Electrical power on military installations is vital for mission accomplishment. Most installations obtain electrical power from a local commercial utility. Although commercial power service has a very low interruption rate, the threat of a sustained power outage resulting from a terrorist act or a natural disaster is of concern. The military should posture itself to prevent such power outages and prepare to mitigate the adverse affects associated with the loss of power. This thesis presents a Value Focused Thinking approach to the development of a decision analysis model to assist a decision maker at a military installation in the generation and selection of back-up energy alternatives. The model attempts to capture the value to be gained by implementing back-up power systems which utilize fossil fuel powered generators in combination with renewable energy resources and assist the decision maker in selecting an alternative which best suits the needs of the installation. The thesis also includes a case study involving the application of this model to the United States Marine Corps installation in Twentynine Palms, California.