The costs of large computing facilities like data centers were dominated by the costs of the information technology (IT) equipment that they have in 1990s. As the indirect cost of IT has increased, Total Cost of Ownership(TCO) analysis is required to find the lifetime costs of acquiring, operating, and changing IT equipment. Nowadays, electricity-related costs such as the electrical power used by IT equipment and the facility costs associated with powering and cooling IT equipment has sharply grown. Nonetheless, those electricity-related costs have been underestimated up to now. In this paper, we will develop TCO model for a high performance computing data center and perform TCO analysis. We will also show that the trend towards growing electricity-related IT equipment costs continue, direct IT equipment acquisition costs will not be an critical factor of the economics of computing services.