June 10, 2004: Wind
turbines typically roost atop the tallest towers practical for one’s
budget and site specifically because higher up is where the most
wind is. That’s also where another naturally occurring phenomenon
presents itself in all its spectacular fury—lightning. But
the popular myth that lightning always attracts to the tallest metal
object is just that—a myth. So said wind power expert Mick
Sagrillo, who guided a day-long Wind Energy on the Farm course last
February as part of the Upper Midwest Organic Farming Conference’s
Lightning is formed by static electricity on a grand scale, Sagrillo
said, caused when two dissimilar materials—in this case the
atmosphere and the earth—rub over each other.
Just like you receive a shock when you touch a doorknob after shuffling
across the carpet in your socks, he said, lightning operates under
the same principal, that is, equalizing the buildup of a static
Of course trees, and sometimes windmills, do get in the way.
“[A windmill tower] is sitting on concrete and that’s
somewhat of an insulator,” Sagrillo said. But certain precautions
can minimize your chances of having your wind energy system damaged
by lightning, Sagrillo said, including grounding each leg of the
tower, as well as the base, “with an 8-foot ground rod as
deep as you can get it.”
When lightning does cause damage a wind machine, Sagrillo said,
it typically gains access from the utility side. “Ninety eight
percent of the time, the lightning came in on the utility grid
[AC] side; it did not come in on the generator side.” For
that 98 percent, Sagrillo said, surge suppressors are beneficial.
While surge suppressors on the AC side—and lightning arrestors,
ground rods and conductor cables on the tower side—do afford
some protection against lightning damage, they provide no guarantees,
particularly against a powerful direct hit. That’s were adequate
insurance comes in.
Detractors of wind power (including some utility lobbyists) point
to the potential eyesore that a tower and large windmill can create,
safety hazards that can result from a loose blade or accumulated
ice that has been shed, potential interference with communication
devices, stray voltage (small amounts of electricity that can leak
from power lines and on-farm equipment that may adversely affect
livestock), and perceived danger to wildlife (particularly birds).
But when you consider alternatives for producing electricity—such
as coal plants that destroy the ozone layer and poison waterways
and their inhabitants, and nuclear reactors with the potential to
core the earth like an apple—you realize that such hazards
present a tradeoff. (Many of these concerns are addressed later
in this piece.)
“Cat’s kill 37 million birds a year in Wisconsin, while
one or two birds per commercial turbine are killed each year. One
feral cat kills as many birds in one week as a commercial wind turbine
does in three years of operating time,” Sagrillo said, putting
this common concern about windmills into perspective. “Every
window in your house is responsible for the death of one bird, minimum,
a year. If we seriously want to save birds, we should be considering
outlawing cats and windows, not wind turbines.”
Are you on the grid or off the grid?
“Off the grid” means that you don’t rely on public
utility systems for electricity (or, in most cases, water and sewage
either). Most people who are off the grid (at least those living
in the United States), rely on some combination of alternative energy
such as wind, photovoltaic or hydro. For these individuals, a wind
system typically includes a control panel serving a bank of batteries
that store generated electricity, and an inverter that converts
the DC (direct current) power into AC (alternating current) before
it is enters a breaker box and individual AC outlets.
Sagrillo pointed out that many homeowners are already tied to the
grid (public utility system), yet they would rather be running on
wind power than contributing to the environmental problems associated
with rampant use of non-renewables. For these people, the Public
Utility Regulatory Policies Act (part of the National Energy Act
passed in 1979 under the Carter administration) allows for you to
tie your alternative energy system right up to your local utility.
In some states, you can even "sell" them back any excess
electricity you generate.
Most state laws allow for the banking of excess electrical generation
rather than selling it.
“When producing excess electricity, the meter runs backwards,”
Sagrillo explained. “When the wind has died down and you are
consuming that energy, you use that credit back up again.”
But utility companies are not always the most cooperative, he said.
“Utilities sort of view you as competition. There’s
no grocery store in the world that’s going to tell you to
go out and grow your own vegetables. Why do we think that utilities
are going to encourage us to generate our own electricity?"
And the economics of the arrangement are skewed toward the utilities,
Sagrillo said. “Anything you consume that you’ve offset
is worth retail, but anything over that is wholesale,” he
said. In other words, Sagrillo said, there’s no money to be
made in selling back power to the big boys. “You’re
not going to win, so you plan to use all the electricity that you
The good news is that required contracts typically protect consumers
more than utility companies, Sagrillo said. “They have signed
a contract with you, effectively admitting that they condone what
you are doing.”
Some of these utility intertie systems, as they are called, also
have battery backup, Sagrillo said, which causes utilities some
level of concern. “That’s a huge amount of current that
can be dispatched,” Sagrillo said. “You could backfeed
it into the utilities. Who’s going to know?” (One of
the concerns, and a valid one, Sagrillo said, is that utility workers
could be injured when they go to work on a “down” line
they assume is dead, yet there’s power flowing the other way
out of someone’s home. But today’s synchronous inverters—which
convert DC power to utility grade AC—and induction generators
contain a device called a line-activated contactor, he said, which
shuts off when the utility is down and resumes the connection when
it goes back up again.)
“One of the down sides of a grid [tied] system is your storage
is on the grid,” Sagrillo said. “If the grid goes down,
you don’t have electricity unless you’ve got batteries.”
It’s not unrealistic to expect to spend $7,000 or $8,000 on
a good battery bank and an inverter, Sagrillo said, and the batteries
only last about 10 years.
Utility companies can be difficult to deal with, Sagrillo said,
suggesting that it often pays to get the scoop on state regulations
guiding grid intertie systems from your state’s Public Utility
Commission before approaching your local utility. Another strategy
he suggested for pealing back the red tape is to find out if your
utility company has ever participated in a wind power of photovoltaic
project and then seek out the person who was in charge.
Getting money from your rich Uncle (Sam)
On the subject of so-called green energy—consumers opting
to buy electricity from utilities that has been produced alternatively—Sagrillo
was a bit sour. “I am not a fan of green power,” he
said. “The message is that you have to pay a premium for renewables
because they’re not cost-effective, and that’s sending
the wrong message.”
According to a July/August 2002 Mother Jones cover story entitled
Prevailing Winds, the cost of wind-generated electricity dropped
80 percent between the late 1970s and 2002 and, in some areas, is
already outstripping the price of producing electricity with conventional
fuels. And a federal tax credit of 1.8 cents per kilowatt hour currently
being considered by Congress would lower the cost of wind generated
electricity by another 30 percent. (Unfortunately for homeowners
and farmers, the production tax credit is only available to corporations
that are in the business of generating electricity.)
Federal programs are already on the books offering a number of
incentives for investing in wind power, particularly in rural areas.
The 2002 Farm Bill made available $115 million to help farmers,
ranchers, and rural small businesses develop renewable energy project
and to make energy saving improvements.
On May 5, USDA Rural Development announced that $22.8 million in
grant funds were available for 2004. These funds are competitive
and cap out at 24 percent of a project’s cost for projects
between $10,000 and $2 million. For wind power projects, this can
run the gamut from home- or farm-sized turbines up to co-op utility
systems (with a maximum project size of about 2 megawatts). The
application deadline is July 19, 2004. Find the full details of
this grant published in the Federal Register at www.rurdev.usda.gov/rd/nofas/2004/energy050504.pdf.
The USDA/Rural Utility Service also offers low-cost financing to
rural electric cooperatives. And the U.S. Department of Energy’s
Wind Powering America Initiative is seeking partnerships nationwide,
including with those willing to form rural utility cooperatives,
in order to increase the country’s use of wind power.
Many states offer major economic incentives for development of residential
and on-farm wind power as well, including income tax credits, property
and state sales tax exemptions, loan programs, and grants. Find
a comprehensive state-by-state list of these programs at The Database
of State Incentives for Renewable Energy (DSIRE) www.dsireusa.org.
Zoning regulations and setback requirements
You will often need to visit your local zoning board for a conditional
use permit or a variance before erecting a wind energy system of
any size, Sagrillo said. Building good relationships—both
with local regulatory authorities and with neighbors who might hold
objections to your project—is critical, he said. Be prepared
to assuage people’s trepidations about wind power by educating
them about the benefits of renewable energy, and be ready to take
this campaign strategy to your zoning hearing, Sagrillo said. Fact
sheets that tackle common concerns such as bird kills, television
reception, property values, noise and lightning can also be a good
idea, he suggested.
A typical setback requirement assures that if a wind system topples
it remains on the owner’s property, Sagrillo said. This often
translates to a restriction that the tower not be built any closer
to the property line than a distance equal to the tower height plus
the length of one blade. (The FAA has its own restrictions concerning
tower height. Any object higher than 200 feet must be reported.
And if you are within 3.75 miles of an airport runway, you must
contact your local FAA office to see if you need to file for permission
to erect a tower of any height.)
Other objections that might come up at a zoning hearing, Sagrillo
said, might be based upon:
- Aesthetic grounds. Be ready to point out the
similarity between a wind tower and existing communications towers,
or even grain elevators and silos, he said.
- Unfair comparisons to wind farms. One farm-scale
turbine does not make a wind farm, Sagrillo asserted.
- Concerns of abandonment. While it introduced
some sound energy policy, Sagrillo said, the Carter tax credit
era also brought with it undeveloped technology, the relics of
which are now eyesores upon the landscape. Be prepared to assure
potential detractors that the wind industry has matured, that
windmills have long warranties and longer life spans, and that
you do not intend to neglect your investment.
- "Flying ice". Ice buildup causes
the blades to slow way down, and it is proper protocol to shut
the machine off to prevent damage. Therefore, ice typically falls
either not very far to the side or straight down (and typically
gradually rather than in large sheets or chunks). You are more
likely to be hurt by ice falling from a tree, said Sagrillo, since
outstretched branches are susceptible to breakage.
- Questionable structural integrity of the tower. Bring
along documentation supplied by your manufacturer or dealer, Sagrillo
- Noise. You can pick up the sound a wind turbine
makes from surrounding noise if you really try, Sagrillo said,
but today’s manufacturers pride themselves on quiet machines.
Again, bring the specs along.
- That a windmill is an attractive nuisance,
meaning a child might be drawn to climb it and become injured.
Again, Sagrillo said, offer comparisons to other existing structures
in the community, such as silos, and be prepared to resist any
fencing-in requirements by drawing on such comparisons.
Such resistance is often the product of society’s exodus
from city to country, Sagrillo said. “One of the biggest problems
is that people who come out from the city have this romantic idea
about what country living is,” he said. “When you start
spreading manure, they don’t want any part of it.”
Dan Sullivan is senior editor at The New Farm. Mick Sagrillo
is owner of Sagrillo Power and light, a Wisconsin-based consulting
firm specializing in home-sized wind-turbine technology and educational