Tuesday, November 6, 2012

Is battery storage the right solution for the intermittency of solar and wind?

Solar and wind technologies have experienced significant advancements in the last decades or so which as resulted in lower prices and improved efficiency of these technologies. However, the question of intermittency is still something for which solar and wind energy industry haven't found the right answer for.

Solar and wind are intermittent energy sources. What this means is that solar panels and wind turbines are not able to generate power all day long but only in certain periods of day. As a result of intermittency their power output can diminish fairly quickly in periods when the wind no longer blows or the sun hides behind the clouds.

In order to provide reliability to these two renewable energy sources the researchers are searching for adequate energy storage solutions, in form of other backup power sources, such as for instance battery storage.

The intermittency of solar and wind isn't a big deal yet because these two renewable energy sources still account for very small percent of total generated power. In U.S. for instance solar currently produces only around one percent of the total power, while wind power currently accounts for only around 2.3% of U.S. total electricity generation. 

However, many energy analysts have predicted a massive growth in solar and wind power capacity which means that there isn't too much time to solve intermittency issue. The countries that plan to significantly expand their renewable energy production by using more solar and wind should therefore be already thinking about what may be the most adequate energy storage solution.

Lithium ion battery storage is for many energy experts a very interesting renewable energy solution to solve the intermittency of wind and solar. Two largest lithium ion battery storage facilities are in West Virginia and China.

Lithium ion batteries are not the only types of batteries used for energy storage. Japan, for instance, is the home to the largest battery farm in the world which uses sodium-sulfur batteries and provides 238 megawatt-hours. The other example includes Alaskan battery farm where they use a nickel-cadmium batteries that provide 46 megawatts in five minutes.

The further technological improvements will no doubt result in the development of other types of batteries that will be significantly more powerful then the ones used today. The battery manufacturing market is constantly growing offering very interesting options for future renewable energy use.

In this sense, battery storage may eventually prove to be the solution to solve the intermittency of solar and wind, but only after the development of cost-effective technologies.