This paper reports the findings of a preliminary assessment of the cost effectiveness of distributed energy resources at Naval Base Ventura County (NBVC) Building 1512. This study was conducted in response to the base's request for design assistance to the Federal Energy Management Program. Given the current tariff structure there are two main decisions facing NBVC: whether to install distributed energy resources (DER), and whether to continue the direct access energy supply contract. Each of these decisions would be made at different levels, involving different decision makers: at the building level for a DER system or at the base level for continuing the direct access contract. This analysis focuses on the potential for energy savings in Building 1512 as the result of either installing a DER system or changing the tariff structure. Building 1512 is the largest electricity consumer on NBVC, but the estimated cost of its energy varies considerably depending on which of three possible electricity tariffs is applied. Monthly bill data and DOE-2 simulation were used to estimate building energy use profiles.