Worcester, like many cities, has a ton of renters. Home could be in one of the city’s 5,000 three-deckers or one of many new apartment buildings popping up like weeds.
Skyrocketing rents are the norm, but many renters don’t live in buildings with solar panels that could lower their electricity bills. They either can’t afford the expense or most likely have no say in whether the building owner will add rooftop solar.
Their situations could change because there’s a relatively new technology, at least in the U.S., called plug-in solar or balcony solar. An individual panel plugs into a wall outlet and the power it generates can produce enough juice to run household appliances. 
It can also cut monthly electricity bills up to 20%, according to some experts. 
The panels are widely used in Europe, and several U.S. states have passed laws to speed up their use. Others, like Massachusetts, are in the process of taking a hard look at the technology. 
Plug-in solar is included in an energy affordability bill that Massachusetts lawmakers are negotiating before the current legislative session ends July 31. 
State Sen. Mike Barrett, a Lincoln Democrat who is considered a leading proponent of clean energy, cautioned that Massachusetts residents shouldn’t expect the bill to have all the regulatory and safety issues figured out by the end of July – so don’t count on Massachusetts residents rushing out to stores anytime soon to get their hands on the panels.
“We’re not quite there,” said Barrett. “There are some grey areas to work out.” 
Those include, according to Barrett, the need for national safety standards which makes it unclear when stores will stock them. He also wants to see packaging with an abundance of safety labels and simple instructions so residents don’t have to pay an electrician to install the panels.
Plus, most solar including rooftop requires an interconnection agreement with the local utility to connect to the grid resulting in delays that drive up costs for buyers.
Last year, Utah was the first state in the U.S. to approve plug-in solar for 1,200-watt systems that ended the requirement for interconnection agreements because the amount of energy discharged back to the grid is miniscule. Sales have stalled, according to reports, because there isn’t a national safety standard.
When safety and regulatory policies are in place, then Barrett sees plug-in solar becoming a big deal in cities like Worcester because many renters have been shut off from solar. Homeowners are another potential customer base, especially those who don’t want rooftop panels or can’t afford them.
“It’s perfect for the renter, condo owner and homeowners,” said Barrett of plug-in solar. It typically cost $500 to $1,500 for a panel and Barrett believes the expense will be recovered in three years from savings on electricity bills.. 
“That’s a good deal,” he said. 
Some advocates claim investor-owned utilities oppose plug-in solar because it generates power off the grid that they can’t charge customers for. One is Paul Popinchalk, a retired energy engineer living in Worcester who is a member of the climate-action organization 350 Central Mass.
He believes plug-in solar is an affordable way to lower energy bills. “That’s why utilities don’t like it,” he said.
National Gird noted in an email that it’s concerned about safety and reliability, not revenues. “While plug-in solar may offer some customers another way to help manage energy costs, it will be important to ensure any proposal includes appropriate safeguards to protect customers, utility workers and the electric grid.”
Eversource, Worcester’s natural gas supplier, shares the safety concern. A company statement said only approved plug-in panels with built-in safety features should connect to the grid to protect customers and Eversource workers.
“We understand that testing is taking place with certification agencies towards meeting these goals, which we believe is a necessary first step,” said Eversource.
One worry is faulty installation of plug-in panels could overload a circuit in a home and cause a fire.
Another is excess energy discharged to the grid that could overwhelm the system and electrocute line workers. The odds of that happening are low, said Worcester Polytechnic Institute engineering professor Carrick Eggleston, because plug-in panels have a built-in feature that shuts them down during a power outage.
“That’s a point worth emphasizing,” said Eggleston.
Barrett isn’t aware of any lobbying by utilities to kill plug-in solar language in the energy affordability bill. There’s too much momentum, he said, for clean energy solutions in Massachusetts for the utilities to stand in the way. 
Besides, Barrett believes the companies know they will have plenty of revenue opportunities as demand for electricity increases as Massachusetts moves on the electrification fast track with heat pumps and other technologies.
“It’s wise of the utilities to lighten up, which appears to be what they’re doing,” said Barrett. 
To fully benefit from plug-in, Eggleston said the panels must be in the direct path of the sun with no obstructions for several hours daily. If that’s not possible, then the financial benefits are greatly diminished.
“It’s potentially extremely useful in cutting electricity costs, 20% if it’s a good situation, which is probably as much as you can expect,” said Eggleston. 
John Odell, Worcester’s chief sustainability officer, believes plug-in solar offers relatively low upfront costs that can be recouped in three to four years by lower electricity bills, based on current National Grid rates. Plus, the panels are portable, so a renter can take them when it’s time to move.
Good exposure to the sun is the “key piece,” according to Odell. He cautioned anyone laying out cash for a plug-in panel should temper expectations because the amount of power generated doesn’t compare to rooftop solar. Odell believes a plug-in panel could cut electricity use by an average of 5% to 10% monthly.
He also noted that half of Worcester’s renters can’t take advantage of plug-in because their apartment faces north. Southern exposure provides maximum benefit. 
Another factor is plug-in doesn’t come with any financial incentives or rebates to lower upfront costs. “The unit’s small size doesn’t have the electricity incentives that rooftop units get, so people need to be aware of that when they buy, but they’re still cost-effective,” said Odell.
As for utilities’ concerns about lost revenue, Odell thinks plug-in won’t move the needle too much unless sales take off.
Popinchalk described the solar panels at his home as a larger version of plug-in.
An inverter on the side of his house takes the direct current power from the panels and converts it to alternating current power for his home. It’s different from plug-in that has a built-in inverter.
Power he doesn’t need is discharged to the grid. In fact, the set up is so advantageous for Popinchalk that he hasn’t paid an electric bill to National Grid in four years. He thinks plug-in solar will take off in Worcester once all the regulatory issues are squared away.
“This opens up the possibility of bringing solar to more people,” said Popinchalk, “From a behavioral perspective, it will help people understand the benefits of transferring to a clean-energy economy.”
Contact Henry Schwan at henry.schwan@telegram.com. Follow him on X: @henrytelegram

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