By Caleb O’Brien
CHICAGO — Not all electricity is created equal.
As America contemplates its energy future, the way we generate and distribute electricity will have important consequences for the environment and the resilience of our energy systems.
At an American Association for the Advancement of Science symposium on February 14, scientists spoke about the challenges of incorporating renewable energy into existing systems and ways to ease the transition.
For decades, according to Peter Karnoe of the Aalborg University in Denmark, we’ve been operating on a model where all power generators play similar roles in the power grid: A coal power plant could be exchanged for a nuclear plant and the power generated would interact with the grid in a similar fashion.
Our electrical grids rely on maintaining a match between energy supply and demand. As electricity use fluctuates, power plants adjust production accordingly. It’s like trying to maintain the level of water in a cup that has a hole in it: add water too slowly and the cup will empty; pour too quickly and the cup will overflow. When generating electricity with wind turbines, however, the supply is at the mercy of the breeze.
Wind—fickle, elusive wind—is less readily bent to match the demands of electricity consumers, Karnoe said. In fact, Danish wind turbines at times generate excess electricity, and those managing the power grid need to dispose of the extra. Heretofore, Denmark has been able to resolve this issue by selling excess electricity to neighboring countries.
On Dec 21, for example, wind power in Denmark generated 105 percent of the country’s electricity needs for that day, Karnoe said. Officials were able to send the excess electricity to neighboring countries. Without such an outlet, the overabundance of electricity could cause trouble for the grid.
Another issue is that when supply outstrips demand, the price decreases. In the case of Denmark, wind-generated power could theoretically drive the price of electricity to zero, Karnoe said. Although this may seem like a dream come true for consumers, such a situation removes the incentive for power companies to stay in business. Without other sources of electricity, consumers could find themselves without power when the wind stops blowing.
Although we’re unlikely to confront too much wind power in the US in the near future, the speakers at Friday’s symposium suggested there are still clear implications for the Midwest: if we seek a future more reliant on renewable resources, changing the source of the electricity alone won’t be enough. We will need to make significant changes to both policy and hardware in order to accommodate the new flavors of power produced by renewables.