We consider the problem of reliably operating a microgrid with solar generation and pumped hydroelectric storage. We show that reliable operation is possible if storage equipment is sufficiently flexible and storage control is sufficiently robust to solar variability. Pumped storage flexibility can be achieved through a ternary configuration; this enables rapid switching between pumping and generating modes. Controller robustness can be achieved through a novel control synthesis method based on convex optimization and resampled historical solar data. The proposed equipment and controller perform well in simulations including twenty months of real solar data at five minute resolution. These results highlight the potential of pumped storage to enable reliable integration of wind and solar power into the grid.
