Impact of operating uncertainty on the performance of distributed, hybrid, renewable power plants

•Operating uncertainty is crucial in distributed, hybrid power plants.•Deterministic modeling is unable to accommodate operating uncertainty.•Stochastic generation expansion is solved to accommodate operating uncertainty.•Hybrids with dispatchable generation are a reliable source to address uncertainty. This paper studies the performance of distributed, on-grid and off-grid, hybrid renewable power plants with short time scale operating uncertainty in solar irradiation and consumer demand. For the same, a multi-stage model using the Stochastic Dual Dynamic Programming algorithm with generation expansion is developed. The impact of operating uncertainty is quantified using this approach in two ways. First, operating and total costs for stochastically optimised hybrid plants are compared with equivalent, deterministically optimised hybrid plants. When accounted for in the generation expansion problem, operating uncertainty results in larger plant capacities in order to guarantee energy delivery and thus higher total costs. The value of having a dispatchable generator as part of the hybrid plant is then examined. This shows that hybrids that feature dispatchable generation have lower operating and total costs because the dispatchable generator can be relied upon to satisfy demand when either the intermittent generator or the energy storage is unable to do so. This highlights the robustness of hybrids that feature dispatchable generators and not just intermittent renewable plant and energy storage.