help with switch

natural_gas

i have free natural gas, what to run generator , with battery wall. need info on switch to turn off and turn on gen when battery go low

BB.

It looks like you would wire the system this way (is this a Tesla PowerWall system?):

                                  Solar Panels=======\/
Utility=>Meter=>Main Power panel=>powerwall=>genset transfer switch=>Main panel/your loads
                                                                     genset=======^

https://www.sunnova.com/watts-up/generator-and-tesla-powerwall

Four Steps to Long-Term Backup Power

Here’s how Tesla Powerwall will work with your generator:

1. During a grid outage, your Tesla Powerwall will automatically turn on before your generator.
2. If your Tesla Powerwall depletes to its minimum setting, your generator will automatically turn on.

During a long-term grid outage, once your Tesla Powerwall is out of energy, you will flip the Manual Transfer Switch to have your solar charge up your Tesla Powerwall.

1. Your solar system and your Tesla Powerwall will not power your home while your generator is running. Instead, if the sun is up, your solar will charge your Tesla Powerwall while your generator powers your home.
2. Once your Tesla Powerwall is fully charged, you will need to manually switch your home from your generator back to your Tesla Powerwall. It’s as simple as restarting your Tesla Powerwall.

Depending on how long the grid out, you may have to repeat this cycle. While almost everything happens automatically, the key point to remember is that every time your Tesla Powerwall is depleted, you will have to restart your Tesla Powerwall once it’s charged, that’s it!

During an extended grid outage, the more conservative you are with your energy use, the less you will have to use your generator and potentially costly fuel.

If your system is a Tesla Powerwall, you will probably have to work with your Tesla dealer/installer to integrate with a genset....

-Bill

Ian

BB we have a Powerwall 2 and after watching some guys charging Tesla vehicles with generators with a good clean output quite successfully we wanted to see if we could do the same in the event we have an extended power outage and the Powerwallwas falling to a low state of charge. The approach was to drop the main supply off and then connect an 10kW alternator in place of the mains we did this at  night to avoid any issues with our Enphase microinverter array. To make the Powerwall charge we switched it to 100% backup mode or storm mode either seemed to work. The Powerwall then saw the alternator as main  power and started charging at about 5kW and the house night time load of about 1.2kW was also carried by the alternator. Once the Powerwall was fully charged we just switched the alternator off and switched the Powerwall to its normal mode to back up the house. You could also reconnect the grid at this point if power was available,
This seems to be a simple approach but I do not know what would happen if you tried to use a smaller alternator. Of course in the daytime I suspect damage to the alternator could result due to backfired from the PV array.