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 is always attracted 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 Organic University.
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 charge.
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 to 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
|"Cats 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."
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.)
“Cats 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
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
But utility companies are not always the most cooperative,
“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 produce.”
||"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?"
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 or 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
full details of this grant published in the Federal Register.
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)
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.
||“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.”
- 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
- "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
- Questionable structural integrity of the tower.
Bring along documentation supplied by your manufacturer
or dealer, Sagrillo said.
- 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
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