Lockheed Martin and Ocean Power Technologies Developing Utility-Scale Wave Power System
13 October 2009
| Individual PowerBuoy and undersea substation. Source: OPT. Click to enlarge. |
Lockheed Martin and Ocean Power Technologies, Inc. (OPT) have signed a commercial engineering services agreement to develop OPT’s wave energy systems for use in future utility-scale power generation projects.
Under the agreement, Lockheed Martin will provide its expertise in systems integration, lean manufacturing, and test and optimization analysis to enhance OPT’s innovative PowerBuoy wave power generation technology to utility-scale. This will allow the two companies to pursue future utility-scale power generation projects in North America. The companies agreed to collaborate on such projects in a letter of intent signed in January 2009.
| PB150 PowerBuoy, dimensions show in feet. Source: OPT. Click to enlarge. |
The OPT PowerBuoys are point absorbers, with a linear generator for a power take-off system. The “smart” buoys, based on integrated patented hydrodynamics, electronics, energy conversion and computer control systems, capture and convert energy from the natural rising and falling of waves into low-cost, clean electricity. The generated power is transferred ashore via an underwater power transmission cable.
OPT’s latest version is its PB150 PowerBuoy. This 150 kW PowerBuoy is being fabricated in Scotland and will be deployed in 2010 at the European Marine Energy Centre in Orkney Isles, Scotland. A second PB150 PowerBuoy is also planned to be ready for deployment in 2010 as the first of ten PowerBuoys at Reedsport, Oregon. The deployment of these two PowerBuoys in the Atlantic and Pacific Oceans will mark a milestone in the company’s commercial development, as it will be the first time two of the same scale utility PowerBuoys are deployed in multiple locations.
The PB150 PowerBuoy will generate power with wave heights between 1.5 and 7 meters (4.9 to 22.9 feet). OPT’s mooring approach and PowerBuoy structure permit deployment of the PowerBuoy system across a wide combination of storm wave, tidal, and current conditions, making it suitable for many wave climates. The PB150 is typically configured in two to three row arrays, minimizing the footprint of the project.
The PB150 PowerBuoy offers a sustained maximum peak-rated output of 150 kW and a power factor of -0.9 to +0.9. Typical capacity factors for the PB150 are between 30% to 50%, depending on location.
| Undersea substation pod. Source: OPT. Click to enlarge. |
OPT has also developed an Underwater Substation Pod (USP) for which a patent is pending, which can aggregate the electrical output from up to ten (10) PB150 PowerBuoys into a single transmission cable to shore. This approach minimizes costs of submarine transmission cable to the shore based interconnection. The USP provides control and SCADA capability for all connected PowerBuoys.
A future 10-Megawatt utility power station consisting of floating PowerBuoy systems would occupy approximately 30 acres (0.125 square kilometers) of ocean space. Such a plant would generate electricity for approximately 4,000 homes.
Earlier in October, OPT signed an exclusive agreement with a consortium of three leading Japanese companies to develop a demonstration wave power station in Japan. The Japanese consortium comprises Idemitsu Kosan Co., Mitsui Engineering & Shipbuilding Co., and Japan Wind Development Co.. Further, OPT has been invited to become a member of the Tokyo Wave Power Initiative, a committee including the city of Tokyo, regional governments and national agencies involved in the promotion of new energy sources.
This agreement marks OPT’ first project in Japan and is in line with OPT’s global strategy to form alliances with strategic partners in key markets. OPT now has a range of power generation projects globally, including those in Oregon and Hawaii, USA; Scotland and Southwest England; Spain; Australia; and Japan.
Separately, the US Naval Facilities Engineering Command (NAVFAC) recently awarded Lockheed Martin an $8.12 million contract to further develop Ocean Thermal Energy Conversion (OTEC) technology, which the leverages ocean’s natural thermal gradient between warmer water at the ocean’s surface and colder water below to produce renewable and reliable power. (Earlier post.)
I wonder if they could increase the size (diameter) of the "heavy plate" and "float" to get more power per unit. At any rate, 150 KW is not bad per buoy assembly.
Posted by: ejj | 13 October 2009 at 10:45 AM
These are good ideas albeit without much in the way of significant funding. Doubtful that this project will end up employing many people. Still worthy and necessary to fill out the portfolio of alternatives.
Also good to see a major defense contractor working on non-combat related energy products.
Posted by: sulleny | 13 October 2009 at 10:51 AM
There would be a trade-off, a larger unit would have more inertia and wouldn't follow the wave action as well. Smaller units could be mass produced to get more power.
And as a side effect you'd get a smoother energy flow; these generate power from the up/down movement of waves so with a single unit the current would stop at each crest and trough. With many units spread-out it's more likely some would be moving up or down while others are stopped, the more units - the smoother the energy flow.
Posted by: ai_vin | 13 October 2009 at 11:02 AM
Here's a thought: Could we combined these with off-shore wind? I picture the float as a collar around the tower's base, sliding up and down with the waves.
Posted by: ai_vin | 13 October 2009 at 11:07 AM
ai_vin,
VERY good idea! They have to build a platform and tower for the wind turbine anyway, so why not?
Posted by: SJC | 13 October 2009 at 11:23 AM
Maybe they should partner with Statoil & Siemens to do the wind turbine + wave energy generator idea...BUT here's the problem - each wave energy generator buoy will produce about 150 kW according to the article...while these new offshore turbines are producing 2.3 MW, so is it really worth all the design/engineering trouble to get an additional 150 kW per wind turbine from a built-in wave energy generator?
http://www.greencarcongress.com/2009/09/hywind-20090911.html
Posted by: ejj | 13 October 2009 at 11:40 AM
I look at it as shared resources. You have to build the wind turbine pole, so might as well put a donut around it and generate for a lower cost per watt than building each separately.
Posted by: SJC | 13 October 2009 at 12:53 PM
I think these are a great idea. You could go very dense too, there is no reason why you couldn't. This is essentially another form of wind energy -- wind makes waves. And there is lots of energy in waves. Just try to push a beach ball underwater.
Also pairing them up with offshore wind farms is a great idea because that area of water will already be compromised to boat traffic by the wind turbines so why not piggy back on all the electrical infrastructure going in and throw in wave energy as well?
Posted by: Mark_BC | 13 October 2009 at 01:07 PM
Combined wind wave would widen the systems resilience spread or 'bandwidth' the respective peak outputs are occurring at different times or days. The minimum output is much higher and suffer less from any indeterminacy. Built in redundacy against total sytem failure.
We know there is a need for reliability guarantees with all power generation.
Posted by: arnold | 13 October 2009 at 03:09 PM
I don't believe there is any way in which your vessel can be excluded from a wind farm. A lease signed between a developer and the MMS gives exclusive rights to the _commercial_ development on that patch of ocean, but it is still explicitly public property. As an example; in the Golf where oil rigs abound, the artificial reef effect of the rig pilings make those areas prime fishing ground for sport-fishermen.
Modern, large wind turbines would be placed at least 0.5 km apart, and the blades would be about 100' above sea level at the lowest point of their arc. The navigational challenge would be minimal, and there would be no risk of being hit by a blade for sail-boats up to 60' or so.
Though there is an advantage to sharing the infrastructure of a sub-station and transmission to shore, locations well-suited for wind are not necessarily well-suited for waves. For instance, Nantucket Sound has about the best wind resource on the country but is sheltered from the waves by Nantucket and Martha's Vineyard, conversely the Pacific NorthWest has great wave resources, but most of the coast drops off too rapidly to permit any ground-mounted structure, which (so far) is required by wind.
Posted by: Nat Pearre | 13 October 2009 at 03:23 PM
Could a floating wind platform work like an elastic storage damper?
Deflection at peak load is absorbed by pushing back in the (wind)troughs.
At high deflection one would dump the air from sail.
Use water as a variable ballast.
Posted by: arnold | 13 October 2009 at 03:50 PM
Combined Wind/Wave power generation stations could share expensive underwater power cable network. Lower power, wave power could biggy-back on the large Wind power cables at next to no extra cost making wave power generators more cost effective.
Waves and Wind are free and will be around for a very long time. Using both to produce clean e-power is as valuable endeavour. The potential is high enough to replace all current 625 coal fired power stations.
Many countries without enough fossil fuel resources have Wind and Waves and could benefit.
Posted by: HarveyD | 13 October 2009 at 04:25 PM
Nat Pearre - read this recent post about Statoil & Siemens developing a deepwater, floating turbine that is anchored to the sea floor....in up to 700 meters of water (that's pretty deep!). Maybe they can deploy these, modified with the wave energy system off the pacific northwest coast.
http://www.greencarcongress.com/2009/09/hywind-20090911.html
Posted by: ejj | 13 October 2009 at 05:20 PM
A word of thanks for the plate/float design would be appreciated. I found the plate needed to be about 41/2 times bigger than the float area.
Good luck.
Posted by: macroshaft | 14 October 2009 at 12:05 AM
I think that there is potential benefit of such power plants for the coastal area to minimize wave damage. Sometimes power generation could be just added value. There are many places where people regularly suffer of coast damage and are employing lot of efforts ad spending resources (New Orleans) to mitigate or compensate wave power.
Posted by: Darius | 14 October 2009 at 05:44 AM
The latest commercial offshore wind turbines are rated at 6 MW, and they are in the process of extending these to 8 - 10 MW.
It would take a lot of bouys to add up to one of these.
Posted by: clett | 14 October 2009 at 06:10 AM
Yes, but the wave power lasts 24/7, not so much with wind.
Posted by: SJC | 14 October 2009 at 06:35 AM
The big offshore turbines here in Scotland are creating peak power about 35-40% of the time and some power for 96% of the time. Not too dissimilar to wave power I would imagine.
Posted by: clett | 14 October 2009 at 07:45 AM
150 kW peak power with that amount of structure and capital cost? What a waste of money (probably US taxpayer money) and engineering talent. Yes, there is a lot of energy in waves but it is even more dilute than wind energy and requires more equipment which must be located in a hostile environment. Wave power may or may not be less variable than wind power. I am not sure and it probably depends on location but it is not 24/7
Posted by: sd | 14 October 2009 at 12:55 PM
The Aus design use onshore generator and pumped water as the working fluid.
Not sure how one quantifies the friction losses. Also the rigidity of the supply pipe. How relevant in this application?
http://www.carnegiecorp.com.au/
Posted by: arnold | 14 October 2009 at 01:57 PM
more. Carnegie.
http://www.ecosmagazine.com/?act=view_file&file_id=EC137p5a.pdf
Posted by: arnold | 14 October 2009 at 02:05 PM
Clett said you would need a lot of Buoys to match an offshore wind turbines @10MW.
It says in the article 30 acres for a 10MW power station. So with 150KW ea I make that 10,000/150 = 67 units.
Sounds feasible. A redesigned substation Pod could be housed in each turbine tower making it easier for maintenance. A shared utility interconnect makes both systems more viable.
Posted by: Carlos Fandango | 14 October 2009 at 07:21 PM