4 ms·

I assume you mean 2kW not 2kWh. And you can; look up "Non-export addition". These are solar panels that are set to zero-export; they will either charge a batte

I assume you mean 2kW not 2kWh. And you can; look up "Non-export addition". These are solar panels that are set to zero-export; they will either charge a battery or the current house loads, but never backfeed into the grid.

quickthrowman 2y ago
> they will either charge a battery or the current house loads, but never backfeed into the grid. I’m not sure I understand how this works unless you split off loads into a subpanel that is fed by a UPS which is fed by solar panels, and also isolated from your utility connected electrical service. As far as I understand it, you can’t have power generated by solar panels feeding loads in your grid-connected panel without backfeeding the grid, same deal as a generator backfeeding a grid-connected panel. You have to kill the MCB or service disconnect to prevent backfeeding. If you have links with info on how this work (one-line diagram would be extremely useful) I’d be curious. I sell and run commercial electrical work, FWIW. I’ve done zero solar jobs so my understanding could definitely be wrong!
- kylehotchkiss 2y ago
  Wouldn't it be like Grid < Primary solar > Battery < Secondary Solar Where the house is powered by inverter directly on the battery (and maybe a second inverter for primary solar to grid?)
- narism 2y ago
  Zero export inverters are grid-tied but monitor the meter/CTs for load changes in order to curtail solar production/shift it to battery charging. I think they can technically backfeed a little bit if load is suddenly dumped depending on the inverter response time. Some have a secondary hard disconnect for additional protection. https://knowledge-center.solaredge.com/sites/kc/files/feed-in_limitation_application_note.pdf https://knowledge-center.solaredge.com/sites/kc/files/feed-i...
  - quickthrowman 2y ago
    Thanks for the info, that clears things up!
- Dylan16807 2y ago
  > As far as I understand it, you can’t have power generated by solar panels feeding loads in your grid-connected panel without backfeeding the grid, same deal as a generator backfeeding a grid-connected panel. You have to kill the MCB or service disconnect to prevent backfeeding. An inverter can limit its output, right? So measure current at a few different points in the system, do some math, and use that to set the inverter's limit.
  - quickthrowman 2y ago
    Thanks for the explanation, that makes sense. Monitor some CTs and let the inverter only discharge enough power to satisfy the current demand without backfeeding the utility.
    - jaredhallen 2y ago
      Or mine some crypto with the excess. I'm only half kidding. Having too much power is a good problem to have.
kylehotchkiss 2y ago
You are correct :) Thank you for mentioning non-export additions! I'll give those a look.

quickthrowman 2y ago

> they will either charge a battery or the current house loads, but never backfeed into the grid. I’m not sure I understand how this works unless you split off loads into a subpanel that is fed by a UPS which is fed by solar panels, and also isolated from your utility connected electrical service. As far as I understand it, you can’t have power generated by solar panels feeding loads in your grid-connected panel without backfeeding the grid, same deal as a generator backfeeding a grid-connected panel. You have to kill the MCB or service disconnect to prevent backfeeding. If you have links with info on how this work (one-line diagram would be extremely useful) I’d be curious. I sell and run commercial electrical work, FWIW. I’ve done zero solar jobs so my understanding could definitely be wrong!

kylehotchkiss 2y ago
Wouldn't it be like Grid < Primary solar > Battery < Secondary Solar Where the house is powered by inverter directly on the battery (and maybe a second inverter for primary solar to grid?)
narism 2y ago
Zero export inverters are grid-tied but monitor the meter/CTs for load changes in order to curtail solar production/shift it to battery charging. I think they can technically backfeed a little bit if load is suddenly dumped depending on the inverter response time. Some have a secondary hard disconnect for additional protection. https://knowledge-center.solaredge.com/sites/kc/files/feed-in_limitation_application_note.pdf https://knowledge-center.solaredge.com/sites/kc/files/feed-i...
- quickthrowman 2y ago
  Thanks for the info, that clears things up!
Dylan16807 2y ago
> As far as I understand it, you can’t have power generated by solar panels feeding loads in your grid-connected panel without backfeeding the grid, same deal as a generator backfeeding a grid-connected panel. You have to kill the MCB or service disconnect to prevent backfeeding. An inverter can limit its output, right? So measure current at a few different points in the system, do some math, and use that to set the inverter's limit.
- quickthrowman 2y ago
  Thanks for the explanation, that makes sense. Monitor some CTs and let the inverter only discharge enough power to satisfy the current demand without backfeeding the utility.
  - jaredhallen 2y ago
    Or mine some crypto with the excess. I'm only half kidding. Having too much power is a good problem to have.

kylehotchkiss 2y ago

You are correct :) Thank you for mentioning non-export additions! I'll give those a look.