Quemacocos
(Click to enlarge)
Installing My
Powerwalls

Mark D Larsen
November 6, 2020



When we built our home and installed our solar array, I wanted to also equip it with a battery backup system. However, at the time the only options available were large banks of bulky, heavy, short-lived lead-acid batteries. I therefore decided to hold off until there was a lithium alternative. Five years later, I was intrigued when Tesla announced its first Powerwall in 2015, but it couldn’t store as many kWh as I had hoped. Finally, the Powerwall 2 was released in 2016, and I decided to take the plunge.


NOTE: You can click on any of the following photos to enlarge them.

Three years and four months ago, I placed this order with Tesla for 2 Powerwalls.

Here is the receipt I received for my deposit. I expected that before too long Tesla would arrange to install them. Little did I know how long I would have to wait. The problem was that Tesla didn’t have approved installers in my area, and the Las Vegas electricians were not licensed to work in Utah.

Finally, thanks to the intervention of the Regional Manager for Residential Product Sales, Tesla trained and certified the team at Solar Zing in Southern Utah for such installations. They came and inspected my setup, I paid them a hefty deposit to order the hardware, and 3 weeks ago they sent me this photo to report that the Powerwalls had arrived. Yay!

Since mine is the first Powerwall installation in this area, Tesla wanted to send a “shadow” quality inspector to be present, guide, and help the electricians from Solar Zing with the project. We scheduled to have the inspector drive up from Las Vegas, and last Tuesday they all arrived at my home to unload the hardware and start working

Here are the two Powerwalls stacked in my garage.

It was fun to see that the boxes’ labels stated they were built at the Gigafactory in Nevada.

Indeed, that is where they were shipped from.

I was thrilled to see the Powerwalls when they opened the boxes. This was really going to happen!

Also in the boxes were the mounting brackets to secure them to the wall. The Tesla inspector recommended that we mount both Powerwalls on the concrete floor, one in front of the other, underneath my solar array’s inverter in the corner of the garage.

This seemed like the best solution to me also, so the inspector showed the team how to secure the bracket on the wall and mount the first Powerwall on its clips.

Here are both Powerwalls mounted in position.

This was about all the team could accomplish that day, but they arrived bright-tailed and bushy-eyed the next morning. The next task was to mount the Gateway, a complicated step.

It was necessary to move connections from the 200A panel on the outside of my garage wall to the Gateway on the inside. The only breaker it would retain would be for our large A/C unit, because its startup amps would likely trip the Powerwalls’ breakers when powering our home at the same time.

The Gateway would now house the 40A breaker for my solar array and a 60A breaker for the two Powerwalls.

Other breakers from outside were then moved through the Gateway to a second panel next to it. This panel would house a 200A breaker to our main load panel in the home, a 20A breaker for our garage GFI outlets, and the 50A breaker for my HPWC that charges our Model 3.

Next to this panel the team mounted another smaller box with two 30A breakers for each of the Powerwalls separately. The box also connects to a shutoff bus through the wall to the outside so that the Powerwalls could be shut down from the home's exterior.

Here are all three of the hardware panels mounted on the wall, to the left of the inverter.

It was now necessary to run conduit to the Powerwalls from the small breaker box and feed the wires through it.

Here you can see where the conduit leads into the first Powerwall through a pop-out section of its outer trim. Time to shut off our power and feed the wires through the setup.

After all the wires were connected, the project was ready to be tested. We opened all the breakers and turned the Power back on. There was one glitch that tripped the two 30A breakers, but the electricians quickly found and remedied the problem in the outside shutoff bus. Voilà! Eureka! The Powerwalls were up-and-running!

With the guidance of the quality inspector, the head electrician signed on to the proper web page to register the Powerwalls for service, and assign them to my Tesla account.

I then had to sign in to my account to authorize the registration. A few minutes later… the Powerwalls were now appearing in the Tesla app!


That last screen shot shows just one of the many displays available in the Powerwall side of the app. This display lets you monitor the power used in the home (blue), the power generated by the solar panels (yellow), how much of it is being stored and then taken back out of the Powerwalls (green), and how much of it is going in and out of the grid (grey). That display is from yesterday, the first full day using the Powerwalls, and you can see that our solar plus the Powerwalls provided most of our energy, including charging the Model 3, shown in the largest, fattest spike early in the afternoon.

I am elated to finally have my Powerwalls, as I would much rather store clean, free solar kWh generated in the day for use at night, rather than swap them for the utility’s dirty, coal-fired, polluting kWh. And the icing on the cake is that they’ll also help us get through blackouts and brownouts. “O frabjous day! Callooh! Callay!”