment decisions.

How we helped

First, we analysed the wind data measured on site, performing a long-term adjustment of the wind statistics (using a Measure-Correlate-Predict (MCP) technique). To optimise the site’s layout, we adopted two different approaches.

1. Creating a wind flow model, using WindPRO and WAsP software, to generate a wind resource map (figure 1).
2. Modelling the turbine wakes to calculate the site’s energy yield. This was followed by a loss and uncertainty analysis to determine the energy yields at various confidence levels: P50, P75 and P90. (Figure 2 refers.)

We recommended the second approach: manual optimisation of the grid layout with the intention of minimising the turbine wake losses. This was because of the flat and simple terrain features, the cold climate and the prevailing wind direction, parallel to the largely rectangular site area.

We also identified the best turbine type based on the site’s conditions, including wind speed and turbulence intensity.

Powerful results

Our work gave 3E the optimum solution for its Shevchenko site, ensuring energy yield was maximised through turbine selection and layout.

• The manually optimised layout (figure 2) would produce approximately 2.5% more energy than the alternative WindPRO approach (figure 1) – enough energy to provide electricity for 1,000 homes.
• The selected layout will reduce electrical cable and road length requirements on the site, helping to maximise the project's profitability.
• Our bankable energy yield assessment brought certainty and confidence to project financing decisions.