It took a lot longer than anticipated, we now have a backup system for our all electric house!
When we were preparing to move in, we had planned to have a battery backup system made by Tesla called the Tesla PowerWall.
This backup would allow us to run part of the house during a grid outage. Primarily the HVAC system, our refrigerator, network, a TV and a couple of outlets.
Welllllll.... with cutting edge products and such, there were a few delays.
Tesla canceled the first gen PowerWall before we got ours, replacing it with a second generation PowerWall with lots of really great improvements. This involved the first of our delays.
Then, as we got closer, a really nasty hurricane hit Puerto Rico, and Elon Musk sent a bunch of PowerWalls and solar panels to a hospital to get it up and running, with or without a local grid.
Seriously, how could I possibly be frustrated with that?
And of course, the normal delays involving shipping an extremely high demand product.
We need what?
Because of the way our system is set up with three inverters and a production meter, it worked best to have three PowerWalls. This was more than we planned for, but gave us some opportunities as well.
Additional room in our mechanical room was also needed, so we combined two of our three electrical panels.
Of course, this shows one of the advantages to knowing all the details when you are designing the electrical system in the first place. If we had know then, what we know now, it would have gone much more smoothly. We weren't willing to wait to build until the batteries were finalized, so I have no regrets about this.
With the advances in the second generation PowerWall, and the fact we were getting three, we made some adjustments to make our plan a little better.
First, the app that controls the PowerWalls allows you to set the system as either backup power, or "sustain" mode.
Sustain mode means the batteries will soak up all the solar energy they can, and then discharge it overnight, or any time the house needs more power than it is generating.
The masterful part of this, is the two can be mixed. For example, you can run in Sustain mode, but tell the system to reserve 20% of the batteries in case of a grid outage.
After running this for a few weeks, I expect to run with a very small reserve for grid outages in the summer, perhaps 10%. During the winter, when it is much more critical that we have power for our heating, we will run with a reserve of 50% or more.
Here is an example of what the App shows. In this image our PowerWalls are charging in the morning. In addition to charging from our solar panels, the solar is also supplying power to the house and even some to the grid.
This can be seen in the image below.
Details Details Details.
Unfortunately, there are always more details. We found an issue with one of our eGauge systems. We have a temporary one it place and are waiting on our original one to be fixed or replace. In the meantime, with the new PowerWalls and some rewiring, eGauge needs a few corrections to get it back to how it was working before.
Although it was a bumpy ride, we got here!
Our PowerWalls are in place doing their job. The install (Thanks to All Energy Solar) was fairly quick, once they got the delivery of PowerWalls from Tesla.
The ease of use of this system, capabilities and speed it cuts in if the power cuts off is amazing! My computer monitor doesn't even flicker!
We were never terribly worried about a day long power outage at our house, but things like that can happen. We are now completely confident in the ability of our house to maintain heat even during a week long power outage in the coldest winter in Minnesota delivers!
Mark really doesn't like to talk about himself, the house is much more interesting.