Dive Brief:

• MidAmerican Energy will test a prototype wind turbine with a 377 foot (115 meter) tall concrete tower it claims will be the tallest in the nation, Midwest Energy News reports. The added height is expected to allow the turbine to harvest significantly more energy than the more common 263-foot (83 meter) wind towers by accessing stronger winds. 
• The size of traditional steel wind towers is limited by transport logistics, but concrete towers can be constructed by components cast and assembled at the installation site, allowing for a larger tower base. A wider base can bear the greater weight of a taller tower.
• Siemens designed and will erect the turbine at MidAmerican’s 154 MW Adams County wind project. It is expected to be online by 2016. The greater height of the nacelle, hub and blades will allow an increased capacity factor from the 2.3 MW machine's nameplate capacity.

Dive Insight:

On completion of its current wind development commitment, MidAmerican Energy, a subsidiary of Warren Buffett’s Berkshire Hathaway Energy, will have approximately 3,335 MW of installed capacity, some 39% of its total owned generation capacity.

As wind turbines get taller, experts expect the resource to become viable in new regions, and more valuable in places it is already deployed. 

Wind resource maps offered in 2014 by the National Renewable Energy Laboratory (NREL) showed the impact of greater tower heights and improving turbine technology on the viability of wind.

With wind technology’s last generation of 80 meter hub heights, a low wind resource led to an estimated annual electricity production potential of 25 TWh in the Southeastern states. But, with taller, 110 meter turbines more common in today’s installations, NREL estimated 1,747 TWh of annual electricity generation potential for the region.

For future generation wind turbine heights of 140 meters, NREL estimated 6,234 TWh of electricity production from turbines operating with 35% or higher capacity factors.

The Department of Energy has been supporting development of taller concrete wind towers through a $1 million grant to fund research at Iowa State University and a project in Massachusetts that Utility Dive highlighted last year.