<prompt> Human: So I just got approved for an 8,600 kWhyear system. 10-year loan 30,371.00 with a 6.49 interest rate 42,054.12 with interest. When I saw this my stomach dropped, I was hoping to spend like 20,000. Thats around 345 a month in payments.It is apparently supposed to save me 150 a month on my electric bills, which are now outrageously high 400-750 for a 1200sqft house. I am mainly doing this to save on electric costs and have redundancy for when the power goes out.I get a 30 federal tax credit on the system, so 9000, and Massachusetts gives me 1000 state tax credits. If I get this installed before the summer, I get enrolled in their SREC system, where for every 1000 kWh, I get a credit to sell on the open market. About 8 total giving me 1200-2000year depending on the market demand.If I wait on this, I would be enrolled in the SMART program and receive around 8000 less in incentives.I tried making a spreadsheet that showed the NPVROI but honestly, it came back negative when I tied my electric bill into it and I wasnt sure if I was doing it right.TLDR; Solar cost seems high, but have to act fast to get in on federalstate incentives before they go away. Is this investment dumb?EDIT: Great info from everyone!! I decided I am going to pull out of the project. Thank you uhmspain for the helpful links on the DIY portion. I found out a similar grid-tied system would cost 11,000, and the idea of managing the project myself sounds much better. I might go this route instead, along with using mass save to make the house more efficient.  <response>: Solar is a huge profit industry right now, meaning it doesnt cost that much to set up, but they charge you a lot for it.I wouldnt bank on this technology and pricing being relevant in 10 years...let alone 18.I think its too new and too costly to know what the long term advancements will do to the market.I say dont invest. It will probably be cheaper in 5-10 years...without government subs.Definitely look in to why your bills are so high and what you can do insulationfans or other repairs to keep the heat or cold in your house. 