|
I recently installed an Enphase home backup system as a DIY project (crazy, I know). The biggest problem with any home-backup system is moving the loads onto their own sub-panel. When the utility goes down, power needs to flow into the home, but not to the rest of the neighborhood. To do this, a switch needs to physically disconnect the utility meter from the main loads panel. If this isn't possible (such as when the meter is integrated into the panel), all the loads need to move to a sub-panel. This is the hard part. Once the meter and main panel are separate, the various backup solutions become pretty similar. The disconnect switch installs between the two, with the solar and battery attached. Sometimes the disconnect switch + solar + battery are all in one unit (like the Bluetti EP900), while sometimes the solar inverter, battery, and switch are all separate units (like Tesla or Enphase). The Tesla switch and battery are sleek & glossy, but the inverters are ugly. The Enphase stuff isn't quite as shiny, but at least the boxes look consistent. Performance-wise, the systems seem pretty similar as well. Most systems are around $10K for 10KWh of capacity, with somewhere around 6-9 KW of peak discharge rate. I imagine these prices will drop a lot over the next decades. If the battery becomes obsolete, just install a different system. Once the home is correctly wired, swapping the storage system should be pretty straightforward. |
It doesn't need to be.
You can just use a physical interlock and toggle between utility breaker and (any input you want) breaker.
You can do this on an integrated meter panel.
This is a dead-simple configuration that you can comprehend - and verify - with your own eyes.
The lock-out switch is NEC compliant, utility approved, etc.:
https://www.amazon.com/Generator-Interlock-Compatible-Homeli...
Yes, you do lose all power for a second or two but ... so much simpler and comprehensible than an ATX solution.