Install costs are high, electric rates are pretty reasonable, and we don't use a lot of electricity. Our five year average monthly electric bill is $87 and $107 for the past year, which was an exceptionally hot year. Of that, $28/month is a flat fee for being connected to the utility so the energy costs were $59 and $79 respectively. The fee would remain even if the net grid electric power usage were zero or below. Payback period is roughly eighteen years for us.
Those numbers are pretty similar to what I had: similar monthly electric bill (About $100/month) and similar monthly forced fee to be connected (just over $30/month). I installed solar last year with a 13 year payback*. One key to the payback calculation is most people increase their electricity usage after installing solar. Be prepared to add in 10% to 20% more electricity usage in your math since now you won't care about the cost of using a bit more energy. So far, most bills are ~$20 total, which means they pay me $10 but I still have the $30 forced fee to be connected.
The keys to a shorter payback: (1) local and federal tax credits, (2) shopping around for solar installers. The cost of the panels is almost nothing, but the cost of the electricians were outrageous here. The estimates for the same installation ranged from $12k to $25k--for the exact same specs. I found that at least here, the electricians that went into solar were about $12k and the solar companies that outsource electricians were all in the $20k to $25k range.
* I am not including any valuation change on the house, since that is hard to estimate. Zillow says solar increases the house value by 4%, but I didn't include that in the payback since it would make the payback almost instantaneous.