diy solar

diy solar

dealing with voltage

Ron

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Joined
Oct 4, 2019
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I put together the parts for my hybrid solar/wind system a while back. Now I have been going over things. My wind power is a 48v three-wire system, but the manufacturer says to be prepared to handle a possible 225v. I admit this is probably in a hurricane. But I planned on hooking the wind gen to a 20A resettable circuit breaker. As recommended by the wind gen maker. Through the rectifier to the batteries, BYD 200AH 48v setup using two 24v batteries. Then to my c-40 controller used as a diversion controller. My plan is for two 1000 watt/48 volt water heater elements to heat water as the diversion load. Installed in series so one backs up the other. c40 info says 125v max open circuit.
In my mind, I see a big wind spike and wonder if my c40 will melt or pass the voltage to the WH elements? https://www.ebay.com/itm/WIND-TURBINE-GENERATOR-1200-WATT-11-blade-MEAN-GREEN-LO
Thoughts on this? and yes, I guess I will find out about how well a wind gen works. I have steady wind where I plan on using this.
 
I don't know enough to answer your question if the controller will melt down. But in regards too...

... be prepared to handle a possible 225v. I admit this is probably in a hurricane...

Power from wind is a cube of the velocity (i.e., P = π/2 r² * ρ), so it probably occurs at a wind velocity a lot lower than you're thinking.

Let's say you get 500W at wind speed of ~11 mph, that's 5m/s. Since r can't change and ρ won't change much for this thought-experiment we can treat π/2 r² * ρ as a constant and simplify the math. So, 500 W = constant x 5³; solve for constant and we get 4.

20 amps @225V = 4500 watts, solving for v (wind velocity, not volts) at 4500 watts and we get (4500 / 4) = v³. So, v= 10.4 m/s ... which is 24 mph.

But check my math and use actual numbers, I'm notorious for not using a calculator correctly. ;)
 
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Get a weather station and monitor the wind before you seriously consider getting a wind turbine.

Don't even think about getting any turbine made in China, 100% junk 100% of the time.

Yes, wind turbines are wonderful at producing energy, but you have to have a lot of wind and it has to be clean and consistent to be of any value.
 
I've already got one. I spent a few more bucks and bought a good one. I will be happy with a little extra power at night. If anything my issue is producing too much power. I have a diversion load set up to heat water with excess power. This helps keep a load on the wind gen. also.
I hope to hook it all up in the near future on an off-grid property. A lot of negativity out there.
 
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