Balancing inflow/outflow in the new electricity grid

I've been reading lately about the rise of new green electricity generation techniques such as wind, solar, geothermal, etc. It's extremely exciting to see that many of these generation methodologies are already far ahead of expectations with regard to the amount of electricity being produced (especially wind power).

Interestingly, the more difficult challenge is now shifting to how best to integrate these higher levels of inputs into the electricity grid. Today's grids have evolved as sort of a "zero-sum" model in which inflows and outflows are kept in constant balance. Through complex routing and load-balancing mechanisms the grid distributes all of the available electricity to match various demand levels throughout the system.

This has worked in the past because most of the input levels could be controlled - such as hydroelectric, coal-fired, nuclear, etc. When less energy was required, the input levels were lowered. In contrast, wind power is less controllable. In effect, "when wind blows energy flows". As long as wind power represented a relatively small part of the overall mix, this could be addressed by reducing other inputs when high winds were producing more electricity (such as reducing the energy flow from dams). Now that wind is representing a high percentage of electricity generation, maintaining a balance in the grid is becoming more problematic. Either the grid becomes overloaded or precious energy goes to waste.

A major part of the answer to this challenge will require significant advances in the ability to store energy within the grid - something that has never really been addressed before. Batteries? Giant capacitors? Or maybe using the energy peaks to pump water to higher ground so that it can subsequently drive hydroelectric turbines?

This is definitely going to be an exciting segment to watch over the next years - especially as the federal government pumps billions into "the new electrical grid". Companies that provide real solutions to the electricity storage challenge will stand to make a lot of money. (Personally, I'm anxious to tell their stories!)
Watch this space for new developments.