When it comes to raw power and absolute reliability, it doesn’t get much better than the tides. That’s why tidal power is such an attractive option as a renewable form of energy. But designing a device to gather tidal energy in shallow water, where the ebb and flow move fastest and the energy potential is highest, has proven problematic. A research group at Brown is working on a solution. Led by Shreyas Mandre, assistant professor of engineering, the group is developing a hydrofoil — a water wing — as a means to harvest tidal energy. And unlike other tidal energy technologies, the wing is a shallow water specialist.