Looong Wire Runs Question

[my t30]

Hey guys.
A friend of mine wants to put solar in at his cottage but his cottage is in the woods about ~600 ft from decent sun. I currently am running a solar array 220 feet from my rv with a voltage drop of 4% and it has worked flawlessly for 2 years.

So my question is this, would there be any problems with a 600 foot run. My calculations are that at 150v and 9A the voltage drop would be ~8% (138v) with 10 awg wire. Obviously there would be power lost but would it not still work with 90% of the power retained?

For that matter why would a 1000ft run not work? 150v and 9A comes to 13% drop (131v) with 10awg wire.

Thanks everyone.

Philip

[Westbranch]

Well, IMO it would be better to split the distance IFF you can truly get 150V constantly to the Classic and then have an inverter from the batt bank to the cabin, or some combination of that.  The inverter output will be constant and the PV is variable due to climatic conditions...

[zoneblue]

As you know PV voltage varys according to a number of factors. Aiming too close to 150V for day to day use will create too much risk of high Voc conditions that even hypervoc may not be able to protect you.

As Wb says, (especially if you are in 230V land) put the inverter in a shed near the array, and run AC.

10awg is not particularly big cable these days, but i understand the trade off you are making. After all, a 1 or 2 extra panels is probably all thats needed to compensate for the loss.

[Halfcrazy]

Yes in reality with the pv prices being down and wire and high voltage controllers (Like the 600 volt controllers) being so pricey voltage drop is not so awful. We got the 2% thing in our head when we had PWM controllers and $10 a watt PV (or at least I did).

MPPT can deal with the voltage drop so no worries there and with PV being 75 cents a watt you can through an extra panel or two on to make up for the losses. On a sunny day the Voltage Drop will be high but on a cloudy day when it is needed the most the Voltage Drop will be almost 0%

The one thing to remember is that the voltage drop is only present under load so you do not want to push the voltage (VOC) higher than the charge controller can handle

Ryan