Summary

SAI Thailand published the results of an audit of local government expenditures on solar-powered streetlight projects over the past five years. SAI calculated that local governments spent a total of over 14 billion baht (USD 430 million) on such projects, using their own funds and government subsidies. The audit identified a number of issues related to improper streetlight installation, absence of maintenance plans and lacking cost-effectiveness. Auditors found that most local administrations failed to conduct thorough cost analyses, covering cost-effectiveness, long-term and maintenance costs in comparison to traditional streetlights. This resulted in some projects exceeding their budgets. Furthermore, auditors found that, in some cases, new solar-powered streetlights had been installed in areas adjacent to existing utility poles or in locations where public safety was not a priority. SAI also found that solar streetlights exhibited defects even during the warranty period, including battery degradation, corrosion of mechanisms and malfunctions. Local administrations lacked clear maintenance plans, which creats a risk of premature deterioration of public assets. SAI recommended that the Department of Local Government of the Ministry of the Interior establish clearer criteria and guidelines for the implementation of solar streetlight installation projects to prevent the misuse of public funds. Local governments are advised to consider the urgency and opportunity costs of using public funds, particularly targeted grants and accumulated internal funds. Local governments are also advised to develop systematic maintenance plans for solar streetlights to extend the lifespan of poles and reduce the risk of future monopolies on spare parts.