The optimum mix of electricity from wind- and solar-sources in conventional power systems: Evaluating the case for New York State

Several countries and states have set targets for substantially increasing renewable energy (RE) contributions in their electricity grids. As the potential for additional hydro-electricity is limited in the US most future RE penetration is envisioned to be in the form of wind and solar. Our simulations, based on hourly resource and load data, demonstrate the maximum penetration achievable in the grid managed by the New York Independent System Operator (NYISO), by wind- and solar-power independently, and when they are combined. By optimizing the synergy between these two intermittent resources, a maximum penetration of renewable-energy in the grid can be accomplished; this is shown for different scenarios of grid flexibility. For example, for an 80% flexible grid, a total penetration of 30% of wind and solar energy can be achieved in the NY state without adding storage and without having to dump more than 3% energy, whereas if this was to be met by wind alone, 12% of energy would have to be dumped. Considering that several US states and countries have high targets for renewable energy penetration, optimizing the mixture of RE to accomplish such goals is valuable for energy managing and planning.