This thesis considers economic factors for reducing greenhouse gas emissions from utility-scale electricity generation in California. The statewide Emission Performance Standard and Renewables Portfolio Standard have led to the announced and projected retirement of many coal power facilities serving California electricity load. This reality requires new baseload power sources to meet growing energy demands over the next several decades. The economic and environmental feasibilities of competitive baseload generation technologies are assessed to determine suitable replacements for decommissioning coal power plants. Geothermal is identified as the optimal replacement due to its economic baseload functionality, low greenhouse gas emissions, small environmental impact, and resource abundance in many regions of California. Developing geothermal capacity from the Salton Sea could provide southern California with a reliable energy source for decades while simultaneously reducing adverse environmental impacts and greenhouse gas emissions from electricity generation in California.