Initial operating experience of the 12-MW La Ola photovoltaic system.

The 1.2-MW La Ola photovoltaic (PV) power plant in Lanai, Hawaii, has been in operation since December 2009. The host system is a small island microgrid with peak load of 5 MW. Simulations conducted as part of the interconnection study concluded that unmitigated PV output ramps had the potential to negatively affect system frequency. Based on that study, the PV system was initially allowed to operate with output power limited to 50% of nameplate to reduce the potential for frequency instability due to PV variability. Based on the analysis of historical voltage, frequency, and power output data at 50% output level, the PV system has not significantly affected grid performance. However, it should be noted that the impact of PV variability on active and reactive power output of the nearby diesel generators was not evaluated. In summer 2011, an energy storage system was installed to counteract high ramp rates and allow the PV system to operate at rated output. The energy storage system was not fully operational at the time this report was written; therefore, analysis results do not address system performance with the battery system in place

Initial operating experience of the 12-MW La Ola photovoltaic system.

The 1.2-MW La Ola photovoltaic (PV) power plant in Lanai, Hawaii, has been in operation since December 2009. The host system is a small island microgrid with peak load of 5 MW. Simulations conducted as part of the interconnection study concluded that unmitigated PV output ramps had the potential to negatively affect system frequency. Based on that study, the PV system was initially allowed to operate with output power limited to 50% of nameplate to reduce the potential for frequency instability due to PV variability. Based on the analysis of historical voltage, frequency, and power output data at 50% output level, the PV system has not significantly affected grid performance. However, it should be noted that the impact of PV variability on active and reactive power output of the nearby diesel generators was not evaluated. In summer 2011, an energy storage system was installed to counteract high ramp rates and allow the PV system to operate at rated output. The energy storage system was not fully operational at the time this report was written; therefore, analysis results do not address system performance with the battery system in place

Analytical Frameworks and an Integrated Approach for Mini-grid based Electrification

Although rural electrification using mini-grids has attracted recent global attention, the concept has been there for quite some time. Consequently, a number of analytical approaches exist to support the decision-making process. This chapter first provides a review of literature dealing with analytical frameworks for off-grid and mini-grid based electrification projects. The range of analytical options includes simple worksheet-based tools to more sophisticated optimisation tools for technology selection as well as assessments based on multicriteria analysis. This is followed by an evaluation of mini-grid based off-grid electrification projects in India that allows the identification of critical factors for the success of such projects. Finally, the chapter proposes an integrated approach for analysing decentralised mini-grid projects in a holistic manner