Researchers at Pacific Northwest National Laboratory are creating new technology that is being used all over the world to help engineers design improved versions of hydroelectric dams.
About 71 percent of the world's renewable energy comes from hydropower. As the U.S. takes greater steps to acquire more renewable energy, dams will continue being built to adapt to these changes.
As fish pass through dams, many of them will die mainly due to water turbulence, turbine blades, and rapid water pressure changes. Dr. Deng and his research team have worked since the 1990s to create fish-tracking technologies used to identify how dams can become more fish friendly.
One of these technologies is called the Sensor Fish.
It acts as a real fish to collect data through radio transmitters while it travels upstream and passes through dams. About 2,000 measurements per second are recorded. Some of these include pressure, acceleration, and rotational velocity. After passing through, the reusable sensor is caught by boat. Weights inside of the mechanical fish are released, allowing it to return to surface level.
"Once we know the fish movement, and also how the fish approach the dams, we can operate the dams or modify the dams accordingly to have better fish passage," Laboratory Fellow Dr. Deng said.
Since 2007, the laboratory has validated its tracking and sensing technologies with more than 100,000 fish in the U.S., Australia, Brazil, Germany and east Asian countries.
Dr. Deng and his team recently released the latest version of the Sensor Fish, the Sensor Fish Mini. This smaller version can be tested in other hydraulic structures with smaller clearances. It can also be mounted onto structures and blades.
Another piece of fish tracking technology created by PNNL called fish tags can also be used to determine how hydroelectric dam designs can be improved for the future.
Fish tags are implanted into fish to help determine the impact of hydraulic structures during long periods of migration. The tag is self-powered and recharged by fish movement, allowing for data to be collected for well over a year. There are several other versions of tags used to study not only fish, but bats, birds, small mammals and amphibians as well.
"With fish tags, you can understand the biological behavior of the fish, then with the Sensor Fish, you can understand the physics, physical conditions, and fish experience when it goes through the dams," Deng said.