349-357In future electrical grids, high levels of Variable Renewable Energy (VRE) penetration including solar photovoltaics
(PV) and wind energy is expected. This poses a challenge in system operation and planning especially in balancing
electricity demand and supply. This paper examines figures of merit for wind and solar integration in electricity grids.
Quantitative tools such as load duration curves, correlation analyses, and the Fourier transform were used to study the
intermittency/variability of wind and solar PV power. Time series data on power production from the European Network of
Transmission System Operators for Electricity (ENTSO-E), and Réseau de Transport d'Électricité (RTE) were used for the
analyses. The analyses illustrate that despite the valuable amount of energy that can be obtained from wind and solar PV,
these energy sources cannot be used as baseload power supply. Solar PV power is available for approximately 50% of the
time year-round. Wind power output on the other hand can reach very small magnitudes of just a few megawatts several
times in a year. More to that, wind is positively correlated over long distances, even exceeding 3000 km and aggregating
wind fleets over a large geographic area might not guarantee continuous availability of wind power. Nonetheless, these
sources can still be integrated in electricity grids in high proportions, provided intermittency mitigation options such as
energy storage, curtailment, and demand-response are implemented