Requiem for LightSail Energy

Image Credit: LightSail Energy

I've published multiple posts concerning LightSail Energy and its Chief Science Officer, Danielle Fong. I was enthusiastic about the the Lightsail Energy compressed air energy storage technology concept, wherein a water mist was to have been used during compression in order to produce a quasi isothermal compression process and consequently reducing thermal losses. And I wasn't alone in my enthusiasm, such notables as Vinod Khosla, Bill Gates, Peter Thiel, Total, and others invested somewhere in the vicinity of $80MM in LightSail.

But, despite the confidence of these very bright investors and the large amount of capital invested, LightSail Energy is, according to co-founder Stephen Crane, in a state of "hibernation." I follow Ms Fong on Twitter and, off and on, have corresponded with her. I haven't read anything from her with respect to the fate and apparent demise of LightSail, but the tenor of her Tweets is that she's moved on.

This saddens me because, the potential of near-term success of hydrogen fusion as an energy source notwithstanding, I am firmly convinced of the urgency of weaning ourselves from near-total reliance on fossil fuels for energy and saving those resources for applications for which substitution is extremely difficult such as transportation fuels (airlines, transoceanic shipping for example). Electricity is the low-hanging fruit here, albeit a pretty high low-hanging fruit! We have wind, solar, hydro, geothermal, and other ways to harvest energy that don't directly involve the burning of fossil fuels and all of them result in the generation of electricity.

But the most bountiful categories are solar and wind (hydro, while certainly a large contributor, has mostly been "built out," i.e., the best sources have already been exploited) and those are intermittent sources. In order for them to provide so-called "base load" power, a method of eliminating this intermittency must be employed. This can be accomplished in part by wide geographic dispersion, but the holy grail would be the ability to store energy when the wind blows and the sun shines.

Currently, nearly all new storage installations involve large lithium ion battery installations. But Li ion batteries, while good and continuing to improve, have downsides. They degrade over time, they require assiduous management both to preserve lifespan and to prevent issues of thermal runaway. And, in comparison to large scale pumped hydro storage (PHS) and compressed air energy storage (CAES), the energy capacity of Li ion battery installations is not as large (see chart below, note the log-log scale).

Image credit: unknown

Image credit: LightSail Energy

In the chart, you'll find the "Large CAES" installations in the upper right hand corner. However, the two installations plotted use underground caverns as their containment vessel and need natural gas heating in order to function. LightSail was developing modular units of much smaller size using above-ground storage in tanks. And, in what now seems to have been a last-ditch effort to continue, LightSail began an attempt to market the tanks they'd developed and, apparently, delivered at least one.

Unfortunately, the LightSail web site is gone and with it, I'm afraid, is the investors' money and the hopes and dreams of Danielle Fong.