This fiscal risk is further enhanced for clean electricity generation as the latter is likely to be subsidised at the beginning of the transition from conventional energy to clean energy (see investment promotion and facilitation section). Governments should therefore undertake careful benefit-cost analysis to justify the subsidy levels and financial analysis to ensure that the liberalisation process is fiscally sustainable, and provides sufficient - yet affordable - stimulus for the participation of clean energy investors. The design of clear procurement rules or of standard power purchasing agreements (which can be adapted to better accommodate clean energy IPPs) is also necessary to protect consumer interests.