Our Offgrid Sytem

[B529]

Been living offgrid for about 5yrs, we're about 3 miles from utility power. Installed everything myself.

Our system includes:
Outback Power Panel 48vdc, 240vac output.
Batteries- UnigyII AGM's, 24 2volt cells, 1140 Amp Hours
Solar- 2200 watts of Sharp 185's, home brew rack
Wind- Proven WT2.5, used Rohn 70' tower previously used for a 10KW Jacobs, 6' stub tower
Wind Diversion- 2 Tri-star TS60's, 2 Milwaukee wire wound resistors in a aluminum cage
Wind Data Recorders-  NRG Wind Explorer @ 61', NRG Wind Watcher @ 35'
Solar Domestic Hot Water- Used Novan 4x8 panels, IMC differential controller, El-Sid DC circulation pump, 20 watt panel
Misc- Bogart Engineering Tri-metric for batteries state of charge..., Tri-metric dedicated to wind turbine to record amp hours..., Utility AC KW meter to record usage

I've learned a lot in the last five years, the biggest change I would make if I could do it again would be to have more hot water panels to heat our house. I put up two anemometers because I wanted to see the difference between the heights, 2.9mph difference in annual average wind speed, huge difference! Used this information to get our county to change the height restriction of towers (w/o paying for a $500 variance) from 35' to 150', proud to take a part in getting the code changed.

[B529]

I'm a data junkie, like to look at the numbers. Here is a years worth of data, wind speed and production from the turbine.

The NRG WindExplorer records "bins" how many hours the wind blew at various wind speeds. What we should take away from the data is I need a turbine that "cuts in" at low speeds and survives high winds. The Proven has done both of these jobs very well. It cuts in at 8.5 mph. Once its spinning, will make power down to 5.5mph. That's very good considering my elevation.

The column on the left is the various wind speeds, below each month is the hours blown at each wind speed.

[Volvo farmer]

I'm curious about your DHW setup, what you think of it, and what you would do differently.  Specifically, drainback or glycol? How many gallons storage?   Nice tower BTW 

[B529]

I'm curious about your DHW setup, what you think of it, and what you would do differently.  Specifically, drainback or glycol? How many gallons storage?   Nice tower BTW 

Very happy with the DHW system. Guessing it covers our 90% of DHW needs  It's a closed loop glycol system. Tank is a 120 gallons, the ratio of sq ft of panels to gallons storage seems to be about right, 96sq ft to 120 gal.  The tank has two internal coils, one going to the solar collectors, the other going to a backup boiler controlled by a thermostat. Ordered a lot of misc plumbing stuff from AAASolar in Albuquerque, great knowledgeable guys.

When I 1st hooked it up did not have a differential controller, sun shines-pump circulates. Worked OK in the summer, winter not so good, it would circulate the cool glycol before the sun would heat it and cool down the tank. I next added a simple 140 degree snap switch interrupting the PV panel, attached it to the top of one of the collector outlets. Had several of those fail in a "open" position, tried different brands. Came across the IMC Instuments differential controller. It works great, much more efficient. Our storage tank commonly gets up to 150+, highest 176. The IMC controller is powered by the 20 watt that also powers the pump, nothing else. And it has a cool digital display showing the tank temp, collector temp, hi-low temp..... It's a well thought out controller.

[SparWeb]

Your wind data make a picture-perfect Weibull curve.   (Didn't think you'd be complimented for your curves, did you?) 

If your system was installed professionally (it sure look like it was) did you get a power + kWhr guarantee from the installer?

I live at 3500' ASL, and I thought my air density was bad - but 10,000?  Have you estimated/measured the effect of altitude on your system performance?

[B529]

Your wind data make a picture-perfect Weibull curve.   (Didn't think you'd be complimented for your curves, did you?) 

If your system was installed professionally (it sure look like it was) did you get a power + kWhr guarantee from the installer?

I live at 3500' ASL, and I thought my air density was bad - but 10,000?  Have you estimated/measured the effect of altitude on your system performance?

Thanks for the compliments on my curve! It is interesting how well it tracks the Weibull curve, I too enjoyed comparing that.

I installed everything. Using a neighbors wind speed data  I guessed on what the turbine would produce, it exceeded my conservative estimates.

Effect from altitude, 22% less than your elevation, maybe? So many other factors come into play.