This page will contain information on Solar and Wind technologies. The plan
is to create a resource and discussion for general information and also
for the DIY'er to actually build a workable system. I am not an expert
on the electronics involved but am learning as I go. Hopefully there will
be some Electrical Engineers and Code Inspectors that can join the
discussions to keep the rest of us out out trouble.
To start this page off, here is a links page to
some useful websites I have found.
Update Spring 2016
-
It's been a while since I updated this page. In the last year I built 3 out of the 4 solar
panels I have frames for. They are pretty heavy with 1/4 termpered glass and are 49" x 49".
They put out around 8amps - so put out a consistent 100+Watts!
The
ensapsulant has some bubbles in them but they (so far) are small enough that they don't seem
to be any issue. At this time I have two of them connected to the workshop and had one
connected to the travel trailer. When I get some larger wire these will be mounted on the
south side of the workshop to feed the set of workshop batteries.I've also invested
in 4 flexible 100W solar panels. These only weigh around 4 lbs each so will be much easier
to be portable for the travel trailer. I've built some pvc frames for these that connect
together and the angle can be easily be adjusted.
I am also ordering 6 new 115amp/hr batteries - three will go in the trailer and three into
the workshop. I'm hoping that's enough battery power to last a couple cloudy days for dry camping.
It will be 400Watts of panels for 345amp hours of battery. The trailer also has a solar charger and
battery monitoring pair so I can see power in and power out and see a % of power left. I also
have a 2k inverter in there for everything except the AC.
Some pics of the new panels
If you have comments or would like to help build this section of the site,
please use the Contact Us page. Please leave your
contact information and I'll get back to you.
Testing...Solar Panel - installed eary May 2010
Update Spring 2016This panel lasted a good 3+ years before finally falling apart.
It was not fully water sealed (no encapsulant was used). Between the sun warping the plexiglas
and the water warping the underlying wood and some molding, enough of the cells finally cracked
and rendered the panel dead.
The first experiment was a small solar panel (40W max). Some pictures here.
I found some cells on ebay that were pretty well priced.
They were small 2x3 cells. I got 80 of these and built a small panel. I soldered these together with
2 sets of 36 in series (to setup 18V) and then in parellel to up the amperage. This panel turned out
rather well and during a nice sunny day I get full voltage and over 1.5A that charges my small battery
pack (2 12V 12ah batteries). The batteries are in parellel so that I have 12V and 24ah. This is run through
a small 400W inverter and currently powers the lights for the chicken coop and goat house. Neither of these
have the lights on for more then a few minutes each day as the days are long, so the batteries are almost
always full.
I have ordered an IOTA 30A Automatic transfer switch. Once that is hooked up, I will add the lights from
my workshop to run from the batteries. Then if the load runs them down, the system will go back to grid
power until the batteries get recharged.
Testing...Wind Turbine - Put up June 13th, June 2010
Special thanks to Scott for supplying the Tower Pole!
To test if wind can be used to keep the batteries topped off - or produce some extra power during
the winter or windy stormy days, I purchased a 500W light breeze turbine from ebay. The turbine looks
great (although it seems the company laid off all their techs so I was unable to get any detailed questions
answered from the seller). I've painted it and put it up on the roof of the workshop.
Some pictures here. I bought a dump load controller and hooked it up to a set
of small hallogen lights. When the battery reaches the overcharge limit, the lights come on and suck power
out of the battery at around 12 amps. The one question
I did get answered was that this turbine should not have a stop switch used with it. They said if the winds
hit 50mph it would fry the turbine. It's better if it just free spins. These turbines are made to handle
over 100mph winds, they do not furl, just generate lots of power...In heavy winds I've seen it putting out
over 35 amps into the battery.
Most of this page (and solar/wind section) is still in the process of being organized (June 1, 2010)
Batteries
Batteries manufactured by: Concorde, Surrette (Rolls), Trojan, Crown, and
Deka. It is generally recommended at a rough estimate around
1-1.5 watts of solar panel per battery bank amp-hours @ 12 volts (double
that for 24 volt, 4x that for 48 volt systems)
PV by the square foot
solar cell production ~12.5 watts / sq. ft.
Wind tip speed
TSR (tip speed ratio)
It has been shown empirically that the optimum tip speed ratio for maximum power output occurs at
TSR(max power) = 4pi/n
where n is the number of blades.
Retrieved from "http://en.wikipedia.org/wiki/Tip_speed_ratio"
Coil creation
The formula used for calculating the total number of turns is N=V/(( Te*A)/ S))
where V= desired output voltage, Te= (magnet gauss*.5)/10000, A= magnet area in
square meters and S= 60/rotor RPM. Lastly, N is divided by the number of coils
to determine the number of turns per coil.
Coil Info
Faraday's law