World Economic Forum (WEF) asked a group of international technology experts to identify this year’s Top 10 Emerging Technologies. After soliciting nominations from additional experts around the globe, the group evaluated dozens of proposals according to a number of criteria. Do the suggested technologies have the potential to provide major benefits to societies and economies? Could they alter established ways of doing things? Are they likely to make significant inroads in the next several years? “Technologies that are emerging today will soon be shaping the world tomorrow and well into the future – with impacts to economies and to society at large”, said Mariette DiChristina, Editor-in-Chief of Scientific American, and chair of the Emerging Technologies Steering Committee. In our constant lookout for the origins of innovation, IO will present WEF’s top-10 emerging technologies in a 10-part series. Today: Storage of Renewable Energy.
If one types the word ‘battery’ into IO’s internal search field, the abundance of articles is overwhelming. It’s proof of the importance of, and of the ongoing quest for solutions in the field of energy storage. No less than 150 articles on every possible shape and sort of battery. We wrote about hydrogen bromine flow batteries, about lithium-ion, about dry-film batteries, about methanol batteries, we even looked at a new class of electrolytes that enables a solid-state battery with a crystal structure that leads to geometric frustration for ions. No wonder that WEF’s Steering Committee chose the battery as its tenth and final emerging technology.
Energy in the back pocket
The way the world gets its electricity is undergoing a rapid transition, driven by both the increased urgency of decarbonizing energy systems and the plummeting costs of wind and solar technology. In the past decade, electricity generated by renewables in the US has doubled, primarily from wind and solar installations, according to the Energy Information Administration (EIA). In January 2019, the EIA forecast that wind, solar and other non-hydroelectric renewables would be the fastest-growing slice of the electricity portfolio for the next two years. But the intermittent nature of those sources means that electric utilities need a way to keep energy in their back pocket when the sun is not shining and the winds are calm. That need is increasing interest in energy-storage technology – in particular, lithium-ion batteries, which are finally poised to be more than just a bit player in the grid.
Lithium-ion batteries will likely be the dominant technology for the next five to 10 years, according to experts, and continuing improvements will result in batteries that can store four to eight hours of energy – long enough, for example, to shift solar-generated power to the evening peak in demand.
Getting to the point where renewables and energy storage can handle the baseline load of electricity generation, however, will take energy storage at longer timescales, which will mean moving beyond lithium-ion batteries. Potential candidates range from other high-tech options, such as flow batteries – which pump liquid electrolytes – and hydrogen fuel cells, to simpler concepts, such as pumped-storage hydropower and what is called gravity storage. Pumped-storage hydropower is cheap once it is installed, but it is expensive to build and can be used only in certain terrain. Equally simple is the concept of gravity storage, which purports to use spare electricity to raise a heavy block that can later be lowered to drive a turbine to generate electricity. Although a few companies are working on demonstrations and have attracted investments, the idea has yet to take off.
Other options are still under development to make them sufficiently reliable, efficient and cost-competitive with lithium-ion batteries. There were only three large-scale flow-battery storage systems deployed in the US by the end of 2017, according to the EIA, and utility-scale hydrogen systems remain in demonstration stages. The US government is funding some work in this arena, particularly through the Advanced Research Projects Agency-Energy (ARPA-E), but much of the investment in those technologies – and in energy storage in general – is happening in China and the Republic of Korea, which have also ramped up storage research.
It is uncertain whether and how much the costs of energy storage will continue to decline. Yet the accumulating pledges by governments to achieve carbon-free electricity production will provide a continued push to bring more and more storage online.
(Most of this article is drawn from the 2019 Top 10 Emerging Technologies report)