In Colorado we are very lucky as we live in a state where the
government has been proactive in stimulating the use of renewable
energy sources. Along with the Federal energy credit of 26% on the
total cost of the installation the State energy credit for solar installations
exempts the 2.9% States based sales tax, and the 1.2% RTD sales tax.
Some local municipalities have also chosen to exempt solar PV system
from their local sales tax.