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PHILIP WEISENBERGER: It’s kind of a place where time stands still. If you can imagine like a few rolling fields and a horse farm not very far from us, and just tall trees and the water. It's pretty nice and quiet out here.

And the mill is like an old concrete building that's three stories high. And it just kind of stood here by this dam and this creek for, you know, a hundred years and it's kind of iconic here in this area.

Nothing's really changed here, so I can still visualize places and things that I did when I was a kid, very young, and still see my grandfather here. Time hasn't changed very much out here, so I can still see the past everyday as I walk through the mill.


ALLISON LANTERO: Welcome to another episode of Direct Current. I’m Allison Lantero.

MATT DOZIER: And I’m Matt Dozier. The voice you just heard is Philip Weisenberger, a sixth-generation mill owner from Kentucky. In today’s episode, he’s just one of several people who will help us take a trip down the river of hydropower history. We’ll get back to him in a minute.

LANTERO: We’re following the course of hydropower’s evolution, from the earliest ripples of invention to its turbulent growth, before flowing on downstream to the wave of technologies that could shape its future.

DOZIER: So, why water? For thousands of years, people have harnessed the power of flowing water. Ancient civilizations from China to Greece figured out that water-driven machines could make strenuous tasks like grinding grain and cutting stone a whole lot easier.

LANTERO: That technology turned out to be so useful, and so reliable, that we’ve been using it ever since. Mills like the one owned by the Weisenberger family are an example of just how timeless and ever-present hydraulic power has been since its discovery.


WEISENBERGER: I am Philip Weisenberger, the sixth generation of Weisenbergers to work here at Weisenberger Mill. We've been in business since 1865. We make flour, cornmeal, grits, different types of baking mixes here in Midway, Kentucky. We've stuck to the way we do things and we've done it. I think that might be one of our secrets, why people like our products because it's done the old-fashioned way and it hasn't changed.

LANTERO: When Philip says it hasn’t changed, he’s being very literal. The mill uses a lot of the same machinery his ancestors used when it was built in 1913.

WEISENBERGER: The mill was built with two turbines in the water. So the turbine is connected to a pulley and the pulley is then connected to a line shaft of the mill through a belt, and that would turn the line shaft, which then turns the rest of the mill. The whole mill we have here is all driven by belts and pulleys.

LANTERO: Mills like the original Weisenberger mill relied on water power to move their machinery, but in the 1880s people realized they could use water to do even more. We’re talking, of course, about generating electricity.

DOZIER: Yeah, did you know that as early as 1880, Grand Rapids, Michigan, was illuminating a theatre and a storefront with so-called “hydroelectric” power? And in 1881 in Niagara Falls, New York, a flour mill powered the street lights.

LANTERO: And it goes both ways. The Weisenbergers have been using electricity to help keep the power running on their mill when the water wasn’t enough.

WEISENBERGER: We've been using electricity for a long time -- I would say probably since the 1950s or so -- in combination with the water. We'd have electricity and the turbine using to turn the mill. You just can't always expect to have enough water to turn the mill every day that we need it to.

LANTERO: Later, in around the 1980s, they put in a generator to help the mill produce more electricity than it used. But that generator wasn’t very efficient. In fact, it used about half as much power as it was producing. Which was why a local hydropower developer approached Philip with a proposal.

WEISENBERGER: He came to us and asked if we'd be interested in I guess being kind of a test site for this permanent magnet generator that would adjust its speed based on the water level.

The way this is set up is that the generator then goes out to the grid. It's not connected directly right to the mill. So the electricity that's generated goes into the electricity grid, the utility company monitors how much electricity is generated, and how much we use, and how much goes back into the grid, and gives us credits on our bill. And it works probably twice as efficient as the other generator. So it's been a big, big difference.

LANTERO: If you think of mills like the Weisenbergers’ as the “headwaters” where hydropower began as a slow trickle, then the 20th century is when hydroelectric generation swelled into a raging torrent.

DOZIER: But before we plunge right in, let’s cover some basics. If you want to generate a lot of electricity using water, you need two things: first, a really big turbine; and second, lots of high-pressure water to turn the blades.

LANTERO: Historically, the way we’ve done that is by building dams. When you dam a river to create a reservoir, all that water held up behind the dam has a ton of potential energy. Release some of it and feed it through a turbine, and gravity does the rest.

DOZIER: The bigger your turbine, the more water pressure you need to get it spinning. And for more pressure, you need a longer drop from the upper pool -- that’s the reservoir -- to the lower pool, called the “tailwater.”

LANTERO: We should point out that turbines aren’t exclusive to hydropower. Nearly every major power source relies on turbines to power the generator that produces the actual electricity.

DOZIER: Energy sources like coal, natural gas and nuclear generate heat, which turns water into steam that moves the blades of a turbine. Some forms of concentrating solar power work the same way. And wind turbines, of course, capture energy from the wind.

LANTERO: From one energy source to the next, turbines are pretty much ubiquitous -- it's just a matter of what turns the blades.

DOZIER: Pretty nifty.

TIM WELCH: Let’s turn the clock back a little bit and talk about the rich history that hydropower has played in the energy infrastructure of the United States. You know, going back to the 1930s and the 1940s, when there were these large water projects that were dominated by hydropower, like Hoover Dam, and that really was very important for the electrification of not only cities, but of rural areas as well.

DOZIER: That’s our Energy Department colleague, Tim Welch.

TIM WELCH: My name is Tim Welch, and I’m the Hydropower Program Manager in the Water Power Technologies Office.

LANTERO: As Tim points out, hydropower really exploded in America around the early-to-mid 20th century, boosted by massive public works projects like President Roosevelt’s New Deal. It played a major role in shaping the growth of the nation, particularly in places like the Pacific Northwest.

TIM WELCH: So the construction of large dams really dominated the landscape in the 30s, 40s, and the 50s, and somewhat the 60s. But then, after a while, maybe in the 70s and 80s, new hydropower projects began to tail off a little bit as all the sites for the new projects were sort of taken up.

DOZIER: In addition to the dwindling number of good sites for hydropower dams, there was also the construction cost to consider -- and our growing understanding of just how much these large structures can disrupt the natural world. Dams are massive infrastructure projects. They can drastically change the landscape, disrupting ecosystems and causing problems for the creatures that live there.

TIM WELCH: Let’s talk about the most obvious one, any time you put any kind of structure in the water that fragments a stream -- and by fragments I mean essentially blocks a stream, like a conventional concrete dam, especially a large one like a Hoover Dam would do -- the first thing that comes to mind for most people is that it blocks migratory fish.

TODD DELIGAN: Can you imagine being an upper river tribe in both Washington and in Canada. Your subsistence for 10,000 years has been salmon. And little do you know, starting in the 1930s and the building of Grand Coulee Dam -- that one day would come, from one year to the next, we have our traditional historic runs of fish, and the next year there's nothing, and there has been nothing since 1939 or 1940 when the river was blocked.

LANTERO: That’s Todd Deligan, the Vice President for Business Development at Whooshh Innovations, the developers of the salmon cannon, which you might have seen on Last Week Tonight with John Oliver or heard about on NPR.


JOHN OLIVER: A cannon that fires fish through a tube and over a dam is absolutely incredible. And if you're wondering what it looks like...

DOZIER: Certain fish species, like salmon, generally swim upstream in the fall to have their babies, but when a dam is built in their path, it prevents them from completing their journey. The salmon cannon helps fish get up and over these insurmountable obstacles. Allison spoke with him about how it works and how the company got its unique name.

DELIGAN: When we then moved into the fisheries arena, we had a very descriptive name, Fish Transport System. But then we thought about other objects as well, and one day our CEO really sort of, was like, you know, standing next to the tube and listening to things going by, and it really makes, objects make some sort of a whooshing sound as they go by.


DELIGAN: And that then became our name.

LANTERO: So the system is kind of based on a fruit transport system?

DELIGAN: It was. It really started with trying to identify a better way to get fruit from a tree to a bin more efficiently.  But we knew pretty quickly that if we were able to move a piece of fruit like a golden delicious apple, which is very easily bruised, and we could move those things over a fairly long distance without having any damage to it. Then we could really think about moving a live fish.

The tube is literally hanging from a wire or a pipe. And we're pushing fish with air, and a little bit of water for lubrication, through that tube. And the cool thing is that they actually sort of swim through the tube. I mean that's why they're making that flopping sound.


DELIGAN: They are doing their normal, like, "I'm going upstream" thing.


LANTERO: So is it a colloquialism, or do you actually call the fish transport device the salmon cannon?

DELIGAN: The salmon cannon, was somewhat of an internal joke for a lot of years, and we let that name slip in an interview that we gave a couple of years back, and that interview went absolutely viral. And so, by the very nature of salmon cannon, sort of being out in the public environment, that's what folks really sort of know us by.

LANTERO: How has the Department of Energy worked with you to get this up and running?

DELIGAN: Several years ago, we had the opportunity to meet with a couple of folks at the Department of Energy. And the DOE has been supportive of alternate technologies over the years. And that has been, that has been just terrific. So when we first approached DOE with this idea of moving fish through tubes, out of water quickly over distance, we weren't immediately thrown out of the room. DOE then sponsored really one of the first full physiological tests of fish being transported through a Whooshh system and comparing that to traditional methods.

And now, we were fortunate to pass sort of our second round of funding through the small business voucher pilot program, and that will, hopefully fund a new, in-river migration study in 2017 to really further the data that we want. So we have been very fortunate and thankful for DOE's participation and support, really since 2012.

LANTERO: And lastly, why do you think this is an important problem to solve?

DELIGAN: Salmon -- they are the Northwest, and anything that we can do to help them repopulate -- help their population -- it’s just such a great goal.

DOZIER: We’re at something of a turning point for hydropower in America. With the growing focus on clean energy as our nation grapples with climate change, you could argue that hydro is more important than ever before.

LANTERO: And yet, not much has changed for the industry in several decades. While renewables like wind and solar have expanded rapidly, hydropower has grown much more slowly. The U.S. actually generated LESS electricity from hydro in 2014 than it did in 2002.

DOZIER: So, where do we go from here?

TIM WELCH: What we’re really looking at is a whole new and different way of looking at new hydropower projects. As I say around here, it’s not your grandfather’s hydro anymore. The days of Hoover Dam and Grand Coulee are over.

DOZIER: Those big dams will keep producing power -- we just aren’t building new ones. The future, Tim says, is all about “thinking big” by thinking small. The Energy Department recently released its first-ever Hydropower Vision Report, which looks at all the ways hydropower could change in the coming decades. The report found big potential in lower-impact hydro projects, like adding generation equipment to more of the nation’s thousands of existing dams.

TIM WELCH: So just focusing on non-powered dams, there are about 80,000 of these dams in the United States, and only about 2,000 of them have hydropower. So there’s a lot of interest in that area. In fact, DOE’s own Hydropower Vision predicts about 11 gigawatts of new hydropower development at non-powered dams by the year 2050.

DOZIER: The report also predicted that advances in technology would lead to more small hydropower projects in some pretty surprising places.

LANTERO: Which brings us to the next part of our journey. Let’s continue on down the river, beyond the rushing streams and massive dams, to a place where the terrain flattens out and the water moves steadily, but slowly.


DOZIER: You’re listening to the sound of water flowing through an irrigation canal in central Oregon. It’s a pretty ordinary canal, to be honest. There are more than 700 miles of canals like it in this part of the state, delivering water to thousands of acres of rich farmland in the Deschutes River Basin.

DOZIER: And it just happens to be the site of one of the most exciting developments in hydropower in decades.

LANTERO: There’s a downhill slope at this particular spot on the canal, and the water rushes down through a narrow channel before resuming its leisurely course. It’s just a slight drop, really -- about 12 feet. Hardly a raging torrent, by hydropower standards. But as one company has set out to prove: that’s all you need.


LANTERO: Natel Energy, co-founded by siblings Gia and Abe Schneider with their father in 2005, has developed a technology that could completely change our perception of where hydropower is possible.

DOZIER: That irrigation canal in Oregon is the site of one of their first projects, in fact. It’s a 250 kilowatt installation that provides power to an Apple data center, and it makes a compelling case for small-scale hydro without massive dams or environmental impact. And it’s just the start.


GIA SCHNEIDER: The starting roots are pretty humble, and actually grounded in family. The technology, so, the hydroEngine, which Natel has developed and then commercialized -- with, actually some support from the DOE -- was originally invented by my father back in the first energy crisis. That was late ‘70s, early ‘80s, So my brother and I basically grew up with this technology.

LANTERO: That’s Gia Schneider. She’s the CEO of Natel Energy. Gia said her father Daniel Schneider -- who was, among other things, a doctor, a sailor, a pilot AND a farmer -- worked for years on his design for a revolutionary machine that could cheaply and efficiently capture hydropower from slow-moving water.

LANTERO: For Gia and her brother Abe, that meant a childhood steeped in scientific curiosity, big ideas -- and lots and lots of spare parts.

GIA SCHNEIDER: Oh, yeah. There were hydroEngine parts everywhere. We had a shop attached to the garage, there was a bunch of stuff in there. Yeah. There was a lot of tinkering.  

DOZIER: Their father called his invention the “hydroEngine,” and it worked very differently from your standard hydropower turbine.

ABE SCHNEIDER: At a simplistic level, every turbine on Earth up to this point has used what is effectively a single shaft with metal blades of some form attached to that shaft, which then rotates to drive a generator and produce power.

LANTERO: Abe Schneider is the company’s chief technology officer. Abe said that instead of the propeller-like shape of a conventional turbine, his father’s design looks a lot more like a conveyor belt made out of flat, slightly curved blades -- almost like a high-tech venetian blind.

DOZIER: So picture this: instead of spinning around like a pinwheel, the hydroEngine’s blades travel in a straight line along one side of the conveyor belt. When they reach the end, they turn around and come right back in the opposite direction on the other side. Water flows through the blades, continuously spinning the belt around to run the generator. It seems so simple, and also completely genius.

GIA SCHNEIDER: Conventional hydro is kind of like jumping off the roof of a building to get to the ground floor. You take all that energy out in one step. We looked at that and said, well, what if we could walk down the stairs? Where, instead of taking one big step, we take many smaller steps. And in hydro, that step is called head. Specifically, going to smaller steps is called low head.

GIA SCHNEIDER: To put numbers around that, if conventional hydro applications are hundreds of feet of head, for us we’re looking at stuff that’s as low as five feet, and our top end is about 60 feet.

LANTERO: To accommodate more water flow for the hydroEngine, all you need to do is make the “conveyor belt” longer, which is way cheaper and requires a lot less digging than building a conventional dam.

DOZIER: The original hydroEngine never took off, but Daniel Schneider didn’t give up on the idea. And over the years, Abe said, manufacturing technology began to catch up with his dad’s forward-thinking design.

ABE SCHNEIDER: He started with a very good idea, and I think the biggest difference between that era and today, on the materials side -- we are able to design with carbon fiber. When my dad had been working on this idea, he had to design the conveyor belt basically out of steel chain. And you can imagine how heavy and clunky and prone to wear this would be. Now, there are off-the-shelf belt components that are as strong as the steel chain that they could replace, but weigh five times less and have no moving parts.

LANTERO: Armed with modern materials and computer modeling tools, Gia and Abe teamed up with their father in 2005 to update the hydroEngine design. They secured a patent, and, in 2009, the trio decided to go all-in on the technology.

LANTERO: Since then, the company has installed projects in Arizona, Oregon and Maine. They’ve also rolled out a new version of the hydroEngine that doesn’t need to be fully submerged in water, making it even easier to fit in tight spaces, like, say, an old mill.


DOZIER: Daniel Schneider passed away in 2011. But before he died, he got to see Natel’s first pilot project come online -- and his passion for the work continued even as his health declined.

GIA SCHNEIDER: That was a tiny project with an irrigation district in Arizona that was grid-connected in 2010. He basically built that plant almost single-handedly. He was literally working on this up until the day before he passed.

ABE SCHNEIDER: I think his driving characteristic was that he was very curious about the world, to the point where I remember as a child being frustrated with it, because we couldn’t go and just have a simple vacation. We always had to be doing something productive and asking questions constantly.

LANTERO: That curiosity and love for the natural world had a strong influence on the company’s approach to hydropower.

ABE SCHNEIDER: We grew up on a farm and spent our summers going to the same watershed over and over again, year after year, in the headwaters of the Rio Grande. This is in the mountains of Colorado, up in an alpine area -- lots of aspen and pine, free stone streams. And we would visit these streams every year for years and go fly fishing and hiking.

DOZIER: Those hours spent in the wilderness also supplied the inspiration for a hydropower technology that not only minimizes its environmental impact, but could even have a positive effect on river and stream ecosystems.


ABE SCHNEIDER: The natural example that we look to is in the way that beavers integrate very naturally with the ecosystem. Beavers are a keystone species that actually anchor ecosystems and allow for healthier ecosystems to thrive, and yet they are creating dams.

LANTERO: All that said, Natel still faces an upstream battle when it comes to breaking into the mainstream hydropower market.

GIA SCHNEIDER: Energy is a pretty conservative industry. People are looking for plants that are going to last for 20 to 30 years. And as a startup, that’s the big challenge for any new generation technology is how do I get early customers to take that risk? When everybody wants to see thousands of machines running in the field for several decades, and there’s no way to do that on day one.

DOZIER: The company has received a bit of help from the Energy Department along the way, in the form of two Small Business Innovation Research, or SBIR awards, as well as funding from our Water Power Program.  

ABE SCHNEIDER: We have been very fortunate to work with the Department of Energy over the course of several different projects, over the course of several different years. That funding was a tremendous boost, both to our ability to accomplish our goals from a technical perspective, but also to give others confidence in what we were doing.



DOZIER: So, after a long journey down this river of hydropower stories, we’ve finally reached the place where all great rivers end -- the ocean.

LANTERO: And that brings us to one final story. One about the vast, largely untapped stores of energy surging just beyond our shores.

DOZIER: If you think about it, the ocean seems like a great source of power. Waves, tides and currents contain mind-boggling amounts of kinetic energy; they’re fairly predictable; and with more than 50 percent of the U.S. population living within 50 miles of the coast, the location of this rich energy resource couldn’t be more ideal.

LANTERO: Oh, and did we mention it’s renewable and carbon-free? But the harsh reality is that while the ocean is an incredibly rich energy resource, it’s also a very, very challenging place to generate electricity.

DOZIER: Corrosion, marine life, storms and rogue waves can cause major headaches for equipment anchored in the sea for any length of time. Not to mention the challenges of finding a location with the right waves or currents, connecting to the grid via an undersea cable, and avoiding conflicts with shipping, fishing, military training and all the other ways we use the ocean.

LANTERO: So bottom line: we haven’t really taken advantage of ocean energy here in the U.S. But one Energy Department-sponsored competition aims to change that in a hurry.


DOZIER: So, it’s not the beach, but this is the closest thing you can get to the ocean in the Washington, D.C., area.

DARSHAN KARWAT: So we are looking at a 12-million-gallon pool that the Navy calls its “indoor ocean.”

LANTERO: Darshan Karwat is the technical lead for the Wave Energy Prize, a public prize challenge created by the Energy Department to jump-start the fledgling wave energy industry.

DOZIER: We’re at the Maneuvering and Seakeeping or “MASK” basin, at Carderock Naval Surface Warfare Center, located on the Potomac River just outside DC. The MASK facility is this enormous hangar housing an equally huge tank of water that holds the equivalent of 18 Olympic-size swimming pools.

DOZIER: It’s loud in here, and dimly lit. The water is a deep blue-green in the half-darkness of the cavernous building, and perfectly calm -- until the wave generators kick in.


DARSHAN KARWAT: There’s 216 individually controlled paddles that line two sides of the MASK basin, and if you imagine keeping your hand vertical and your fingers together but then slightly moving each one of your fingers, that’s the way in which those paddles move to generate waves.


DOZIER: Those computer-controlled paddles can create pretty much whatever size or shape of wave engineers desire. The Navy ordinarily uses this facility to test ships in simulated ocean conditions, but right now it’s serving as the testing grounds for the Wave Energy Prize finals.

LANTERO: Over the past several weeks, they’ve been putting their designs to the test in the MASK basin one by one, running a gauntlet of different “sea states” to show how well they perform in conditions ranging from gentle to extreme.

DOZIER: I got a chance to venture out into the middle of the basin with Annie Dallman, a member of Sandia National Labs water power team who’s on assignment at Energy Department headquarters.

ANNIE DALLMAN: We’re right out in the carriage, which is hanging off a huge bridge that goes across the basin. This is where all the data acquisition takes place. We actually had to take a pontoon out here, it’s a neat experience to drive around a dark pool (LAUGHS).

DOZIER: So we’re just out here and they’re getting ready to test the next wave energy device, right?

ANNIE DALLMAN: Right. So we’re just up here for a minute, so we can stay out of the way -- the team’s coming back after a short break so they can start running waves again.

DOZIER: Back on dry land, I asked Annie about the frankly underwhelming size of the waves.

ANNIE DALLMAN: These are scaled waves, because the device is at 1/20th of the full scaled prototype, so the waves are also smaller.

DOZIER: We’ve got mini-devices and mini-waves.

ANNIE DALLMAN: Yeah. But this is actually pretty big, the 1/20th size. A lot of other wave tanks in the country aren’t able to handle such big devices and large waves. So in the previous round of testing, the devices were at 1/50th scale, testing at different universities across the country. And this is kind of the big deal, where they’re going up to 1/20th, they’re at the premier testing facility in the nation.

DOZIER: In between testing runs, Harvest Wave Energy cofounder Stewart Bible talked about his team’s challenging start.

STEWART BIBLE: At the end of the day we got to run some test waves, and we saw a little problem, so last night we went to Home Depot and picked up a lot of material and built a 1/200 scale model of the deployment -- the mooring lines we have out here -- to determine if we could come up a fix, and we did at about 11:00 and we just finished fixing that this morning.

DOZIER: So, you just kind of on the fly built a-

STEWART BIBLE: A very rudimentary... just getting the concept down between the mooring lines so that our device doesn’t move as much as it does yesterday.

DOZIER: And it’s-- how are you feeling? Is it pretty much ready to go?

STEWART BIBLE: It’s a little behind schedule, but it’s really rocking right now. It’s really ready to go.

LANTERO: That’s the kind of flexibility and ingenuity these teams need to stick to the competition’s tight schedule in the face of everything the virtual sea throws at them.  

DOZIER: Out in the parking lot, the co-founders of team Aquaharmonics from Portland, Oregon, were preparing for their upcoming testing run.

MAX GINSBURG: My name's Max Levitus Ginsburg, I'm part of the Aquaharmonics team.

ALEX HAGMULLAR: I'm Alex Hagmullar, also Aquaharmonics, out of Portland, Oregon.

DOZIER: What’s been the biggest struggle for you guys so far, throughout this process?

MAX GINSBURG: Both of us have full-time day jobs, and the schedule for coming up with a prototype I feel like was fairly aggressive. That’s definitely been a big challenge, I’d say.

DOZIER: So you said you have full-time day jobs? Is this kind of like, just a side project for you?

ALEX HAGMULLER: Essentially, yeah. It’s a-- you could call it an “aggressive hobby.” (LAUGHS)

LANTERO: The hope is that by offering entrepreneurs like these a shot at more than $2 million in prize money, the Wave Energy Prize will help push promising wave energy technologies from the realm of smart ideas into commercial success, and the winner will be announced in November.


DOZIER: Hydropower is our nation’s oldest and largest source of clean, renewable energy, and it remains a hugely important part of our nation’s energy future.


LANTERO: As the world adopts more and more renewables like wind and solar in response to the growing urgency of our fight against climate change, hydro offers two very important advantages: flexibility and reliability. Tim Welch explained how “pumped storage hydropower,” which basically means pumping water uphill so you can use it to generate power on demand, has immense potential as a way to complement renewable sources that aren’t “always on.”

TIM WELCH: We all know that the sun doesn’t shine at night and the wind does not always blow. But that’s where hydropower comes in and really can play a major role in keeping grid stability because hydropower can be there to be a constant source – in some cases, with pumped storage, as a battery that has a very quick startup – that can provide needed energy to the grid at times when these variable renewables cannot.

DOZIER: So while we may not see any more of the landscape-transforming hydro projects of decades past, a shift to smaller, low-impact technologies could create new opportunities in places we’ve never even thought of. The industry needs to adapt. And if you ask Tim, that’s not a bad thing.

TIM WELCH: I don’t really look at it as being good, or bad, or fast, or slow. It’s just different. It’s just a different way of thinking about hydropower, but always playing a very important role in the energy grid of being sort of the “backbone” of the grid.



DOZIER: That wraps it up for this episode of Direct Current. You can learn all about hydropower and check out more great stories on our website,

LANTERO: And if you have questions about this episode or any other episode you can email us at or tweet @ENERGY. If you’re enjoying Direct Current, help us spread the word! Tell your friends about the show, and leave us a rating or review on iTunes. We appreciate the feedback.

DOZIER: We’d like to give a big thank you to Tim Welch, Sarah Wagoner and the rest of the Water Power Program.

LANTERO: Thanks to Philip Weisenberger of Weisenberger Mills and Todd Deligan from Whoosh;

DOZIER: Gia and Abe Schneider of Natel Energy;

LANTERO: And to David Brown Kinloch and Steven Smith.

DOZIER: Thanks as well to Darshan Karwat and Annie Dallman with the Wave Energy Prize team, Stewart Bible, Alex Hagmullar, Max Levitus Ginsburg, and to the fine folks at Carderock for accommodating us.

LANTERO: Direct Current is produced by Matt Dozier, Simon Edelman and me, Allison Lantero. Art and design by Carly Wilkins. Support from Paul Lester, Pat Adams, Daniel Wood, Atiq Warraich and Ernie Ambrose. And special thanks to our boss, Marissa Newhall.

DOZIER: Thanks to John LaRue, the Energy Public Affairs Team and the DOE Media Team. We’re a production of the Department of Energy and published from our nation’s capitol in Washington, D.C.

LANTERO: Until next time, thanks for listening!



Hydropower is America's oldest and largest source of clean, renewable energy. But can it grow to meet our changing needs? Follow our hosts on a journey from hydropower's origins to the new wave of technologies that could shape its future.

Read on for more about the topics we covered in this episode, or head over to our Water Power Technologies Office for all things hydro -- including the groundbreaking Hydropower Vision Report.

How Hydro Works

Do you know your penstocks from your spillways? Explore the inner workings of a hydroelectric dam with this interactive graphic

Hydropower History

Humans have been harnessing water to perform work for thousands of years. Follow the history of hydropower from ancient times to today in this interactive timeline from our Water Power Technologies Office.

Keep on Grindin'

A mill owned and operated for six generations by the Weisenberger family has been grinding grains in the heart of Kentucky since the Civil War. Now, it's generating all the power it needs and more thanks to an upgrade funded by the Energy Department.

Up and Over

Dams and other structures that block waterways can be a real headache for migratory fish like salmon. To help these vitally important species get up, over and onward to their destination, Seattle-based Whooshh Innovations cherry-picked technology designed to move fruit for their clever fish transport system -- popularly known as the "salmon cannon."

Big Idea: Small Hydro

Hydropower only works at big dams, right? Wrong. Natel Energy's cutting-edge, low-impact hydro technology could shape the next generation of hydropower in the United States. Learn how the company is carrying on a family legacy of curiosity and big ideas in this blog post

Catch the Wave

Wave energy has tremendous potential to power our nation, but the technology has yet to make a big splash in the United States. Learn about how the Energy Department's Wave Energy Prize is driving the industry forward by offering teams state-of-the-art testing facilities and more than $2 million in total prizes.