In many areas of the country, residential solar customers recognize the energy resiliency advantages, long-term economic benefits and environmental friendliness of solar + storage systems. But they still likely have questions on just how a solar array and battery will affect them on a personal level.
“My thing with storage in the pandemic was the realization that it’s a lot for people to sign on to a $30, $40, $50, $60,000 contract for a product that they’ve never had before,” said Daren Goldin, owner of Miami-based solar installer Goldin Solar. “They’ve never had solar before, they’re usually the first of their friends or family to buy this, and so there’s a lot of trust involved in that and in the sales process.”
To establish that trust, Goldin invites customers to view a functioning solar + storage system — at his own home.
Goldin has an 11.7-kW solar array on his townhome in Coconut Grove paired with three Tesla Powerwalls. His house was also the first in the Southeast United States to use a Tesla Backup Gateway 2, and has become a demonstration site for Goldin Solar to show potential customers how reliable the technology is.
Goldin will walk customers to his side yard and point to a light fixture inside that’s connected to the main breaker on the home. He tells the customers to keep an eye on that light and flips the breaker, simulating a power outage, showing how quickly the system will switch over to battery backup power.
“You hear the click and it’s like a flash — if you blink, you’d miss it,” he said.
Coconut Grove is a suburb in southern Miami — a regional hotbed for hurricane activity, with the superstorms causing annual grid outages, making energy resilience a necessity for residents weathering the storms.
“Chances are that you’re going to want to be able to keep your family at home during hurricane season,” Goldin said. “Chances are this hurricane season is going to be worse than normal. They just get worse because of climate change.”
Goldin’s home is a modern townhouse, like the ones appearing in upscale neighborhoods across the country. The unit has a flat roof with an 18-in. parapet wall surrounding it, concealing the array from street-level view. The rooftop array is made of 41 SolarWorld 280-W modules and accompanying SolarEdge P300 optimizers, a SolarEdge SE11400-US inverter, SnapNrack Series 100 racking with 18-in. standoffs and custom-made thermoplastic polyolefin (TPO) boots for flashing.
The roof covering is a newer version of TPO and required the custom-made boots that were welded to the surface with additional TPO material.
“That was the only challenge that we really had on the installation because it was a different process, it was a bit more sophisticated,” said Aldo Sosa, installation manager and crew leader at Goldin Solar. “It’s not just making holes and putting in the screws with some water-tight sealant.”
Solar was originally installed on the building in December 2016. Goldin Solar added three Tesla Powerwalls and the original Backup Gateway in 2020. After the manufacturer contacted the installer about the new model, Goldin added the Gateway 2 system later that year in June.
The Gateway 2 is the component connecting the Powerwalls to the grid. It monitors the batteries and transfers power to backup storage when outages occur.
“The idea is, basically, in any traditional solar system the inverter is the brains of the system and it’s also the interface with the grid,” Goldin said. “You have to make sure that you don’t send power to a grid that’s down and accidentally electrocute a powerline worker that’s trying to fix the grid. Instead of going straight from the grid to your loads, it goes first to the Backup Gateway and then to your loads and that’s what shuts out the grid and allows you to have a little power island.”
Since Goldin’s solar array already uses a SolarEdge inverter, the Powerwalls are connected to the system through AC-coupling, and Tesla’s Gateway communicates with the entire system through AC lines. AC-coupling allows for multiple Powerwalls to be installed in succession and easily retrofitted on existing solar systems.
Since the initial installation of the solar + storage project on Goldin’s home, his company and crew of installers are putting Tesla energy storage solutions on about 30 solar arrays each month, with about half of those on new solar installs. Batteries can prevent homeowners from purchasing and burying gas-powered generators in their yards, which is beneficial in metropolitan areas like Miami where there’s not much free land to do so.
“I have a 5-ft-wide side yard. There’s no way in the world I could ever fit a generator on that house, but that Powerwall is 6 in. off the wall,” Goldin said. “Battery backup is vastly superior to a generator because of no fumes, no noise, nothing to refill. Forget about the three-block-long line out of the gas station as the hurricane is coming.”
Goldin reduced energy consumption in his home to take advantage of the solar + storage system, outfitting it with LED lighting, a hybrid water heater and an electrical panel that reports individual performance of its breakers, giving him the ability to see how much power something like his refrigerator is consuming and direct power loads where they’re needed most.
“His house is the most optimized that I have worked on, but he’s passing that on to other properties as well. I hope in the future that not only people with money can, but people with less resources can be able to access it,” Sosa said.