Rethinking Energy Storage for a Green Future
2/23/2011 12:31 AM EST
Energy production and storage are in the midst of some major paradigm shifts as businesses and governments focus more intently on matters of sustainability and environmental impact. In the past decade, the way these sectors look at energy has shifted dramatically. While it took many of those years for the energy vision to evolve, electrical engineers also spent that time working on storage solutions that could accommodate a greener future.
The source of all energy on earth is the sun, of course, which relies on photovoltaic converters and wind generation to capture and store electricity. Today, the main source of stored energy is fossil fuel, including crude oil, natural gas and coal. To a lesser extent, nuclear fuels are also used in the production of electrical energy. Both sources of fuel have fallen into disfavor, though, as the question of clean and available energy becomes more pressing.
The market is shifting toward renewable sources of energy such as wind and solar, which presents a new set of technical problems to engineers. The most desirable situation for a commercial producer of electrical energy is to supply energy at a constant rate. However, reality requires utilities to respond to rapid changes in demand, and thus, to have a reserve on hand to meet increases in demand.
There are lots of potential solutions for this problem: spinning reserve, pumped-hydro, flywheels and high-pressure air. However, all of these have significant drawbacks: they are not portable, they require expensive infrastructure and added transmission, and they are inefficient for addressing short-term sags. The more realistic way to address the short-term sag problem is with batteries, ultracapacitors or a combination of the two.
If the vision for renewable energy is to be realized, we’ll need both long and short-term storage methods. As the electrical infrastructure evolves, the market will be forced to increase its arsenal of storage devices to include an intermediate solution that can function in both arenas and make the production of local electrical energy more practical.
As we move toward a green energy future, local production that uses renewable sources will go a long way to relieve stress on the grid infrastructure. In order to make this a reality, we will need to develop energy storage media that will likely include improved batteries and high-energy density ultracapacitors, both necessities in a world that continues to consume energy at an exponential rate.
(Brendan Andrews is the vice president of sales and marketing at Ioxus, Inc. He is responsible for the leadership and coordination of Ioxus’ sales and marketing functions and for educating the global market regarding existing and future ultracapacitor technologies).