The dream of wave-powered electricity, like most renewable energy ideas, is sweeping and transformative. The vision builds to utility-scale ocean generators lighting up cities as they bob in the ocean.
But successful commercial wave energy may start smaller, say, by lighting up a buoy, and emerge from a place without large ocean swells, like Rhode Island.
That’s the vision of researchers at Electro Standards Laboratories in Cranston, who for the last five years have been working with the University of Rhode Island on systems to power the thousands of ocean buoys around the world without batteries or sunlight.
It’s not as flashy as lighting homes, but there’s certainly a need for power on buoys that, among other things, monitor the weather, listen for enemy submarines, watch for tsunamis, measure the salinity of the water, track ocean currents and warn of navigational hazards.
“Now we have an energy source that exists in the middle of the ocean and can power anything with a sensor,” said Electro Standards President Raymond Sepe Sr. “We can also communicate with the sensors and operate them remotely.”
Today, most buoys are powered by one of two methods – batteries and solar power – that have distinct drawbacks.
Batteries are dependable and powerful in all kinds of offshore environments, but they need to be replaced.
While changing a battery on the side of the road is simple, thousands of miles from land, in a heaving ocean, it’s a lengthy, expensive proposition.
Solar power has the opposite problem.
It can run forever under the right conditions, but those conditions often don’t exist where the devices are needed.
In high latitudes sunlight is scarce for half the year. In milder climates, sea birds find raised solar panels an ideal perch. Their droppings can compromise even the most-efficient solar cells.