Previously, solar has been difficult to justify strictly on the numbers. The price of install has been high, payback was 10-12 years, and returns were in single digits. As solar became more prolific, the price of hardware and engineering got more competitive. Then in 2005, the Energy Policy Act began tax credits.
In 2007, the government increased that tax credit to 30%. Coupled with accelerated depreciation and continued decrease in installation cost, solar has reached a financial nexus of value. With payback as quick as 4-5 years and returns in the high teens to low twenties, well above most companys’ hurdle rate.
Implementation and hardware costs are down 75% in 10 years, plateauing as the tax credits were set to expire. But, the 30% credit was extended in 2016, creating a four year window of above-market returns.