This document shows the importance of policies for electric energy savings and efficient energy utilization in power planning. The contributions of economic, social, and environmental items were evaluated according to their financial effects in the delay of investments, reduction of production costs and decrement of environmental emissions. The case study is Baja California, Mexico; this system has a unique primary source: geothermal energy. Whether analyzing the planning as usual or planning from the supply side, the forecast for 2005-2025 indicates that 4500 MW additional installed capacity will be required (3-times current capacity), representing an investment that will emit 12.7 Mton per year of CO2 to the atmosphere and will cost US$2.8 billion. Systemic planning that incorporates polices of energy savings and efficiency allows the reduction of investments and pollutant emissions. For example, a reduction of 20% in the growth trend of the electricity consumption in the industrial customers would save US$10.4 billion over the next 20 years, with a potential reduction of 1.6 Mton/year of CO2. The increase in geothermal power generation is also attractive, and it can be combined with the reduction of use and energy losses of utilities, which would save US$13.5 billion and prevent the discharge of 8.5 Mton/year of CO2. (C) 2011 Elsevier Ltd. All rights reserved.