Is there a maximum length of wire that can be ran with a Solar Panel?

[phil]

Will there be any loss of energy running a 15ft wire from a solar panel to the load?

Is there some sort of rule of thumb for how long a wire has to be before significant power loss?

Thanks

Phil

[MarineLiner]

Can also browse in this forum

Will there be any loss of energy running a 15ft wire from a solar panel to the load?
Is there some sort of rule of thumb for how long a wire has to be before significant power loss?

[MarineLiner]

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[EnviroNut]

There are two issues that affect the maximum length of a wire that can be used. The first is the gauge of the wire and the second is the current that is being used.

If the resistance of a length of wire is 100 ohms and the current that is going down the wire is 1 amp then V=IR, so the voltage drop on the wire is 100 volts. If the resistance is 50 ohms and the current is 1 amp then the voltage drop is 50 volts. Your resistance and current are no where near those values. When making calculations you have to remember the length has to include from the panel to the battery and back from the battery to the panel.

This website (http://www.stealth316.com/2-wire-resistance.htm) will allow you to calculate the voltage drop on the loop. The other thing to remember is that as the battery charges and the voltage in the battery increases then the current decreases, which also means that the voltage drop in the wires decrease as well.

Using the calculator, a 20 foot piece of wire with a current of .25 amps, will produce a voltage drop of 0.0518 in the wires, using 20 gauge wire, which is a lot smaller than the 14 gauge wire that is in your house electrical system. If you used 2 conductor 14 gauge wire the voltage drop would be 0.0129 over the 20 foot loop between the panel and the battery, this should not be significant.

Put the maximum current provided by the panel and then you can calculate the gauge of wire that you would need to use.

[Off Grid Solar]

Solar panels are DC power only. DC power can be lost in lenghts that exceed 50 feet. It is important that the proper wires sizes are used as not to cause resistance on the power output. Resistance will reduce the power produced by solar panels.

[Arkamond]

yes and no you could run a wire around earth of copper and gold and youl still get electricity just to tiny to see. It matters how many amps and volts you are putting into your wires and how big they are if your looking for 100w then you could run it more than 10 miles lots of maintenance though and would only lose about 10 or 5 wats depending on where the wires are sitting on if there rubber or plastic coating then not as much will be lost if there open 1 keep children far far away although good for cooking potatoes 2 you would lose more electricity because the ground can actually take the electrons out of the wires decreasing your electricity by alot. plus the more wires you have with all this the more complicated it is to fix put together by the end youl want to destroy your solar panel with a big mallet if you use too much without knowing much about how to interconnect the cords onto the grids and circuitry. but to answer your first question no, you wouldnt have a significant lose of electricity mattering apon how big the wire is and if your rich you could use gold wire much more conductive thats why its used in computers hehe.

[Mike90250]

Will there be any loss of energy running a 15ft wire from a solar panel to the load?

Is there some sort of rule of thumb for how long a wire has to be before significant power loss?

Thanks

Phil

The rule of thumb is no more than 3% loss in a complete run ( plus & minus wires both contribute to the loss, a panel 30 feet away has 60 feet of wire to calculate for)

Wire resistance loss (copper loss) can be cured by using a larger wire size, which gives less loss. At some point though, the thick copper wire gets pretty expensive, which is why some find it becomes less expensive to series wire panels and use 48V batteries.

here's a link to a wire size calculator (AWG) (a spreadsheet, excel or openoffice) that will work for you,

http://www.uwgb.edu/nevermab/voltage_drop_calculator_.xls

some cells are locked, some are slaved to another cell, you may have to hunt around the spreadsheet a bit to find the inputs.

[garybeck]

there is no maximum wire length, technically speaking.
for any given wire run, you can calculate the proper wire size, knowing the voltage, amerage, distance, and maximum voltage drop tolerance.
once you know this, there is a fairly easy way to calculate the proper wire size. you can calculate it with the instructions here:

http://www.libertysolar.com/wiresizingchart.htm

[Mike90250]

Solar panels are DC power only. DC power can be lost in lenghts that exceed 50 feet. It is important that the proper wires sizes are used as not to cause resistance on the power output. Resistance will reduce the power produced by solar panels.

Power in AC or DC, can be lost in ANY length of wire, if it is not the proper size. Those 120V wires from the pole in the back yard to everyones house, are big fat cables. They just look small because they are way up in the air.

[garybeck]

Power in AC or DC, can be lost in ANY length of wire, if it is not the proper size. Those 120V wires from the pole in the back yard to everyones house, are big fat cables. They just look small because they are way up in the air.

Mike is correct... the formulas for voltage drop and ampacity are the same for DC and AC.

AC is typically a higher voltage, but it doesn't have to be. In fact with these new grid-intertie systems you often have higher voltage on the DC side than you do on the AC side.

So either way, check your voltage drop and your ampacity and you'll be fine. (see my previous post for the link to the formula).