Earth2Tech. The source of that post was the recent Wall Street Journal’s Eco:nomics conference where Bill Gates commented on a company that he was involved with that was doing “gravel on ski lifts.” Also, included was a link to our patent and our operational video. I'd like to comment on a few of the things mentioned, and not-mentioned, in the article.
Reduced Technology Risk for Ease of Market Adoption
Energy Cache's design philosophy, from the company's founding, was that energy markets want minimal technology risk. This has been my experience starting with my early engineering career developing fuel cell technology, to my more recent experience as an investor in solar companies. In both those cases, the technological unknowns were the least appreciated by the established, conservative, market. While Energy Cache has made impressive technological developments, we developed the technology so that we could, as much as possible, co-opt the existing expertise, supplier base, and operational knowledge from existing industries and use them to solve the problems that we wanted to address with energy storage. This is how our small team has been able to design and construct our 50kW installation on impressively efficient schedule and budget.
Ease of Siting
The difficulty, for current technologies, as stated in the article, is siting and permitting times. Pumped hydro needs two large reservoirs; compressed air energy storage (CAES) requires an underground cavern that doesn't leak (the efforts of "above-ground" CAES solutions excepted). At the recent ARPA-E Summit, Secretary Chu stated that "geologic solutions" would be necessary going forwards, regardless of the current siting and permitting difficulties. This is a view echoed by Pike Research. However, one of the pieces of brilliance in Energy Cache's approach comes from the fact that we will likely not experience the same siting and permitting difficulties of pumped-hydro and CAES. This comes, in part, from the flexibility achieved by using a low-cost base unit. A typical pumped hydro facility consists of a single, or very few pumps/generators (PG&E's Helms Pumped Storage facility consists of three 400MW turbines, for a total of 1.2GW). This is the only way to make either the technology, or the economics, work - build at very large scale. In doing so, such installations become very difficult to find appropriate sites for. Energy Cache's system deploys many units and can be far more flexible in terms of economic operating size. Therefore, we have already found a tremendous number of sites suitable for our more flexible technology that would be inappropriate for CAES or pumped hydro. In addition, we have several other benefits, which I won't discuss here, that we expect to greatly reduce the permitting difficulties that have previously been mentioned.
The article says that "Terrestrial storage isn’t cheap." This is true in absolute terms, due to the size of these projects (as mentioned above). However, on a kW or kWh basis, pumped hydro storage and CAES are among the cheapest technologies currently known, as listed in EPRI's Energy Storage Report, page 4-22. Pumped-hydro storage is the de facto storage solution that every utility would like to deploy. We believe, and this is backed up by the data, that Energy Cache will have a compellingly competitive cost structure as compared to these technologies. In addition, Energy Cache has solid data that demonstrates that we will be one of the highest revenue earning storage technologies possible. This puts us in a class of our own in terms of potential profitability.
With a substantial number of operating sites identified, extraordinary economics, a rapid path to market, and the backing of some extraordinary investors and technology visionaries, I'm very proud of what Energy Cache has accomplished in such a short time, and where we'll be headed in the future.