If you want to do this in several "bites"... You might think of doing the batteries + inverters + generator first.

Batteries run lights, TV, radio, ceiling fans and such. Generator kicks in for recharging (at relatively high recharging levels) small uses and powering your A/C.

Typically, your most costly fuel use is when a generator is under 25% load or so (cheaper once are probably pretty fuel inefficient under 50% load).

That will cut your initial system costs by roughly 1/2. Later, you could always add solar panels + charge controllers to charge the batter bank and still run the generator for A/C... And, just sizing your battery system to supply everything but the inverter will cut the size/cost of your system by another 50-75%+.

later, if or when you decide you want to run the A/C too with solar/battery--then you will have several years of experience to see what works and what does not--plus some actual usage numbers.

In the end, sizing your RE system to handle all of the normal household loads, except A/C and 5 hair driers at a time, will be the most cost effective.

And, if the heavy loads (A/C, renters, 5 hair driers, etc.) are very part time--sizing your solar/RE system for those loads means you have way over-sized it with respect to the rest of the time the system is in use...

At least fuel costs are directly proportional to electrical demand. Solar RE costs are only proportional to the peak demand.

-Bill

kind of along the lines I was thinking.

A side note. Has anyone investigated propane powered A/c. I did come across it in my research. Just wondering if anyone actually has any thoughts, as a propane powered system would probably cost a bit more maybe alot, but the solar system would be magnitudes smaller.

Something like this in propane. Obviously a bit smaller
http://www.sanyoaircon.com/products/gas-driven-vrf/



Anyway thanks for your time.

I think your under estimating the need of AC, your climate has a higher need of AC than mine, and it takes a 12kwh solar system to net out the use of grid power here in florida. This is a well built and insulated block home with a 5 ton AC.

I don't have 4 more people living here and use my appliances as needed. If this was you personal home I would be agreeing with BB, you can learn to live with less, but you will have a fulltime house keeper running loads and I'm sure the rents will make extensive use of the AC ...

I've pretty much run out of input, so well wishes to your adventure

You may actually be surprised sometimes. Obviously most people seem to abuse the system in my other rental properties, but there are actually weeks here where the temps range low 90's to around 80. And they do not turn on the ac at all. I am actually surprised when I see these people. AS if I had ac in my house here I would use it. I am in process of moving my personal residence here and Just have 2 floor fans in the apartment right now. Although it is just me and the wife.

Hmm. Interesting Sanyo system. Running off of natural gas would seem to be an interesting option here in California...

I was trying to figure out the fuel consumption though... 16-54 kW based on 40MJ/NM3... Not quite sure how to convert that...

But just as a guess, these systems may range from somewhere around 1-6 gph of propane (just a SWAG--no solid info).

One other question... From my limited experience, the sealed electric refrigeration compressor was a God-Send for smaller A/C systems. Seal leaks around compressor shafts were always a problem (appears that this is a belt drive from the propane engine to the compressor(s)).

I would wonder if you would be just increasing mantenance issues with support required for two propane engines (generator and A/C system), plus compressor maintenance...

Don't know--just asking questions.

-Bill

I have no idea about maintenance, but hoping If, (huge if) use a different a/c system rather than straight electric I may be able to down size solar system alot. If i was on the grid I would not mind too much, but I do not have that luxury, I am at a loss.

Anyway I am off to investigate different alternate a/c operations. Definately report back my numbers.

S.G. do you have any energy consumption usage for your a/c system and what is the actual ac system.


Thanks

Well still waiting on some quotes for the solar or gas driven absorption cooler systems.

Will be back to this thread when I do.

Something that caught my eye recently, has been Dry Stack Concrete Block, starts with a conventional foundation, and then the blocks are stacked dry. A coating of something like stucco (but strong fiber reinforced) is applied inner and outer surfaces, and you have solid walls. After they set, you fill the corners and every couple of feet with rebar and concrete. Insulate the OUTER wall, and then the mass of the concrete blocks helps reduce the thermal swings.

What's the humidity like ? Really dripping wet, or dry like Arizona ? That may influence the amount of A/C needed. Also, there is a new A/C unit in development that uses a water bath to cool the working media (freon), supposed to be more effective than finned tube and fans. Just need a shaded evap pond to keep the water bath somewhat cool.

Going to probably go an strong block wall. Filled with concrete and rebar.
Going to use foil black insulation. Something like and r-10. Then a 4 inch fiberglass insulation space. Then just sheetrock. Probably getting into the low 20's in the respect or R values.

Dripping wet humid. Makes ac more needed.

Was going to go foam block fill rebar and concrete but it uses much more rebar. And prices have skyrocketed here recently. Close to up 100 percent in about a year. That would have had around an R-20.
Plus the layer of foil back insulation. Would have brought it to a R-30 with a great thermal mass. But I will put the difference in construction expense to alternate energy system. And other efficiencies