As of July 2011, Connecticut authorizes municipalities to pass a local ordinance to exempt "Class I" renewable energy projects from paying building permit fees. Class I renewable energy projects include energy derived from solar power, wind power, fuel cells (using renewable or non-renewable fuels), methane gas from landfills, ocean thermal power, wave or tidal power, low-emission advanced renewable energy conversion technologies, certain newer run-of-the-river hydropower facilities not exceeding five megawatts (MW) in capacity, and sustainable biomass facilities. (Emissions limits apply to electricity generated by sustainable biomass facilities.)
Public Act 15-194 effective October 1st 2015, requires each municipality to incorporate residential solar photovoltaic systems on its building permit application process. The municipalities are allowed to waive the permit application fee for such systems.