by Julian Spector
March 14, 2019

Editor's note: This column serves as a companion to the earlier roundup of extant flow battery vendors. To complete the picture, we're turning this week to the non-flow technologies staking a claim on the grid storage market.

Lithium-ion owns the grid storage market now, but that might not always be the case.

The most numerous type of challenger to the mass-produced battery technology is the flow battery, which we profiled in January. But they're not the only ones taking on the quixotic quest to beat the most widely available, cost-effective product on the market.

This week, we'll check in on the rest of the challengers, which we might categorize as exotic or unconventional technologies, because they take such varied approaches to the task of storing electricity for long periods of time. This cohort includes gravity-based, compressed air, super-cooled gas and zinc-air storage.

Crucially, they all have avoided bankruptcy, as peers like Aquion, LightSail and Alevo fell by the wayside.