The Centre's National Solar Mission faces a major roadblock as banks argued that the current structure of the power-purchase agreement (PPA) was not bankable due to the credibility of many states. The existing PPA structure provides for a trader PPA with NTPC Vyapar Vidyut Nigam, which passes on the risk of default by state distribution companies (discoms) to the developer.

Major banks, including SBI, Bank of India and Central Bank of India, have argued that many discoms were delaying and sometimes defaulting on payments, and therefore, have asked the Centre to contemplate a tripartite agreement between the developer, the state discom and the RBI to ensure the PPA bankability.

Banks opine that solar power is a risky and expensive option, despite the support being provided by the Centre and the state governments.