Powerwall Upgrade Denver Area

[Frontrange PV]

Now a few weeks in having our Powerwall 2 upgrade added to last year’s Enphase IQ8 based solar installation.

Very pleased so far. Some testing still to complete but the system appears to be working as advertised so far, and quite well actually.

Very high wind event last night had Xcel utility killing grid power for the better part of 24 hours just north of us. We never lost power but feeling less foolish about this upgrade.

Stormwatch has engaged as expected since we enabled the new hardware.

This kind of pre-emptive grid outage is new for us in our area. I’ve been anticipating this kind of thing since the Marshall fire in 2021.

System:
18 west facing REC Alpha Pure Black 400 panels online since 5/23
3 new east facing REC Alpha Pure Black 405 panels added 3/24
21 IQ8A Enphase micro inverters
1 Enphase Combiner Box
1 Powerwall 2 battery added 3/24
1 Backup Gateway 2 added 3/24

Combined nominal rating: 8.4kW

AC and car charging circuits excluded from back up. All others covered.

Installed by Photon Brothers.

As our baseline usage runs about 16kWh per day, and we don’t live where we need to run the AC long hours hardly ever, we went with the system spec’d above. We have mostly gas heat.

We own a 2019 Leaf SL+ as an urban corridor runabout. It works well for how we use it.

Running 50% backup reserve under self-consumption, and the battery can effortlessly carry the house from sundown to nearly sunrise overnight, unless we’re charging the car.

 

[charlesj]

Welcome @Frontrange PV .
I have a 12-year-old Enphase system with 2 batteries added in May 2020.
A number of us here Enphase systems with Tesla batteries.
I had one inverter go out a couple of years ago and that replacement went out as well, also replaced with a new, free Enphase Envoy.
System worked well even with that one outage. Love it, especially when I read string inverters going out, system down for a good bit of time.

 

[Frontrange PV]

The next phase, if needed, would entail adding a bi-directional charger to provide extended backup. Not sure if or when that will make sense, but I've been thinking about options.

Option 1: Add MTS to generation/backup side of the Gateway, hang the backup circuits off the MTS and hook up a bi-directional charger as a second power source. This would allow us to isolate our existing power supply system from the bi-directional charger, so that the backup house circuits would either run as they do today OR off the car, but the Gateway would not need to be compatible with the car charger.

The scenario here might be, in Denver, we're dealing with multiple weeks of bad smoke from wildfires with multiple days of preemptive grid outages. If we're not making enough solar to carry the house AND re-charge the Powerwall, then we could run the house off the car for a while, multiple days, and have what solar is available recharge the Powerwall. After the Powerwall is charged, switch the house back to it, and go drive the car to where there is enough power to recharge it and bring that power back home.

I'm pretty certain this would work, even if Tesla chooses not to support bi-directional charging on non-Tesla vehicles. We would be able to run basically indefinitely in that scenario. December/January might get hard, but doable. We have had both multiple weeks of really bad wildfire smoke and now also one instance of grid power being shut down preemptively. So this scenario sounds plausible.

Option 2: Add Tesla Universal Charger if Tesla decides to make that compatible with a non-Tesla vehicle as a bi-directional unit. This would obviously be much easier and likely cheaper.

Our Leaf is already bi-direction capable from the factory, but based on Chademo, of course. There are 3rd party bidirectional chargers announced, but none really on the market in the U.S. yet to my knowledge. I'm also less inclined to invest in one for Chademo, preferring instead to wait for the J3400 standard to become widespread here.

I'm not open to owning a Tesla vehicle. They don't meet our needs for a variety of reasons.