A wind power startup has created a high altitude kite to capture wind energy in upper air, and now an “underwater kite” has been developed to intercept the fluctuating ocean energy at the seabed.
SRI International joined hands with the UC Berkeley to research and develop a tidal energy equipment Manta based on the idea of a stingray. The stingray-like equipment is formed with polymer syntactic foam and glass fiber, and works just like a kite, but the string is fixated to the power generator at the seabed.
Manta resembles an underwater kite, which floats alongside the waves and tidal, and rotates swiftly back to the original location when the string is pulled to the lowest end in order to actuate the power generator to rotate and generate power, where the repeated process eventually incorporates or stores the electricity into the grid and batteries. Although the retraction of the reel also requires additional power, the required degree is fewer.
The Manta system of SRI is able to utilize the enormous energy presented in tidal and rivers. Roy Kornbluh, senior research engineer at SRI, commented that the several MW of undeveloped energy in the ocean, rivers, and estuaries is waiting to be converted into clean and renewable energy.
According to the report of IEEE Spectrum, the target of SRI is to achieve 20KW in the average power for each underwater kite, which although is an insignificant power generation volume, the cheaper setup is easier in installation compared to other underwater turbines, and creates fewer impact to the environment and wild animals, making it suitable in both small scale installation and expanded scale through modularization.
The particular project has also received a 3-year subsidy of US$4.2 million from the Submarine Hydrokinetic and Riverine Kilo-Megawatt Systems (SHARKS) of the Advanced Research Projects Agency-Energy (ARPA-E). Compared to the current latest technology, ARPA-E hopes to reduce the overall cost by another 60%, and lower the electricity price of the public utility equipment to US$0.1/kWh, and US$0.25/kWh in remote areas.
(Cover photo source: SRI International)
