Two questions: 1) With the solar electric option can it completely power a normal house off grid? 2) How much does it add to the cost?

1 - Yes and No - Keep in mind there are different solar systems and different demands
2 - 15,000 to 35,000 for a 4 bedroom home . They match your power demand , the more you need the more panels you need to install . 70% of the cost is panel only

How it works;
The one we installed on the home that won the GREEN Star Award cost 25,000 break even estimated 7 to 9 years combined with solar water. During the day "normal home" the electric meter runs backwards and puts power back on the grid at night the meter runs forward - The goal here is the forward and backward runs of the meter should cancel each other out and you get a 0.00 electric bill . Here the Electric Company does NOT in anyway pay you for the power that goes back on the grid <-- Used to get that question every day

Real life on the system we installed , which by the way you can monitor the system via web site. Pretty cool even shows you how many trees and emissions your saving per hour

We installed the system on our top of the line Model Home its open 1 to 5 weekdays and 10 to 5 weekends . I am also in charge of the models .

Now since they are models we built in A/C and all lights are turned on and I mean every lamp and ceiling light . Now I inspect the models before they open and yes the meter does really spin backwards but after I flip everything on , whoooweee it really spins in fast forward . Before we installed the system the average bill for that model was in the 545.00 range after was in the 250.00 range so about a 45% in savings

Keep in mind this is a model - A normal home during the day , owners are at work and certainly would not run the A/C everyday with all the lights turned on

Reasoning the cost; 25,000 for the system
I always get this one too . People are more concern about where is the Break Even Year and you tell them 7 to 9 years they freak out "oh no that is to long and cost to much blah blah blah

I respond

1 - The cost is included in the home , so even with interest over a 30 year loan "We calc out" about 25 to 30 bucks more a month

2 - You get to enjoy the electric savings immediately - the average Big Island electric bill is in the 200 per month thats 2,800 per year dollar range -vs- 25 to 30 bucks per month on your mortgage = It's a no brainer to me

3 - Adds resale value to the home and attract-ability , just shows better

Heres the kicker
4 - Say you sell your home in 5 years , you get back the 25,000 you spent on the system and you walk away with 14,000 in savings