How much percentage GHG reduction with percentage of PV home rooftop systems installed?

I believe so, though there are broad assumptions at play and keeping in mind this is just rooftop solar. 

The impact of utility scale solar may be significantly bigger. I think on market it could go for $1/watt for capacity vs $3/watt for rooftop. So that means utility scale solar could make 2-3 times the impact at the same level of investment.

  • Impact of rooftop solar investment:
    Xcel Energy has 1,485,000 residential meters; Black Hills 189,600 (sorry don’t immediately have statewide meter stats)
    • If 1:8 homes goes solar, that’s 185,625 homes
    • If avg size is 4kW at state avg price of $3/watt = market of $2.23 billion
      • 1kW of capacity in Denver = 1,604 kWh/year avg
      • 185,625 x 4kW x 1,604 kWh/yr = 1.19 billion kWh/yr or 1.19 million MW/hr
      • Offsets need for .213 coal-fired power plants or equivalent of taking 183,557 passenger cars off the road per year (can you clarify, Bryce?) The amount of electricity produced by 1:8 homes in IOU territory going solar could offset 1/5th of a coal power plant or be the climate equivalent of removing that many cars off the road.
      • 844,020 metric tons
  • Colorado’s goal is to reduce emissions from 135 MMTCO2e to 67.5 MMTCO2e by 2030. 844,020 metric tons reduction of CO2e would represent 1.25% of the reduction required to achieve the 2030 goal of 50% emissions reduction.