Sun and wind are seen as the most abundant sources of clean, renewable energy, but as many 'ocean-hugging' countries know, the energy of ocean waves is also both powerful and endless. Looking for the most efficient ways to capture that energy, the U.S. Department of Energy has announced a $1.5 million-prize competition for new ideas.
The department estimates that waves and tides along the U.S. coasts generate 1,420 terawatt-hours of energy annually. That is equal to the output of more than 330 nuclear power plants.
Unfortunately, the efficiency of today’s technologies for capturing that energy is only about 20 percent, too low for the investment to be economical, says Jose Zayas, director of the Wind and Water Power Technologies Office at the Department of Energy.
“We’re really looking to step-change that into the high 30s-40s [percent] and I think… once you achieve that, then the economic competiveness of this industry really comes to life and that’s really the target that we are shooting for,” says Zayas.
To encourage development of new technologies, the Department of Energy has launched a nationwide competition, called the Wave Energy Prize.
Developing new devices to capture wave energy can be a challenge. The environment in which wave capture machines must operate can be very harsh and unforgiving, with crushing blows of notoriously corrosive salty medium.
Competition organizers expect that most of the new ideas will be coming from existing energy companies, but also from the academic sector and research institutions.
Zayas says testing of the proposed technologies will be done in several phases.
“We would have 1/50th scale testing where we would do the first fundamental evaluation of their performance, as well as making sure that they are in a pathway that can assure them success towards a prize. We will then down-select again, and near the end we will have about 10 teams… it’s our hope to be competing at 1/20th scale,” says Zayas.
Testing of the scaled models will be done at the U.S. Navy’s huge indoor testing pool, with machines capable of generating ocean-size waves.
Zayas says the models will not be required to produce electrical power. Instead they will have to prove how much of the wave energy they can capture.
“We are looking at how the companies, architectures, have the ability to capture that energy and, of course, through high degrees of data analysis, acquisition sensing, actually quite easy to convert that mechanical kinetic energy into electrical energy, giving us confidence that at least the attributes of the machine are in line with the objectives of the prize,” says he.
Zayas says the ultimate goal of the Wave Energy Prize is to inspire a new set of power-generating technologies for the 21st century. Developers of the three best performing devices will be awarded prizes ranging from $250,000 to $1.5 million.