07-05_editorial.html (Apr-2007)

	Vol. 228 No. 5
PERRY A. FISCHER, EDITOR

Constructive destructive technology. I thought adding “constructive” to the title might be a little more positive. But some technologies really can be game-changers, which is why it’s odd that some of them are so poorly known.

This month's column could be called Electricity Storage Part 2, having discussed the topic in some detail last November. Pumped water impoundment is still king in this category, with over 300 installations worldwide, and more than 40 that are in the 1000-MW range�which is equal to a good-sized nuclear power plant. They are reasonably efficient�about 70 to 80% in recapturing the electricity stored in them. However, they are fairly expensive to build, requiring large, lined tunnels and two huge reservoirs: one high and one low. But you can’t always pump water uphill if there’s no hill, or no water.

In cases where pumped water impoundment is impractical, another little game-changer is gaining ground. If it becomes commonplace, it could have far-reaching implications for better use of existing power generating capacity, as well as enabling renewable energy such as wind and solar. It’s a kind of a battery/fuel cell combination known as a “flow battery.” If you’re not technically minded, skip the next two paragraphs, else, here’s how it works:

At its heart is a proton exchange membrane, called PEM, which is common to most fuel cells. The PEM separates two chemicals, one donates electrons, the other accepts them, in what is known as a simple redox reaction. The two chemicals are stored in large containers and are pumped across either side of the PEM, creating current flow into, or out of, the liquids.

The quantity of chemical relates to how long electricity can be stored, which can be as much as six to eight hours, perhaps longer. Electricity is stored, among other reasons, to maintain a constant supply, which is ideal for intermittent and variable generation, such as wind, or to augment a rate or even provide a burst of power when production rates begin to fall below peak demand.

There are at least three firms that are in the early stages of commercializing the technology. Issues that differentiate the various technologies include environmental impact/safety of the chemicals used, number of charge/discharge cycles, depth of cycle, life of the PEM membrane, contamination of the chemicals across the PEM, efficiency of the storage process and, of course, cost.

Japan’s Sumitomo Electric has been working on vanadium-based flow batteries for 20 years�it has the most experience and the largest installed base. The company installed a 1,500-kW, 1-hour flow battery for voltage and load leveling. It also has a 6-MW, 1.5-hour flow battery for a wind farm, and five other installations.

One of the first large-scale tests of the technology was supposed to occur in the US, when the Tennessee Valley Authority (TVA) wanted to install a wind farm near Columbus in northeast Mississippi. A flow battery installation was a key element to smooth the intermittent nature of wind supply. The $25-million, 12-MW project was well along in 2003. Then, a couple of events stopped the project. NIMBY-ism took hold, when neighboring landowners discovered that the flow battery would use polysulfide/ sodium bromide, or PBR (brand named, Regenesys). These particular chemicals are inherently toxic and, if some mechanism caused them to be released in a vapor cloud, could conceivably kill folks.

The British firm Innogy Technology Ventures was building the flow battery at the TVA site and another one in the UK at Little Barford. The giant German utility company, RWE, which had recently purchased Innogy, unexpectedly pulled its support for the projects. RWE paid the TVA $15 million for the right to back out of the Tennessee project at such a late date.

Subsequently, RWE made an exclusive licensing deal with Canadian firm Vanadium Redox Batteries (VRB), which has future plans for the PRB-based flow batteries. Meanwhile, VRB is proffering its own system that, according to spokesman Simon Clark, is superior in terms of less toxicity, cycle tolerance and several other characteristics.

In the US near Moab, Utah, a flow battery built by VRB was recently installed instead of a substation. Power to a small town was inadequate for peak demand, so a flow battery bank was installed to store electricity during low-demand periods, and supply it at high demand. VRB says the installation was very cost-effective.

Another flow-battery project looks like it will proceed. VRB should have contracts finalized in the next two months to build a flow-battery bank for a 6-MW wind-farm addition in Ireland. A technical study, paid for by Sustainable Energy Ireland, found that a small wind farm could see a 17.5% rate of return by using the flow batteries, which is dramatically more than the 10% return at most Irish installations.

Plurium is a new company that was started in 2002 (as PSI) to commercialize a zinc/cerium flow battery. These chemicals are fairly benign, and the company claims the process is the most efficient flow battery available�except it’s not quite available, yet. The company has connections to Canada, the US (Nevada) and, in 2005, the company and ITI Energy�a Scottish Enterprise (read, government sponsored) company, formed a joint venture called Plurion Ltd. ITI has pledged $18 million in investment.

As flow-battery technology becomes perfected�it can already be called “proven,” even though it’s in a fledgling state�it could reduce the number of power plants needed, since a great deal of excess capacity is built to handle peak demand, and then idled at night or when demand is low�not a very efficient use of capital or resources. Moreover, the technology can enable wind power to function in a more constant manner, increasing the attractiveness of wind and further reducing conventional power plant baseload.

Given the payback in investment, you’d think that governments�certainly the US�would be laying out the cash. A mere $10 billion or so ought to do it. But to get that kind of money, you need a lobbying group to extol the virtues of 1960s nuclear power or starch-based ethanol or some other very mature technology.

So, these mostly maverick companies will struggle to raise money through stock offerings, venture capitalists and, if they’re really lucky, a few crumbs here and there if some legislature sees fit. It’s a shame, since this is one game-changing technology that could really benefit the world from a large government-investment “shot in the arm.”