Western Area Power Administration Transparency Act This bill directs the Western Area Power Administration (WAPA) to establish a pilot project to provide increased transparency for its customers. WAPA must publicly display on its website a database of specific information dating back to FY2008, including rates charged to customers for power and transmission services, listed by power system; the amount of capacity or energy sold by power system; and a detailed accounting of its expenditures and costs by region and for the headquarters office. Additionally, WAPA must annually update the information it provides on the website. The updates must include specified details regarding changes to the information, the reasons for the changes, and the amount of unobligated balances retained. The pilot project shall terminate in seven years.