From EIA:
https://www.eia.gov/todayinenergy/detail.php?id=36813
Based on 2016 EIA data for newly constructed utility-scale electric generators (those with a capacity greater than one megawatt) in the United States, annual capacity-weighted average construction costs for solar photovoltaic systems and onshore wind turbines declined, while construction costs for natural gas generators increased slightly. These three technologies accounted for about 93% of total electric generating capacity added in 2016. Across the United States, investment in electric generating capacity in 2016 increased more than 50% from 2015.
Solar: The cost of construction for solar photovoltaic (PV) projects has steadily decreased since EIA began collecting data in 2013. Average construction costs reached $2,436 per kilowatt (kW) in 2016, down from $3,705/kW in 2013. Nearly 500 PV generating units totaling 8 gigawatts (GW) were added to the electric grid in 2016, making it the second-most common technology installed in 2016, after wind turbines.
Solar PV systems vary by the type of panel used and whether the system uses tracking technology. In 2016, crystalline silicon solar PV systems with tracking were the most-added solar technology and the least expensive, at $2,243/kW.
While the cost has gone down, the fees from local electrical companies for being "off grid", have gone up. Not to mention that locally, the buy back allowance is about 12% of what they charge customers that are on grid. And usually doesn't cover the costs for being off grid. So in the long term, solar becomes a net loss financially. Because in 12-15 years, you're going to have to replace those panels for a variety of reasons.