This seems like a good article on which to talk about something I've recently been reading about: Michael Reynolds and his Earthships.
So this guy, for almost 45 years now, has been building homes out of recycled materials (tires, cans, and bottles mostly). They're designed to as close to "carbon zero" in their energy requirements as possible. They collect their own water from the roof and store it in cisterns rather than needing public water infrastructure or pulling from an aquifer. They are heated and cooled passively by the sun, both in the dead of winter and the height of summer. That of course cuts out the bulk of any energy requirements, since heating and cooling require more electricity than anything else in a typical home. Earthships also treat their own waste water on-site using a greenhouse full of plants. So every piece of public infrastructure that a typical home would require is all taken care of on-site. Water, power and sewer.
Even with drastically lowered power requirements compared to a conventional house, the complete solar power system to run an Earthship costs $25-30,000. That's a few solar panels, a few heavy duty batteries, inverters, charge controller, etc. Now triple or quadruple that setup for a conventional home, unless you just want enough for emergency power, in which case you might as well just have a 7kw-10kw generator installed. What many people are doing is just installing solar panels tied to the power grid to decrease their electric bill. That kind of installation pays for itself within a few years, but of course does absolutely nothing to give you power in emergencies since your local inverter shuts down when the grid shuts down and you have no battery bank to store the power even for overnight usage.
In short, Earthships clearly demonstrate that true grid-independent solar power is still extremely expensive, at least in the initial setup cost. Solar installation should not be talked about in terms of absolute cost but in terms of how much stress it will remove from the public infrastructure and how it will help decrease the country's dependence on centralized energy production. That's not to mention how many millions of people won't have to lose power, water and sewer every time there's an outage. That's really the major benefit to putting in a complete solar power system: partial or complete independence from the grid. Not saving money. If even 10% of homes were Earthship style homes, the impact on the public of major infrastructure outages would be lessened quite a bit. Decentralizing weak points of infrastructure should always be seen as a good thing.
Anyone who's interested in sustainable and/or off-grid housing should visit the Earthship website (earthship.com) or view some of the videos on YouTube. Look for "Garbage Warrior" and "Earthship seminar". Michael Reynolds has been demonstrating for decades now that it is possible to build sustainable homes that don't require any infrastructure for about the same overall price as a conventional home. But you definitely need to think a little bit outside the box.