Notre Dame Captures Top Plant Award for South Bend Hydro Project

A run-of-river hydro project on the St. Joseph River in downtown South Bend, Indiana, spearheaded by the University of Notre Dame, was one of the first ever in the U.S. to utilize the StreamDiver propeller turbine. The innovative plant, more than 90% of which resides out of sight, buried beneath a public park, earned recognition as a 2024 POWER Top Plant award winner.

The University of Notre Dame is an iconic institution of higher education with a long history. The university got its start on a cold afternoon in late November 1842, when a 28-year-old French priest—Rev. Edward Sorin—and seven companions took possession of 524 snow-covered acres that the Bishop of Vincennes had given them in the Indiana mission fields. “A man of lively imagination,” according to the university’s website, Father Sorin named the school “L’Université de Notre Dame du Lac,” which translates to English as “The University of Our Lady of the Lake.” On Jan. 15, 1844, the school was officially chartered by the Indiana legislature.

South Bend’s Hydro History

Around the same time, industry began to inundate the area around the university, especially along the St. Joseph River in South Bend. The first usable dam was constructed on the St. Joseph River in 1842, according to The History Museum. Early industries were located on two races (or man-made canals), one on each side of the river. The races were logically called the East Race and the West Race. Many major industries started on one of the two races, harnessing waterpower for their production needs.

In 1903, the ownership of the West Race was purchased by James Oliver, founder of the Oliver Chilled Plow Company. The company constructed a hydropower plant on the West Race, which was reportedly so efficient and powerful that it could supply electricity to the Oliver Opera House, Oliver Hotel, factories, and other Oliver properties for light, heat, and power. The hydro plant operated for several decades before it was retired when larger and more-economical sources of power found their way into South Bend.

Nonetheless, a dam has remained on the St. Joseph River, with regular maintenance and upgrades made over the years. In the 1980s, while completing a fish ladder project around the dam, the city applied for and received a Federal Energy Regulatory Commission (FERC) exemption to construct a new hydro plant on the dam. Yet, for decades a plant was never constructed, mainly due to economic reasons.

The University of Notre Dame was made aware of the exemption in about 2010. While a for-profit power company would have difficulty justifying the cost of a hydro plant on the dam due to the low head and limited money-making potential, the university had other things to consider. “For us, what we were more interested in was getting the ‘green energy,’ creating the carbon offsets, and having a very long-term payback,” said Paul Kempf, PE, assistant vice president of Utilities and Maintenance with the University of Notre Dame.

In 2014, FERC prompted the city to act. The commission effectively said, “You’ve had this exemption for 30 years, if you’re not going to use it, we’re going to take it back.” That’s when discussions with Notre Dame got serious and the project became more than just a concept.

“It was a great project for us to partner with the city, because frankly, the site was a city park and will be again,” Kempf explained. “And so, we went about designing this facility that gets built on essentially an island between the East Race and the river. And on top of everything we’ve buried underground is this beautiful park that they’re finishing this summer. And all we really take up is a small area for the electrical equipment spaces above ground and then some accesses, but basically, 90 some percent of the park is accessible for use again.”

StreamDiver Turbines

To kick things off, Notre Dame’s engineers set about looking for the best technology to utilize in the unique application they had at hand. “That’s when we hooked up with Voith Hydro and the StreamDiver turbine that they make, and went on from there to start the design in 2016,” Kempf said.

Voith Hydro calls the StreamDiver a “flexible, environmentally friendly, robust, and cost-effective solution for low-head applications.” The compact StreamDiver propeller turbine (Figure 1) can be integrated into existing infrastructures, scaled up into a group of multiple units as required, and even used in ecologically sensitive environments.

1. One of the StreamDiver hydro turbines is shown here being installed in South Bend. Courtesy: Voith Hydro

With a turbine generator powertrain including all bearings exclusively lubricated by river water, the oil- and grease-free operation is especially compatible with the environment. The concept, which Voith Hydro says is deliberately kept simple in terms of design, minimizes the probability of failure and avoids the use of sealing systems. This allows maintenance intervals of 10 years and beyond, effectively cutting operating costs.

“The StreamDiver is a perfect solution for low-head power stations,” said Albin Atzmueller, small hydro concept specialist with Voith Hydro. “We developed this turbine specifically for projects like South Bend and like others that are following right now. We currently have 35 units in operation worldwide—10 of those in South Bend—and another 32 in construction in various stages from installation to newly signed contracts, literally everything, so we are very proud of that. Right now, there are nine locations that operate StreamDivers, one of them is South Bend, and there are eight more currently in construction.”

Timing Is Everything

Of course, projects rarely go off without a hitch. “We ran into a lot of engineering issues we had to solve along the way and we just had to kind of find our way through each of them as they became apparent,” Kempf recollected. “From 2016 to 2019, it took us like a year just to get the application approved with FERC, and then there were some property issues that held the project up almost another year from being able to start just to get them resolved. So, we had a lot of timing issues that had more to do with things outside of actually building the project—logistics of site and other parties.”

The actual construction began in August 2019. “Obviously, we ran into COVID, and we ran into interesting aspects of dealing with FERC and all the other governmental agencies that you can well imagine come into a project like this, so it took us about two and a half years to finish the construction—May of 2022 the plant went online and has been running ever since,” said Kempf.

Atzmueller noted that it’s not uncommon for red tape to hold up projects in the hydro industry. “The whole licensing and all that’s involved with authorities is a very challenging, time-consuming, and a difficult-to-plan process,” he said. “We’ve seen delays like this happen at many hydro sites.”

Learning the Intricacies of Operation

The dam in South Bend is an overtopping dam, which means there’s flow over the top of it at all times. Meanwhile, the FERC permit has reservations established for the various features that exist at the dam, which includes a flow of water over the cascade, through the East and the West races, and for the fish ladder. “They all get the first 530 cubic feet per second [CFS] that comes down the river and then we’re allowed to use anything above that,” explained Kempf.

There are 10 StreamDiver SD 13.10 turbines installed in South Bend, each with a 0.3-MW capacity. The number that are placed in operation and the output of each is a function of flow and head level, that is, the difference between headwater and tailwater elevations.

Turbine operation is fairly well automated. The control system starts and stops turbines based on head level, and manages secondly based on power. As long as the running turbines are able to operate within their minimum and maximum load range, the system is happy, but when a maximum setpoint is reached, another turbine is started, and when a minimum setpoint is reached, a turbine is shut down. The remaining operating turbines will either ramp up or down based on the change.

Yet, Kempf said things aren’t always as straightforward as they may seem. He noted that on one spring day, for example, the river was flowing at about 4,500 CFS, which meant about 4,000 CFS was available for the turbines. Each turbine takes about 350 CFS during maximum operation, so in the above scenario, a person might think you could run all 10 turbines at full power. “Well, the problem is, when you run all 10, you pull the head down so far, that there’s no head left,” Kempf said. “So, it’s a balance between flow and head level, and head level gets tricky, because where’s the tailwater? In an extreme—almost a flooding situation—you actually can have less head, because there’s so much water coming down the river it picks up the tail.”

As previously alluded to, the University of Notre Dame didn’t pursue the South Bend project because it was the cheapest form of energy available; rather, the school chose to add hydro as part of a sustainability initiative. “It’s not uncommon for universities to feel like, to some extent, we should be leaders for society in the path of what we all should be doing,” said Kempf. “We’re fortunate enough to have some resources to do that. So, that’s what’s driven us to get away from coal on campus, moving toward a suite of renewable and recoverable energy projects.”

“It was a great pleasure to work together with the University of Notre Dame. This was a unique project, and one of the first projects that we sold with the StreamDiver technology,” said Atzmueller. “Having a customer that really is interested in a novel technology, a new way of installing something, and thinking out of the box, that is not easy to find in our industry. And we are very, very happy that the university was convinced to follow this project through with us.”

—Aaron Larson is POWER’s executive editor.