Next generation energy storage technologies key criterion for the grid
Renewable energy still only provides less than 5% of global electricity demand, despite double-digit increases in capacity. Although technology has boosted the efficiency of solar and wind farms, they are hampered by lack of a reliable means for storing the excess energy produced when conditions are good. High-capacity batteries, based on sodium, aluminium or zinc have been shown to be capable of serving factories, towns, or isolated rural communities. They are more cost-effective and safer than lithium batteries and better suited to support solar and wind transmissions systems. Battery improvements are crucial to the task of removing most carbon emissions from power generation in the coming decades, while at the same meeting the increased demand for electricity.

Editor's Note: This article is part of a special report on the Top 10 Emerging Technologies of 2016 produced by the World Economic Forum. The list, compiled by the Forum’s Meta-Council on Emerging Technologies, highlights technological advances its members, including Scientific American Editor in Chief Mariette DiChristina, believe have the power to improve lives, transform industries and safeguard the planet. It also provides an opportunity to debate any human, societal, economic or environmental risks and concerns that the technologies may pose prior to widespread adoption.

Solar and wind power capacity have been growing at double-digit rates, but the sun sets and the wind can be capricious. Although every year wind farms get larger and solar cells get more efficient, thanks to advances in materials such as perovskites, these renewable sources of energy still satisfy less than 5 percent of global electricity demand. In many places, renewables are relegated to niche roles because of the lack of an affordable, reliable technology to store the excess energy that they make when conditions are ideal and to release the power onto the grid as demand picks up. Better batteries could solve this problem, enabling emissions-free renewables to grow even faster—and making it easier to bring reliable electricity to the 1.2 billion people who currently live without it.

Within the past few years, new kinds of batteries have been demonstrated that deliver high enough capacity to serve whole factories, towns or even “mini-grids” connecting isolated rural communities. These batteries are based on sodium, aluminium or zinc. They avoid the heavy metals and caustic chemicals used in older lead-acid batteries, and they are more affordable, more scalable and safer than the lithium batteries currently used in advanced electronics and electric cars. The newer technology is much better suited to support transmission systems that rely heavily on solar or wind power.

Last October, for example, Fluidic Energy announced an agreement with the government of Indonesia to deploy 35 megawatts of solar panel capacity to 500 remote villages, electrifying the homes of 1.7 million people. The system will use Fluidic’s zinc-air batteries to store up to 250 megawatt-hours of energy in order to provide reliable electricity regardless of the weather. In April, the company inked a similar deal with the government of Madagascar to put 100 remote villages there on a solar-powered mini-grid backed by zinc-air batteries.

For people who currently have no access to the grid—no light to work by at night, no Internet to mine for information, no power to do the washing or to irrigate the crops—the combination of renewable generation and grid-scale batteries is utterly transformative, a potent antidote for poverty. But better batteries also hold enormous promise for the rich world as it struggles to meet the formidable challenge of removing most carbon emissions from electricity generation within the next few decades—and doing so at the same time that demand for electricity is growing.

The ideal battery is not yet in hand. The new technologies have plenty of room for further improvement. But until recently, advances in grid-scale batteries had been few and far between. So it is heartening to see the pace of progress quickening.