Instead of going off the grid, I think it's more positive to think of how much you can give back to the systems on which we all depend. That means using electricity during off-peak hours, growing food and giving it away or trading it, being a part of your communities rather than pulling back into some sort of imagined self-sufficiency. You'll do more good in the long run.

Some people can also be hooked into the grid, but produce enough energy at certain times of the day that they use more than they need, and send power back into the grid.  Thus, they actually produce more energy than they use.

Under law, utility companies must purchase the electricity that gets put into the grid.  Produce enough excess energy, and it can add up.  There are some people in Houston who make enough off their solar panels that they get $200-$300 a month from the utilities.  Their electric bills actually have little negative signs in front of the amount to show that the utility owes THEM money, and not the other way 'round.

Also, when sizing your system, don't be alarmed at the prospect of cooler indoor winter temperatures. Lower room temperatures will lead to brown-fat led metabolic heat generation. All that green and a leaner body to boot.

And this is in Houston.  We get WAY more than 5 hours of productive sun, even in the winter.

I also know of several homes that have small wind turbines as well, and my old old office had both wind and solar power.

Second, I don't know what the rate is that the utility is paying them back for the energy.  I kinda wonder where you got the 10 cents for kwh figure from?  Did you just make that up, or was it based on rates in your region?

Third, you also stated that the average home is 30 kwh per day.  I already said that the homes were NOT average.  They were, in fact, quite small (as I already said), and most had taken steps to improve efficiency beyond what an average home does.

Third, if you would like more proof, the local stations also did news stories in which several of the owners (including the cargo container residence) reported the amounts (and showed their bills to prove it), several months ago.  I remember in particular the local ABC (channel 13), CBS (channel 11), and PBS (channel 8) stations did news reports on it.  They also reported that the container house was applying for LEED certification, but I don't know if they ever got it.

However, I don't know how much all of them paid to have the panels installed (though I do know that one of them spent well over $50,000), so even though they are makin' money from it on a month-by-month basis, the total rate of return could be quite small, in terms of money spent.

1) Productive hours. I actually live in Pittsburgh. I generally get more than 5 productive hours in the dead of winter, even when it is snowy, cloudy, or raining moderately or lightly. I have a tiny 5 panel / 0.875 kW system. From Jan 1 to 5 minutes ago on May 1, they've produced 490 kwh.  This month (ending April 20), I broke even for the month. Many days, the panels were producing for 12 hours or more, and we're only 10 days past the equinox. I expect to be ahead in May, June and July. I suspect you are talking about "hours over a particular threshold" or "hours producing at peak capacity." That's a lower number, naturally.

2) array size. I fit 5 panels on a bit of flat roof over 1 small bathroom on a low budget. Plenty of people could put on 30 panels or more, and some probably have 40 or 50. So lets re-think your calculation. If the average person has about 2 kw of production, figure that the low end is probably well-represented by older arrays or smaller arrays in the 0.5 to 1 kw range, like mine. That leaves plenty of room in the "average" for some 5 to 10 kW systems. If a system like that got the same rather weak winter performance as Pittsburgh, they'd have made 2,800 to 5,600 kwh in the last 4 months--again, that's mostly the unproductive, cloudy, short day length winter months. I expect to get double that, roughly, in the most productive 4 summer months. (That's when it is needed, when kids are home, demand for cooling is high, and I instead have the sense to open the door from the basement to the hallway, and the north window into the basement, and get cool air that way). A 5-10 kW array here might be making 5,600 to 11,200 kwh in those months. At 10 cents a kwh, that's $560 to $1120 for those 4 months. Divide by 4 to get as much as $252 a month, for total generation. Admittedly that does not include use. Which takes us to the final false assumption:

3) most people who bother to put in a huge bank of panels will first no doubt reduce their own use to a modest fraction of the national average. If I can come out ahead in summer with my measly 0.875 watt system (in an area that has more haze than TX and enough rain that I don't have to water my yard) then someone who's using a 5 or 10 kW array may very well use as little as, say, 5 or 10 percent of what they are generating. So even if the buy-back is at cost (as per your assumption) $200 a month strikes me as quite possible. Also, I believe the efficiency is higher on the inverter for a larger system (could be wrong) which would improve those numbers, relative to mine. Finally, in many areas, power companies both charge and pay a premium for "green energy." If your company does this, you might either pay (or get!) 25 cents, 50 cents or more per kWh, rather than 10 cents.

Garbage Warrior is a feature-length documentary film telling the epic story of maverick US architect Michael Reynolds and his fight to introduce radically sustainable housing. An extraordinary tale of triumph over bureaucracy, Garbage Warrior is above all an intimate portrait of an extraordinary individual and his dream of changing the world

Reynolds believes that we need to be able to experiment with new types of housing, and this effort is hamstrung by very complex housing codes.