Initiative strengthens, modernizes cooperative's infrastructure

As Basin Electric moves on in years, so does its infrastructure.

The cooperative’s infrastructure spreads out across its service territory throughout nine states and includes maintenance of 2,534 miles of high-voltage transmission lines and 89 substations. Most of the infrastructure was installed between the 1960s and 1980s.

“All equipment eventually does wear out, and we are approaching the upper end of the equipment’s design life,” says Derik Johnson, manager of Basin Electric Transmission System Maintenance (TSM).

The concern of aging infrastructure is not only an issue at Basin Electric, but for the electric utility industry as a whole across the country. 

“We’re up against a cliff event in the industry and if we don’t start investing in our aging infrastructure, we are going to see higher failure rates, which means reduced bulk electric system reliability, and it just keeps snowballing down,” Johnson says.

In the fall of 2018, Basin Electric’s TSM and Headquarters engineering departments started developing a strategy to prioritize replacing the cooperative’s aging substation equipment to stay ahead of the curve. The Aging Substation Infrastructure Replacement Initiative was unveiled in October 2018 as the cooperative’s approach to strengthen and modernize its infrastructure. 

The initiative was based off several evaluations that involved input from multiple departments and divisions across Basin Electric. TSM engaged Headquarters engineering staff to assist in ranking TSM equipment replacements using a risk-based approach. The initial ranking included TSM field observations and input from TSM engineering, transmission planning, and cooperative planning and marketing. With the assistance of information systems and telecom and business system analysts, a software platform was created to enter in the ranking data.

In addition to evaluating equipment age and test data, TSM also looked at the availability of manufacturers who can support the aging substation equipment.

“The original manufacturers of most of this equipment are not in business anymore, or they’ve morphed into different companies that no longer support this equipment,” Johnson says, “We don’t have the luxury of buying parts for the equipment. We’d have to go to a third-party market, and it gets difficult or impossible to procure parts.”

The initiative was used in the spring of 2019 when TSM, along with Headquarters engineering, populated the Long-Range Engineering Plan using the equipment ranking as a guide. Headquarters engineering and TSM spaced the projects far enough apart to ensure resources will be available to support them. 

“Instead of doing this one project at a time, we thought it was important to develop the initiative to show the investment we’re putting into these substations and to show this is what it’s going to take to get this infrastructure replaced over the next several years,” Johnson says. 

The first project on the initiative’s list was the Pahoja substation upgrade. At the January 2019 board meeting, the Basin Electric board of directors approved a $2.1 million budget for upgrades to the Pahoja 230-kilovolt substation, located in the northwest corner of Iowa. Most of the upgrades were completed by the end of 2019. 

The project included:

  • Replacing all transmission line surge arresters;
  • Adding an additional AC station service to provide a redundant feed;
  • Upgrades and replacements to the AC/DC systems, HVAC (Heating, Ventilation, and Air Conditioning), and control and protection systems; and
  • Upgrades to substation security.

The upgrades gave the substation some new features not available in the old system:

  • Human-Machine Interface software, which can show technicians what is in alarm at the substation; and
  • The microprocessor-based relays, digital fault recorders, and remote terminal units on the new control and protection system, which will allow technicians to download fault records and other digital data to assess what happened.

A unique aspect of the project is that TSM acted as the general contractor for the project, which helped save money.

“TSM doesn’t serve as a general contractor on all projects, but the scope and schedule of this project worked well for us,” Johnson said. “Because we were able to do the project in-house, we saved the cooperative money.”

The next project on the list is the Rapid City (South Dakota) DC tie upgrade. The project to upgrade the control system at the Rapid City DC tie kicked off December 2018. Basin Electric and Black Hills Energy, both owners of the tie facility, are working on this project together. The new control system will be installed and commissioned by the end of this year. Leading up to this, it will take two years for the contractor to develop the design and conduct simulations.

See the infographic below for other projects in the works.

The initiative is scheduled to span seven years. All projects are anticipated to be complete by 2025.

One project at a time, and with the Aging Substation Infrastructure Replacement Initiative serving as the guide, Basin Electric is ensuring reliability into the future for its members.