Increasing reliance on renewable generation poses challenges

By Steve Downer, MMUA’s The Resource, January 2020 edition; reprinted with permission

Minnesota electric utilities are ready to serve peak load reliably for winter 2019-2020, but incorporating increased renewable generation may lead to reliability issues. Those were among the conclusions to be drawn from a Midcontinent Independent System Operator (MISO) quarterly update meeting held Dec. 13 at the Minnesota Public Utilities Commission (MPUC).

According to a presentation from MISO staff, adequate resources are available this winter to meet normal load under typical conditions. However, over recent years, MISO has seen an increase in total outages during the winter, particularly in January, while the base of renewable “limited use resources” has grown.

Total generation outages, including forced outages, have almost doubled from January 2015 to January 2019, from 24,681 megawatts (MW) to 44,411 MW. Much of this is due to “significant challenges” presented by increasing reliance on wind generation, which typically goes off-line at -22 degrees Fahrenheit.

The capacity adequacy of intermittent wind and solar generation is “always a concern,” said MISO’s Jordan Bakke. “Sun is not well matched to load.”

“Transmission solutions” are needed to further utilize renewable resources, and to significantly reduce curtailment. At 30 percent renewable penetration, MISO’s Renewable Integration Impact Assessment (RIAA) “indicates integration complexity increasing sharply.” At 40 percent renewable penetration, “the transmission system is insufficient to further facilitate renewables and access the diversity in renewables and load.”

The MISO presentation contained information from its RIIA, which studies capacity and energy adequacy and operating reliability, including the ability to withstand unanticipated component losses or disturbances, such as occurred during last winter’s coldest days.

MISO’s RIIA found that integration complexity increases sharply beyond 30 percent renewable penetration. The probability of losing load is “expected” to be one day in 10 years, over all penetration levels.

The effects of a high percentage of wind in the MISO North geographic footprint include a reduced effective load carrying capability (ELCC) during winter.

From its Base to 50 percent renewable “milestone,” MISO assumed the majority of its thermal fleet remains available to maintain adequacy (with 17 gigawatts retired), and 100 gigawatts of renewable capacity added.

As renewable penetration increases, the change in fuel mix at various electric demand points drives changing reliability risks. Increased percentages of wind generation coupled with decreased natural gas generation leads to increased reliability risk. Constantly shifting wind and solar generation leads to the need for increased ramping up and down of thermal (fossil-fueled) generation.

System-wide voltage stability is the main driver of dynamic complexity starting at 40 percent and worsens at 50 percent, which requires transmission technologies equipped with dynamic-support capabilities.

After the presentation from MISO, utility industry representatives responded to the presentation and Commissioners added some comments and questions. The discussion at this point revolved around batteries, electricity storage and various other technologies that, it was generally acknowledged, are not yet commercially available.

Electronic aids will likely be applied in various upcoming situations, but the ultimate electronic solution is not yet identified and MISO staff warned that without thermal, rotating generation, the grid “loses ability to remain stable.”

As the region’s generation portfolio becomes more weather dependent, the transmission system gets more stressed. Given our “current tool set,” said an ITC representative, more wind means more 345-kilovolt lines. And, significant transmission upgrades “won’t happen overnight.”

Repower project set to wrap up

From the Wessington Springs True Dakotan; published December 24, 2019; reprinted with permission.

Construction activity will soon be winding down at a Jerauld County wind farm located south of Wessington Springs.

“Wessington Springs Wind,” a subsidiary of NextEra Energy Resources, has undergone repowering project over the course of the last several months.

The site, which began commercial operation in February 2009, currently consists of 34 General Electric (GE) 1.5 MW turbines with 77-meter blades. Each wind turbine is 262 feet tall from the ground to the center of the blade hub.

A crane waits to lift new blades onto a turbine at the Wessington Springs Wind farm.

The GE turbines are capable of generating enough electricity to power more than 12,700 homes, create no air or water pollution, use no water in power generation and allow land to remain in agricultural use.

NextEra Energy Resources upgraded the performance of the turbines by installing longer, 91-meter blades. According to the company, the longer blades can capture more wind energy to convert it to electric energy, making the turbines more efficient and improving their performance.

“This repower provides an upgrade to newer, more efficient turbine technology, extending the benefits of the project to the community and to landowners for a longer period,” said Jeffrey Bryce, NextEra Energy Resources Associate Project Manager. “The repower will allow the site to operate at peak efficiency with lower wind speeds. The increased efficiency reduces the cost of generating clean, renewable energy and extends the operations of the site for the foreseeable future.”

A discarded rotor hub, which the three blades attach to on a functioning turbine, sits near the base of a turbine at the wind farm. The components within the rotor hub are responsible for controlling the pitch of the blades for desired turbine output.

Through a long-term purchase power agreement with NextEra Energy Resources, Heartland Consumers Power District, the provider of wholesale electric energy to 30 municipalities including Wessington Springs, purchases the full output of the turbines at Wessington Springs Wind.

Nate Jones, Heartland’s chief operations officer, said that Heartland maintains a diverse power supply portfolio, including the output from the wind farm in Wessington Springs to serve their customer base.

“All the resources we have, we use for our customer base,” said Jones, when speaking about the Wessington Springs Wind output contract. “This is part of the energy mix that provides enough resources to service all our customers.”

Heartland officials recently visited the wind farm along with staff from NextEra Energy Resources to check on progress of the repower. From left to right, Heartland Customer Relations Manager Kelly Dybdahl, Chief Operations Officer Nate Jones and Director of Market Operations McCord Stowater.

Jones said that the repower project puts in place the newest and best equipment to produce more wind energy.

When it comes to the flow of energy, Heartland picks up the wind farm output at the high voltage power line. From there, the energy becomes part of the larger mix of energy Heartland uses to provide power to all of its customers, including Wessington Springs.

“It’s hard to describe energy flow,” Jones explains. “Electrons, or energy produced, goes out on the bulk grid and gets used up. Our Wessington Springs Wind contract gives us the right to the energy produced there.”

The repowering project brought approximately 100-150 crew members to the area for this project.

Officials from Wessington Springs also recently toured the wind farm. From left to right, Heartland Director of Market Operations McCord Stowater, Chief Operations Officer Nate Jones, NextEra Energy Resources Wind Tech Leader Darin Clabaugh, Wessington Springs city employee Bailey Willman, Wessington Springs Area Chamber and Development Director Loree Gaikowski, and Heartland Customer Relations Manager Kelly Dybdahl. Not pictured is Wessington Springs Electric Superintendent Phil LaBore.

Heartland says that in addition to efficiencies, this project will also financially help their customers.

“Heartland will receive a lower wind energy rate due to increased efficiencies from more wind power produced and reduced maintenance costs,” said Heartland Chief Finance Officer Mike Malone. “Heartland’s customers, in turn, will experience wholesale rate stability as a result.”

A gearbox, rotor shaft and brake assembly from Turbine #1 of the wind farm.

Bryce said that additional repower projects will not be needed in the future. He explained that this repower will not only increase the efficiency and performance of the site, but also include state-of-the-art monitoring systems that will allow NextEra to predict required maintenance and prevent unscheduled outages.

“Wessington Springs Wind will continue to bring clean, reliable energy to Jerauld County for many years to come.

With the repower comes state-of-the-art monitoring systems, which allows NextEra to view real-time data of each wind turbine.

Wessington Springs wind tower project lights the way to new turbine tech

Longer blades, updated gear boxes increase efficiency with lower wind speeds

By Kristi Hine, True Dakotan

Construction activity is beginning to surge at a Jerauld County wind farm located south of Wessington Springs.

“Wessington Springs Wind,” a subsidiary of NextEra Energy Resources, is a repowering project with construction slated to begin this month.

The site, which began commercial operation in February 2009, currently consists of 34 General Electric (GE) 1.5 MW turbines with 77-meter blades. Each wind turbine is 262 feet tall from the ground to the center of the blade hub.

The GE turbines are capable of generating enough electricity to power more than 12,700 homes, create no air or water pollution, use no water in power generation and allow land to remain in agricultural use.

NextEra Energy Resources will be working to upgrade the performance of the turbines by installing longer, 91-meter blades. According to the company, the longer blades can capture more wind energy to convert it to electric energy, making the turbines more efficient and improving their performance.

“This repower provides an upgrade to newer, more efficient turbine technology, extending the benefits of the project to the community and to landowners for a longer period,” said Jeffrey Bryce, NextEra Energy Resources Associate Project Manager. “The repower will allow the site to operate at peak efficiency with lower wind speeds. The increased efficiency reduces the cost of generating clean, renewable energy and extends the operations of the site for the foreseeable future.”

Through a long-term purchase power agreement with NextEra Energy Resources, Heartland Consumers Power District, the provider of wholesale electric energy to 30 municipalities including Wessington Springs, purchases the full output of the turbines at Wessington Springs Wind.

Nate Jones, Heartland’s Chief Operations Officer, said that Heartland maintains a diverse power supply portfolio, including the output from the wind farm in Wessington Springs to serve their customer base.

“All the resources we have, we use for our customer base,” said Jones, when speaking about the Wessington Springs Wind output contract. “This is part of the energy mix that provides enough resources to service all our customers.”

Jones said that the repower project puts in place the newest and best equipment to produce more wind energy. 

When it comes to the flow of energy, Heartland picks up the wind farm output at the high voltage power line. From there, the energy becomes part of the larger mix of energy Heartland uses to provide power to all of its customers, including Wessington Springs.  

“It’s hard to describe energy flow,” Jones explains. “Electrons, or energy produced, goes out on the bulk grid and get used up. Our Wessington Springs Wind contract gives us the right to the energy produced there.” 

The repowering project will create construction job opportunities and bring approximately 100-150 crew members to the area for this project. NextEra Energy Resources said that the company aims to hire locally, whenever possible. 

Heartland says that in addition to efficiencies, this project will also financially help their customers.

Heartland will receive a lower wind energy rate due to increased efficiencies from more wind power produced and reduced maintenance costs,” said Heartland Chief Financial Officer Mike Malone. “Heartland’s customers, in turn, will experience wholesale rate stability as a result.”

With this project scheduled to be completed by the end of the year, Bryce said that additional repower projects will not be needed in the future. He explained that this repower will not only increase the efficiency and performance of the site, but also include state-of-the-art monitoring systems that will allow NextEra to predict required maintenance and prevent unscheduled outages.

“Wessington Springs Wind will continue to bring clean, reliable energy to Jerauld County for many years to come.”

SPP sets wind record

Wind power continues to proliferate the market

Southwest Power Pool set three wind- and renewable-related records on the morning of December 4, 2017.

The regional transmission organization (RTO) set new records for both wind and renewable penetration: the amount of load served by wind generation and by all renewable fuel sources, respectively.

Southwest Power Pool metrics and milestones. Courtesy SPP

Wind generation at the time was at 13,271 MW and served 56.25 percent of SPP’s load (23,591 MW), beating SPP’s previous wind penetration record of 54.47 percent set on April 24, 2017.

An additional 467 MW of hydropower pushed total renewable penetration up to a record of 58.23 percent, breaking the RTO’s previous record of 57.71 percent set on March 19, 2017.

SPP also set a record for peak wind generation, beating the previous record of 13,342 MW set on February 9, 2017. A new wind peak of 15,690 MW was reached just eleven days later on December 15.

Earlier this year on February 12, SPP became the first RTO in North America to serve more than 50 percent of its load at a given time with wind energy, setting a then record of 52.1 percent wind penetration.

The proliferation of wind power in the SPP region has grown significantly over the last decade. As recently as the early 2000s, SPP’s generating fleet included less than 400 MW of wind, and for years, wind was reported in the “Other” category in SPP’s fuel mix data.

Wind is now the third most-prevalent fuel source in the SPP region. It made up approximately 15 percent of the organization’s generating capacity in 2016, behind only natural gas and coal.

Installed wind-generation capacity increased in 2016 alone by more than 30 percent — up 4,000 MW from 12 GW to more than 16 GW. SPP’s maximum simultaneous wind generation peak rose from 9,948 MW in 2015 to 12,336 MW in early 2016.

Many were recently unsure of wind’s future with the Tax Cuts and Jobs Act, which in its original form would have eliminated the Production Tax Credit (PTC) for new projects. However, the final bill which was passed and signed in late December preserves the phase-out of the PTC through 2019.

CEO’s Report: The Certainty of Regulation

If there’s one certainty in the electric utility industry, it’s the uncertainty of regulation. Regulation is a reality we must live with, but because it is constantly changing and evolving, there are always unknowns in our future. At Heartland, we believe in protecting the environment. After all, we want to ensure clean air for generations to come. That’s why our newest and largest resource, Whelan Energy Center Unit 2, was built with all the latest pollution control technology. However, we also believe that cost must be considered as an important factor in any regulation as to not place an unnecessary burden on consumers.

The Clean Power Plan (CPP) would have an enormous impact if implemented as written, significantly increasing consumers’ electric bills and creating an unnecessary burden for many. Fortunately, the Supreme Court stayed implementation of the plan pending judicial review. Oral arguments were pushed back to late September and will take place before all the judges on the D.C. Circuit rather than the traditional three-judge panel. The granting of a review by all of the judges on the D.C. Circuit is rare and underscores the importance of the case.

This past June, the EPA proposed changes and clarifications to the CPP’s optional Clean Energy Incentive Program (CEIP), and is giving the public a chance to weigh in on those proposed changes. The EPA said the CEIP was designed to help states and tribes meet their goals under the CPP by encouraging early investments in zero-emitting renewable energy generation and by removing barriers to investment in energy efficiency in low-income communities. The idea is to reward early investments in renewables and demand-side energy efficiency measures.

The changes would provide for a limited expansion of the types of projects that would be eligible for the CEIP. The EPA said its proposal would help guide states and tribes that choose to participate in the program when the CPP becomes effective. While APPA has committed to providing comments on the CEIP, a number of states have stated they will not expend any resources on any CPP-related activities, including commenting on the CEIP, because of the stay.

A group of state attorneys general and other state-level officials on August 1 asked the EPA to extend the comment period for the proposed rule. They argued that the comment period should be extended for at least sixty days following the termination of the CPP stay because if it “does not survive judicial review, the CEIP should then simply be withdrawn.”

The EPA also recently defended itself against a group of states who asserted that a recent federal appeals court ruling supported their arguments against the CPP. The states said a recent decision by the U.S. Court of Appeals for the 5th Circuit on a different EPA-related matter supported two of their key arguments. They argue a July 15 decision supports their arguments that the EPA rule on carbon dioxide requires congressional approval and that the EPA has failed to show that the CPP will not undermine the reliability of the nation’s power grid.

The EPA responded that the 5th Circuit’s ruling has minimal relevance to the CPP because, among other things, it “concerns a different regulatory program.”

Numerous flaws continue to be found with the CPP. FTI Consulting recently issued a white paper stating the EPA “was overly optimistic to simply assume that the nuclear industry would continue to be available to produce clean electricity.” This comes after a stream of announcements of nuclear power plant closures and retirements since the CPP was released. They also stated that the nuclear industry is facing challenges due to economic, regulatory and political pressures, which could “lead to significant reductions in the size of the nuclear fleet in the near future.” Recently announced retirements amount to 8.3 GW or 8 percent of total current nuclear capacity.

On the other hand, new wind power capacity swelled in 2015 and is likely to continue rapid growth over the next five years, according to an annual wind energy report from the Department of Energy. Wind power contributes about five percent of the nation’s electricity supply and represented the largest source of U.S. electric capacity additions in 2015, according to the report.

Wind power continues to grow because of the extension of the federal production tax credit as well as improvements in the cost and performance of wind power technologies. Prices offered by newly built wind projects are incredibly low. However, not everyone is happy with the growth of wind power as many feel turbines dotting the landscape are an eyesore. A South Dakota company recently withdrew its application for a state permit to build a 201 MW wind farm after hearing some pushback from residents.

Heartland resource Laramie River Station is currently affected by a different regulation and will undergo an extended outage in 2017 in order to implement regional haze improvements as required by the EPA. The EPA’s Regional Haze Rule superseded the state of Wyoming’s original state implementation plan and eventually the EPA came to a settlement agreement with plant owners to install one selective catalytic reduction (SCR) and two selective non-catalytic reductions (SNCR). The settlement resulted in large cost savings for LRS compared to the EPA’s original plan.

Because regulations bring on extra and often unnecessary costs, Heartland remains committed to advocating on behalf of our customers. We continue to monitor all activity at the federal and state levels affecting our industry and partner with trusted experts to ensure our message is being heard. While we are committed to producing an environmentally-friendly product, we are also committed to reliability and affordability.