Wave Energy Treading Water in Southern New England
April 29, 2014
The eternal quest to harness the power of the sea is showing promise off the coast of southern New England, but dwindling financial and policy support have stalled efforts to bring it to market, according to the developers of this unique source of renewable energy.
Modest grants, sweat equity and student classwork, so far, have produced separate yet similar projects in Massachusetts and Rhode Island for harvesting energy from waves.
Wave-energy buoys — also called wave-energy absorbers — are in development at the School for Marine Science and Technology at the University of Massachusetts-Dartmouth. A second public-private partnership is ongoing between Electro Standards Laboratories (ESL) of Cranston, R.I., and the University of Rhode Island College of Engineering.
Wave buoys developed through both projects generate electricity from the constant bobbing, or heave motion, of cylinders sealed within partially submerged, watertight ballasts. The moving cylinders pump generators that deliver immediate power for onsite use.
Prototype buoys have confirmed that moderate East Coast waves have the potential to support both inshore and offshore energy needs.
“The idea is, it’s just kinetic energy and you want to capture it,” said Raymond Sepe Jr., vice president of research and development for ESL, a family-owned technology company.
A 2008 international report entitled “Ocean Wave Energy” claims the world’s oceans contain sufficient wave energy to match global energy consumption. While only 10 percent to 25 percent of the power can realistically be captured for electricity, the energy is nonetheless adequate to significantly curtail fossil-fuel use, the report concluded.
Early models demonstrate that wave-energy buoys are suited to replace the batteries in navigation beacons and floating weather monitors. A cluster of buoys might also provide supplemental electricity for an offshore research platform, or even recharge a submersible vehicle.
In the long term, bigger wave buoys are projected to deliver greater output through utility-scale projects.
“For mass energy production, the same concept could be applied to create a farm of many point absorber buoys,” said Stephan Grilli, professor of ocean engineering at URI. “This would be a very promising way of producing megawatts of power.”
The electrical output of wave-energy buoys, so far, is too low to feed into the electric grid, but a charge of about 10 watts is adequate to power offshore monitors that detect tidal waves and oil spills.
“We’re not going to replace a fossil-fuel electric plant,” said Daniel MacDonald, professor of oceanic engineering at UMass Dartmouth and manager of the school’s buoy project. Wave-energy buoys, he explained, also have nearshore uses as well, functioning tethered to a dock, port area or mooring to recharge or power recreational or maritime electrical devises.
Low cost and durability are major benefits of locally generated buoy power. It’s also a technology that, with funding, can be operational fairly soon.
Other wave-energy technologies that seek to harness bigger waves, such as those in the Pacific Northwest, can’t yet withstand the battering from heavy seas, MacDonald said. “It’s double-edged sword. There’s a lot of energy [in that region] to destroy things.”
Big-wave technology, he estimated, is at least a decade away from commercial viability. “Let’s get something in the water instead in a fraction of that time, so we’ve got something generating power,” MacDonald said.
MacDonald initially envisioned the buoy idea as a means to temper waves causing coastal erosion. The concept may yet be utilized as erosion worsens from climate change, he said. “Why not capture that energy and put it somewhere useful?”
Wading in slowly
While wind, solar, biomass and even geothermal get the bulk of attention and money, an array of alternative energy sources are needed to ultimately reduce the reliance on fossil fuel-based power plants, according to MacDonald.
Using a student-built prototype, MacDonald and his students’ research projects that only a few years are needed to develop a marketable buoy that generates about 1 kilowatt of power. At an estimated price of $1,000 apiece, the buoy would be low maintenance and financially viable for both nearshore and offshore use.
For now, the UMass Dartmouth wave energy converter (WEC) project focuses on nearshore applications. Dry indoor tests with the prototype buoy coupled with mathematical models of wave data from a cove in New Bedford show viability of the buoy as an energy source for devices near docks, marinas and piers.
In order to proceed, the project needs a second prototype buoy and more funding. But a slowdown in government spending on renewable energy caused by federal sequestration enacted in March 2013, coupled with a drop in private green energy investment, has stalled the flow of capital.
The URI/ESL project has hit the same financial wall. Since it began in 2007, the public-private partnership has spent about $2 million to design, build and test two working buoys for harvesting wave energy, one of which is showing strong results.
The first is a 12-foot direct-drive model that resembles a giant yellow lollipop. The round buoy suspends a single linear generator that thrusts underwater like a shock absorber with the wave movement.
The second and more technically advanced is the resonant-drive model (video below). It also utilizes a single, linear generator housed within a long sealed cylinder, or spar, surrounded by four shorter satellitespars that offer greater stability and wave absorption. A major benefit of the resonant-drive model is that all moving parts are contained within the spars, thus nearly eliminating the corrosive wear caused by seawater.
Both are hybrid systems, meaning thin-film solar panels are wrapped around the pontoons to enhance energy generation.
Like the UMass Dartmouth buoys, the URI/ESL ones produce electricity from the Northeast’s moderate-size 1- to 2-foot waves. As a self-sustained power systems, the URI/ESL models can operate offshore or tethered to a dock, port area or mooring.
URI students tested the buoys in wave tanks at the university’s Narragansett campus. They also designed the early prototypes with URI faculty and staff. URI also fabricated many of the key components, while ESL employees — several of them URI graduates — engineered and assembled the buoys several miles from the water at its facility in a office park. Students and ESL staff participated in open water testing done at the mouth of Narragansett Bay, near Jamestown.
“It’s a partnership that’s been very good for both of us,” Sepe said. “It’s been a good example of how industry and academia can work together.”
Big splash needed
Yet, the jump from promising prototype to a commercially viable system requires more funds. “That’s the barrier to entry,” Sepe said.
Funding, so far, has been awarded from the Office of Naval Research and the Rhode Island Science and Technology Advisory Council (STAC).
The next step is securing additional capital and determining the ideal buoy size to match ocean conditions a mile or so from shore. The latest URI/ESL prototype will increase to 40 feet, but the focus continues on minimizing parts and making them rugged and durable. Funds also are required for permitting and maintenance. As the buoys get bigger other costs also increase, such as the need for a larger boat.
Real-world uses for the buoys await, Sepe said, but without funding the partnership halts and a promising market goes untapped.
As a 2013 report shows, the URI/ESL project is a viable technology developed in a region that offers the commercial and academic resources as well as the technology and engineering expertise.
“However, a lot more R&D is required,” Grilli said.
Leadership is also needed to grow the partnerships, Sepe said. He said funding from sources such as STAC is small and sporadic, while support for new investment in promising technologies is lacking.
“What’s missing is the vision to put it together and follow through,” Sepe said. “I believe that the state … from the governor to our senators to our economic organizations should be trying to find ways to get us resources, not looking for ways to disqualify them.”
Sen. Sheldon Whitehouse, D-R.I., who recently visited ESL, said protecting existing federal renewable energy tax credits and incentives from further cuts is a top priority.
Marion Gold, commissioner of Rhode Island’s Office of Energy Resources, said she was unaware of the URI/ESL wave project but wanted to learn more. “At this time, however, we are not actively engaged in research and development activities centered around wave energy,” she said.
The public, Sepe said, needs to learn about new technologies and how they can succeed through local partnerships. “The battle here is to get the word out about what we are doing to sustain development,” he said.
The UMass Dartmouth project continues to operate on a shoestring — the $50,000 stretched thanks to extensive work from students to build a land-based prototype and draft a technical report. MacDonald said at least another $50,000 is needed to get the prototype in the water for more trials. An additional $150,000 advances the prototype to commercial development, he said.
Many government funding programs for renewable energy tend to focus on more mature renewable technologies, such as solar and wind, where production time is shorter, and jobs in the manufacturing, installation, and maintenance sectors can be realized on election cycle timeframes. The stage of research and development funding that is required for wave energy conversion can sometimes be a tough sell, acknowledged MacDonald.
The federal sequestration cut renewable energy funding from sources that have typically supported emerging renewable energy, such as the National Science Foundation’s Sustainable Energy Pathways program.
MacDonald is exploring other financing options such as private investors and start-up accelerators such as Cleantech Open. A New Bedford company is considering the UMass Dartmouth buoys as part of an offshore telecommunications network.
Other new sources also could help fill the financial gap. MassCEC recently launched InnovateMass, a matching fund program for pre-commercialization projects. Funding is considered “technology agnostic,” meaning all green technology projects get a fair shake, said Galen Nelson, director of market development for MassCEC.
Rhode Island also offers grants and loans through newly revised funding programs through the Commerce Corporation. This year, the Renewable Energy Fund has enhanced programs for commercial development, pre-feasibility studies and early-stage development projects.
“There’s a lot of opportunity here,” Sepe said. “I believe our area can become a pioneer in ocean renewable energy and in wave harvesting energy.”
This story was funded through a grant from the Marion-based Island Foundation. It’s the first article in a four-part series on grassroots renewable energy efforts ongoing in southern New England.
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