Family battles stray voltage
By CHRIS HARDIE Local news editor
That passion was paying off by the mid-1990s, when his 60 Holsteins produced an average of nearly 27,000 pounds of milk apiece per year, good enough to rank 65th in the nation in production. “We had a real track record,” said John, who has a degree in farm management. His wife, Debra, also has an agricultural degree. “For 16 years, we did well,” he said.
But there were struggles. In the early 1990s, John said, he started to notice problems with his cows. Mastitis cases — an inflammation of the udder — were high. Suspecting some electrical problems, Beyerl consulted with Clark Electric Cooperative and had additional ground rods installed. The problems continued, and, in 1994, Beyerl installed an isolation transformer — a device that prevents the neutral current from the utility line from entering the farm wiring. Even with the problems, the Beyerls believed their continued success as farmers depended on expanding the herd. Like many dairy farmers at the time, the Beyerls thought that becoming more of a dairy business and hiring help would keep them competitive.
So they expanded the herd to more than 100 cows and installed a pit milking parlor. With the same veterinarian, same nutritionist, same carefully selected breeding program, the Beyerls looked for more success.
They haven’t found it yet.
Milk production began to fall and has fallen ever since, dropping below 20,000 pounds. The cows don’t eat and drink as much as they used to and can’t keep on weight. Many cows have died and the survivors hobble about, many with digestive problems. All are problems the Beyerls attribute to stray voltage.
The Public Service Com mission of
Many cases of stray voltage are caused by on-farm problems, said Mike Herro, Northern States Power Co. spokesman. “There is stray voltage on every farm. It can come from imbalanced loads or a bad connection on the farm or insufficient grounding. There are ways to solve those on-farm sources by improving wiring and things.”
And many problems are solved. A 1998 study from the Minnesota Public Utilities Commission on earth cur rents and effects on dairy cows said of 752 farmers surveyed in
But a growing number of farmers like the Beyerls are not satisfied. Despite spending thousands of dollars and working with their utilities, their problems are still uncorrected.
“We really know less about farming than we ever did,” John Beyerl said. “Now, everyone is second-guessing us. It’s been an absolute fight for everything.”
The Beyerls rewired, put in new milking equipment, worked with consultants, nutritionists and veterinarians. They began to doubt themselves until they started talking to some of their farming neighbors. They, too, were having problems.
“It just wasn’t us,” John said. “All our neighboring farms had the top herds in
The Beyerls’ problem is not conventional stray voltage, says Dave Stetzer, a Blair electrical contractor who has taken thousands of electrical readings on farms like theirs. Stetzer says the wavelength of those electrical currents flowing through the ground are at a higher frequency than power line electricity. Regular exposure to that frequency, even at low volts, causes harm to the cows and may harm humans, Stetzer claims.
“This isn’t rocket science,” Stetzer said. “I did not find something that nobody else knew about. I just found something that nobody wanted anybody to find.”
Stetzer and Martin Graham, a retired electronics professor from Berkeley, Calif., say the current is the result of harmonics, distorted electrical current that comes from most new electrical appliances like computers, TVs and stereos as well as industrial motors. He says the neutral line — which carries unused current back to the substation — is not adequate to handle large harmonic spikes. Those spikes, Stetzer said, flow down grounding wires, then enter the ground and flow back to the substation, going through barns and homes on the way.
Local utility officials say harmonics do not put excess current into the ground and say the neutral lines are adequate and safe. And they would like to see proof that the frequencies Stetzer measures harms cows and humans.
“David Stetzer and Martin Graham have an opinion that they are communicating with farmers and utility customers that harmonics and earth currents cause cancer and 20 other disorders,” said David Jenkins, head of the Wisconsin Federation of Cooperatives. “We’re concerned about those allegations and would like information to substantiate that.”
David Oelkers, Riverland Energy Cooperative general manager, said his technicians do not look for the higher frequencies that Stetzer measures when they test for stray voltage at a farm. The instruments they use often don’t even measure the higher frequencies. That’s because they have to follow state testing guidelines, Oelkers said.
“To gather the information we have to have an established protocol,” he said. Utilities have instruments to measure higher frequencies, but have no cause until the PSC sets up a new testing procedure, Oelkers said. “Yeah, we can go out and duplicate (Stetzer’s test), but what does it mean? Dave is choosing his own definition. How can I commit millions of dollars to a theory that is Dave Stetzer’s?”
Duane Dahlberg, a retired physicist who has studied ground currents and stray voltage since 1983, says the theory isn’t just Stetzer’s. “Dave Stetzer is a professional electrician and when he makes measurements, he knows what he’s doing,” Dahlberg said. “What he finds and what I’ve found are very similar. I give him a lot of credit for what he’s doing. None of us have all the answers, but he’s been able to come up with a good portion of it.”
Dahlberg said he doesn’t believe that all the ground current frequencies measured by Stetzer are caused by harmonics. He said regular 60-hertz current from power poles that enters the ground can become distorted by the earth, causing it to change frequencies. “I don’t think correcting the harmonic problem will solve the earth current problem,” Dahlberg said.
Stetzer says his tests do follow protocol that were established by the Minnesota Public Utility Commission. And he consistently finds that physical responses from the cow — like kicking or flinching — occur with voltage spikes.
Dahlberg said most stray voltage testing — including a several-year study being conducted at the
Dahlberg said new tests should look at how other electrical frequencies — such as microwaves — affect cows because there is enough information from existing studies to suggest that the shock model of testing cannot explain why cows in herds like the Beyerls continue to exhibit signs of stray voltage.
“I’ve been on hundreds of farms throughout the country and I’ve seen it over and over again,” Dahlberg said. “It’s one of the most disturbing problems I’ve ever been involved with.”
Herro said NSP would welcome additional studies. “NSP responds to our customers’ concerns with experts in the field,” Herro said. “We want to make sure claims are based on the science and we’re willing to look — either ourselves or through other organizations at scientific studies, but they have to be controlled studies.”
Dahlberg said testing is critical because stray voltage is not just a rural issue
“This is affecting people all over the world,” he said. “People have to understand that you can’t go to a large department store or a shopping mall that has a concrete floor without noticing the same things that are happening on a dairy farm. The same currents in those buildings are getting into the dairy farms.”