On 4/14/2010 5:25 AM, wrote:

Who said anything about running an electric cooker off this system?

The AGM batteries will not double the cost, require zero maintenance
and in this application will likely last 8-10 years. Possibly more.
They can be located in a broom closet, basement, or anywhere else you
wish. They can even be hung upsiide down from the ceiling if you like.

Oh, and I have a gas range that can be operated manually just fine,
even when the power goes off. Not that that has anything to do with
this subject.

Try and pay better attention, dopey. You "might" learn something.

What is the cost of installing geo-thermal (system only)?

What is the cost of the solar panels?

What is the cost of mains interconnect (if planned)?

What is the cost of the charger/power supply/conditioner?

Batteries?

http://www.windsun.com/Batteries/Battery_FAQ.htm

It is never advised to store battery banks inside the residence. Back
in my off-grid days every source I ever referenced insisted that the
batteries be stored in their own shack, separate and at a safe distance
from the residence. Just because it is a sealed, VRLA battery does not
mean that it will not off-gas, hence the inherent fire hazard and the
need to store them away from structures and *NOT* have the electronics
inside their enclosure.

At that time (mid 90's) Trojan's were the recommended battery, were not
cheap, and at 6 volts each, required twice the quantity to obtain 12
volts, and four times the quantity to get 24.

Batteries do wear out and getting more than seven years out of them is
not to be expected.

Solar is inefficient and your expected Ah output for charging should be
halved when designing a system unless you plan on using a motorized
tracking system, and your expected useful output should be ~2/3 of the
sunrise/sunset time.

Note: This does not account for cloudy days. Only plan on getting 1/4
of the output in winter (this does not account for winter
weather). This accounts for shorter days and the lower
intensity of sunlight (more atmosphere) striking the panels.

Depending on location, 10% of rated output is the norm.

Solar panels wear out, too.

Whatever you *THINK* you need, double it.

Do plan on using grid power if you do not want *ANY* down time.

Other than for light loads, solar is only supplementary unless you
want to shell out the cost of a vehicle or two, and still not have
100% independence without another form of off-grid power.

It all depends on what you plan on running with the system. Motors
are not a favored load for a small system, since you not only have
to power the motors with the solar panels, you also have to charge
the batteries on top of the load. Two or more hot/cold, cloudy days
will get you, every time.

Plan for the worse, build for twice that.