Energy Products

How does the Powerwall 2 limit exports to the grid?

We have several small utilities here in NC that don't support net-metering. They will not allow a PV system to export to their grid. I know in Hawaii exports are not allowed. I understand there is a setting on the powerwall that will not allow exports. I'm just wondering how that works.

If your off grid and the PV is making too much power or the battery is fully charged the PW uses frequency shifting to turn off a normal grid tied PV inverter. If the grid is there how can it shift the frequency? How does it turn off the PV to prevent exports? Enquiring minds want to know...


  • edited November 2018
    I'd also be interested in understanding this. In my case the feed-in tariff is limited to 5kW capacity (exceed and you will get nothing) and I already have a 5kW solar inverter connected so the PW would need to ensure total export remains below this limit. I understand it can do this (indeed, somehow with frequency shifting and thereby forcing other inverters to reduce output) but I'd also like to add further solar capacity. So can the PW limit exports no matter how much inverter capacity is connected?
  • edited November 2018
    I live in a state (WA) that fortunately supports net metering, and I have averaged 5.8 MW/year exported to grid. The way the pW2 works in self powered mode is that after suppling home usage it then charges PW2. When battery is fully charged all excess energy is directed back to grid. I do not see a setting on our Energy Goateway PW2 app that shuts that pathway down. Contact Tesla Energy, perhaps they have a work around for your question. Too bad your electricity provider is so backward.
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