Using watts, again

New regenerator technology uses previously wasted energy

January 1, 2010

3 Phase Energy Systems, an offshoot of Laser Cutting Northwest, has developed a way to generate electricity from the exhaust of dust collectors.

Anyone who's read Ayn Rand's Atlas Shrugged is familiar with the question and probably will give a glint of a knowing smile. In the book, the question is an expression of helplessness and despair about the current state of affairs. As the plot unfolds, we find that John Galt is actually an engineer who developed a motor that runs on static electricity, a technology that could change the way we power the world.

As the pragmatic president of Laser Cutting Northwest (LCNW), Pete Agtuca's vision isn't so grandiose as Rand's fiction, but he and his team of engineers and technicians may have developed something big all the same. They've maximized efficiency with a generator that produces more watts at lower rotations per minute.

The Aha! Moment

Agtuca long had been on a quest to reduce energy consumption at his 28-employee, 30,000-square-foot metal fabrication shop, LCNW. In 2006 the voters of Washington State passed an act that directed the state's utilities to get a portion of their power from renewable resources. The ultimate effect, Agtuca found, was that power rates were going to increase from 6 to 18 cents a kilowatt (kW). The contract metal fabricator has several Amada cutting lasers, a MultiCam high-speed router, waterjets, press brakes, and welding cells—and together they add up to quite a power bill.

"We were using a lot of energy," said John Shoemaker, vice president. "Our power bill was roughly $12,000 a month."

So the company invested in high-efficiency lighting as well as variable-speed motors for the compressors, and even sealed up all the cracks in the building walls. But all this, unfortunately, wasn't making much of a dent in the power bill.

At this point Agtuca and his team noticed the shop's Donaldson® dust collectors that filter particulates produced as the lasers cut metal. The collectors blew exhaust constantly to the outside. Just then the epiphany came. They found that air moved at a constant 73 MPH. If any landscape had wind blowing constantly at that speed, "there wouldn't be a tree standing," Agtuca said. That air is a source of constant, predictable kinetic energy. Would there be a way to harness it?

At this point LCNW called on a physicist, an electrical engineer, and an industrial engineer from the University of Washington. Their problem: Conventional generators don't produce any significant electricity until they reach several thousand rotations per minute. Building something small and efficient with a conventional generator, retrofitted directly onto the dust collector, just isn't practical.

After several years the team developed a system that generates significant electricity at just 200 RPM. It includes a sound-abatement replacement of the dust collector's muffler and this new regenerator, which captures the exhaust energy and increases the dust collector's efficiency, resulting in overall power generation of 2,500 watts an hour (see Figures 1 and 2). That's enough to power a third of the shop lights.

After seeing the results at their own shop, Agtuca and Shoemaker recognized a major opportunity. In July 2007 (lucky 7/7/07, in fact), they spun off the project into a separate company called 3 Phase Energy Systems. What began as an internal project, aimed at reducing LCNW's energy consumption, eventually may become the company's most successful product line.

Producing MoreWith Less

A standard generator is wired in what's called a delta configuration that starts producing significant electricity at several thousand rotations per minute.

"Unless it's operating at a specified RPM, it's not producing a significant amount of energy," said Shoemaker. "Ours is wired in a star configuration, and we have wired it so that at 200 RPM it's producing significant power. Because we have a known wind speed that is consistent and predictable, we can engineer the generator to match that wind speed."

The delta configuration on a standard motor generator has the windings on the outside with two magnets rotating on a shaft. Say that conventional generator has a shaft diameter of 5⁄8 in. and, with the two magnets attached, a diameter rotation of 1 in. Multiply 1 in. by pi (3.14) and you get a 3.14-in. circumference, or the distance traveled over one rotation.

"We have 40 magnets instead of two," Agtuca said. "And instead of the magnets rotating inside the copper coil, we have the copper coil between the magnets." So, say the copper coil has a 10-in. diameter. Multiply it by pi (3.14), and you get a circumference of 31.4 in. Though the numbers are simplified just to illustrate the point, this dramatic increase in travel per rotation, from 3.14 to 31.4 in., is the key to generating significant energy at low RPMs.

The Business Plan

When launching 3 Phase Energy Systems, Agtuca again contacted the University of Washington, this time the business school, to commission a study. It revealed some eye-opening marketing opportunities. There are more than 200,000 exhaust systems in the West alone. Most industrial sectors use them, from metal fabrication to wood shops to pharmaceutical manufacturing.

Considering this, it might seem like a no-brainer for Agtuca to charge ahead with immediate expansion. But one major hurdle stands in the way: the economy. Potential customers are impressed with what they've seen, but companies aren't loosening the purse strings just yet.

Grant money may accelerate growth. At this writing, 3 Phase Energy Systems was working with Puget Sound Energy, the local utility, on a grant that could fund up to 70 percent of the cost of the regenerator for qualified businesses. Though these grants are related to energy efficiency, not renewable energy, they will fund a technology that decreases a customer's power draw from the grid, so it indirectly helps utilities meet renewable-energy mandates.

As Shoemaker explained, "All the potential customers we've talked to are very interested. It's just not financially feasible at this point in time." But a grant covering up to 70 percent of the cost may change matters. "The customers will reduce their electricity consumption, [which will help] the utility meet its renewable mandate," he said.

When that opportunity comes to fruition, Agtuca anticipates a major growth spurt for 3 Phase Energy Systems, one he's betting will happen during the first half of this year. With Puget Sound Energy leading the way with its grant program, other utilities may follow suit, and with that may come a significant wave of demand.

"We may increase our work force by 100 to meet the demand," Agtuca said (see Figure 3). "We're bracing ourselves. As we go into the first half of next year, and we start meeting these orders that we're forecasting, we'll need an assembly and testing facility, because there's already not enough room in our current facility for what we do now."

First Steps

The growth plan takes into account various opportunities. The most immediate will come from the dust collector regenerator, which is ready for commercialization this year. The device is placed on top of the collector, in the path of the exhausted air, which rotates the turbine and moves the generator.

Before putting on the system, installers take a series of measurements on the dust collector, including static pressure, motor load, airflow, and energy consumption. They use this as a baseline, so that any energy the regenerator produces isn't consuming additional energy. "It actually does the opposite," Shoemaker said, "because by removing the muffler, we're freeing up energy, and it improves the efficiency of the [dust collector] motor." So the benefits are twofold. The regenerator captures the energy, and it increases the dust collector's efficiency by decreasing the load on the collector's motor.

In its current permutation, this isn't what you'd call "pure green" technology. The regenerator takes wasted energy that came from the power utility, which may have generated its power using fossil fuels. Still, it does use that energy again—hence the term regenerator.

"The greenest watt is the watt never used," Agtuca said. "The next greenest is the watt used twice."

Most generators use gears to get rotation to the required RPMs, but with that gearing-up comes reduced torque. With 3 Phase Energy Systems' generator, torque matters more than speed. As long as the generator receives enough torque to ramp up to the desired RPMs, you're in business. Another plus is that a system running off a high-torque energy source is easier to control. Each pedal stroke on a bicycle in low gear (with high torque) produces only a small, incremental change in speed, so the exact MPH in theory can be precisely controlled in small increments. The same is true for the regenerator.

Second Steps

The company's unit is built for high-torque, low-flow situations—and exhaust sysem applications may be only the beginning.

"Once you have the mechanical motion, it doesn't matter if it's wind, water, or weight," Shoemaker explained.

The company has several additional products in development. One may provide an alternative source of hydroelectricity, what Agtuca calls "microhydro" power. The company is working with the city of Leavenworth, Wash., to install a low-flow, microhydroelectric generator at its wastewater treatment plant. This application involves fluid flowing 300 to 1,200 gallons per minute. That's an extremely small amount of water by hydroelectric standards, but it turns out to be just right for 3 Phase's technology. The wastewater treatment plant has water flow with predictable pressure, which means it could provide consistent, high torque for the generator. "We see a lot of pressure in this application, and pressure is power," Agtuca said.

Collaboration

Agtuca isn't the fictional John Galt. He and his team haven't built a product that will change the world, at least not by itself. The regenerator, like any real-world technology, has limitations—torque and flow requirements, for instance. But it does have obvious potential, most of which may come through collaboration with other green technology companies.

Agtuca compares the green energy movement today to that of the early- to mid-1990s dot-com era, when hosts of young people launched companies in their garages. Many failed, while some collaborated and merged with other companies. He sees the same happening with green.

For this reason, managers are talking with a number of other companies that tout complementary technologies rooted in generating energy from rotational motion. "I see the market developing through collaborative efforts between those using a number of different technologies that complement each other, to solve our nation's energy crisis," Agtuca said.

The new company won't solve the energy problem on its own, but it may fit nicely as one small piece of the puzzle.

Images courtesy of 3 Phase Energy Systems, Laser Cutting Northwest, 3205 C St. N.E., Auburn, WA 98002, 253-735-5277, www.lcnw.com, www.3pesi.com

Amada America, 7025 Firestone Blvd., Buena Park, CA 90621, 714-739-2111, www.amada.com

Donaldson Co. Inc., 1400 W. 94th St., Bloomington, MN 55431, 888-338-3878, www.donaldsontorit.com

MultiCam, 1025 W. Royal Lane, DFW Airport, TX 75261, 972-929-4070, www.multicam.com