Inherit the Wind
With the rising costs of fossil fuels, government tax incentives, and wider awareness of the problems of global warming, there is little wonder that the wind energy market is building.
The movements of wind and nature itself have fascinated Steve Apfelbaum all his life. Thirty years ago he began a business—Applied Ecological Services, Incorporated—to focus on large landscape-restoration projects.The firm has grown in size to include some 110 employees in five offices across the country. Apfelbaum’s home and the offices of his company are energy efficient and environmentally friendly. But it was 9/11 that spurred him to do even more. He had been visiting a client in the World Trade Center Towers just two weeks before that fateful day. So he was particularly affected by the unfolding news when, back in his home state of Wisconsin, he sought to make sense of the chaos.
“I had to do something,”he recalls. “I had to do something with my community, something physical, and something for our environment.”Apfelbaum had been nurturing ideas and researching wind generators for at least two decades, and so he acted by moving forward on his ideas. Four years later, a 20 kW Jacobs wind turbine captures the energy and nuances of the wind coursing 120 feet over the gracefully rolling, open farmland of south central Wisconsin, not far from the Illinois border.
By adjusting to face the brunt of the winds that sweep through, the turbine is sending out some 25,000 kWh annually into the utility energy grid to which it is connected. It is more than enough power to meet the needs of his family’s home a half mile away, with some left over to supply clean renewable energy to the neighbors. Apfelbaum gets a wireless update every 15 minutes to his home desktop computer, giving him a two-dimensional view of the wind energy passing through, and showing a storm’s fingerprint, as Apfelbaum calls it, for study and reflection.
Catching the Wind
Apfelbaum is not alone in his interest in wind energy.After years of being treated as a fringe resource at best, wind-produced energy is mushrooming, although it’s still a minor player in overall energy supply.The Global Wind Energy Council reports that in 2004, the installed wind power capacity around the world totaled over 47,000 MW, up nearly 8,000 MW from the year before.
While the installed wind energy of 6,700 MW in the United States lags a distant third to Germany’s 16,600 MW and Spain’s 8,260 MW, wind energy in the United States is gaining ground. More state governments are building renewable energy into their long-term energy plans while eyeing it as a source of new jobs. Based on its survey of wind turbine manufacturing plants, the American Wind Energy Association anticipates that another 2,500 MW will be installed in the United States in 2005.With the rising costs of fossil fuels, government tax incentives, and wider awareness of the problems of global warming, there is little wonder that the market is building.
One (or Two) Windmill’s History
Before harvesting wind energy, Apfelbaum first created a home that would need the least amount of energy and still be comfortable.“We had spent considerable time in refurbishing a 158- year-old farmhouse to make it energy efficient,” Apfelbaum explains. “We added R-96 insulation in the ceiling and R-42 in the walls.We updated the electrical circuitry and installed solar hot water panels on the roof that produce approximately 90% of the home’s hot water needs year round; the hot water also provides radiant heat to the house through a poured slab in the basement. We converted all the lights in the house to compact florescent and LED. An addition to the house used recycled building products and was designed to provide active and passive solar heating.”
After 9/11,Apfelbaum discussed with his partner, Susan Lehnhardt, and her son Noah Klinge the need to do something in their community, and they decided that putting up a wind generator on their 80-acre farm was a positive step forward. The down payment was made September 25, 2001, and plans were made to set it up over the next four
months. Involving neighbors and colleagues in a project can help it to become successful. In this case, the interest of Apfelbaum’s longtime business associate Doug Eppich led him to become a partner in the project. Together, Apfelbaum and Eppich finalized the requirements of the system they wanted and they began to locate the components. A 20-kW system seemed the right size for the task at the time, more than enough to supply their own typical annual energy use of about 3,500 kWh (see “The Equipment”).
Each of the three blades is approximately 13.5 feet in length and is constructed of white Kevlar, with a leading airfoil-edge fabric to reduce wear and abrasion that, for example, might occur when it operates in ice storms or from the normal abrasion of dust carried in the wind currents.The blades and rotor drive the generator using the equivalent of a rear differential from a pickup truck. During very high winds, the blades furl, which reduces the blade angle and rotational speed. The turbine is an upwind turbine; the blades are the first part of the unit addressed by the wind.
The metering for the wind energy system is constant and in real time. Simply put, as the wind turns the rotor, the generated AC electricity is converted in the inverter to DC, and then reconverted to AC as it is fed onto the power grid.As the energy is fed onto the grid, both an internal meter and an Alliant meter turn backward—the symbolic wonder of a net-metering experience. All energy is sold to the grid at the same rate per kWh as it is purchased at Steve, Susan, and Noah’s home.
They found a source for the components—the tower and a Jacobs wind turbine and controls—from Palouse Wind and Water, Incorporated, in Idaho.One hitch, though¡ªthe dealer had two used towers to sell, and he would only let them go as a package at a lower per-unit rate. This led Apfelbaum to contact Mike Sands, environmental team leader for Prairie Crossing, an environmentally friendly community 100 miles to the southeast in Grayslake, Illinois, and one of Applied Ecological Services’ clients.
“We decided to put one up at the same time, too,” says Sands. So a virtually identical wind energy system was added at their 677-acre development, which today includes 359 single-family homes with a mixed-use district of retail and 36 condos now being completed. Prairie Crossing was the first production- focused new home community with every home built to the standards of DOE’s Building America program. The homes consume roughly 50% of the energy consumed in comparable houses in the area. Though Sands says the energy output of the windmill does not come close to meeting the electric needs of the whole development, the tower and the windmill are an icon for Prairie Crossing, and serve as a visible symbol of the community’s values and ethics.
Apfelbaum first had to go before town and county boards to get the required conditionaluse permit for a tower more than 100 feet high, and to the local utility for permission to sell any excess energy back into the grid through a net-metering agreement with the utility. At the time, the procedures had not been well defined because few people in the area had traveled this path before. The approvals came, and then they could start to work on putting up the system.
Both Apfelbaum and Sands involved their respective communities in the process of putting up the towers.“I just started calling around to those I knew in the area who had the skills,” said Apfelbaum. Among the skills brought in were a heavy-equipment operator to dig the footings for the 120-foot tower, concrete suppliers for the eight cubic feet in each of three footings, help in tightening about 600 bolts on the self-standing steel tower, a crane operator to raise the tower, and an electrician to run the wires and make the connections in the Jacobs’ Mastermind that monitors and controls the system from the nearby utility shed.“I enjoyed helping out on the project,”said neighbor Jerry Montfeldt, who helped properly tighten each bolt during the week-long tower-raising project.“We accomplished something every day.”
And both projects had widely publicized dedication events in 2002:Apfelbaum and Lehnhardt’s on Earth Day in April and Prairie Crossing’s on July 4. “We brought people together for an event that raised consciousness within the community about energy use and the wind,” says Sands of the Prairie Crossing event. And that consciousness has continued in the years since. For example, a Leadership in Energy and Environmental Design (LEED)-certified, public charter school building was recently erected in Prairie Crossing.
When all was said and done, Apfelbaum reports, their system costs totaled about $39,000, with some $19,000 going toward the generator, tower, and electronic control components, and the balance paying for construction.Today he figures he could have shaved some of those construction costs because of what he knows from the experience (such as using smaller tower footings). But there is not much he would have done differently.
Was the Promise Kept?
Apfelbaum knew that doing something and involving the community were not sufficient for real learning and advancement.He decided to get feedback in order to see how his wind system measured up to what he had anticipated. Every month, he collected his utility statements, which reported kWh produced and resulting payback.The energy produced has ranged in the area of 1,600 gross kWh generated monthly during the first year, as they were making certain the system equipment worked properly, to more than 2,000 kWh per month today, for an income of about $140 (purchased back by the utility at the rate of $0.089/kWh).
In the middle of 2004, the partnerships for wind energy grew again, after Apfelbaum shared a rental car from an airport with Kevin Little, founder of Informing Ecological Design, LLC of Madison,Wisconsin. Little has developed energy monitoring software that gives building users a real-time view of a building’s energy flow in electricity or natural gas or solar energy produced. He had been concentrating on working with schools to build the energy flow information into their classroom lessons and with medium-size office building owners to help better manage the commissioning and operations process. But it was not until the chance ride with Apfelbaum, after a flight was canceled, that he started to consider applying the SenseDat system to real-time wind generation reporting.
Encouraged by Apfelbaum, Little created a setup, completed in December 2004 at a cost of about $1,500, that wirelessly transmits a signal from a meter on the alternating current side of the generator¡’s inverter to Apfelbaum’s home computer a half mile away. From home, Apfelbaum can easily and quickly call up the program that shows him the pattern of the wind that has moved through as recently as 15 minutes earlier.
“The graphs that SenseDat presents are truly wonderful for me as a scientist,” says Apfelbaum. “They take the spinning of the generator and give me a twodimensional model of what is happening in the energy forces that swirl through our farmstead.They make tangible for me the energy that I see in the movement of the trees, the response of the birds floating overhead, and the sway of the restored prairie grasses and flowers.” (Go to www.prairiecrossing.com for real-time data.) Apfelbaum is delighted with the solution, which came in at a cost of about 50% less than those of other monitoring solutions he was exploring.
“For the first time, I am starting to understand the energy that is contained in the wind,” says Apfelbaum. “The average wind estimate reports for my area would predict wind speeds in the range of 13 miles per hour. What I’m finding so far through this real data—and not an estimate—is that we may be getting 3 to 4 miles per hour better than that.”Three to four mph may not seem like a big difference, but because the power in the wind varies with the cube of the speed, 16 mph versus 13 mph means that 86% more power is available.
Where the Wind Blows
As he moves forward,Apfelbaum will continue to study and communicate what he is learning to others who are interested. “The real data will help tremendously in better projecting returns on investment in wind generators, and it will help me tune my ability to understand the wind generator’s performance and my ability to recognize winds of varying magnitudes. Although I can make adjustments in the electronics controlling at what wind speed the generator turns on or off—and thus the power production in relationship to wind speed—the equipment has been adjusted to normal operational ranges. These are designed to save wear on the bearings and other moving parts.
“As I work with this more, I will correlate the wind data to the performance of the generator and will seek to classify the nature of wind events into four or five key categories.These include wind speed, duration, regularity or consistency of the wind speed, and wind direction. The characteristics of different energy production events, for example, include air masses with heavy sustained high winds for a few days or air masses with irregular and shifting high winds that are far less productive because the direction of the wind generator has to keep changing and in so doing it loses efficiency. Another class of wind production would be light or gentle winds for several days that provides minimal electric production, typically of one to three kilowatts. The specific information can help with better siting of the generators or help others do better cost projections.”
Most homeowners won’t be as ambitious as Apfelbaum at his farmstead and Sands at Prairie Crossing.David Blecker, founder of Seventh Generation Energy Systems, which supports community based renewable energy projects, says that, typically,homeowners are interested in something smaller, probably in the 5- to 10-kW size range. In the past few years, Blecker says, manufacturers and designers have worked out many of the issues raised around wind generation. Generator blades are quieter (those associated with the two systems referenced in this article reported no complaints about noise) and, with fewer moving parts, require lower maintenance.
And, finally, local zoning officials and utilities are more accustomed—if not welcoming in some instances—to locally generated renewable energy sources. Thanks to the pioneering work of Apfelbaum, Lehnhardt, Sands, Little, Blecker, and many others on behalf of this age-old, clean energy source, the standards and methods of utility tie-in have become much clearer, making the path a bit smoother for those following who are looking to draw on the energy blowing in the wind in the twenty-first century.
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