Study finds wind energy costly to state

LINCOLN -- The Nebraska Power Association Board of Directors has released the results of a yearlong, statewide study that determined various cost and operational impacts of adding large amounts of wind-powered generation to the state's electric power grid.

A key finding of the study revealed that in addition to the physical infrastructure and operating costs for the wind turbines and equipment and the associated transmission facilities, there is an extra 10 percent cost for the wind energy to the Nebraska utilities, or $5.41 a megawatt-hour, to integrate the wind generation into the state's resource generation mix.

This cost, according to the study, was evaluated at the 10 percent wind generation level and takes into consideration the expense of using other generation facilities to help balance the wind resource's added variability and uncertainty.

The study group looked at what it would cost to integrate wind-powered resources into the state's existing generation mix at much higher levels than exists today. The specific levels evaluated included new wind-powered generation, as a percent of total Nebraska electricity needs, at 10, 20 and 40 percent levels for the base year 2018.

"Because there is no economical way to store large amounts of electricity, utilities must balance the electricity generated by power plants with the consumer's demand for that energy instantaneously," explained Clint Johannes, chairman of the NPA joint planning committee that helped author the study. "Adding more wind-powered generation, which is a variable resource, changes the way utility operators achieve this balance and impacts how and when existing thermal-based units, such as coal and natural gas-fired facilities, generate."

Results of the study were determined by using large-scale computer models and data from an existing three-year database of wind details. The study looked at year 2018 across a broad 25-state area.

"Since Nebraska is part of the Eastern Interconnection, which electrically interconnects the eastern two-thirds of the United States, changes in the levels of wind-powered generation in Nebraska impacts the entire region either directly or indirectly," said Johannes. "Nebraska's generating utilities, which are part of regional operating systems, must consider these impacts both inside and outside of the state."

According to the study, the Nebraska wind-powered generation amounts modeled range from 1,249 to 4,727 megawatts, which is eight to 31 times the amount of wind-powered generation currently operating in the state. This compares, the study said, to approximately 8,700 megawatts of other "non-wind" generation resources expected to be available in Nebraska in 2018.

Johannes said some generating utilities in Nebraska have put into place strategic goals of adding 10 percent renewable generation resources to their total mix by 2020 and other entities are exploring the idea of exporting wind for profit.

"Results of this study are an important first step in helping us better understand how the addition of more wind power in the state impacts electric utility costs as well as the operational impacts to the electric utility system in Nebraska and regionally," he said.

The complete report can be downloaded from the NPA Web site at www.nepower.org.