A Little Gray Switch Is a Hot-Button Issue for Solar Homeowners

PHOTO CREDIT: SUNPLUGGERS.COM

By Dan Fink

Published Feb. 20, 2010

What's gray, half the size of a shoebox, costs under $100 at Home Depot and has the potential to impact both homeowners and the entire solar-electric industry to the tune of millions of dollars?

It's called a Utility External Disconnect Switch, and it's a very hot topic in the photovoltaic industry right now. A UEDS is simply an extra disconnect in a utility-interactive solar-electric system, located between the grid-tied inverter and the home's main breakers. It is always located outside the home so that utility workers can access it easily – and always includes a hasp so those same workers can disconnect the system from their grid, then slap a padlock on there so that only they can reconnect it.

The idea is that if utility workers need to make repairs on power lines in a neighborhood during a blackout, emergency or natural disaster, they can deactivate and padlock each nearby PV system with the UEDS to ensure that no system in the area can possibly back-feed electricity into the grid and electrocute a line worker. When repairs are complete, they remove each padlock and reactivate each system.

PHOTO COURTESY OF INTERSTATE
RENEWABLE ENERGY COUNCIL
The Utility External Disconnect Switch
is at the lower right, below the meter.

The result is that some states and utilities require all utility-interactive home PV systems to include a readily accessible outdoor UEDS. That usually sounds reasonable to the general public – it costs only $100, and safety first, right?

Not really.

The solar-electric industry has long opposed UEDS requirements, pointing out that they are redundant, expensive, and provide little if any extra safety factor. The National Renewable Energy Laboratory, Interstate Renewable Energy Council,  and Solar America Board for Codes and Standards all concur.

During a recent industry seminar, engineers Michael Sheehan of IREC and Michael Coddington of NREL pointed out that all code-compliant utility-interactive PV systems already have at least two (and often as many as four) other fail-safe mechanisms to prevent electrical back-feed to the grid. All of these would have to fail simultaneously to present any danger – something that has never happened with any of the more than 61,000 grid-tied systems currently in place in the U.S. Most systems are even “witness-tested” by the utility itself to prove that they are safe before being put into commission.

PHOTO CREDIT:
SUNPLUGGERS.COM

Mr. Coddington was also quick to point out a far more serious safety threat: the (estimated) hundreds of thousands of home backup generators purchased and installed – often improperly – by homeowners before the Y2K scare. “Home Depot and Lowe's even sold the transfer switches,” Mr. Coddington said. “These are a far greater danger than PV.”

The actual installed cost of a UEDS is far more than $100. A licensed electrician must perform the work, and if wires must be run (for example) through a brick or concrete wall, costs could easily spiral into the thousands of dollars for a single switch.

Do Utilities Use UEDS?

Ironically, utilities rarely if ever use those UEDS they have required. They simply don't have the infrastructure in place. Consider a “green development” of 500 homes, many with grid-tied PV systems on the roof. Such communities will be found more and more in coming years, especially in sunny regions such as California and Arizona.

PHOTO CREDIT: SUNPLUGGERS.COM
An inverter for a residential solar
installation. All code-compliant utility-
interactive PV systems already have at
least two (and often as many as four)
fail-safe mechanisms to prevent
electrical back-feed to the grid.

During a power emergency, the utility would need to know at what address each switch is located. Of those that even keep that kind of data, few have any way to communicate this information to their line workers. Then figure the estimated 5 to 10 minutes per UEDS it would take to locate the switch in each backyard and lock it out – and after the emergency, the time needed to unlock each switch.

“The practicality of this has to come into question,” said Mr. Coddington.

“I don't think there's a utility truck out there that carries 500 locks,” added Mr. Sheehan.

Safety or Politics?

The primary reason for utility UEDS requirements has far more to do with the politics of big energy than with safety. Many utility companies have long resisted any sort of consumer-owned distributed generation, fearful of watching their residential electricity business evaporate. Adding onerous requirements and extra costs for both homeowners and PV installers is a simple way for them to discourage competition from customer-owned renewables, under the guise of “safety.”

“Utilities are, by nature, conservative,” said PV consultant, author and solar energy pioneer Joel Davidson. “Society wants stable, reliable people managing our electricity, water and waste services. But instead of accepting change, utility managers defend the status quo to maintain monopoly control.”

UEDS requirements may even have been used to apply political pressure during contract negotiations between a utility and labor union.

In 2002, according to a Home Power magazine article published at the time, the International Brotherhood of Electrical Workers turned off and locked out newly installed residential PV systems in the service areas of the Los Angeles Department of Water and Power. Residential systems are often installed by non-union electricians. The LADWP's management notified utility customers that their private PV systems were being temporarily disconnected to “insure the safety of field workers.”

Commercial systems, usually union-installed, were not being locked out, the magazine reported.

“This politically motivated lockout delayed projects, caused PV businesses to lose income, put an unwarranted shadow of doubt and fear in customers' minds, and undermined decades of PV industry work to provide safe solar-power systems,” Mr. Davidson said.

When the lockout ended, “People who observed the locks being removed by utility field workers said that no safety inspection was performed,” Mr. Davidson added.

Utilities of the Future

In 1960, Harvard Business School Professor Theodore Levitt published a seminal article in the Harvard Business Review titled “Marketing Myopia,” which encouraged businesses to look beyond their current marketing models into what their markets could and would become in the future – whether they liked it or not. He used examples such as the failure of the railroads and the corner grocer in favor of automobiles and supermarkets, and the success of Hollywood in redefining itself from being in the movie business to being in the "entertainment" business when faced with potentially devastating competition from television.

Mr. Levitt also predicted accurately and with eerie prescience the financial predicament that many utilities find themselves in today. When he made these statements, commercial photovoltaic cells had been in existence only six years, were used only in spacecraft and a few products such as light meters, and cost $1,795 per watt to manufacture compared to $1 a watt or less today.

“Who says that the utilities have no competition?” Mr. Levitt wrote. “They may be natural monopolies now, but tomorrow they may be natural deaths. To avoid this prospect, they too will have to develop fuel cells, solar energy and other power sources. To survive, they themselves will have to plot the obsolescence of what now produces their livelihood."

Utility companies today that are proactive and forward-thinking in their adoption of corporate policies that encourage grid-tied home PV systems are seeing increased growth, increased federal and state tax credits and subsidies, easier compliance with renewable-energy portfolio standards, favorable public opinion and positive media coverage.

Utilities insistent on adhering to the antiquated and monopolistic business models of the past may find themselves struggling to survive.

Dan Fink, a renewable-energy author, lecturer and consultant, has lived off the grid, 11 miles from the nearest power line, since 1991. He is co-author of the book "Homebrew Wind Power," and his work appears frequently in renewable-energy magazines such as Home Power and Back Home.