Case Studies: Cavitation Repair, Small Hydro, and Marine Energy
CLEAN CURRENTS 2026
Time: 11:15 AM - 12:15 PM
Day: 9/24/2026
Room Number: Water Power Intelligence Theater
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This session features the following case studies:
Click a case study below to jump to its details:
The American Tidal Energy Project - harness the power of the ocean.
Filling in the gaps: Taking on cavitation with collaborative data and new materials
Advancements in Cavitation Resistant Coatings
Design Choices Matter: A Side‑by‑Side Case Study of Two New Small Hydro Projects on the Same River
The American Tidal Energy Project - harness the power of the ocean.
Hatch
Tides have the ability to be forecasted years in advance and can provide a tremendous source of predictable renewable energy supply in an energy market experiencing an unprecedented growth in energy demand. Harnessing tidal energy is an emerging market globally and has not been commercially developed in the United States.
Ocean Renewable Power Company, Inc.’s (ORPC) received government funding to initiate their American Tidal Energy Project (ATEP or the Project) in Alaska. The initial funding award provided ORCP with the opportunity to further evaluate and characterize the Project site, develop plans for a tidal and demonstration site, engage with Tribal, local, state, labor, and regulatory partners, build local commercial and supply chain relationships, and develop a plan for needed infrastructure at the site to ultimately install a 2 megawatts (MW) of tidal turbine capacity demonstration/pilot site at the Project.
The ATEP is strategically and well-positioned to support the United States in achieving the vision of leading the commercialization and testing of tidal energy to serve its population’s energy needs and sharing lessons learns with the broader, international and global market. The ability to harness tidal energy is especially advantageous for remote and energy-isolated communities and industries. The US is resource-rich in energy potential from tidal and/or current sites, especially in the state of Alaska, where remoteness and energy-isolation is common.
The location of the ATEP project in the Cook Inlet off the coast of East Foreland/Nikiski, Alaska provides the opportunity to capitalize on the largest tidal resource in the US (roughly 40 times the potential of the next largest US resource site outside of Alaska). The ATEP site is also near existing electrical grid infrastructure and potential industrial off-takers, further supporting the ability, and increasing the merit, of developing the ATEP site into a long-term, commercial operation capable of 100MW+ of generation capacity.
This topic will cover the efforts performed by ORPC and the Project team through the first phase of the ATEP to develop a greenfield site in a new energy market: site/resource characterization, risk management, preliminary environmental licensing and planning, procurement and supply chain planning, infrastructure assessment, stakeholder engagement, electrical grid interconnection, health and safety, technology development and evaluation, and lessons learned.
Filling in the gaps: Taking on cavitation with collaborative data and new materials
Chelan County PUD
In reaction turbines, such as Francis and Kaplan units, some degree of cavitation is almost unavoidable, especially over decades of operation. So the best strategy for hydro operators is to predict it, manage it, and repair it before it significantly reduces efficiency or becomes a structural issue. Another important factor is the level of maintenance required to keep it in check. Repair to “frosted” conditions cost significantly less than having to excavate and grind for weld repairs of “pitted” areas. Knowing when to expect cavitation and what is causing it are crucial to ensuring operations are optimized.
In 2026, inspections on Chelan PUD’s equipment found frosting and cavitation damage on the runner blades and discharge liner, which led to an investigation of the correlations between run time, operating in known and unknown cavitation zones, and the type and frequency of repairs.
Three primary correlations were discovered as a part of this analysis:
1. Higher starts-per-runtime lead to increased cavitation. Units with a high number of start times per 1,000 hours of runtime saw structural cavitation requiring liner repair.
2. Cavitation location shifts with operational aggressiveness. Both long exposure times and heavy cycling led to damage, though cavitation was seen in different locations in each operational scenario.
3. Cavitation damage grows exponentially over time if not corrected in the “frosted” condition.
These correlations were discussed within the HRI (Hydropower Research Institute) community as were methods to fill cavitation damage instead of welding.
The classroom presentation will provide an overview of the initial findings that led to the larger correlation analysis, discuss additional findings from analysis of other utilities’ data including correlations between operational and field data. Data highlights will include integrating HRI data to look more broadly across the industry and how this can be utilized as part of a predictive tool.
Chelan PUD is participating in this analysis as part of the HRI. The HRI combines hydropower operational (SCADA), event (GADS) data, and maintenance data and anonymizes it, and allows members to use that data for research. The HRI has data from utilities: Chelan County PUD, NYPA, OPG, Southern Company, USACE, and USBR.
Advancements in Cavitation Resistant Coatings
Bureau of Reclamation
Hydropower infrastructure such as turbine runners, valves, and pipes is frequently exposed to high-velocity water flows that cause cavitation damage. Traditional repair methods, including stainless steel weld overlays, are costly, time-consuming, and often require frequent maintenance. Existing commercial coatings fail quickly under mild to moderate cavitation conditions, leading to increased downtime, reduced power generation, and higher operational costs. There is a critical need for a durable, field-applicable coating that can extend the service life of these components and reduce maintenance frequency.
The research focused on developing and testing a series of polyurethane elastomer coatings engineered for cavitation resistance. Laboratory results showed these new materials out-performed commercially available technologies. Field trials were conducted to validate the laboratory testing. This presentation provides the results after a 21-month long field trial on a 15 megawatt turbine runner.
Design Choices Matter: A Side‑by‑Side Case Study of Two New Small Hydro Projects on the Same River
presented by David Brown Kinloch, Appalachian Hydro Associates
This presentation features a rare, side‑by‑side comparison of two new small hydropower projects—Lock 12 and Lock 14—developed on the same river, with essentially identical flow and net head, but executed using different design concepts, equipment selections, and operational strategies. Because the sites are only miles apart and share nearly identical hydraulic conditions, they offer an unusually clean case study for understanding how design decisions directly affect schedule, capital cost, constructability, and performance.
The presentation will walk the audience through the development timeline for both projects, from licensing and concept selection through construction and commissioning, highlighting where design complexity either accelerated or slowed progress. Lock 12 illustrates how first‑generation solutions—while innovative—introduced technical risk, integration challenges, and operational constraints that impacted both schedule and availability. In contrast, Lock 14 demonstrates how incorporating lessons learned led to a more streamlined design and smoother path to construction.
A core takeaway will be how equipment selection drives total project cost, not just through upfront capital expenditures but through secondary impacts on civil works, electrical complexity, and maintenance requirements. The audience will see how changes such as eliminating gearboxes, variable frequency drives, and individual turbine pits reduced concrete quantities, simplified layouts, and lowered both capital and lifecycle costs at Lock 14.
Operational performance will be another major focus. Using real‑world experience from Lock 12, the presentation will show how debris management, flooding resilience, and equipment reliability often dominate actual energy production at low‑head river sites. The evolution from conventional trashracks and raking systems to log booms and ultimately to a submerged horizontal trashrack concept underscores how operations and maintenance considerations must be central to design, not afterthoughts.
Finally, the presentation will emphasize a broader industry lesson: replication without reflection is risky. Even on the same river, small hydro projects benefit enormously from iterative design, performance feedback, and a willingness to abandon underperforming technologies. Attendees will leave with practical insights they can apply to future small hydro developments to reduce risk, improve constructability, and maximize long‑term value.
