How far can charge controller be installed from Wind Turbine

pleekit

Hello Everyone,

I am looking at purchasing a wind turbine for my off-grid cottage just to charge my battery.

It's a small 12V/24V 400W Pikasola Wind Turbine Generator Kit from Amazon

My question is: Wind Turbines usually come with a 3-phase AC output, how far can I place the charge controller from the Wind Turbine generator ?

Trying to avoid losses when it converts to DC and then use a long run to connect to battery.

BB.

Welcome to the forum Pleekit,

In general, the "long cable run" should be between the wind turbine/alternator and the charge controller. You can have a couple volts drop and everything will work OK (yes, there are more losses with higher voltage drop). Typically aim for 1% to 3% voltage drop on this cable run.

Where you want short/heavy cable/low voltage drop is from the controller to the battery bank/bus terminals. You want the charge controller to accuratly measure and control the charging voltage at the battery. For a 12 volt battery, want around 0.05 to 0.10 max voltage drop (at maximum charging current). For 24 volt battery bus, around 0.1 to 0.2 volt maximum drop.

Need to know if your system will be 12 or 24 VDC battery system. And specifically which Wind kit you are looking at (different voltage and current ratings).

Anyway, just to show you how it works. Say you are using 10 AWG cable (rated for 30 amps NEC). The wiring from the alternator being 3 phase, the current will be reduced by sqrt(3) or 1.732

• 30 Amp battery charging rating / 1.732 (3 phase conversion) = 17.3 Amp @ 3 phase

Using a voltage drop calculator and "playing with distance" we rind 17.3 amps @ 18 volts at alternator @ 10 AWG cable will have 3% drop at a distance of:

https://www.calculator.net/voltage-drop-calculator.html?necmaterial=copper&necwiresize=2&necconduit=pvc&necpf=1&material=copper&wiresize=0.4066&resistance=1.2&resistanceunit=okm&voltage=18&phase=ac3&noofconductor=1&distance=15&distanceunit=feet&amperes=17.3&x=0&y=0&ctype=nec

15 feet
Voltage drop: 0.53
Voltage drop percentage: 2.97%
Voltage at the end: 17.47

Now, if we assume the alternator outputs 18+ volts and the controller/battery needs at least 15 VDC to charge properly, that gives us ~3 volts of "allowed" voltage drop:

https://www.calculator.net/voltage-drop-calculator.html?necmaterial=copper&necwiresize=2&necconduit=pvc&necpf=1&material=copper&wiresize=0.4066&resistance=1.2&resistanceunit=okm&voltage=18&phase=ac3&noofconductor=1&distance=85&distanceunit=feet&amperes=17.3&x=0&y=0&ctype=nec

85 Feet
Voltage drop: 3.03
Voltage drop percentage: 16.82%
Voltage at the end: 14.97

And now looking for 0.05 to 0.10 volt drop from controller to battery bank using 10 AWG cable @ 30 amps:

https://www.calculator.net/voltage-drop-calculator.html?necmaterial=copper&necwiresize=2&necconduit=pvc&necpf=1&material=copper&wiresize=0.4066&resistance=1.2&resistanceunit=okm&voltage=14.5&phase=dc&noofconductor=1&distance=2&distanceunit=feet&amperes=30&x=0&y=0&ctype=nec

2 feet from controller to battery bank
Voltage drop: 0.14
Voltage drop percentage: 0.98%
Voltage at the end: 14.36

Even 2 feet @ 10 AWG is a bit excessive for "optimal" battery charging (0.05 to 0.10 VDC suggested drop).

There are lots of other questions and issues to address with wind turbines... Don't mount to side of your home, must be installed in "clean air" (no turbulence) which needs a 10 meter (typical minimum) tower, etc.

And wind turbines generally only begin to generate "useful" power at ~12 MPH (19 km/H or 5.4 m/s). And typically max out around 25 MPH (40 km/H, 11.2 m/s)... Typically "miserably" windy conditions.

I am not a fan of small wind--If you can find any wind turbines near you and find out how well the work over time--I would suggest talking with the owners.

I highly suggest designing a solar power system first--Then add wind turbine (if you still want it) for poor weather conditions:
http://www.solarelectricityhandbook.com/solar-irradiance.html

Princes Town Trinidad & Tobago
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 80° angle from vertical:
(For best year-round performance)

Jan	Feb	Mar	Apr	May	Jun
6.29	6.37	6.27	5.88	5.89	5.52
Jul	Aug	Sep	Oct	Nov	Dec
5.74	5.73	5.68	5.72	5.49	5.89

Overall, you (guessing) live in a very sunny location--So solar is a good start for your system.

-Bill