A question of cost
Whether such systems will really enable renewables to go head-to-head with conventional energy sources, such as coal and nuclear power, is going to depend on cost and societal factors.
While Liquid Metal Battery Corp. is reportedly targeting the $100/kWh figure, all battery manufacturers are said to have a long way to go, according to experts. Another recent study by Lux Research, "Grid Storage Battery Cost Breakdown: Exploring Paths to Accelerate Adoption," predicted that lithium-ion batteries will reach $506/kWh, and vanadium redox flow batteries will hit $783/kWh by 2022. Predictions of even $250/kWh are still considered far-reaching, according to the study.
Still, some countries are moving away from traditional energy sources, especially in light of the 2011 problems at Japan's Fukushima nuclear plant. What's more, some island communities are paying exorbitant rates for their power. "If you go to the islands of Indonesia, Mediterranean, Caribbean, or even Hawaii, they are often paying 30 cents, 50 cents, and even a dollar per kilowatt-hour for their power," Hennessy said. "Clearly, that's an issue, which is why the storage market is growing astronomically in those places."
Even for non-island communities, however, storage could be critical when renewable penetration grows. Hennessy and others have said that the intermittent nature of wind and solar will create problems if renewables compose more than 20 percent of the overall power. In some locales, rising use of renewables is already causing problems, Hennessy said. "There's been a huge increase in renewable penetration in Germany, Italy and other areas of Europe," he said. "And, as we predicted five years ago, it's already becoming unstable."
That's why battery makers are confident that grid storage systems are on the cusp of taking off. They believe storage will see use in applications ranging from utilities down to single-family homes, and everything in between, especially if governments continue to push alternative forms of energy.
"People love renewables," said Donald Sadoway, LMBC founder and the John F. Elliott professor of materials chemistry at MIT. "They love solar. They love wind. But both of those technologies are intermittent. And we don't need intermittent boosting of the grid; we need reliable power."