Energy Products

Connecting powerwall 2 to a generator

Hi I have a powerwall 2 installed and overall I am happy with the performance. I would like to connect a generator to my system. Tesla representative advised me that this is not possible at present and suggested to upgrade to the new gateway with the backup option. This does not make any sense to me because of the cost( is £2k for something that I will probably never use) and the fact that if there is no solar available the system will not work anyway. I would like to have the option to connect a portable generator to my system. Can anyone advise of how to connect the generator safely( through a transfer switch?) and if this affects the battery at all? Thanks.


  • The big risk I can see is if the generator shuts off for any reason while connected to the PW, the PW may attempt to send power into the generator, which could damage the generator and/or overload the PW. It really needs a fast automatic disconnect that a gateway switch can provide.

    Another consideration is the generator's waveform. Often it looks good at no load, but at even 50% load it has a lot of harmonic distortion. How the PW will deal with it is an unknown. It could damage its electronics, but perhaps it's tolerant of such waveform distortion.
  • As Nancy Reagan used to say..."Just say no".
  • > @"" Many thanks for the reply. Yes, I fully agree with your concern but is it possible to connect the generator to the gateway 1 safely?
    Without the PW I had the option to connect my system to a generator. Now, it appears that I do not have the option. As I mentioned gateway 2 is no use, if there is no solar power available. Again thanks for your time.
  • I am not sure if this will be useful if you are looking for a way to charge the power walls with a generator (which would be nice!) I had an interlock and a connection for a generator installed in my panel years ago. When Tesla recently installed the solar and power walls, they installed a panel outside the house. It became the breaker for the mains. The panel in the house became a sub-panel. If I turn off the mains breaker on the panel inside, I can then open the breaker that allows the generator to power the house. It cannot send power to the power walls since it is now isolated from the Tesla panel. I can't charge or use the power walls or the solar with the generator, but it does mean I can run most of the house on the generator if the power walls are low which will remain handy during a prolonged outage which is always possible in Florida. I had hoped for a way to use the generator with solar and power walls, but it is not doable in the Tesla scheme. The problem, as noted above, is when the Tesla gateway wants to send energy unneeded by the house back to the grid. You have to have a place to dissipate it. This can be done, but did not seem worth the expense and hassle in my case plus I bet Tesla would not be happy with having this sort of extra stuff installed ahead of their system.
  • Yup. The TEG will try to send the excess power from the PV out to the "grid", which in this case would be a gasoline-powered generator. If you're lucky, this would simply destroy the power output section of the generator. If you're unlucky, you could get an explosion that includes the gasoline powering the generator.
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