Having owned a home, installing solar on it, and then subsequently selling it within the past 18 months in Southern California I think I can offer some real-world experience to the topic.
The first thing is when I moved to the desert I wondered why there was no solar pretty much anywhere. The utility co. is building out huge solar farms along the 8, or rather a 3rd party entity that will lease them to the utility co., but very little rooftop solar in what would seem like a no-brainer.
After installing our solar, I can understand a lot better. The first thing is that we have cheap electricity by California stanards. No TOU but also .11/kwh after taxes and fees, which is roughly 1/3 to 1/4 the cost of the more populated areas of the state. I also had to bring contractors from Arizona because no one in the more populated areas was familiar with the environment and few were willing to travel to the desert for the install. It wasn't helping that rules were changing across the state creating a rush on the installs before years end.
Second up were the roadblocks the utility co. threw my way. There were tremendous hurdles in getting the paperwork done let alone getting anyone on the phone or in person who knew what to do or how to do it--largely on account of there not being many installs in the area but also because they aren't incentivized to throw the switch on for "their" customer. After the install was finalized, it took about two months for them to throw my switch. The installer actually threw the switch after about 3 weeks and just told me to turn it off before the final inspection. I'm pretty sure I got double billed for those few months: billed for both what I pulled and billed for what I pushed to them since the meter wasn't smart enough to figure out what was going on...or I wasn't smart enough to read it. It's hard to tell and the entire processes and systems are purposely obfuscated to create this consumer difficulty. The bottom line is that the meter didn't "spin" backwards until a good six months into it and after numerous checks with a local electrician and the utility co.'s techs.
When it was all said and done? None of the savings that were penciled in. Between the moving target the law has allowed with regards to how utils charge customers, the environmental effects on panels (not just less sun, but also reduced efficiency from too *much* heat as we found the case to be in an environment that consists of most of the day under the sun in the most perfect angles all year round), and the tax tomfoolery there exists a lot of daylight between the cost on paper and the cost my bank account reflected.
Just one example: the utils charge a mandatory monthly service fee for all customers. That's not new, but what is new is the amount of that charge varying depending on whether you are a net producer or consumer. It used to be that if you produced 1kw of energy you put that into your bank and could draw it later. The utils started charging for that over and above the customary montly surcharge. If you were grandfathered, like our old system, they interpreted the rules (and contract I signed formalizing that agreement I just outlined above) to allow them to charge retail for energy pulled but only credit energy pushed at the wholesale level. That's currently at .03/kw and I'm not even sure they get it that cheap yet. Regardless, the writing is on the wall for that one and it will only drop lower from here. I anticipate by the time solar farms are widespread the wholesale cost to utils will be quoted at .01/kw, if that. My anticipated prouction was supposed to cost me about .09/kw. I think I was hitting that even with all these things I'm talking about but it changed the ROI to almost double, which was well over 10 years. At the time, we had planned on retiring in that home so I wasn't worried about it. But it did clarify for me why no one in the area was bothering to do it. The savings were so marginal and the costs/frustrations were so high it wasn't viable for most of the area's population. We had access to a little over $20K for the system, but I don't think that's a common situation for homeowners these days.
My lender warned me that the average home owner stays in a home for 7 years. She also said everyone thinks they won't be an average home owner. I think she said most sell long before the 7 year mark, as in closer to 3-4. We refused the ARM with closing costs covered because we weren't going to be the average (we were going to retire in the home)...and then we sold it 4 years later!
...such is life
Since the time we had installed the panels and sold the home, the rules had changed again. I hope you all understand the trend that things never change for the better for a consumer in terms of lower costs in a situation like this. That's my experience anyway and it's worth looking into the trends in your area to see if they are like mine because it has important implications for tying yourself to a system for 20+ years. Even with my contract the co. was still managing to find room for interpretation to raise various rates and refuse to payback at agreed upon rates. Even in months where I used less than I made, I started to pay extra because they categorized me as a "net producer," which meant that I was being paid back at the wholesale level in credits. The surprise happened at the end of the year, when they "settled" the bill: I believe I had about $250 dollars worth of credit but only received about $86 dollars when I cashed it out.
So that was the cost side of things. The selling side of things were also different from what one reads.
Solar panels are a liability when selling a home. Anyone who says otherwise hasn't placed such a home on the market and tried to sell it. They don't add 1:1 value to a home--they aren't even considered part of the home. They are personal property and finding an appraiser who is going to give anything for them and an underwriter who is willing to make sense of them are only part of the problem. Underwriters (controlling the loan) don't want a liability like that and they don't want to figure them out, either. Remember, appraisers and underwriters are risk-averse and anything that is difficult to analyze is going to create an issue for the lender and ultimately the buyer.
I was able to show all the paperwork and all the documents showing the system was paid outright. That helped in clawing back *some* value but we only managed to get about half of it. Most of the battle was "proving" to any potential buyers we owned it, the benefits of owning over leasing, and all the convo that is going on in this thread. In an area more populated with rooftop solar the situation might have been easier but the bottom line was no one wanted to pay extra for anything compared to a similar home without any of the extra. All remodeling, adding, and improving did to our home's value was make it stand out at the top of the list. The price we listed it at, however, was almost entirely driven by sq ft and comps. Condition and solar had a few thousand value add here and there, but compared to the cost of housing in California they were more accurately regarded as rounding errors rather than driving value and price. Solar seems to be like a pool in some regards: requiring a specific buyer to be interested, the buyer is likely to be more savvy about that particular feature, and is likely to leverage the fact that other buyers either won't care about or flat out won't want that particular feature and leverage those factors against you in negotiation.
Anyway, I probably have a lot more to say about this but the bottom line for us was that we aren't planning on doing solar at our new home because of that experience. We also got rid of our eGolf for much of the same reason. Costs don't correlate very well with prices. Cost for all of this is going down while pricing for consumers is going up. It makes it more difficult to see how this fleshes out with all the incentives propping up these pricing structures.