Recent content by Hedges

  1. Hedges

    Newbie exploring a PV array in my field about 50m from the house UK based

    How about adding more PV panels, oriented differently, paralleled with your existing panels into existing inverter? No higher wattage exported, but more hours. I figure you can deliver up to 1.4x the kWh this way.
  2. Hedges

    48v residential total off grid system

    BMS for each string is better. That would be 16s3p If you paralleled 3 cells, did that 16 times then connected in series that would be 3p16s. Only one BMS. 16s3p is better for several reasons. Current handling is approximately 3x (except for imbalance in current draw.) If one BMS fails you can...
  3. Hedges

    Newbie exploring a PV array in my field about 50m from the house UK based

    25000 KWH Per year / 365 days/year/5 hours sun per day = 13 kW PV array Oh, sorry. Double that for the UK, always overcast. (Smart *ss enough for you?) 13 kW requires about 15 to 16 kW (STC) of panels, which can cost as little as $2000 if used panels are available. Up to maybe $8000 for new...
  4. Hedges

    48v residential total off grid system

    4 strings x 50V x 280 Ah = 58,000 Ah (gross) Maybe you use 80% to 90% of capacity, 45 kW to 50 kW Sounds like 3 strings would do it. Or 4, a bit extra, if you want. Then you have to chose between 3p16s and 16s3p (how many BMS, max current, etc.)
  5. Hedges

    Long time dreamer wants to jump in

    https://legionsolar.com/ "No permission solar" If you get a zero-export system (current transformers clamped around utility feed so inverter can avoid exporting), that makes things simpler.
  6. Hedges

    Long time dreamer wants to jump in

    Washing isn't really necessary. 20 x 15 = 300sf or 28m^2 One full sun is 1kW/m^2; panels can harvest 14% to 20% so up to 0.2 kW/m^2 28 x 0.2 = 5.6kW (STC) available, about 5kW (PTC) Power outlets with PV plugged in isn't a UL listed approach. Possible problem is 20A from breaker + 15A from PV...
  7. Hedges

    I maybe the dumbest person I know

    The BMS should function to disconnect charging of a series-connected pack, if any cell goes over-voltage. With the pack assembled, your supply could deliver 6A at 12 to 14V or so, which charges 4x faster than in parallel. Once the first cell reaches 3.65V or whatever target, you can top each...
  8. Hedges

    48v residential total off grid system

    Check out Ghostwriter's new love. She has lots of experience buying cells. https://diysolarforum.com/threads/our-new-go-to-lifepo4-vendor-09-20-21.28696/
  9. Hedges

    Our NEW GO-TO LiFePO4 vendor...09.20.21

    I see studs, so I assume tapped terminals. We eagerly await your verdict on thread quality, report of orthogonality, and pull-out strength tests (inadvertent, if necessary)!
  10. Hedges

    I maybe the dumbest person I know

    So you're charging at 1.5A, 0.005C Should only take about 8 days (if starting from empty) Do you have a BMS yet?
  11. Hedges

    Want to build system to run fridge

    I think this link says today the Sun's zenith is at zero degrees 41 minutes North. https://www.timeanddate.com/worldclock/sunearth.html If you're in Arizona, that would be about 34 degrees https://latitudeandlongitude.org/arizona-latitude.php sine(34 degrees) = 0.56 So it seems to me your...
  12. Hedges

    Finally, the start of my 25kw Ground Mount grid-tie system

    If you want battery to feed loads only, zero backfeed, then current transformers on the main utility feed could be read by a suitable inverter. If backfeed is OK, then you might just use a timer to enable inverting from battery during peak use rates. AC batteries like Tesla PowerWall and SMA...
  13. Hedges

    Want to build system to run fridge

    3 x 195W (STC) = 585W (STC) 350W/585W = 60% I think PTC rating of panels (output under full sun but normal operating temperature) is often 85% or so of STC. What you don't know is if you have "one full sun", or somewhat attenuated by something in the atmosphere. The days are getting a bit...
  14. Hedges

    Enphase AC to hybrid system

    For my SMA string inverters, default frequency range is 59.4 to 60.5 Hz. That is the standard in-spec frequency range, so your microinverters shouldn't go offline below 60.5 Hz. Start at that frequency (or higher), would like power output to ramp down with frequency. Mine are 100% at 61 Hz...
  15. Hedges

    Enphase AC to hybrid system

    For my SMA string inverters, default frequency range is 59.4 to 60.5 Hz. That is the standard in-spec frequency range, so your microinverters shouldn't go offline below 60.5 Hz. Start at that frequency (or higher), would like power output to ramp down with frequency. Mine are 100% at 61 Hz...
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