In a recent Q&A with Public Power Current, Troy Adams, general manager for Wisconsin Public Power utility Manitowoc Public Utilities, detailed how a power plant boiler refueling project being pursued by the utility offers a variety of benefits for Manitowoc Public Utilities.
Adams, who commented on this and other topics in a recent interview with APPA’s Public Power Now podcast, has served as General Manager of the utility since June 2020. Prior to his current role, he served as general manager for Minnesota public power utility Elk River Municipal Utilities.
Adams said that in addition “to just things being different during the pandemic, there was a lot of pressure for utilities to be evaluating their portfolio, power plants.”
The utility is “part of MISO for our power grid and there was definitely a lot of pressure financially to consider shutting down power plants because the cost of operating a coal power plant...power plants weren't being economically dispatched on that fuel source.”
One of the first things “we were looking at is are we going to shut down our power plants or are we going to try and do something to get them in the money or position them for longer success? Our Commission has been really adamant about the community has paid for these power plants, they're paid for,” Adams noted.
One was one of the two boilers “that we have was built in the mid 90s, the other one in the mid 2000s. In the world of power plants, these are new. We have no debt. And the Commission felt very strongly that we need to take a hard look at how can we extend the life of these power plants and not have stranded investment.”
Of those two power plants, one of the fuel sources “we've been using, we had been blending coal. We had been blending pet coke and we'd also been blending a small amount of a renewable fuel source, a renewable biomass since the 90s. So we had some experience with this, this alternative fuel from a local source.”
Adams noted that Wisconsin is a paper industry state. “Lots of lumber. Lots of paper products come out of the valley and there's a significant amount of waste with that, so this waste product ends up in the landfill.”
Some of this waste product had been diverted “to two of our partner companies that would take that and press this waste product -- clean industrial waste so it's not post-consumer. It's clean industrial waste. Press it into a pellet. Similar to like a wood stove pellet. The partners had worked with the EPA and the DNR to go through the process to get this certified. The pellets are recognized as a renewable fuel in the state of Wisconsin.”
When the utility was burning those, “we were actually getting renewable fuel credits for the volume that we were burning. So we've been blending that in since the 90s, at a very small rate, and so when we were trying to decide what we were going to do with these power plants, that was actually the cheapest fuel that we had. Especially when things happened in Europe with the war in Ukraine. We saw coal and PetCo prices skyrocket. Because solid fuel was being shipped over to Europe -- shipped elsewhere. And supply and demand created an artificial market.... upward pressure on fuel pricing.”
At the same time, there were a lot of challenges with transportation. “We couldn't get a train. We were struggling with transportation costs with trucking, so this engineered pellet that was locally sourced ended up being significantly less cost than all of these other fuels.”
The utility started looking at what would it take to run at 100% on this fuel.
Adams noted that it behaves differently in the boiler. “It was engineered to be similar BTUs to that of coal. But it's a lighter fuel. It's intensified because it's pelletized, but it's definitely lighter than coal that would go into our boilers and they're both CFB style boilers. So we can just kind of dump in whatever fuel we want. But the fireball ends up sitting higher in the boiler. Air flows needed to be different, so we spent probably about a year working with the OEM for the smaller of our two boilers. It's a 23 MW CFB.”
The utility “ended up working with the OEM to go through what I'd call tuning and kind of optimize airflow and feed rate and everything with that boiler. And we ended up getting 6% increase in output, which was pretty exciting to realize that maybe out of desperation, maybe out of opportunity, we were going to switch to this fuel and try and run at 100% on this renewable fuel that's locally sourced and would otherwise go to a landfill,” he said.
“We were able to switch to that run at 100% and actually run more efficiently. So with that, that was kind of maxed output from our partners, the pelletizing companies we've been working with – we were taking all they could give us. So that began the next phase of our project where we are looking to expand and increase volume of pellets locally...we've worked with those partners to increase output at their existing facilities.”
The utility is currently looking at a way to add existing production of pellets locally, “just to have some diversity and location of pellet production, but add another facility locally that would get us to the point where we could run both of our boilers at maximum output, so the volume that we're setting as a target is about 18,000 tons a month.”
The goal is to be diverting 18,000 tons of this waste product from the landfill and make energy out of it versus having it turn into methane in a landfill, “so it ends up being a pretty significant swing from an environmental perspective,” he pointed out.
“And not that that wasn't a consideration when we started looking at this, we were just looking at number one, the economics and how can we preserve the asset. And then we start researching it a little bit more and discover that this is positioning us really, really well from an environmental goal standpoint.”
The utility has been working with the state “with that and this project -- because it really crosses the aisle politically -- have had great support helping us move this project forward because it's a little bit outside of the box and everyone else is talking about shutting down power plants. And here we're talking about extending the life of a power plant. But because we're taking care of another issue in our state, we've gotten all the support, so it's pretty exciting times right now at the utility.”
“Safety is Foundational”
In the interview, Adams also discussed the steps the utility has taken to earn APPA’s Safety Award of Excellence for safe operating practices and a diamond level Reliable Public Power Provider designation from APPA for providing reliable and safe electric service.
“Well, at least for us, and I would imagine with everyone, safety is foundational. Safety culture is the most important thing in any utility -- more important than rates and reliability, although those are extremely important,” he said.
“Safety is the primary goal for all utilities. So that's the same here. Happy to have received the recognition -- it really just affirms that we have a safety culture that's healthy and people are looking out for each other to make sure that they go home every night to their families.”
The RP3 program “is a wonderful program and full disclosure, I was on the RP3 panel for the last seven years. Great experience for me. I grew as a leader in public power through that process because you get to see the best of the best and that program is designed to push utilities to use best practices,” Adams said.
“It's funny how humans work. If you challenge people to say this is best practice, they're going to continually try and get better. So RP3 establishes that bar of best practice and utilities that are participating in that -- just by no other reason than participating in it, continually get better because they're reading about best practices as they're reading the application and their utilities are evolving their policies and processes to be best practice, so it's a wonderful thing that APPA had created and love that it's helping public power become more successful, more sustainable and put us in a better position within our communities.”
Manitowoc Located on the Shores of Lake Michigan
Manitowoc is located on the shores of Lake Michigan. “We’re maybe 30-40 minutes South of Green Bay...and a little more than an hour north of Milwaukee. Our town is kind of situated just far enough away from the bigger cities that we have...population is about 35,000. The utility serves electric and water. We just took on wastewater from the city,” Adams said.
“We have a steam utility. We also have dark fiber that we serve in the community. From the electric side, we're about 18,000 meters. Pretty good industrial customer load -- our overall peak is about 110 megawatts.”
