AIR FORCE, BIG APPLE MAKE WAVES (AS TESTS)

The National Science Foundation’s grant to the U.S. Air Force Academy for the study of devices that generate wave, tide and current energies has a double-edged implication.

On the one hand, it gives further legitimacy to a kind of New Energy that still lags behind wind and sun in its commercial and popular acceptance.

On the other hand, 300 grand? For an energy source that many experts say could someday provide 20% of U.S. electricity?

One reason for ocean energy’s continued status as an ongoing experiment is that no single harvesting technology has emerged from among the many competing to be chosen. The Air Force Academy’s aeronautics researchers have a unique and rare expertise in feedback flow control and fluid dynamics from decades of research on aircraft. They might develop the insights that will make it possible to identify the one technology that can most efficiently and durably harness wave, tide and current energy.

It may be, however, that there is no ONE technology that will be the most efficient and durable across the many conditions where water flows.

Case in point: Verdant Energy’s efforts to harness the “currents” of the East River flowing past Manhattan Island. Turns out the East River isn’t really a river, just a channel for the tides flowing from Long Island Sound to New York Bay. So capturing the energy there requires the durability of facing ocean, not river, conditions. And it requires propellers on posts that can rotate into tides flowing in and then rotate again into tides flowing out.

The difficulties have been many and daunting. Verdant Power is on its 3rd generation of turbine design. They are not, however, discouraged.

Dean Corren, director of technology, Verdant Power: “We’re failing better all the time…”

Verdant Power’s persistent efforts to achieve a breakthrough in the translation of ocean energy into electricity is a perfect example of why the Air Force is the perfect institution to turn to.

Trey Taylor, co-founder, Verdant Power: “We look at our technology like the Wright brothers…”

It is entirely likely that Verdant or somebody out there, some lone inventor or some brothers (or sisters) as yet unknown, will someday be famous for the breakthrough that turned ocean energy into a commercial proposition. The inventor might even be a student at the Air Force Academy this year.

The Verdant Power East River installation. From Verdant Power via YouTube.

Academy awarded $285,000 for wave energy research
August 20, 2008 (Air Force Link)
and
A Futuristic Energy Plan, 100 Years in the making
Jim Dwyer, August 22, 2008 (NY Times)

WHO
United States Air Force Academy (USAFA) Aeronautics Department (Dr. Stefan Siegel, head of research project); National Science Foundation (NSF); Oregon State University (OSU); Verdant Power (Trey Taylor, co-founder; Dean Corren, director of technology)

WHAT
The Air Force Academy has been awarded an NSF grant to study ocean energy devices. At the same time, Verdant Power will place 3rd-generation turbines on the bed of NYC’s East River to capture tide flows.

How tidal power works. From GreenpeaceUK via YouTube.

WHEN
- Air and waves are both three-dimensional flows across propellers that challenge energy conversion devices because the flow field fluctuates in time.
- Air Force Academy cadets will participate in the basic research as part of their senior year Aeronautics 471 class.
- The wave energy research is funded by NSF through 2011.
- Verdant Power’s 1st 2 tries at the riverbed technology were in 2006 and 2007.

WHERE
- USAFA will utilize the OSU wave tunnel for research purposes and partner on findings.
- The research project will investigate the capture of energy from unsteady flow fields of both deep and shallow water waves by cycloidal propellers.
- East River “current” is actually the flowing in and out of tides in the straight between Long Island Sound and Upper New York Bay.
- The Verdant Power installation will be in the riverbed off Roosevelt Island. The capture electricity will be delivered to the Island via riverbed cables.

WHY
- The NSF grant to the USAFA Aeronautics Dept: $285,619, for cyclodial propeller wave energy converter research.
- The basic idea: Put propellers underwater and let the motion of incoming and outgoing tidal flows or river currents turn the propellers to generate electricity.
- USASFA will try to understand how to improve turbine efficiency and durability in both shallow and deep water, the factors that have prevented large-scale application of the technology.
- The USAFA research will also consider the effectiveness of tugboat propellers in producing thrust.
- The Academy’s research is part of an Air Force-wide push to address energy related issues.
- The Verdant Power turbines sit on piles driven into the riverbed floor and rotate to harvest energy from both in- and out-flowing tides.
- 2nd-generation Verdant Power blades were made of aluminum magnesium but failed after 2 months of use.
- 3rd-generation Verdant Power turbines are made from a stronger aluminum alloy and have been shown more durable in extensive testing.

BioPower Systems' concept solves the problem of durability with simplicity. From BioPower Systems via YouTube.

QUOTES
- Dr. Stefan Siegel, head of research project, USAFA: "Wave power has the potential to provide a large portion of the world's electric energy needs, if it can be tapped in an efficient way…"
- Dean Corren, director of technology, Verdant Power: “[The Verdant Power turbine blades] broke on the first deployment…”