Energy efficiency costs are 1.5-3.5 times less than costs of new power generation

While energy efficiency investments reduce energy use and energy bills, the energy efficiency measures do have an up-front cost, which is ultimately covered by energy bill savings. 
Studies from American Council for an Energy Efficient Economy and Lawrence Berkeley National Laboratory found that on average, across all sectors, energy efficiency programs are costing program administrators about 2.4 cents per kWh saved over the lifetime of the energy efficiency measures installed. These costs are significantly lower than the costs of meeting electricity needs with new power plants (see figure above).