While we’ve long known that wind and solar power hold a lot of potential for our future (and present) energy needs, their widespread adoption by the mainstream depends mainly on future electrochemical storage being more affordable, according to Electrochemical Energy Storage for Green Grid in March 4th’s Chemical Reviews. This report, based on research at the Department of Energy’s Pacific Northwest National Laboratory, suggests that electrochemical energy storage (EES) systems must evolve vastly to viably compete with other energy sources, such as natural gas and other fossil fuel production. In addition to being more technically advanced, these battery systems will need some hefty lifespan improvement to safely operate for more than 15 years with little to no maintenance.
Advanced EES batteries will allow us to diverge from our current methods of utilizing renewable energy — such as solar and wind power — with non-portable and ultimately inefficient “flywheels and pumped hydro and compressed air systems,” says the report. While escaping from the need to use the energy as it’s produced, the envisioned EES batteries of the future will be able to store this energy for later use — like modern household batteries made large.
The four electrochemical energy storage system candidates that researchers designate as holding the most hope for the future’s renewable energy storage needs are:
- Vanadium redox flow battery: Rechargeable, the vanadium redox flow battery keeps its energy in two tanks of electrolytes. It is most promising as backup energy storage “for durations of up to 12 hours,” integrating wind and solar power in residential areas and industrial parks. As energy is required, electrolytes from one tank are pumped into the other, and the chemical energy is converted into electrical energy. As energy needs to be stored, this process is switched to reverse. The vanadium redox flow battery has potential if it can be manufactured in a greater variety of sizes, is more portable, and — most important — more affordable than our current models.
- Sodium-beta alumina membrane battery: Typically tubular (like, totally!), the sodium-beta alumina membrane battery reversibly charges and discharges electrical energy using sulfur, sodium, and aluminum oxide. Researchers say this is the best candidate for use in vehicles hoping to harness the power of renewable energy and other applications requiring short bursts of energy as its energy density is quite potent — lots of power in a small package. Alas, the elements required for this kind of electrochemical energy storage system are costly, and its operating temperature can run dangerously high. Bringing down its price tag and its heat are problems that scientists are tackling today.
- Lithium-ion battery: Could Li-ion batteries put a ti-iger in our collective tank? Storing energy in layers of lithium, manganese, and cobalt, this familiar battery is used in many household electronics and newer electric vehicles. But, like the sodium-beta alumina membrane battery, the greatest challenges faced with improving this technology for storing renewable energy involve bringing down material cost, making it safer, and extending its lifespan.
- Lead-carbon battery: Evolving from the lead-acid batteries that our cars have used for years, the lead-carbon battery adds carbon to the mix — which greatly increases its lifespan by reducing its corrosive properties. This is probably the most tried and true of the four electrochemical energy storage options discussed, but “the capital cost of the technology remains at $500 per-kilowatt hour and they believe it needs to be reduced to between $150-$200 per-kilowatt hour to be viable,” according to the report.
As disheartening as this may seem to those of us who would love to be taking advantage of the endless bounty of renewable energy today, I see this as a hopeful beacon that we’re almost there. The technology, as it tends to do, will get cheaper — it’s just a matter of time. I’m just crossing my fingers that we won’t run out of options before we arrive.