Article written by Barbara Rook
Cold climate (CC) locations offer the most productive, yet most challenging, development opportunities in the wind industry.
According to The International Energy Agency Wind (IEA Wind) Task 19’s most recent Recommended Practices report, “lack of knowledge…and the lack of proven and economical technological solutions” at these locations have limited wind development of CC sites.
“Cold climates offer better wind energy,” explains Ville Lehtomaki, Managing Director at Finland’s Kjeller Vindteknikk Oy. Lehtomaki acts as the coordinator for IEA Wind Task 19. “The lower the temperature, the higher the air density — which equates to more energy in the wind,” he adds, noting that wind speed is the primary criteria in wind-farm site selection considerations.
On the other hand, CC projects involve higher risks and additional costs, states Task 19’s annual report. One of those risks is ice throw, which Task 19 addresses in a new publication that was released at the end of 2018. Low-temperature working conditions and population density must also be considered. For example, countries such as Canada and Scandinavia where population density is low, typically offer lower safety risks, Lehtomaki explains.
No matter the type or location of a site, mapping all potential risks is the key to any successful wind-farm investment, says the Task 19 report. That means using existing icing and wind maps, predictive models, and onsite measurements. Site assessment is the most important phase, as other project decisions are based on those results.
Extensive site measurement is among the best practices Task 19 identified previously, including ice measurements for at least a year, which must account for year-over-year variability. These factors can impact site access and working conditions
A thorough risk assessment should also factor in the quality of the selected turbine, as well as the experience of the project installers, contractors, and operators. Ideally, the risk assessment should inform the requirements for the wind turbines, equipment, manufacturing, installation, and operation.
In addition, a risk assessment must ensure that the selected turbines are only operated under the conditions for which they have been certified. Consider site-specific conditions when assessing if an ice-protection system may be required, and evaluate different ice protection systems for their site suitability
Other critical considerations in wind-farm site selection include site power supply; health, safety and environmental concerns; and low-temperature climate classifications, among others.
The U.S. Department of Energy’s WINDExchange offers tools for modeling, mapping, and optimizing wind-power applications. That includes models for predicting financial and economic outcomes, understanding potential habitat implications and identifying legal considerations. WINDExchange also offers multiple wind site analysis tools.
For example, the Wind Prospector tool: “Helps developers view high-level siting issues with large-scale wind farms by providing easy access to GIS-based wind resource datasets and other data relevant to siting wind power projects,” according to the WINDExchange website.
Among other available maps is the Wind Power Icing Atlas (WIceAtlas) from Finland’s VTT Technical Research Center. Using historical icing weather condition data, WIceAtlas estimates the impact of icing on annual energy production. This information is “critical, since there are no international standards for estimating icing losses in any way,” notes VTT.
The publicly available WIceAtlas also identifies ice throw risks, turbine lifetime, and appropriate wind-turbine models for the intended site.
In addition to consulting cold hard facts, Task 19 also recommends surveying nearby land and wind farm owners about CC conditions in the area. The updated report focuses on available technologies for solving CC challenges.
“We want to gather all the available information and be a hub for all best practices,” says Lehtomaki. The updated 2019-2021 Work Plan is “extremely ambitious,” adds Lehtomaki. “We’re going to be doing some very new things.”