BY CATHY CASH
It seems easy enough. You set up a solar panel or two and its small generator-type device outside, plug the thing into a wall socket in your house, and before you know it, electricity is flowing and lowering your power bill.
These portable, DIY solar energy systems can generate several hundred watts and are marketed like appliances that only require a regular outlet. But as plug-in solar becomes more popular, consumers should be aware that these products require important safety considerations.
So, what should you know about behind-the-meter, plug-in solar kits?
Safety comes first
First, these systems have the potential to put lives and property at risk. Electric utility leaders note that almost all of these devices lack U.S. safety requirements, such as certification under UL codes or standards. UL has only recently developed a safety certification for plug-in solar systems.
Unlike rooftop solar and electric vehicle charger installations, these plug-and-play packages attempt to bypass existing interconnection protocols, oversight and inspections.
If a home’s wiring is not up to snuff to support plug-in solar, the consumer wouldn’t know because they didn’t call a licensed electrician to install the equipment or an inspector who could spot that hazard.
That can be dangerous on multiple fronts, leading to overheated wires in a residence, property damage, fire and even worse, serious or deadly electrical shock.
“Plug-in solar introduces real safety risks at the consumer-member level,” said Jeffrey Groenewold, National Rural Electric Cooperative Association (NRECA) senior energy solutions manager. “Existing residential wiring standards were not designed for generation through standard outlets, so plug-in solar increases the potential for fire and shock hazards.”
A charged solar system can backfeed, or send electricity back to the grid, and re-energize power lines without your electric cooperative’s knowledge. This could be fatal for lineworkers.
“The evolving plug-in solar industry must work to ensure these systems are properly managed and controlled to prevent unintended backfeed,” said Groenewold. “This is critical to protecting cooperative lineworkers and keeping them safe when they are out working to restore power.”
Unplugging the system does not eliminate its risk. Contact with the power cord energized by the solar panels can cause devastating injury.
Will Morris, a consultant to NRECA Business and Technology Strategies Group, underscored that these systems are not harmless appliances and should not be treated as such, especially around children.
“When we were growing up, our parents taught us if you would just unplug a blender or an iron or something like that, you’re putting that device in a safe state. With this, it is the complete opposite,” he said. “If somebody has this on their patio plugged into an exterior outlet and they unplug it and drop it in a puddle ... you can get 800 watts going to you. That can be a real bad day.”
Weighing the costs and benefits
Then there’s the affordability factor. Is plug-in solar really a good deal?
The equipment for this behind-the-meter energy resource can cost a few hundred dollars to more than $1,000, but its output, even in areas with plenty of sunshine, will shave only an estimated 40 to 80 cents per day off your power bill, according to industry experts.
“I would be very surprised if in our markets plug-in solar makes financial sense because the average cooperative consumer rates are pretty low,” said Morris. “It would take a long time to recover that investment.”
European apartment dwellers who face very high electricity rates have been eagerly buying “balcony solar” for a while and expect to pay off their investment in a couple of years, he said.
In Germany, where rates are particularly high, the plug-and-play packages are designed within the country’s safety mandates and must be registered with the 
grid operator.
“So, the German utility knows when that device is being utilized and that they have potential for energy to flow back into the grid,” he said.
But in the U.S., states are at various stages of potentially regulating plug-in solar to ensure safety.
“We’re at the Wild West phase of it right now,” Morris said. “You can buy a system and plug it in. It’s like buying a hairdryer, except the hairdryer is UL certified.”
Members are encouraged to contact their electric cooperative for knowledgeable advice on plug-in solar and to inquire about requirements for installing such a device.
“The bottom line is if you’re looking to lower your electric bill with some behind-the-meter device, please let your electric cooperative know,” said Groenewold. “Co-ops have a variety of programs to partner with you to save money and to do it safely.”
Cathy Cash writes on consumer and cooperative affairs for the National Rural Electric Cooperative Association.
