There are two components that make up a residential electric utility bill. The Base Rate, which accounts for approximately 68% of the bill, covers all expenses the utility incurs in providing service, such as operation and maintenance expenses, depreciation, taxes and return on capital. The Base Rate is determined by the Public Service Commission in a 42T case filed by the utility. The remaining portion of the bill, approximately 32%, is the Expanded Net Energy Cost (ENEC) and includes expenses the utility must pay to purchase power or the fuel to generate electricity and certain specified environmental compliance and construction costs related to generation and transmission. The ENEC rate is determined in an annual review and true-up process by the Commission.