SANDY -- Vaughn W. North vividly remembers the moment when the idea came to him, a solution to the age-old challenge of generating electricity from the power of ocean waves.
He was in Matzatlan, Mexico, treating his youngest son, Jeff, to a week's vacation after Jeff completed his LDS mission. "I was walking along the beach one morning -- a beautiful day," he said."And as I put my foot down on the sand on the beach there was an immediate pressure response. You've seen it. You step on it -- it takes very little pressure -- immediately, the sand turns with water pressed away."
Suddenly the thought struck him -- that is the key to converting wave power to electrical power. Below the surface, sea sand must be reacting to the pressure of the weight of waves above it. As it reacts, "You've got the essence of a pump."
If something is pumping, it's a short leap, the spark of a synapse, to imagine a pump device generating electricity.
The idea of making power from ocean waves has been around a long time -- probably since Thomas Edison thought of using rivers for hydropower. In fact, the notion of sea power was a plot device during an episode of Knots Landing, when "Professor Joseph Barringer" experimented with the idea.
But so far, as North well knew, nobody has been able to make it work on a commercial basis.
Using the insight gained through his footprint-in-the-sand epiphany, North came up a possible method to generate power from the sea's endless rocking -- a system so reasonable that on Sept. 21 the U.S. Patent and Trademark Office awarded him United States Patent 5,955,790 for an "apparatus for converting tide/wave motion to electricity."
North is a patent attorney with the firm Thorpe, North and Western. Not only does he work to patent the inventions of others, but he comes up with his own designs and patents, too. The wave-electricity device is just the seventh in a string of patents he has earned, including a card device to both advertise products and record credit- and debit-card expenditures.
"I said to myself, the whole key is pressure. . . . All I need to do is put a pressure device down at the bottom of the ocean and let the changing height of the water pump, just like a water pump."
A two-foot wave will add about 1 pound per square inch to the top of a device located at a depth of 30 feet, he calculates. A plate like the one on his pod, about 100 square inches, will experience 100 pounds of pressure with each wave that rolls in to shore. Experts confirmed to him that this pressure difference is translated right down through the water column.
In his third-floor office, North demonstrated with a prototype of his device, a drum with a flat plate on top and an inner-tube membrane connecting the plate to the sides of the drum. Extending from the apparatus was a cord connected to a flashlight bulb. Inside the device was equipment to convert the mechanical motion into electric power, just as a bike wheel's motion will convert a tiny generator into power.
"The pod sits down on the bottom of the ocean, and it's stabilized," he said. "When a wave rolls over the top, it pushes it down."
He pushed down on the plate, forcing it into the drum. Imagine that the force of his hands was the pressure of sea waves transmitted down through the water onto the apparatus. When he stopped shoving, the plate rebounded, as it would when the wave had passed. As he worked, the bulb flickered on and off.
"There are dozens and dozens of patents trying to capture the energy," he said.
"Most of them put floating barges on top, and they bend and they twist, and they run piezoelectric crystals for electricity. Or they pump pumps, or turn cranks or rachets to generate electricity through mechanical means.
"But they put tons of money into it, and then a storm comes through (and) rips everything apart. They've lost all their capital investment."
The key to making a successful device, he realized, is to protect it from the storm. And the best way to do that was to put it on the ocean floor, 20 or 40 feet below the turbulent surf.
"There is no more ferocious environment than the ocean," said North, who goes on scuba-diving expeditions to St. Thomas in the Virgin Islands. "Water can tear anything apart."
In the calm below the surface, however, his generator will be quietly pumping, converting pressure to power.
A pod the size of the demonstrator won't put out much electricity. Maybe it will only produce 40 milliwatts continuously, he said. But a bank of 1,000 could produce 40 watts of output, enough to run equipment.
And it wouldn't take much power to keep a strobe light going, a warning beacon posted on a buoy above dangerous rocks. The advantage of the Lunar Power device over solar power is that it will do its job day and night, during cloudy weather as well as clear skies, immune from storms ripping apart glass panels.
At today's cost fuel, the device probably would not be a major source of electricity. But perhaps a remote island research station or summer home could get its power from the waves.
"Probably the most useful things . . . will be the isolated locations along the shoreline, where it's just not economical to run a power line," North said.
The devices could be installed by someone in a boat, lowering weighted racks of the pods overboard.
The cable would settle in the sand and eventually become covered by it. All that shows on the beach or dock would be a cable coming out of the ocean, supplying a battery pack.
In a year or two, the power generated by his pods may be enough to make up for the initial cost. If so, from there on, it's all gravy.
The device presented several special problems, said Duane O. Hall, of Sandy, a consulting engineer with Hall Electronics who carried out much of the engineering. They included adapting a mechanical generator to the slowness of waves, canceling out the pressure exerted by the water depth rather than wave height, limiting the motion of the plate so a huge wave wouldn't jam it into the mechanism, keeping cost reasonable and making sure the device is durable.
"We've gone through about four different systems as we tried to refine it," Hall said.
Last week, North traveled to the Scripps Institution of Oceanography in La Jolla, Calif., to talk with experts there about testing the device.
"He came to the hydraulics lab to find out if we could run some tests for him," said Charles S. Coughran, a senior engineer at Scripps' Center for Coastal Studies. "That's a possibility."
Scripps tests equipment under contract with private developers, using its extensive wave-generating chambers to check all sorts of conditions. According to North, the chambers can vary the speed and size of waves, measuring its performance under varying conditions.
"We didn't go into any great detail" in the discussions thus far, Coughran said. But, "conceptually it looks like a reasonable way to generate energy from waves."
A lot of devices look reasonable, he added. "Generally they fail not because they don't generate energy but because making things that will survive in the ocean is a difficult thing to do, and it makes them very expensive. They fail on economic grounds rather than technical grounds."
North and Hall are excited about the possibilities.
"Anything that sits on the surface of the ocean or just above the ocean just takes a beating from the elements. This one is actually below the surface of the ocean and is not made to move with the ocean, and so the durability is much, much higher."