In practical terms, it could supply more renewable electricity without the same environmental footprint that comes with carving out a brand-new dam site.<\/p>\n\n\n\n
A hidden power source<\/h2>\n\n\n\n
Depending on how the dams are counted, official sources put the number of U.S. dams at around 80,000 to 90,000, and only about 3% of them currently generate electricity. ORNL\u2019s latest update puts the broader untapped hydropower opportunity at roughly 29 gigawatts across thousands of sites.<\/p>\n\n\n\n
Also Read: China\u2019s 16 MW floating wind turbine rises 270 meters from the sea, and its scale shows how fast offshore energy is moving into deep water<\/a><\/h4>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\nThat does not mean every quiet dam is suddenly a power plant waiting for a switch. A more conservative Department of Energy assessment found that adding power to existing non-powered dams could provide up to 12 gigawatts of new renewable capacity, with much of that potential concentrated in a relatively small number of sites.<\/p>\n\n\n\n
Still, 12 gigawatts is not pocket change. Idaho National Laboratory<\/a> notes that the same estimate would be enough electricity for about 4.8 million homes, which is why these old structures are getting a fresh look.<\/p>\n\n\n\nWhy 3D printing matters<\/h2>\n\n\n\n
The problem has never been only water. It has been money, engineering time, and the awkward reality that small hydropower sites often need custom parts because each dam has different flow, height, space, and seasonal conditions. <\/p>\n\n\n\n
That kind of one-off work can make a promising project too expensive before it ever touches the grid.<\/p>\n\n\n\n
That is where Oak Ridge National Laboratory (ORNL) and Cadens come in. Cadens, a Wisconsin startup, partnered with the Department of Energy\u2019s Manufacturing Demonstration Facility<\/a> at ORNL to explore whether additive manufacturing could produce lower-cost parts for low-head hydropower systems.<\/p>\n\n\n\nResearchers used large-format additive manufacturing, computer-aided design, and 3D printing tools to make parts including a draft tube, wall thimble, runner housing mold, PVC end-fitting, pipe supports, and a runner system for a Fixed-Kaplan S-turbine. In plain English, the goal is to make custom hydropower hardware less painful to design and build.<\/p>\n\n\n\n
Not just a lab trick<\/h2>\n\n\n\n
This is not only a shiny prototype sitting on a table. ORNL says the operational prototype at Cadens\u2019 facility has run continuously for more than six years, giving researchers data for turbine design, material testing, energy conversion, and future improvements.<\/p>\n\n\n\n
ORNL also lists a potential 40% reduction per kilowatt compared with traditional methods, a number that explains why the industry is paying attention. For small hydro<\/a>, shaving costs can decide whether a project gets built or remains a nice idea in a report.<\/p>\n\n\n\n\n\n\nAlso Read: Vestas will test a single 379-foot red blade on seven offshore turbines in a 760 MW Dutch wind farm to cut bird collisions, using contrast as a low-tech fix for one of wind power\u2019s hardest optics problems<\/a><\/h4>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\nThe question, of course, is not whether every dam should be retrofitted. \u201cThe challenge is looking at thousands of non-powered dams in the U.S. to determine the most promising location,\u201d said Jakob Meng, a power systems engineer at Idaho National Laboratory.<\/p>\n\n\n\n
What it could mean for the grid<\/h2>\n\n\n\n
Hydropower already has an important place in America\u2019s energy mix. The U.S. Energy Information Administration says conventional hydropower produced about 6% of total U.S. utility-scale electricity in 2025, and about 23% of utility-scale renewable electricity.<\/p>\n\n\n\n![\"A](\"https:\/\/okdiario.com\/techy\/en\/wp-content\/uploads\/2026\/05\/ornl-3d-printed-hydropower-turbine-retrofitting-dams-1.jpg\" "\\"\\"")
By using large-format additive manufacturing, researchers are creating custom hydropower hardware that makes retrofitting thousands of U.S. dams cost-effective.<\/figcaption><\/figure>\n\n\n\nThat matters because the grid is getting more crowded and more complicated. Solar panels help during sunny hours, wind farms help when the wind is right, and hydropower can add another renewable source that is tied to flowing water. No single technology solves the electric bill or alleviates oppressive summer heat by itself, but a stronger mix can help.<\/p>\n\n\n\n
There is also an environmental argument here, though it needs nuance. Retrofitting existing dams can avoid some of the biggest impacts of new dam construction because the concrete structure is already there, but projects still have to deal with permitting, river health, fish passage, sediment<\/a>, and local concerns.<\/p>\n\n\n\nThe limits are real<\/h2>\n\n\n\n
The technology is promising, but it is not magic. ORNL\u2019s own project involved a mix of direct 3D-printed parts and printed molds, including a runner housing mold that was later cast in fiberglass and finished with machining and sealing.<\/p>\n\n\n\n
\n\n\nAlso Read: This offshore platform stacks solar panels, a wind turbine, and wave power in one machine, and it could be at sea within years<\/a><\/h4>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\nThat detail matters. Parts that sit inside wet, pressurized, debris-filled systems for years need to prove they can survive real-world conditions, not just look good in a demonstration. ORNL says Cadens is still working on scale-up, cost reduction, debris management, and biofouling resistance.<\/p>\n\n\n\n
For now, the promise is practical. Thousands of dams are already blocking and guiding water. The question is whether America can turn some of that idle infrastructure into lower-impact electricity before the grid gets any more crowded.<\/p>\n\n\n\n
The official statement was published on Oak Ridge National Laboratory<\/em><\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"America may already have one of its next clean energy opportunities sitting in plain sight. It\u2019s not in a desert … <\/p>\n
Why 3D printing matters<\/h2>\n\n\n\n
The problem has never been only water. It has been money, engineering time, and the awkward reality that small hydropower sites often need custom parts because each dam has different flow, height, space, and seasonal conditions. <\/p>\n\n\n\n
That kind of one-off work can make a promising project too expensive before it ever touches the grid.<\/p>\n\n\n\n
That is where Oak Ridge National Laboratory (ORNL) and Cadens come in. Cadens, a Wisconsin startup, partnered with the Department of Energy\u2019s Manufacturing Demonstration Facility<\/a> at ORNL to explore whether additive manufacturing could produce lower-cost parts for low-head hydropower systems.<\/p>\n\n\n\n Researchers used large-format additive manufacturing, computer-aided design, and 3D printing tools to make parts including a draft tube, wall thimble, runner housing mold, PVC end-fitting, pipe supports, and a runner system for a Fixed-Kaplan S-turbine. In plain English, the goal is to make custom hydropower hardware less painful to design and build.<\/p>\n\n\n\n This is not only a shiny prototype sitting on a table. ORNL says the operational prototype at Cadens\u2019 facility has run continuously for more than six years, giving researchers data for turbine design, material testing, energy conversion, and future improvements.<\/p>\n\n\n\n ORNL also lists a potential 40% reduction per kilowatt compared with traditional methods, a number that explains why the industry is paying attention. For small hydro<\/a>, shaving costs can decide whether a project gets built or remains a nice idea in a report.<\/p>\n\n\n\n The question, of course, is not whether every dam should be retrofitted. \u201cThe challenge is looking at thousands of non-powered dams in the U.S. to determine the most promising location,\u201d said Jakob Meng, a power systems engineer at Idaho National Laboratory.<\/p>\n\n\n\n Hydropower already has an important place in America\u2019s energy mix. The U.S. Energy Information Administration says conventional hydropower produced about 6% of total U.S. utility-scale electricity in 2025, and about 23% of utility-scale renewable electricity.<\/p>\n\n\n\n That matters because the grid is getting more crowded and more complicated. Solar panels help during sunny hours, wind farms help when the wind is right, and hydropower can add another renewable source that is tied to flowing water. No single technology solves the electric bill or alleviates oppressive summer heat by itself, but a stronger mix can help.<\/p>\n\n\n\n There is also an environmental argument here, though it needs nuance. Retrofitting existing dams can avoid some of the biggest impacts of new dam construction because the concrete structure is already there, but projects still have to deal with permitting, river health, fish passage, sediment<\/a>, and local concerns.<\/p>\n\n\n\n The technology is promising, but it is not magic. ORNL\u2019s own project involved a mix of direct 3D-printed parts and printed molds, including a runner housing mold that was later cast in fiberglass and finished with machining and sealing.<\/p>\n\n\n\n That detail matters. Parts that sit inside wet, pressurized, debris-filled systems for years need to prove they can survive real-world conditions, not just look good in a demonstration. ORNL says Cadens is still working on scale-up, cost reduction, debris management, and biofouling resistance.<\/p>\n\n\n\n For now, the promise is practical. Thousands of dams are already blocking and guiding water. The question is whether America can turn some of that idle infrastructure into lower-impact electricity before the grid gets any more crowded.<\/p>\n\n\n\n The official statement was published on Oak Ridge National Laboratory<\/em><\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":" America may already have one of its next clean energy opportunities sitting in plain sight. It\u2019s not in a desert … <\/p>\nNot just a lab trick<\/h2>\n\n\n\n
Also Read: Vestas will test a single 379-foot red blade on seven offshore turbines in a 760 MW Dutch wind farm to cut bird collisions, using contrast as a low-tech fix for one of wind power\u2019s hardest optics problems<\/a><\/h4>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n
What it could mean for the grid<\/h2>\n\n\n\n
The limits are real<\/h2>\n\n\n\n
Also Read: This offshore platform stacks solar panels, a wind turbine, and wave power in one machine, and it could be at sea within years<\/a><\/h4>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n