MidAmerican narrows list to five Iowa sites for next wind farms

MidAmerican Energy has been in discussions with wind project developers who have interconnection rights and land holdings in several counties in Iowa and has found five sites that would be suitable for new wind project development.

MidAmerican on June 13 filed with the Iowa Utilities Board a series of answers related to its May 10 application for approval of its 1,050-MW Wind VIII program. Wind VIII is not a specific project, but would cover a series of projects that would total 1,050 MW.

MidAmerican’s current projections do not show a need for added generation capacity to meet peak load until 2023. Thus, MidAmerican does not propose to add Wind VIII primarily as a source of new capacity, although it will defer capacity deficits. Rather Wind VIII is proposed as a meaningful new source of energy production that is environmentally beneficial and will offer system benefits like fuel diversity.

MidAmerican said in the June 13 filing that has reviewed more than 1,250 MW of potential sites and identified five potential projects of varying sizes that MidAmerican reasonably believes can be developed in time to meet the qualification requirements for federal production tax credits (PTCs) and that have relative certainty in regard to interconnection costs and timing. The five sites range in size from approximately 44 MW up to several hundred MW. Under the current PTC program passed by Congress, projects have to begin construction by the end of this year.

The 44-MW site is an expansion of MidAmerican’s existing Vienna wind farm. MidAmerican recently closed on the purchase of the 138.6-MW Wellsburg site in Grundy County. Two additional sites are located north of I-80 and west of I-35, and one site is located south of I-80 and west of I-35.

There was also a heavily redacted section about a wind deal that MidAmerican is working on with a Facebook affiliate called Siculus related to a new Facebook data center. “MidAmerican plans to file the Siculus contract with the Board, soon, as a flexible contract,” the utility said. “While the basic parameters of the contract were largely agreed upon between MidAmerican and Siculus at the time of the Wind VIII filing, the complete terms and conditions had not been agreed upon at that time.”

New MISO standard causes minor changes in reserve margin figures

In another matter, the utility has previously indicated that MidAmerican’s planning reserves requirements ranges from 11.1% to 12.3% over the next 12 years. It was asked if this requirement would change with the new Midcontinent Independent System Operator (MISO) requirement that reserve calculations be based on a load serving entity’s (LSE) load coincident with the MISO peak.

MidAmerican presented to the board an updated load and capability summary, to reflect the new MISO coincident peak methodology and it shows a new installed capacity reserve margin of 14.2%. “MidAmerican’s peak demand that is coincident with the MISO system peak demand is 94.5% of the Company’s system peak demand,” the company added. “No other changes were reflected in the loads or generation capabilities from the load and capability summary submitted as part of MidAmerican’s Wind VIII filing.”

MidAmerican was also asked to provide actual capacity factors over the past three years for all of its current wind farms and compare that to the 36% value assumed for the Wind VIII projects.

“Capacity factors are dependent in large part on the wind regime specific to a wind farm location and the size and model of the wind turbine deployed,” said MidAmerican. “Specifically, all else being equal, the evolution of wind turbines, with increasing blade length, has resulted in capture of more energy from the wind resulting in improved capacity factors versus earlier wind turbine designs. The 36% capacity factor used in the Wind VIII modeling is believed to be a reasonable estimation based on the wind profiles of potential development sites, the newer turbine technology being targeted, and historical performance of MidAmerican’s existing wind generation fleet, which has generally performed near the mid-30% range. Based on information supplied from potential turbine suppliers and wind project site developers for the Wind VIII project, capacity factors for the potential Wind VIII sites are shown to be in excess of 40%. In addition, the existing MidAmerican wind farms with the most comparable technology and wind regimes to the targeted Wind VIII sites and turbine type are Eclipse, Morning Light and Vienna, which all have current capacity factors in excess of the 36% capacity factor used in the Wind VIII economic analyses.”

Wind VIII would have only a slight impact on MidAmerican’s coal units

Another question had to do with a prior MidAmerican indication that wind capacity tends to displace coal. “The statement that ‘wind primarily displaces coal generation’ is focused on the region, not the output of MidAmerican’s coal plants,” the utility responded. “It further recognizes that coal generation is on the margin more of the time than other generation resources in the region and thus is displaced with additional wind. To a lesser degree, natural gas generation is also displaced when it is the marginal generation.”

MidAmerican added: “It is important to recognize that MidAmerican’s units are bid into the [MISO] market, thus the local clearing price is the determining factor with regards to plant operation with the exception of emergencies or local area protection requirements. As such, MidAmerican’s analysis reflects the dispatch of its units against an hourly electric price forecast. Any change in MidAmerican’s coal generation is a function of the unit’s dispatch costs and the electric prices in the area into which it dispatches.”

MidAmerican developed electric price forecasts for three projected years, with and without Wind VIII, to reflect the change in prices due to additional wind generation, and then dispatched its generation against the new price forecasts. In those estimates, coal-fired electricity output for MidAmerican is unchanged in 2016, with or without Wind VIII, while coal output drops slightly in 2020 and 2025 with Wind VIII.

Wind VIII is the latest in a series of MidAmerican wind projects. The prior Wind VII program was comprised of two phases totaling 1,000.3 MW: the 593.4 MW Phase I component was constructed in 2011; and the 406.9 MW Phase II component was constructed in 2012. 

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.