Seems like a bit more compatible than once thought. At least for the western power grid.
From the link:
More than a third of the electricity in the western United States could come from wind and solar power without installing significant amounts of backup power. And most of this expansion of renewable energy could be done without installing new interstate transmission lines, according to a new study from the National Renewable Energy Laboratory (NREL) in Golden, CO. But the study says increasing the amount of renewables on the grid will require smart planning and cooperation between utilities.
The NREL findings provide a strong counterargument to the idea that the existing power grid is insufficient to handle increasing amounts of renewable power. As California and other states require utilities to use renewable sources for significant fractions of their electricity, some experts have warned that measures to account for the variability of wind and solar power could be costly. At the extreme, they speculated, every megawatt of wind installed could require a megawatt of readily available conventional power in case the wind stopped blowing. But the NREL findings, like other recent studies, suggest that the costs could be minimal, especially in the West.
“The studies are showing the costs are a lot lower than what people thought they were going to be,” says Daniel Brooks, project manager for power delivery and utilization at the Electric Power Research Institute. Even if wind farms had to pay for the necessary grid upgrades and backup power themselves, they could still sell electricity at competitive rates, he says.