Gravity sparks inventor’s curiosity

What goes up must come down, and Galen Calvert says his latest invention will produce electricity on that descent.

Undeterred that no one has come up with the money to build his pivot-wing spacecraft (chronicled in the Missoulian last June), Calvert recently sent the U.S. Patent Office the schematics and narrative for his newest brainstorm: "A system for converting the energy of gravity to electricity by utilizing the potential and kinetic energy of land vehicles descending from higher elevations."

By JOHN STROMNES of the Missoulian

http://missoulian.com/articles/2004/04/18/news/local/news04.txt

He said in an interview Monday that the invention could lead to many more patents and many benefits to society, the most obvious being generation of cheap electricity and conservation of fossil fuels.

"There could be patents coming out of this idea long after I’m deceased," said Calvert, 77.

The Patent Office accepted the application March 30, giving him time to build a prototype of the device. The "patent pending" protection expires in one year unless he receives a full patent. That costs several thousand dollars – money he does not have because his primary source of income is his Social Security check, which he and his wife live off of.

His earlier patents, such as the pivot-wing shuttle concept, were based on his interest in aerodynamics and fostered by his career as an Alaskan bush pilot. None of those ideas has enjoyed commercial success, but he’s enthusiastic about the latest one.

"This could be very big," he said.

Western Montana is ideally located for the invention’s commercial success. First, there are lots of mountains. For example, the hill between Hot Springs and Perma – which has a Bonneville Power Administration electricity substation at the bottom on the Hot Springs side – is an ideal location to test it, he said.

He said the inspiration for this latest invention came as he was driving back to western Montana from California in January after a relative had delivered bad news: One of his recent concepts was doomed to be a washout, apparently because it refused to conform to the laws of physics.

"My nuclear physicist cousin rejected that invention," he said.

As Calvert drove across mountain ranges and over mountain passes, he pushed aside disappointment. Instead, he considered one immutable and familiar physical law – the Law of Universal Gravitation, first described by Isaac Newton in 1665-66.

Calvert’s take on the law, as it applies to motor vehicles and mountain passes, is this: A vehicle that drives up a hill powered by fossil fuels wastes a whole lot of energy coming down the other side. What if all that energy used getting a vehicle to the top of a grade could be recaptured as the vehicle descends?

Here’s his answer, taken directly from his provisional patent application: "This invention proposes the production of electricity from the gravitational pull on the weight of vehicles in basic ways similar to the way water is now used (to produce hydroelectric power).

"Currently this energy is converted to economically detrimental equipment wear (on brakes, transmissions, tires, and such), and to useless, if not environmentally damaging, heat.

"Just one medium-sized semi, weighing 40,000 pounds, in descending a road grade involving 176 vertical feet, now wastes 213.33 horsepower of energy. An estimated maximum use of just one array of the inventive devices proposed will convert this energy to well over 1.5 megawatts of electricity.

"Multiply this simple fact by vertical feet traveled by the number of down-grade-traveling vehicles in the world and we have millions of megawatts of electricity going to waste daily."

He proposes a couple of solutions to capture and convert this energy to electricity.

They both employ hydraulic pressure, using fulcrums or levers built into a roadbed to power a generator that moves a turbine that provides energy to a transmission grid. He said he will leave the exact details of the devices to engineers and other technical experts.

But the concept is clear. In one solution, vehicles traveling downhill would drive onto a ramp that would compress a series of hydraulic pistons. The hydraulic pressure would power turbines to produce electricity.

In another, designed for steeper grades, an array of "restraining vanes" would be compressed as vehicles passed over them. The vanes would act as brakes on the vehicles and while at the same time activating hydraulic cylinders that in turn move the turbines and generate power.

Calvert admits that there may be some difficulties in getting everybody to travel sensible speeds so the devices would work right and leave an appropriate amount of space between vehicles so traffic jams, or worse, wouldn’t result.

"This might work better in China or Russia, where the political system is different," he said.

But mining and timber-hauling are two industries where the concept could be applied, since you wouldn’t have the traveling public on those roads.

Log- and ore-hauling trucks also would be ideal for such an energy-recapture system because these vehicles typically go uphill unloaded and downhill loaded, thus providing more weight to drive the hydraulic pistons.

He said his system is similar in some respects to power plants that capture wave and tidal energy, such as the La Rance tidal power plant on France’s Atlantic coast. But Calvert’s land-based proposal avoids one of the most challenging and expensive problems of tidal electric generators – getting the electricity to shore and into the grid. There also is no salt water to rust the machinery in Calvert’s invention.

It’s a time of rising energy prices and growing scarcity of fossil fuels, Calvert said. The fossil-fuel energy that takes vehicles to the top of hills "is already paid for. Let’s start getting some of that energy back," he said.

Reporter John Stromnes can be reached at 1-800-366-7186 or at [email protected]