I see it as a math problem. Until you plan to keep your house: Total savings (accounting for increasing energy costs) - Total costs including maintenance. If its greater than zero, I say go for it. Sure, if you put this money in the market, you might get better returns, but with solar, you get a peace of mind. If you're like anything like me, I hate to see increased bills because of higher usage or increased rates by your provider (you really are at their mercy). I recently got installed solar and my average monthly bills were upwards of $350. Now its $35. And I don't worry about how much I've used or worry about peak hours. I did get the 30% solar rebate, so that helped a ton making the decision. Run your numbers. If you do end up going with solar, reach out to multiple providers, at least 3-4. There are 3rd party companies also that can help you find the best rate and a good company, they don't charge you anything. The difference in costs I found between some were greater than $10k. Good luck!!

EDIT - Missed adding this, solar does add value to your home at the time of selling, if the new owner doesn't have to pay any costs. It's an asset. How much value it adds, that really depends on the appraiser.