Small-Scale Hydropower: An Inside Look at Making Renewable Energy

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The Bowersock Mills and Power Co. is a small hydropower plant in Lawrence, Kan., that is certified as a low impact hydroelectric facility. This is a “run of river” plant, meaning that it doesn’t significantly alter the river’s flow.
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Sarah Hill-Nelson is co-owner of the Bowersock Mills and Power Co., along with her father, Stephen Hill. Her great, great grandfather completed the current dam in 1878.
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Sarah Hill-Nelson shows off one of the plant’s seven generators. The plant is rated at 2.35 megawatts (MW). On a good day, it produces enough electricity to power about 1,800 homes.
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Bowersock Power is currently working on a proposed expansion of its facility. This turbine will be used in that project if it’s approved. Steven Chu, the Secretary of Energy, has estimated that similar hydropower projects at existing dams across the United States could produce 70 gigawatts (GW) of renewable energy. That’s the equivalent of about 70 nuclear power plants or 100 coal-fired plants.
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This governor works as a safety mechanism to keep the turbine from turning too quickly. It works purely on mechanical energy, no electricity required.

Hydropower is a major source of renewable energy, and it’s not just big dams that are supplying all the power. Some are small, low-impact hydropower plants, such as the Bowersock Mills and Power Co. in Lawrence, Kan. This small hydroelectric facility on the Kansas River  is planning to expand — a move that would triple the dam’s power production with almost no additional environmental impact. Here’s a conversation with Sarah Hill-Nelson, who is a co-owner of the plant and has been running the business for seven years. She talked to us about how hydropower works, the business of selling renewable energy, and why she loves her job. 

Hydropower History

How much electricity does the Bowersock plant produce?

In an average year we produce about 11 million kilowatt hours (kWh). The plant is rated at 2.35 megawatts (MW). On a good day, we make enough electricity to power about 1,800 homes.

How long has it been in your family?

My great, great grandfather, J.D. Bowersock, completed the current dam in 1878. It was in our family until 1923, when it was taken over by another business partner. My dad bought it back into the family in 1972 and it’s been with us ever since.

What do you like most about your job?

I love generating renewable energy, and I love working on the river. I love the history of the plant. I also enjoy being around staff that’s doing interesting work that requires intelligence and strength. I don’t think there are that many jobs that offer both intellectual and physical challenges. I like the business aspect of trying to run a tight ship. There are very few things that I don’t like about my job.

How many people work at the plant?

Right now we have five full-time employees.

And the powerhouse is always generating power, so is there someone here all the time?

Yes, we have someone here 24-7. We don’t have to do that. Our plant manager, Rich Foreman, actually lives here, but if he goes out of town or something we have an on-call system, so if a problem comes up we can take care of it right away.

Let’s talk more about the challenges of the work that you mentioned. What kind of issues do the staff here deal with on a regular basis?

A lot of times we might have a problem with a turbine or a generator, and the guys have to figure out how to solve it. Sometimes it’s an ongoing problem, such as something that’s getting out of alignment all the time. Well, why is it getting out of alignment? What part is not functioning? There are so many moving parts to these turbines and the generators that the problem could be any number of things.

Another example is that recently one of our turbines needed a new draft tube, which is like the tailpipe on a car or engine only it exhausts water. Rich and his team built their own draft tube, which is amazing. Then they had to figure out how to get the new piece back into the building and underneath the turbine.

So they ordered these giant water barrels, and made a raft. They floated the draft tube around the building, and into the plunge pool, lifted it up and welded it into place. And it worked! That was just total ingenuity. The other solution to that problem would probably have involved a crane, which would have been incredibly expensive.

When I was touring the plant, you mentioned that one of your generators had been there since 1918. Can you talk a little bit about how old some of the equipment is?

Yes, a lot of our turbines and generators date to the 1920s. Hydropower is a very capital intensive business, and we never replace anything unless it’s broken. One of the beautiful things about hydro as a science is that it was mature at the turn of the previous century. In other words, people knew pretty much everything we needed to know about the science of generating energy from water at that time. So, the fact that our equipment is old doesn’t mean it’s subpar in any way. In fact, a lot of our equipment is manufactured to a higher standard than stuff we would get today.

And when something breaks, you can repair it.

Exactly. Because it was a well-designed piece of equipment to begin with.

Putting a Price on Renewable Energy

Right now you’re working on a possible expansion to the plant, which would be on the north side of the river. Can you talk a little bit about the proposed expansion?

We have the opportunity here to triple our energy production on this existing dam. And we can do that with little to no additional environmental impact. In fact, our concrete footprint with the new plant will be less than what it is today, because today we have this full spillway covered in concrete. The actual footprint of the new plant will be less than that of the spillway.

We have applied for our license through the Federal Energy Regulatory Commission (FERC), which can be a long process. But one of the things we did that I think has been helpful is that the first thing we did when we were thinking about this project was to contact the neighborhood associations and the regional environmental groups. We had one-on-one meetings with everyone, and said “This is what we’re thinking about doing, what do you think?” We got everybody’s input from the get-go.

Our community here has been very supportive of us. This is a huge project for a small family business to take on, and I think a lot of the reason we’re as far along as we are today has to do with the support we’ve gotten from the federal, state and local levels. The person I work with at FERC has been remarkably helpful.

That’s something you don’t hear a lot about federal agencies.

No, but my experience to date has been positive. In fact, one of the things that FERC did is what’s made us successful today. FERC orders 888 and 889 went through in the 1990s. Basically, when we used to sell our power in the ’70s and ’80s, things were really bad for us. Our only option was to sell to our regional, investor-owned utility. And we would have to go to them hat in hand and say, “how much will you give us for our power?” Because when we would try to sell it to others, they would charge us big wheeling fees, or transmission fees. By the time you calculated the wheeling fees it was too expensive for us to sell to somebody else, so we sold it to them for very little.

So 888 and 889 said that everyone has to pay the same transmission fees. And once the big companies had to pay the same fees that we did, suddenly, the transmission fees became very reasonable! That totally opened up the market for independent power producers. Now we can take our power out and shop it around. This is huge for us.

I would say that the two things that make it possible for us to do this north plant are number one, orders 888 and 889, which changed the market for independent power producers. And number two is the value of renewable energy today, through renewable energy credits (RECs), and through the fact that states have renewable portfolio standards. Perhaps equally important, is the Kansas government’s decision to exempt renewable energy producers from ad valorem taxes.

MOTHER EARTH NEWS has written about renewable portfolio standards before, and how they encourage the development of renewable energy.

We’re very strong advocates of both state and federal renewable energy standards, and I think there’s some misperception about how that would impact our power rates. But the way that I try to talk about it with people is to say that we need to develop a strong domestic renewable energy supply. And a renewable energy standard is an economic stimulus that will help us become more self-sustaining as a country.

We’re addicted to sources of energy that are not healthy for us, and that are not domestically produced. If we can force ourselves to take the one hard step of putting a renewable energy standard in place, the long term economic and environmental benefits far outweigh the benefits of staying on cheap, polluting energy. Life’s going to get better if we make this choice.

Can you talk more about RECs? Just the basics. I know it can get pretty complicated.

It does. But here’s how I would explain it. When people pay more for their renewable energy, it’s like paying more for your organic apple. You’re willing to pay more for an organic apple, because it doesn’t have pesticides and you feel that it’s better for you, it’s better for the community, it’s better for the planet. It’s the same thing with renewable energy.

The problem is that we can’t really differentiate our energy once it gets on the grid. So a REC is just a way for us to account for the value of that renewable energy before that energy hits the grid. We earn one REC for every 1,000 kWh that we generate. And we sell those all to the Bonneville Environmental Foundation (BEF), in Portland, Ore. We love working with them. It’s a not-for-profit, so all of the proceeds that they make from buying and selling RECs go to support their mission, which is to establish new renewable energy generation and to repair damaged watersheds, a cause which is also near and dear to our hearts. Their mission is our mission, and so we love working with BEF. We have great respect for them. And the fact that we can count on those RECs is part of what has helped us even contemplate putting in this new plant.

So if people wanted to buy power from you, they’d go to the Bonneville Environmental Foundation and buy green power.


Low-Impact Hydropower

You’re certified as a low-impact hydropower facility through the Low Impact Hydropower Institute (LIHI) . What was involved in getting that certification?

It was a long process. We had to work with state and federal agencies that were looking at our cultural impact, how are we impacting any archeological resources, how are we impacting the river. It was an exhaustive and a challenging process, and we feel very proud of that certification. It’s been very advantageous to us, because our RECs are worth more to people because we’ve been through this process.

We feel that there should be a mechanism to distinguish the low-impact plants. There’s some controversy about this within the industry. Some people think that it’s going to draw the line between good hydro and bad hydro. I think we would like to think of it as good hydro and better hydro.

I learned a lot through applying for this certification, and I’ve been well prepared to do our FERC application for the north plant based on that process.

So what’s the plan for the north powerhouse?

We would put in four larger turbines in the north powerhouse. These turbines on this side of the river can produce around 300 kW apiece. On the north side they would produce around 1,000 kW apiece. With the expansion, we would be able to take advantage of the quantity of water that comes down the Kansas River, and make better use of the water that flows by.

We are “run of river,” which means that we don’t make any changes in the river flows. We don’t hold water back, we don’t cause fluctuations in the river flow, or rarely. If we do, it’s minimal. The water just passes through us and continues on downstream.

And that helps makes you low impact?


Rolling With the River

Doesn’t being run of river make it more challenging when you get hit with a drought, or a flood?

Yes, we have to be prepared for those low water years. We have to operate so that we have a backlog, or we need to have some kind of escrow account so that when we have a dry year or when we have a flood year, we’re ready, because we’re not going to be able to generate. You know, we’re not going to be making energy.

Can you say more about the flood years, because with a dry year I think it’s a lot more obvious why you won’t be able to generate as much power, and with a flood it’s not as evident.

A lot of people have said to me in the past, you know when we have really high water and it’s just ripping over the dam, people say “Yeah, you must really be cranking it out down there!” And we say “Well, actually no, because we lose our head.”

The head is the difference between upstream and downstream of the dam, or using the technical terms, between the millpond and the tailwater. The smaller that differential, the less power we’re making. And this dam is a low-head dam. So at really high water it looks like a speed bump in the river, you can’t even see it. We usually have to stop generating when there is about 35,000 cfs [cubic feet per second] in the river.

Where are you at today? We’ve been getting a lot of rain this week, and the river’s really rising. Is it getting high enough to cause problems for you?

We’re at about 20,000 cfs today. I haven’t been on the NOAA [National Oceanic and Atmospheric Administration] website this morning, but it’s great, I can get on and find out what our flow is predicted to go to. So we have about another 15,000 cfs before we’ll shut down. But today isn’t a really great day for us. We have all seven generators on, but my guess is that right now they probably getting between 60 to 70 percent efficiency.

But it doesn’t happen very often that you have to shut down. It’s just a matter of being prepared for when it does.

Right, and that’s one of the nice things about our power for purchasers, we can let them know in advance. It’s not like with the wind, all of a sudden it stops blowing and you have no idea when it’s going to happen. We can look ahead and say well, it’s going to get down to 18 degrees tonight, we’re going to get ice that’s going to shut us down. Then we can call and let them know and they can schedule other power.

Because hydro is very predictable, as you mentioned on our tour of the plant. It’s 24 hours a day, a very steady power curve.

Yes, we’re solid. In the energy industry, everyone wants to be baseload, and that’s essentially where we are. We respond to the river, but in terms of our predictability, we’re right up there with coal. Because even a coal-fired power plant is going to have unexpected outages. They’re going to have turbines that go down. It will get even better with the new powerhouse. We will have enough turbines that when we lose one, we can fill that hole in. If one needs to be worked on, no big deal. We keep the exact same power curve. It’s just a smooth curve, very sexy.

I’m not sure I should quote you as saying that.

[Laughs] Well, for people who are into energy, a smooth curve like that is good.

Hydropower Potential

Is it unusual that you’re growing, as a hydropower plant? One thing I keep hearing is that hydro is a big piece of our renewable energy in the United States right now, but there’s not a lot of potential for it to grow. All the dams have already been built.

There is actually a lot of potential for hydropower expansion right now. Last fall, Steven Chu, the U.S. Secretary of Energy pointed this out in a White House forum on clean energy technologies. He called it one of the best kept secrets. His point was that there are over 70 gigawatts (GW) of additional hydro to be developed that would have minimal impact.  It comes from adding turbines on existing dams — dams for flood control or water supply. Seventy GW is the equivalent of about 70 nuclear power plants or 100 new coal-fired plants. That’s a lot of good, clean energy.

In the big scheme of things, Bowersock’s additional energy is a small amount, but as David Orr has said, as far as meeting energy demand with renewable energy, there is no silver bullet, only “silver buckshot.”  Seventy gigs of buckshot is a pretty nice size bullet, so we are feeling optimistic about the role for hydro.

You can read more about what Secretary of Energy Steven Chu said about the potential of hydropower in the Renewable Energy World article Chu Pledges to Push Hydropower. Find more information about small scale hydropower on the Bowersock Mills and Power Co. website.

Megan E. Phelps is a freelance writer based in Kansas. She enjoys reading and writing about all things related to sustainable living including homesteading skills, green building and renewable energy. You can find her on .