Posted by JNJ on October 10, 2003, 1:12 am
I'm at the point that I'm ready to start planning my solar power system. I
intend to put this system together a little at a time and yes, I'll be
DIYing it to keep costs down. I thought I'd hit the group up for
Since one of my improvement projects here involves rewiring the house, this
seemed the logical point to begin assembling the system. I'd like to put an
inverter and charge controller in to be ready for up to 1200 watts in 24V
Any suggestions on equipment to use?
Posted by Zathera on October 10, 2003, 3:38 pm
Rewire the house, why? Why not just shut all the circuits down and megger
them. That will tell you if there are any insulation issues. A battery
powered megger and inject 500 v should do the trick. The rule of thumb is 2x
voltage plus a hundred or 2x voltage plus a thousand if you have medium
voltage, over a 1000 volts below 69 kv volts.
Unless of course the wiring is so old that you do not have grounds, then I
would consider a rewire. I have done several and they are not a lot of fun.
Especially when you have to bust holes everywhere to pull the wire in. Attic
work ,,, ug not with my knees any more.
Posted by JNJ on October 10, 2003, 4:40 pm
You're close. Over the last several years, I've been rewiring a little at a
time as projects warrant it. Two big problems -- knob and tube throughout,
Growing up here I remember that we used to blow fuses (yes, fuses) all the
time because most of the house was on the same circuit. Years ago, my Dad
moved us over to breakers to handle loads better and save the bucks on
replacement fuses. He did not rewire the house at that time so we still
have many of the same wiring issues. At least he did wire up some entirely
new circuits for window AC units.
I bought the home a little over 10 years ago and since then we've installed
central air and a new furnace, plus done some pretty major remodeling (tore
out a bedroom, bathroom, closet, added floor joists, new wall and plumbing,
all new electrical, etc.). Part of our long term plans have been to move
the rooms off to the circuit that was put in for the AC units -- that gives
ample capacity for a room with lights, TV, etc.. It also gives an
opportunity to remove knob and tube wiring in favor of newer wiring.
If all goes well, I'll have everything but the upstairs rewired by the end
of the year. At that point, I'll be ready to run a new wire upstairs and
it's time to pull the knob and tube out of the breaker box. I figure that's
a good time to put in the inverter and charge controller whilst I'm at it --
might as well get all of the major rewiring done at the same time while I've
got the electrician here. (Although I DIY most jobs, I get an experienced
pro to help with the more complex tasks to be safe.)
Posted by Mitch Dickson on October 27, 2003, 4:09 am
First of all James, you have to get down here in the real world. 1200 watts
at 24 volts is only 240 watts at 120 volts. You can run 2 and 1/2 100 watt
lights off of that :( But only when the sun is shining!
First thing you gotta do is throw all that tree hugger crap out the window
and forget saving the world! Green power don't mean doodlie! Get down to
it. The easiest (and the cheapest) way to use solar power is to create
heat. The easiest way to store that heat is water! Water will store 6
times more heat than earth or stone!!!
Now your two highest bills are your heat bill and then your hot water bill.
Average home this runs about $500 a year for heat and about $40 a year for
hot water. Range uses about $0 a year and Dryer about $0 a year. The
rest of your electric bill is probably no more than about $0 a month! So
attack those items first that are draining your assets! All of them have to
do with heating something!!! So first off convert to propane if you got the
dollars or natural gas and cut all the above in half! Next we will apply
that $,000 a year you will save to cut the gas bill by 80%!!!! Then and
only then should you worry about solar electricity! Here is a good rule of
thumb, if your electric bill is below $5 a month, that is the time to go
solar! Get it there first!!!!!
If you do get serious, a 24 foot by 4 foot solar furnace laced with 3/4 inch
black pipe and covered by double insulated sliding glass door panels and
surrounded by 8 inches of insulation on sides and bottom and 3, 4 by 8 foot
mirror panels aimed at 36 degrees (or whatever your latitude is) facing due
south will get up to nearly 190 degrees in the furnace and make a hell of a
lot of hot water!!! Use 2 or 3 solar panels to run a DC pump and you have a
system that will come on as the sun gets up and shut down as it sets
automatically. Build yourself a storage tank about 10 feet wide and 24 feet
long and 5 foot high, line it with one piece of rubber commercial roofing
and surround it with 20 inches of insulation (I used Styrofoam) and fill it
from roof rain runoff and you have a solar storage battery that will do you
some real good! Use an old truck radiator as a heat exchanger and pipe it
to your furnace and seal it and fill it with antifreeze and insulate the
Soon you will have about 12,000 gallons of 170 degree hot water and a very
quick recovery capability! Set another radiator in your tank and pump it
with a very small electric pump (your gonna want this one to run day and
night) to another radiator placed in your heat duct intake and hooked to a
thermostat and all you will need to run on your heat unit is the fan (this
should also be a closed system filled with antifreeze)! You just cut that
$00 propane bill to less than $00.
Run a 100 foot copper coil of 3/4 inch copper in your tank and hook it to
you cold water and hot water inputs (you will need to bring another cold
water pipe to where you join onto your hot water and place 2 mixing valves
as 170 degree water will scald you!) and you just eliminated the $40 a year
hot water bill!
Heck you can even use an old heater core out of an old car to convert a gas
dryer (tumbler runs off 110) and even eliminate the $0 a year there!
If you build this yourself you can do so for less than $,500 if your
careful or you could spend about $50,000 to do it with panels :) You will
still have your gas for convenience to cook and dry your clothes and back up
heat, about 2 grand extra in your pocket, an electric bill of less than
$0, plenty of time and money to explore stirling engines and PV panels, and
heck, even the tree huggers got to love ya :)
"Come by and sit a spell with me at www.volstate.net/~mitch/ "
Posted by Joe Fischer on October 27, 2003, 4:36 am
You should have wrote :-) instead of :-( when you
make such a mistake. :-)