摘要： Economical, stand-alone, solar microgrids can be quickly implemented in most un-electrified regions of the world. Solar resource maps developed by the National Aeronautics and Space Administration (NASA) and the National Renewable Energy Laboratory (NREL), together with HOMER Pro software, have been widely used to determine the optimal design of microgrids. Repercussions of imprecise predictions of solar resources and electrical power generation lead to an increased likelihood of energy shortage in a stand-alone microgrid, or increases overall project costs. Actual solar energy productions of two sites in Kerala, India, were compared with solar electricity generation, predicted by the HOMER Pro tool. For both test sites, the results showed that the simulated, solar production was within 8.1% of the actual annual production. However, monthly variations in solar production led to unanticipated energy shortages in the simulated microgrids. These findings reaffirm the inexorable need of the following actions for cost-effective design of microgrids: a) systematic analysis of reliability of electrical supply, and b) deployment of schemes for demand response and flexible load. Statistical analysis of temporal variation of solar irradiance in the United States were used to inform recommendations for stand-alone microgrid design.