Here's a great article in Clean Technica by Zachary Shahan on the falling prices of solar (PV). The cost per watt is the key measure to follow. Basically a rule of thumb is that $3 per Watt installed should be profitable, before any tax credit considerations. In 2006 the cost was $3.50 per watt for the panels. Now prices have dropped below $0.50 and would be lower if there wasn't a trade tiff going on with China. Even with $1 to $2 per watt installed, the prices are getting to be crazy low. The Investment Tax Credit dropped to 26% percent in 2020 and will drop to 22% in 2021, but the installed costs after tax benefits should be less than $2 per watt. That's a crazy profitable investment, especially for businesses. (See our discussion and Solar Calculator on the residential and business PV investments.)
