Innovation in energy technology is taking place rapidly. Five technologies you may not have heard of could be ready to change the energy landscape by 2020.

[Here are two.]

Recent breakthroughs in natural-gas extraction highlight the speed with which game-changing technologies can transform the natural-resource landscape. Just over the horizon are others—such as electric vehicles, advanced internal-combustion engines, solar photovoltaics, and LED lighting—that are benefiting from the convergence of software, consumer electronics, and traditional industrial processes. Each has the potential to grow by a factor of ten in the next decade.

Placing rapidly evolving technologies such as these on a resource cost curve, however, is difficult: their impact could be very big or very small. And that’s even more the case for technologies that require significant scientific and engineering innovations to reach commercial scale at viable cost. This article describes five technologies that could start arriving in earnest by 2020 or so: grid-scale storage, digital-power conversion, compressor-less air conditioning and electrochromic windows, clean coal, and electrofuels and new biofuels.

Not all of these will succeed in the market; they will earn a place only if they can outperform the rising bar defined by other rapidly advancing technologies. But even if only some of them pan out, those could transform the energy landscape. It’s possible, in fact, that the development of energy technologies is approaching a tipping point that will generate increases in energy productivity on a scale not seen since the Industrial Revolution.

Grid-scale storage. The large-scale storage of electricity within electric power grids allows power generated overnight to meet peak load during the day. Today, this kind of grid storage costs about $600 to $1,000 per kilowatt hour (kWh) and can be used only when the local geology supports pumped-hydro or compressed-air storage systems. Innovations using flow batteries, liquid-metal batteries, flywheels, and ultracapacitors could reduce costs to $150 to $200 per kWh by 2020 and make it possible to provide grid storage in every major metropolitan market. At these prices, by 2020 the United States alone would want to build more than 100 gigawatts (GW) of storage (the capacity equivalent of the current US nuclear-generation fleet).

That much storage capacity would be transformative: currently, our power grid tends to use only 20 to 30 percent of its capacity because we build it to meet very high demand peaks. With storage, we can flatten out those peaks, reducing capital requirements for transmission and distribution and making power much cheaper to deliver. Power companies also could use storage to smooth variability in the supply of weather-dependent renewables, such as solar and wind power, thereby converting them from intermittent power sources into much more reliable ones.

Digital-power conversion. Large-scale high-voltage transformers, developed in the late 1880s, set the stage for the widespread development of the electrical grid. Virtually the same technology is still in use today. A typical transformer costs $20,000, weighs 10,000 pounds, and takes up 250 cubic feet. High-speed digital switches made of silicon carbide and gallium nitride have been developed for high-frequency power management for everything from military jets to high-speed rail. They use 90 percent less energy, take up only about 1 percent as much space, and are more reliable and flexible than existing transformers. Today’s advanced applications include consumer electronics and variable-speed industrial drives for manufacturing. As such applications expand and the major semiconductor manufacturers begin to produce these technologies at scale, they could replace conventional transformers in the utility industry (at less than one-tenth the cost) by 2020. China is particularly well positioned to benefit from adopting digital-power electronics because of the scale of its planned grid expansion.