Renewable energy such as solar is a great source of power in the morning and mid afternoon, but drops in power output in the late afternoon into the evening. Currently utility companies have to compensate by firing up coal and natural gas production. The answer to clean grid energy storage may just lie in an older battery technology.
Flow batteries have been operating consistently for decades, but have struggled to gain a broad foothold in commercial and municipal operations due in part to their enormous size, high operating costs and comparably low voltage. Researchers at the University of Colorado Boulder have developed a low-cost high-performance battery by re-examining flow battery chemistry.
The researchers found that by combining organic binding agents with chromium ions in order to stabilize a potent electrolyte was the key. This binding agent known as “PDTA” allows the battery cells to supply 2.13 volts, which is almost double the operational average for a traditional flow battery.
PDTA is a spinoff of EDTA, an agent that is found in hand soap and food preservatives, which makes it non-toxic, easy to get, and affordable. It also has a relatively neutral pH of 9, unlike other battery types which use highly corrosive acids.
The next step for the researchers is to continue optimizing their system, to expand the cycle life of the battery.