HAWAII WAVE ENERGY
(THOMPSON/ROTHMAN/WOLFF) PBS NHWE
MEGAN THOMPSON: The
east coast of the Hawaiian island of Oahu is known for its breathtaking beaches
and ocean vistas. But these beautiful waters aren’t just a draw for
surfers and tourists. They are also a potential, untapped source of
renewable energy – power generated from waves.
MEGAN THOMPSON: What’s the potential for wave energy?
PAT CROSS: It's huge. The resource around the world is enormous.
MEGAN THOMPSON: Pat Cross is an oceanographer with a PhD in meteorology who
manages the wave energy testing site off the Marine Corps Base Hawaii.
Since launching two years ago, it’s been one of the few places in the
world testing out different technologies to harness energy from waves.
PAT CROSS: The hard part is just how you capture it in a reliable and
commercially viable way. The resource is huge, but the challenge is great-- to
capture it.
MEGAN THOMPSON: So far, no wave energy developers have figured that out, and
that’s where this testing site comes in....it’s a joint venture by private
business, the military, the department of energy, and the Hawaii Natural Energy
Institute at the University of Hawaii, where Pat Cross works.
PAT CROSS: People are trying very different concepts about how best to
capture the energy that's packed into those waves. So one wave energy device
looks very different from the next right now. And it remains to be seen kind of
what the winners will be.
MEGAN THOMPSON: Wave energy is different from tidal energy, which harnesses power
from the pull and push of tides with devices usually located underwater, and is
already deployed in a handful of places around the world. The wave
devices tested here sit mostly on top of the water. One looks different
from the next, but they all use the movement of waves to turn a turbine, winch
or hydraulic system to generate power. One device tested for a year and a
half is called “The Azura.” It’s designed by a company called Azura Wave Energy
based in Portland, Oregon. The steel device weighs
about 45 tons and is the length of a flatbed truck. As the device rocks
back and forth and up and down in the water, a float in the middle moves and
rotates.
PAT CROSS: As it does that, it pushes hydraulics that runs a motor and makes
electricity.
MEGAN THOMPSON: Last spring the Azura was lifted out of the water for cleaning
and modification. After observing how it performed at the test site,
researchers added a larger float to the middle to try to generate even more
power.
PAT CROSS: So this is another wave energy conversion device….
MEGAN THOMPSON: Pat Cross showed us the second device tested so far, named the
“Lifesaver,” because of its shape. It was developed by a Norwegian
company called Fred Olsen.
PAT CROSS: You may have noticed that it looks nothing like the other wave
energy converter that we saw. And it works in a very different way.
MEGAN THOMPSON: The device is connected to the ocean floor with 200-foot cables.
Those cables are coiled around three winches - like pulleys - on the top of the
device.
PAT CROSS: And so as the as the wave device rocks in the waves, those taut
connections cause the winches to turn. So and you're doing that in three points
around the device.
MEGAN THOMPSON: The Lifesaver came to shore last spring at the Pearl Harbor Navy
Base so researchers could make adjustments to the undersea cables and power
connections. The U.S. Navy and the federal Department of Energy are funding the
testing. Kail Macias is the technical director
at The Naval Facilities Engineering and Expeditionary Warfare Center. He
says the Department of Defense hopes wave energy might one day provide power to
ships at sea or bases on remote islands.
KAIL MACIAS: It's all about energy security. Really critical for us. When you
look at the logistical constraints of what it takes to provide energy as far
forward as possible for our Naval and D.O.D. forces, it does create quite a
challenge. So when we buy, store, distribute fuel, it is a logistical
constraint. So the nice thing about wave energy as it develops,
diversifies our portfolio, and gives us another opportunity to provide another
energy source.
MEGAN THOMPSON: Researchers plan to test at least eight more wave power devices
in the coming years. The next one up is called an “oscillating water
column” and works a bit differently than the others. Waves push and pull
air through a chamber and then through a turbine, which spins and generates
power. Researchers are also monitoring environmental impacts but so far
have not found anything significant. The devices - as much as a mile
offshore in Kaneohe Bay - are all connected to land by cables that come ashore
here, and then feed into this old world war two bunker on the marine base
that’s been converted into work space. It’s also where the wave devices
connect to Oahu’s power grid.
MEGAN THOMPSON: This is the only wave energy testing site in the country
connected to an electricity grid, and researchers say if they can get the
devices to start generating a meaningful amount of electricity, it could be a
more reliable source than wind or solar.
PAT CROSS: It can be quite consistent day and night, which of course solar
is not. And-- and it's predictable fairly reliably
out to the order of five days to a week. So you can kind of plan how much
you're gonna get from wave energy devices to feed
into a power grid, for example.
MEGAN THOMPSON: George Hagerman, an ocean energy researcher at Virginia Tech,
says beyond Hawaii, the entire Pacific coast of the U.S. has the most potential
for wave power …and that it could one day supply electricity to millions of American
homes. But, Hagerman cautions, that day is still a long way off.
GEORGE HAGERMAN: Wave power is popularly thought, and I think with some with some
validity, to be at the stage where solar electric panels and land based wind
turbines were in the late 1980s, early 90s. So maybe a decade or two in terms
of really reaching the point where the technology is commercially widespread
deployed.
MEGAN THOMPSON: Before that happens, researchers must figure out how these
devices can toss about with the waves and survive harsh ocean conditions for
prolonged periods of time. Until recently, Hagerman says, ocean-going
devices have been designed with the exact opposite goal in mind.
GEORGE HAGERMAN: Historically, all of our mathematical modeling and understanding
of the fluid dynamics of how. Waves interact with ocean structures is for
structures that we design not to absorb wave energy. So a ship is designed to
be of such a length that it doesn't pitch violently or everyone to get seasick
on the ship. So vessels and oil and gas platforms are designed not to resonate
with the wave, because you want the platform not to fatigue and fail
prematurely. Now we have to design structures that very efficiently take in all
that energy. So that's one of the challenges too. It's a whole new mindset.
MEGAN THOMPSON: It's difficult to develop this technology. It's still in the very
early stages, but you do believe that you are gonna
get to commercial viability one day?
PAT CROSS: I do. You know, there are, it's, can I guarantee? No.
But I think there's a lot of enthusiasm in the wave energy business right now.
The prize is great. There's a lot of energy out there, and it's really, just
makes, it wouldn't make sense not to pursue wave energy as part of-- the-- the world's, the Navy's and the country's and the world's--
power needs.
###
|
TIMECODE |
LOWER
THIRD |
1 |
1:10 |
PAT CROSS HAWAII NATURAL ENERGY INSTITUTE |
2 |
1:29 |
Ocean Renewable Power Company |
3 |
1:36, 2:37 |
Rover Studios |
4 |
1:40 |
Azura Wave Energy |
2 |
2:48, 6:14 |
Fred Olsen LTD./Rover Studios |
6 |
3:45 |
KAIL MACIAS NAVAL FACILITIES ENGINEERING COMMAND |
7 |
4:10 |
Ocean Energy USA LLC/ Eco Eye TV Series |
8 |
5:17 |
PAT CROSS HAWAII NATURAL ENERGY INSTITUTE |
9 |
6:22 |
Eco Wave Power |
10 |
6:32 |
GEORGE HAGERMAN VIRGINIA TECH |