Get to Know Your Hydro: Conduit Hydropower
For over a century, hydropower has brought electricity to millions of Americans. But somewhere along the way, we’ve lost sight of its value to the system: clean, reliable, renewable power. In fact, hydropower has great potential to do more, especially through new, innovative technologies. Become an expert in the many ways water can generate power with this series, called Get to Know Your Hydro. Lesson one tackles conduit hydropower.
Thousands of miles of man-made canals, pipes, tunnels and aqueducts in the United States are constantly carrying water — for irrigation, to larger bodies of water, to your tap, or from your house into your city’s wastewater system. Did you know this same water can also produce power? It’s called conduit hydropower and it improves upon existing water infrastructure to produce power without the need for a large dam or reservoir.
It’s all a diversion
The act of channeling water into a tunnel, pipeline or canal is called diversion. These projects divert water from a reservoir, lake or river through a pipe of some kind — known as a conduit, hence the name conduit hydropower. The water flows through hydraulic turbines on its way to its ultimate destination, which may be to irrigate vegetables that eventually end up on your plate or the water you use to cook them.
By fitting these existing pipes with turbines, a new, efficient, innovative power source is born out of generation that’s otherwise uncaptured. The systems are efficient, too. Conduit hydropower systems typically have a pretty steady flow of water, which also means that estimating the power potential is pretty reliable compared to traditional hydropower projects.
More Pipes, More Opportunities
The Imperial Irrigation District in the Imperial Valley of California is a great example of conduit development. As the largest irrigation district in the country, IID maintains more than 3,000 miles of manmade canals, with 14 new conduit hydropower projects in the pipeline. That’s significant power potential.
IID already has about 80 MW of hydropower on its system, said Mario Escalera, the district’s operations and infrastructure manager. The 6 MW of new conduit power that the district was approved to develop will help meet renewable energy goals and provide power at an extremely low price. That’s thanks to the existing infrastructure and the free, unlimited power source — water flowing into IID’s pipes from the Colorado River.
“There’s no fuel cost, of course,” Escalera said. “And the canals run 24/7. The 12 renewable sites that were approved produce about 32 million kilowatt hours of annual generation — a value of about $3.8 million in net revenue with an average levelized cost of energy of 5 cents per kilowatt-hour. That’s a substantial savings.”
Standard green power prices are somewhere in the neighborhood of 7 cents per kilowatt-hour. The first new conduit units IID is currently installing are coming in at about 3 cents per kilowatt-hour. “We looked at what opportunities were available within IID and saw this opportunity to harvest power at a very low cost for savings we can pass on to our customers,” Escalera said.
The technology IID is using, the Micro Hydro Screw Generator, to pull power from some of its conduits is new to North America.
The turbines, which are 45’ screws that are 14’ across, come from the Netherlands. Escalero said if the current projects come online on schedule, they will be the first of their kind for the United States.
Innovations in Efficiency
Conduit projects create not only the opportunity for efficiency, but also a great platform for innovation. Portland, Oregon, for example, is using new technology to harvest power from its municipal water pipelines.
Lucid Energy, a Portland-based startup, developed the LucidPipe Power System, which is placed in-line in the pipes of a water transmission network, to generate electricity from excess pressure in the pipeline. Riverside Public Utilities in California also installed Lucid’s technology to power its streetlights.
Creating New Opportunities
With the passage of the Hydropower Regulatory Efficiency Act of 2013, which opened the doors for certain conduit projects, now is a better time than ever to harness the synergy of this technology.
The Federal Energy Regulatory Commission provides a permitting exemption to conduit projects less than 5MW, expediting the otherwise notoriously lengthy hydropower permitting process. Since its passage, more than 76 projects representing 20 megawatts of capacity have qualified for a federal exemption, only requiring state and local permits to be constructed.
This article was written by LeRoy Coleman, NHA’s Communications Manager
