Building on ACEEE's landmark research (report E052) on the links between energy efficiency and natural gas prices, this report projects the impacts of increased investment in energy efficiency and renewable energy for the Pacific West states (CA, OR, and WA) over the next 15 years. Using the EEA Natural Gas Markets Model, this report shows that better use of efficiency and renewables could cut gas prices by up to 38% and retail prices by 20%, saving about $100 billion in gas costs for energy users in the region through 2020, and over $300 billion nationwide.