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 specific information dating back to FY2008, including rates charged by power systems to customers for power and transmission services, the amount of capacity or energy sold by power systems and a detailed accounting at the functional and budget activity level of all its expenditures and capital costs by region and for the headquarters office. Additionally, WAPA must annually update the information it provides on the website, including the changes it publishes, the reasons for the changes and the amount of the unobligated balances it retains at the end of the prior fiscal year within each marketing area and at headquarters. The pilot project shall terminate in seven years.