Given today’s power-hungry residential and commercial interests, switching back to 100% renewable energy would be a huge step backward.
True, we have renewable energy systems, including photovoltaic solar panels, concentrating solar power plants, wind turbines, hydroelectric turbines, just to mention a few, but they do suffer an important deficiency: intermittency. The problem is not the devices themselves, but the sources they draw their energy from.
Renewable energy sources, such as solar and wind are especially vulnerable to environmental changes, as a passing cloud may momentarily reduce power output of a solar panel, or wind may not be blowing consistently. Experts agree that, for now, a mix of nonrenewable and renewable energy is the only way to assure a consistent energy supply.
In order to solve the renewable energy intermittency problem, pumped storage plants can store energy, but can only release it slowly over a long period of time, perhaps a few hours. Battery backup can release power faster, but to increase capacity is insanely expensive. A recent interview with Maxwell Technologies systems engineer Shaw Lynds shed some light on a new supercapacitor project that is aimed at short-term intermittency problems.
Last week, Maxwell was awarded a $1.39 million contract to develop an ultracapacitor-based energy storage system for Soitec’s concentrated photovoltaic [CPV] system installed at University of California – San Diego. A commercial-scale system is to be developed for Soitec’s solar power plant in Southern California by 2015.
Lynds agrees that it would be prohibitively expensive to develop supercapacitor energy storage for anything longer than a few minutes right now, saying it would be “five to ten years, at minimum, before it is economically viable to store energy on these kind of time scales. This is why we are focusing on shorter time scale firming where we believe energy storage can do the most good in the near term.”