Features
All Systems Green: Wind, Waste, Water, and WPI Alumni
Andrew Stern '92
Thousands of wind turbines send power from the broad prairies of North and South Dakota to the high-rises of New York City, providing enough electricity to keep the Big Apple humming. Meanwhile, waste becomes a thing of the past when the by-products of farms, lumber mills, and construction sites are no longer dumped into landfills but instead burn cleanly, producing heat, air-conditioning, and pure, distilled water and ice. Such scenarios could become reality in the next few years, thanks to the vision and perseverance of two WPI alumni.
Andrew Stern ’92 wears a lot of hats, but all of his titles and organizational affiliations boil down to one goal: to implement alternative energy projects that demonstrate successful solar, wind, and water power, and other sustainable solutions to solve the energy crisis.
In 2006 he founded New England Windpower, a private, for-profit environmental consulting firm, and co-founded the nonprofit Action for Clean Energy. As well, he’s an associate with Maxis Capital, a Boston-based private technology buyout group, where he serves as the firm’s clean energy expert. With all three organizations, Stern is involved in bringing wind power to various communities.
At New England Windpower, he’s working with Cape Cod Community College on a wind turbine bid for the school. At Maxis, Stern is consulting with 18 Native American tribes in North and South Dakota who are examining the fiscal feasibility of a 2,000-unit wind farm in the two states. The electricity generated by this whirling collection would be enough to power a major metropolis, such as Manhattan, which consumes nearly 12 million MW/h annually. Stern hopes to see the tribes’ project begin within two years. "The opportunities for wind power are vast in the Dakotas," he says.
Meanwhile, as director of Action for Clean Energy, Stern leads education and outreach efforts to help communities replace nonrenewable energy sources with sustainable, clean supplies like wind. For one such project, he works closely with town officials from Hull, Mass., to scope out a hydrokinetic tidal turbine power project. Hydrokinetic turbines, a relatively new entry to the sustainable energy field, are known to leave a very small environmental footprint. The water turbines produce electricity using coastal tides and currents, an energy source that can be relied on 24/7/365. "And water is about a thousand times denser than wind," Stern notes.
With broad support among town residents and leaders, it is likely that within two years, four hydrokinetic turbines will be placed in Hull Gut, a deep-water channel off the coast. Together, these four units would produce one to two megawatts for the town, further shaving its reliance on conventional electricity.
Although he’s based in eastern Massachusetts, Stern’s projects have global impact. Through Action for Clean Energy, Stern brings officials to Hull from as near as Massachusetts and as far as South Africa. He inspires and instructs visitors about the wind turbines and discusses other alternative energy and fuel projects with his guests.
"Leaders from Vermont, Jamaica, Haiti, and other places are trying to wrap their minds around how they can use clean technologies to solve their pressing energy problems," he says.
As a result of discussions with Stern, Haiti is considering a carbon-friendly biofuel project. The flat island nation could be an ideal location for growing Jatropha, a nonfood crop that generates an easily crushed nut for a dense, oil-based energy source. The million-acre project under consideration would employ thousands of residents. Refuse from the harvests could also be used by locals for heating and cooking.
With Haiti’s interest piqued, Stern turned to WPI professor of chemical engineering Robert Thompson, who in late 2008 brought in Stephanie Kavrakis ’09 to study the yields from several Jatropha oils, as part of her MQP. Kavrakis will also assess the impacts that a biofuel industry could have in Haiti "given the available land, the typical oil yields per acre per year, and the biodiesel yields of the conversion process," Thompson says.
Power to the people
Hull Wind 1 (rated power of 660 kilowatts) cost the town close to $700,000. In its first year, it produced 1,597 megawatt hours (approximately three percent of the annual 51,000 MW/h that Hull Municipal purchases). After paying for the town’s street lighting, sales of this energy reportedly exceeded $150,000. Hull Wind 2 (rated at 1.8 MW) cost $3 million and came on the grid in 2006. During that year, it produced 4,088 MW/h, about eight percent of the town’s requirement.
The proud town has earned numerous state and national awards for its greening efforts, including the 2007 Wind Power Pioneer Award from the U.S. Department of Energy for 'advancing the use of wind power in a coastal community.'
Hull Wind 1 (rated power of 660 kilowatts) cost the town close to $700,000. In its first year, it produced 1,597 megawatt hours (approximately three percent of the annual 51,000 MW/h that Hull Municipal purchases). After paying for the town’s street lighting, sales of this energy reportedly exceeded $150,000. Hull Wind 2 (rated at 1.8 MW) cost $3 million and came on the grid in 2006. During that year, it produced 4,088 MW/h, about eight percent of the town’s requirement.
Heartened by these successes, Hull began laying plans to install four wind turbines offshore to boost the town’s wind production to 15 MW, or enough to supply all of the town’s electricity annually. As of late 2008, Stern reports, town officials were examining the new turbines’ financial feasibility.
"Projects like the Hull wind and tidal turbines help demonstrate that clean energy can be done," he says. "But it’s not the whole picture. We also need government incentives and policies that reward alternative energy industries. When the government gives clear signals that clean energy is a priority, we’ll see real and lasting progress toward a future we can all live in."
Bernie Podberesky ’58
Bernie Podberesky ’58 works enthusiastically to solve a major problem—or two or three. His interests lie in transforming biomass and other waste streams into clean power.
"We see our technology as an ideal way to eliminate some difficult issues in a number of applications worldwide," says Podberesky, president of AgriPower Inc. He has held this position since 2004, but he has been involved with the company’s predecessors since 1998.
AgriPower’s biomass-to-energy technology produces clean combined heat and power, and its latest units are rated at 300 kW per hour. The company’s closely guarded technology eliminates two common problems associated with using biomass for fuel. The entire air-to-air electric power generation system is contained in an easily transportable, modular mini-turbine, making it easy and inexpensive to transport the units to places where they are needed. And AgriPower’s patented design—in which the biomass fuel combustion products are separated from the gas turbine cycle—greatly reduces costly and time-consuming problems with turbine maintenance and operation.
These waste-to-energy workhorses use virtually free or inexpensive biomass and other materials for fuel. Everything from coffee bean shells, corn cobs, and nuisance plants, to furniture, wood chips, and sawdust, to construction debris— even that containing paint and creosote—can be tossed into an AgriPower hopper (once cut into chips) and burned, producing clean energy. For items such as finished woods, utility poles, or railroad ties, toxins can be scrubbed and set safely aside with an add-on scrubber. If distilled water or ice are required, a co-generation converter addresses this need.
"When we started the enterprise, we immediately saw the market for replacing diesel generators," says Podberesky, pointing to the fact that most of the world’s island nations, and many other remote rural areas, rely on diesel fuel as their main source of electricity. "There are several hundred thousand diesel-run machines operating globally, and although we wouldn’t be appropriate for all of those applications, that is still a very large pool of potential customers. Our units are so portable, versatile, easy to operate, and low-maintenance, they could really help out in many of those areas."
"We’ve also identified applications where companies face waste streams with costly tipping fees," Podberesky continues, referring to the price of dumping refuse at landfills. "In these situations, burning waste is quite advantageous, especially when you can also generate your own power, and sell electricity back to the grid. So what started as a niche market has expanded."
Small- to medium-sized lumber mills in remote areas could also use the units. "The hot air stream could dry the lumber, replacing natural gas kiln drying," says Podberesky. "The rest of the energy could supplant some of the mill’s electricity needs."
Podberesky is proud of AgriPower’s technology assessment regimen. Rigorously testing units for four years, the earlier, 80-kilowatt-hour unit was proven at a lumber mill, where wood chips and sawdust were burned as fuel. AgriPower also tested gas flows and heat transfer dynamics in its design and manufacturing facility near Sacramento, Calif.
After accounting for the energy used in running itself, each of the company’s new 300-kW-hour units produce 270 kW per hour. With fuel prices at upward of three dollars per gallon, the unit pays for itself in less than 18 months.
"These fuel savings," Podberesky says, "don’t include the considerable value of the co-generation and thermal energy the unit produces, nor the carbon credits it could generate annually from using biomass as a fuel."
Fueling the Spirit
Whether he’s troubleshooting with the research, design, and manufacturing team, or meeting with investment bankers or potential customers—state and federal agencies, waste man management companies, consumer paper goods manufacturers, energy mills, and others—Podberesky is running hard.
"We see a high degree of interest," he says, "but with the current financial crisis, deals are scarce. We’re actively seeking additional financing sources to help us move into commercial production."
Like many visionaries, Podberesky would like to see more than just his own project succeed. "If we could get the AgriPower units to all of the villages and towns in Africa that desperately need them," he says, "the residents could grow their own fuel and power their villages. This kind of change could really build local economies across the world, and do it cleanly."
Maintained by webmaster@wpi.eduLast modified: April 01, 2009 16:05:44