White paper: How sodar makes wind projects more profitable

A white paper released by DNV KEMA and Second Wind quantifies how Triton can make a wind development project more profitable by improving the debt/equity ratio in project financing. This cost-benefit analysis examines the application of Triton in two areas key to a thorough wind resource assessment: wind shear measurement and site characterization. More effective wind resource assessment lowers uncertainty and can improve project financing, but how much? How cost-effective is it to expand an existing measurement campaign?

Traditionally, a met mast has been used to collect measurements for one to three years. The developer wishes to reduce the uncertainty of the wind resource assessment — either to improve project financing terms or to make financing feasible in cases where it’s difficult to obtain with the existing data. Should the developer add another tower, Triton, or both to the resource assessment campaign in its last several months? The white paper provides a detailed cost-benefit analysis of different measurement methods.

Where to focus
The report states: “To make the greatest impact on the financing of a project by reducing wind resource uncertainty, a project developer must evaluate the uncertainties and focus on reducing the largest uncertainty categories.” The white paper looks at two project development scenarios. One project, the “Tall Tower Scenario,” is in simple terrain with 100-m hub height proposed turbines. The site has two years’ worth of data from two 60-m met towers, and an initial evaluation shows that vertical extrapolation is one of the largest contributors to the overall uncertainty. For the other project, the “Complex Terrain Scenario,” with an 80m proposed turbine hub height, spatial variation is the largest contributor to uncertainty. DNV KEMA’s proprietary cost models incorporate data from numerous operating projects and reflect the company’s depth of experience in independent engineering and due diligence reviews for wind projects. The project cash flow models yielded an understanding of where reductions in uncertainty would have the greatest impact on project debt size.

Tall tower scenario
For the tall tower scenario, analysts determined that the greatest area of uncertainty arose from extrapolating 60-m measurements to the 100-m hub height. Three additional measurement campaigns were compared; in each case the new sensor was deployed in an area of the project where the wind resource was not well characterized by the previous met measurements.

Complex terrain scenario
In complex terrain, the greatest amount of uncertainty arises from spatial variation. Because of the terrain, a 100-meter mast was not an option. Three options were considered for a new, similarly complex, location on the site. The report concludes, “Deploying a Triton Sonic Wind Profiler can achieve benefits in a cost-competitive manner. Conventional met masts can also provide increased project returns…”

  Read the full white paper to learn:

• What the largest uncertainty categories are in wind resource assessment
• How some major uncertainty categories disproportionately impact the overall uncertainty
• What factors to consider when choosing equipment for an additional measurement campaign

Second Wind
www.secondwind.com