Posted by Alex on February 6, 2006, 7:36 pm
I live in Central Texas where we have very warm summers plus with our
electric cost going up (currently at 13.75 cents per kWh and going up
monthly it seems) I'm looking at alternative ways to bring the bill
Ideally I'd love to convert as much to Solar as possible, but I don't
have thousands to spend on doing it. I'd like to start working on a
system that starts small, maybe one solar panel and a couple of
batteries to run some lights, the TV, and possibly other small
appliances, and eventually grow from there.
I have no idea how to calculate watts and amps useage from batteries
and what kind of recharging time or power I'd need from solar panels.
Also do I need special types of batteries to get 110 volts or is it
feasible to use 12 volt batteries for such a project.
Thanks for any ideas or starting points --
Posted by Robert Scott on February 6, 2006, 7:22 pm
If all you want to do is bring your electric bill down, then forget solar for
now. It is great for heating, but the payback is a long time on electricity.
Instead I suggest that you look very closely at your biggest electrical load.
It is probably your air conditioner. By comparison, your lights and TV comsume
almost nothing. Look at lifestyle changes to reduce the need for air
conditioning by conditioning only the rooms you are actually in, and only when
you are in them, and only to the mininal extent necessary. Reduce air
infiltration and reduce solar gain in the summer by sealing aroung windows or
planting trees to shade your windows. See if your attic is getting too hot and
radiating down into your living space. If so, install and attic vent -
preferably one that does not use electricity. This may involve enlarging the
venting on your overhangs too. All these boring measures will make a much
bigger dent in your heating bill than anything you could do with solar without
Posted by D.S. on February 8, 2006, 1:15 pm
Try this and let me know what you think. . .
Robert Scott wrote:
Posted by SQLit on February 6, 2006, 8:18 pm
Look at COSTCO and Harbor Freight. Both sell small systems. What your going
to find pretty fast is that other than lighting and some non-heating
appliances solar is a LOT MORE expensive than grid power.
A non moving 100 watt panel will generate ~50-60% day in and out when there
is sun. A moving panel might get up to 80-90%. Opps you said not much
Then there are the batteries and inverters. Gad there are tons of inverters
most are not sine wave and that starts another discussion.
Want to save money? Reinsulated the attic, change to CF bulbs, shade screen
all direct sun windows. Put a timer on the ole water heater, install a set
back t-stat. Check all windows and doors for leaks and repair as necessary.
Your water heater can be a large part of your electric bill. A solar water
heater can help a lot on that load. I had a 4 x 10 flat plate on a home
that I owned. 8 months a year it gave me all the hot water a person could
stand. 2 months a year is was better than 60%. 2 Months a year it became
not much other than a tempering tank and the electric back up ran then.
If your HVAC is older than 5 years you might think about spending several
thousand dollars on a more efficient one. I would do the above first.
Check with your local utility and state and see what they are pushing this
Posted by SJC on February 6, 2006, 9:37 pm
I agree, AC is a big user of power. Venting the attic and overhangs or awnings
can be a far more cost effective solution to reducing electricity bills. Solar
hot water would be good, if you have electric water heat.