PV systems designed to self-consume solar energy are coming back into vogue. Reasons include rising utility rates, the addition of electric vehicles, and — the biggie — public utility commissions rolling back net metering payback rates for exported solar energy, for both home and building owners. In this article from the Q1 2024 issue of Solar Builder, we’ll stay out of the politics of net metering and instead highlight a compelling piece of hardware that efficiently interconnects and distribute solar power on site. This is just part of a longer feature from the Q1 2024 issue of Solar Builder.
Solar installers often run into issues at the home service panel in terms of breaker space or amperage constraints, especially at older homes. The current trendy solution for inadequate service panel capacity is to just throw a bit more technology at it — smart circuit breakers, smart panels, smart appliances.
Those solutions are compelling for all the benefits they provide the contractor and the homeowner who can afford it. But, considering …
- The affordability of solar is already a big hurdle, and low- and moderate-income (LMI) households have been historically underrepresented in the growth of the solar PV market.
- Households earning less than $50,000 per year represent 37% of all U.S. households.
- These households are more likely to be older homes connected to older grids.
… adding another ~$5,000 to $10,000 to the PV price tag to upgrade and/or smarten electric service at the home is just not a great solution for all customers.
For solar to become a ubiquitous and affordable addition on a wider array of homes, the smartest solution might be a cheaper piece of hardware with a much simpler point of connection: the meter socket.
“You literally have a universal socket on the side of every home,” says Whit Fulton, CEO of ConnectDER, the company that is hoping to take advantage of that socket with a universal adapter. This adapter upends the standard way of interconnecting solar, storage and (eventually) EV chargers. It involves no complex custom wiring or software.
Picture the typical electric service setup: Two electrical legs coming from the grid that run through the meter socket and land in the service panel with circuit breakers. When you use a Meter Socket Adapter (MSA), you connect safely to the home through the socket with a dedicated circuit breaker. Instead of having two hot connections into service, the hot, neutral and ground go into the adapter.
“When you run the PV system into the adapter, we are connecting to the load side just like you are connecting to the service panel, with a circuit breaker dedicated to the solar,” Fulton says. “We just move the connection point from the panel to the meter. It is electrically identical. You don’t touch the service panel or worry about the 120% rule.”
At retail, a ConnectDER Meter Socket Adapter costs $500. A qualified electrician can install an MSA in about 15 to 30 minutes. Including labor, that’s about $600 all in vs. $2,500 or more for just a standard service panel upgrade (not to mention the delay that comes with main panel upgrades).
“This simplifies things for installers,” Fulton says. “Everything is color coded, and it is just a plug and socket interface outside the house. We have a lower rate of inspection failures because once the AHJ understands it, it’s very hard to mess it up versus messing up a service panel tie in.”
And that truly is it, which is refreshing. No app, or WiFi code, or pitches for AI-driven smart insights. ConnectDER just enables the fast and simple connection of DER.
“The majority of what we do is not data enabled; it’s just a physical connection point that is safe and UL listed. That’s our driver. Installers and homeowners lower their cost to interconnection,” Fulton says.
Some limitations:
- At the moment, a ConnectDER adapter is limited to solar, but the company expects to offer an EV meter socket adapter later this year.
- Another hitch is when adding energy storage. Right now, the ConnectDER adapter can handle ESS installed for retail arbitrage, but there is no whole home disconnect, so batteries installed for backup power would need to be run through a subpanel. However, a future version of the MSA will enable batteries for backup as well. That is likely coming in 2025. “Once we have that, it’s the end all, be all,” Fulton says.
- Last but not least, the ConnectDER adapter must be approved by utilities before it can be installed. Some areas may only allow utility personnel to install the actual adapter as well.
The utility hitch
Technically, ConnectDER’s meter socket adapter is an installer’s dream. The only hitch — and it’s no small hitch — is the MSA needs to be tested and approved by the local utility to use in their interconnection tariff.
“Historically, we work with utilities closely,” Fulton says. “We have redesigned [the adapter] five times based on their feedback, and now it’s just a matter of getting through approvals with each utility.”
Rooftop solar, as you all know, is generally not a priority for utilities. But ConnectDER has seen success with utilities they’ve engaged with.
“They have decarbonization goals,” Fulton says. “If we make it a priority and show them the usability and safety, we have seen success.”
For example, after earning approval in Green Mountain Power territory in Vermont six years ago, without doing any marketing, ConnectDER became the predominant interconnection method.
Today, ConnectDER is available in 20 states, and growing, including some of the biggest solar markets in the country. There is a Con Edison-led program in NYC. New Jersey and Colorado recently passed bills to support DER connection via meter sockets. In Arizona, APS and other prominent utilities have also approved the adapter for general customer use.
“You could see that evolving into a solar + storage program where utilities dispatch the storage as needed for grid service and then if power goes out, isolate the power there and keep them online,” Fulton says of the potential of these utility-led initiatives. “They get the benefit of the rental fee / backup power at no cost.”
Here is a map of ConnectDER’s MSA availability across the country.
That’s just an idea for down the road. If you’d like to use the ConnectDER MSA in your area today, and it isn’t yet approved by your utility, ConnectDER has a “playbook” they can share with their steps for getting it approved.
“We’re leveraging all the success we’ve had in that and bringing that messaging and communication to those who want to see it happen in other places,” Fulton says.
Chris Crowell is the Editor-in-Chief of Solar Builder.
— Solar Builder magazine
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