|
| Author |
Message |
beachman
Member
|
# Posted: 17 Sep 2018 20:52
Reply
ICC - you stated in a recent post that your PV panels were 200 or 300 feet away. Without trying to drive DC power that far with very large cable, do you place the inverter at the panels and drive more voltage the long distance? I too have a better spot for the panels but farther away. Very curious.
|
|
Nate R
Member
|
# Posted: 17 Sep 2018 22:39
Reply
I assumed MPPT was the way to go there....With multiple panels, voltage drop doesn't matter as much. I mean, you'll still lose power, but still the controller can still work just fine if MPPT.
|
|
ICC
Member
|
# Posted: 17 Sep 2018 23:21 - Edited by: ICC
Reply
Yes, MPPT, but there's more to it than just that.
DC from panel array to the charge controllers. Charge controllers at the batteries which are all in one location at the shop that is an integral part of the home. Two distant panel arrays, one just under 200 feet to the southwest and the other just under 300 feet to the north.
The array at 300 feet is 16 x 270 watt panels all in series. The wire is #8 AWG, two conductor plus ground underground direct burial copper. Maximum Vmp is about 480 volts at a maximum of 9 amps. That length of wire provides a maximum voltage drop of less than 1% which is great. The same wire was used for the 200 foot array which is also 16 of the same panels in series. High voltage and low amps = smallest possible wire size.
Each run feeds into a Schneider Conext charge controller located at the battery bank. One controller for each panel array. The batteries are a 48 volt bank of GBS brand LiFePO4. The inverter is a Schneider XW, 240 VAC model.
The 8 gauge wire was bought in a 500 foot spool which was relatively cheap but I did have to buy high end inverters to get the ability to transmit the power at such high voltage. The Schneider is extremely good equipment though. Using the same brand inverter means it all works together with a single remote panel.
Depending on the maximum AC amps you need running 120 VAC power a couple hundred feet may still need a large-ish gauge wire. Depends on the variables; how many PV panels, the volts and amps to run and on the AC side how many amps at 120 VAC you need to be able to supply with minimal voltage drop. For me it made the most sense to run all the PV in series over smaller gauge wire and have batteries and inverter together.
I can help with running power losses for different wire sizes, different voltage and currents.
EDIT: I should probably also mention there is a third array of panels located on the flat roof of the shop. It also uses a Schneider Conext charge controller but the 150 volt version with a series - parallel arrangement of panels. Each of the three arrays is oriented in a different compass direction so there can be good charging available throughout the hours of the day, whenever the sun shines. About 290 days a year are cloudless.
|
|
beachman
Member
|
# Posted: 18 Sep 2018 11:47
Reply
OK. Now that makes sense. Thanks!
|
|
NorthRick
Member
|
# Posted: 18 Sep 2018 14:42
Reply
That's quite the setup for a cabin ICC.
|
|
toyota_mdt_tech
Member
|
# Posted: 18 Sep 2018 15:05
Reply
Excellent reply ICC, your post are always nice to read, very educational. 
|
|
ICC
Member
|
# Posted: 18 Sep 2018 15:59
Reply
NorthRick, the forum may be directed towards cabins and some on here live fulltime in theirs. Like the majority, I used to have a fulltime home in one place and a cabin in another. I am retired and a few years ago built the present place, my combined fulltime home with space for all the playthings. Heated and cooled living space is about 1000 sq ft and let's just say the workshop and playthings space is a lot bigger. The old home, and it was an real New Mexican oldie, was sold. The old cabin in still there but not used much. I may sell it off one day.
toyota_mdt_tech, thank you for the appreciative words.
|
|
|
