Plug Pulled on Regenesys

Utilipoint’s Issue Alert on Jan 22 did a nice job of reviewing several developments in energy storage (I highly recommend getting on the distribution list for these daily missives):

“Energy Storage Shows Promise”

There are nice plugs for Active Power and Beacon flywheels (though Pentadyne is really the one to watch, I think). Curiously, Beacon is focusing not on very short duration, but instead is going after the lead acid battery applications.

The big news was the stopping of all work on the big TVA Regenesys project, and the curtailment of the work on its sister project at Little Barford in the UK.

The Regenesys flow battery works by storing or releasing electrical energy by means of a reversible electrochemical reaction between two salt solutions—the electrolytes. The electrolytes are pumped through hundreds of individual cells, which are separated by a membrane. The electrolytes are stored in 700,000-gallon tanks; the concentrated solutions are sodium bromide and sodium polysulphide. (Many references are available on the technology.)

The history of the business is a bit complicated. Originally begun under National Power in the UK, the program was placed (in around 1999) into a subsidiary company, by the name of Innogy. Later, National Power was split up into International Power and a domestic utility business. The domestic utility portion took the name Innogy, meaning that the technology subsidiary had to be renamed Innogy Technology Ventures Limited before a further renaming as Regenesys. Recall that Regenesys was being prepared for an IPO, which was suspended when tech stocks dropped in 2001. It was the utility business, Innogy, which was subsequently acquired by the German giant, RWE in 2002. RWE was rounding out its British invasion, having previously bought Thames Water, a major water supply company, and some smaller energy services companies. The technology development subsidiary, Regenesys, was simply an incidental piece that came with the deal.

Note that Regenesys is the only flow battery technology effort that had decided to focus entirely on very large utility scale applications (“pumped hydro in a box”), e.g., at 10-20 MW. Actually, it only really makes sense at this kind of size. (The other flow battery developers have been targetting much smaller projects, in the 1 kW to 1 MW range). Prior to the RWE acquisition, Regenesys had acquired Electrosynthesis, a small electrochemical consulting company in Buffalo NY to boost its resources, and laid plans for a serious assault on the North American market. Meanwhile, work continued on the first commercial 120 Mwh demo at the Little Barford power plant in the UK.

At TVA, the $25 million facility was just about complete, but TVA needed the electrochemical modules, when RWE decided it wasn’t prepared to continue funding development, leaving the program with nowhere to go. TVA made a very quiet announcement in December, but because of other news around the holiday season it wasn’t picked up by the US press til mid January. (See for example,

TVA is exploring ways to move forward, including other possible uses of the site.

The general view is that the technology is viable but RWE estimates the technology has another 5 years of work ahead before it’s truly commercial. Because the Barford project had slipped far behind as well, RWE simply doesn’t want to continue putting cash in that long; there are other business priorities for RWE.

The future is up for grabs. Regenesys may just be put on the shelf, or be sold off. Meanwhile, a major report on flow batteries is in the works by Escovale, in the UK. “Flow Batteries: Technologies, Applications and Markets” is being prepared by a team that includes Anthony Price, who was marketing manager for the Regenesys program prior to becoming an industry consultant. I have more information on this report.

Anthony would be a good starting point to delve into the implications and opportunities represented by this latest development. 011-44-1666-840-041

Other contacts:
Mark Kuntz, Regenesys Ltd, Chicago (thru June) 630-562-1271
Joe Hoagland, TVA, 256-386-2108,

Travel Reports

In September, I attended these three conferences. They were all different, but also had a great deal in common. This writeup attempts to capture major themes and to provide highlights of some of the more interesting developments that came to light. Please don’t hesitate to let me know if you’d like further details on anything discussed below (or anything you see on the agendas that I didn’t mention).

EESAT Electric Energy Storage Applications and Technologies Conf.
Sept 18-20, 2000, Orlando, FL

Distributed Power Strategies and Business Opportunities
Sept 25-27,2000, Washington, DC

Clean Energy Roundtable
Sept 27-29, 2000, Aspen, CO


One major common theme–

“Attack of the Killer Investment B’s”

Many investment banking firms are cranking up bigtime to get a piece of the action in high9s-clean-distributed energy technology. They’re starting to “get it” and don’t want to miss out, though there’s a lot they don’t know about it (and their in-house utility analysts aren’t much help). They’re attending these events in ever increasing force, and also putting on their own!

BofA Securities, CIBC World Markets, Robertson Stephens, First Albany, Deutsche Banc Alex Brown, Morgan Stanley, Goldman Sachs, Lehman … They’re issuing research reports, initiating coverage, and investing in and pushing services to companies in this industry. Not only are they coming to energy conferences, they’re putting on their own, usually invitation-only for clients and other investors.

– Goldman Sachs will be handling Powercell’s (zinc-bromine flow battery) next financing, following a recent $30 Million infusion from a variety of investors.

– Credit Suisse First Boston is acquiring DLJ, which is doing a private placement for ZBB (the other zinc-bromine flow battery).

– Bear Stearns, famous for their very popular 250 page research report, “Distributed Energy Services” back in April, is coming out with one on microturbines in the next couple of weeks, with more to follow.

– Beacon Group, recently acquired by Chase H&Q, has been actively doing energy technology investments alongside their extensive array of more traditional energy sector plays.

– Price Waterhouse Cooper is helping STM (stirling motor) to raise $4M each coming from a coalition of DTE, Delco Remy, Ricardo (engine consultants) and a group from Singapore, to be followed in the near future with a probable private offering.

The main drivers behind all this excitement include deregulation/competition, demand for premium power, environmental concerns (new regs, Kyoto, etc.), and technology advances (renewables, distributed resources, and the internet). Add to that the general supply crunch here and abroad. While there are some aspects of the investment “flavor of the month”, these trends are seen as real, irreversible, and significant.

Traditionally, development stage companies are financed by venture capital or corporate money. Now, however, companies are going public earlier and earlier (“pre-earnings” and even “pre-revenue”). This means that retail investors are engaging in “public venture capital” as it has been called, taking on the higher risk of early stage companies.

Speaking plainly, there’s a bubble in the pre-ipo and public company stocks that is similar to what’s been happening in the dot-com world and elsewhere. The players are piling on, and both good and bad can come of it. While this industry enjoys all the attention and increased capital (and valuations), there will be a continual shaking out, with big winners and losers–as we’ve seen very recently. One just hopes the losers won’t put a drag on the whole sector.


Clean Energy Roundtable

This is one in a series of invitation-only conferences, many in Europe, targeting senior executives. The “Aspen Clean Energy Roundtable” meeting was the 7th annual such event, with many repeat attendees. A number of major energy companies, bankers, and NGO’s were represented, plus a sizable contingent from the DOE National Labs, but just a few utility people. Speakers are strongly discouraged from doing sales pitches, but rather to shed light on big trends and issues.

The biggest trend and issue — a widely held view that is an absolute necessity to come up with a “low/no carbon” energy future, in light of global climate risks and population growth and economic development. Furthermore, hydrogen is the key, as the main energy carrier of the future. There were a few visionaries who began talking about the potential of a “hydrogen economy” in the mid 70’s (during the first oil crisis). Maybe their day is coming.

Another prominent theme was the evolving role of government, from “Nanny” to enabler. Bruce Stram of Enron Energy Services spoke about this historic role of government, intervening heavily to cope with market imperfections, as less necessary as telecommunications and information flow improve. Instead, government should avoid “command and control” and instead punish social externalities with penalties, and support a vigorous R&D program.

Swiss Re reviewed their outlook that global climate issues represent huge risks to the insurance industry, noting losses from hurricanes and other weather-related damages. They’ve been very active promoting Kyoto, emissions trading, and clean development mechanisms.

Shell Hydrogen is a new independent business within the Shell group. CEO Don Huberts explained the parent company’s commitment to sustainable development (disposed of coal assets, and set up Shell Renewables and Shell Hydrogen). He described a 250 kW SOFC installation in Norway integrated with fish farming, use of an SOFC with injection of CO2 into depleted wells and deep aquifers, commercial and residential CHP with SOFC or PEM, and a proprietary natural gas processor to make hydrogen for residential fuel cells.

Valuing Renewables — Shimon Awerbuch of ICF Consulting reviewed his work on using a portfolio approach to valuing renewables. Traditional engineering-based approaches are completely inadequate–they ignore financial risk; they didn’t work in manufacturing (completely missed computers, robotics, and CAD); and they don’t work for high capital, low operating cost projects. Portfolio concepts are routinely applied in securities investment, where adding even a higher cost (lower return) investment to a portfolio can reduce the total risk, for an overall better result. See his articles Public Utilities Fortnightly, Feb 15, 2000, and Energy Policy (to be published)

Other presentations included:

CMS Energy is pursuing environmentally friendly technology solutions, including microturbines for gas field pumping operations, a methanol plant installed in Africa to eliminate a massive gas flare, and their own “virtual power plant” program they’re calling Elan (electric local area network).

Honeywell’s microturbine group sees their devices fitting into a seamless array of energy management systems, controlled over the internet in real time.

Stirling Energy Systems, in Phoenix, is gearing up to develop huge solar power farms using dish concentrators with the Swedish-made Kockums stirling engine.

H-Power is aggressively pursuing rural markets for their existing commercial small scale PEM fuel cell systems.


Electric Energy Storage Applications and Technologies Conf.

The message is similar to the June ESA meeting [See UFTO Note, 25 April, 2000]
–storage is coming into its own, as part of the boom in new energy technology, along with DG, renewables, premium power, etc. The complete proceedings will be published in hardcopy and on a CD, by early December.
Keynoter Bill Parks, the lead for DOE’s new Distributed Power effort, [UFTO Note May 31] noted the convergence of many issues, including growth (economic, population and energy demand), price spikes, high oil imports, power quality needs, air and water quality, and climate change. New companies are entering, and everyone proclaims to be green. On top of that, average energy efficiency in the US hasn’t improved, capacity margins are below 10%, and power infrastructure is aging. DOE’s expanded efforts will go beyond the core technology R&D emphasis, to deal with systems, and to address institutional barriers. For example, the IRS is reviewing depreciation schedules for CHP and DG.
Value of Storage – Tom Jenkin, Brattle Group, described an LP model they’ve developed to analyze in detail the arbitrage possibilities for a storage system. The model calculates the maximum net revenue over a one week period by optimizing the use of a generic storage device, hour by hour. At any given time, the device can do one of four things: charge (i.e. buy energy), sell energy, sell reserve capacity, or do nothing. Using price data for the California ISO, initial results suggest a capital cost of $250-$750/kW can be supported in this kind of application., 617-864-1576.
At EA Technology (UK), they’ve developed a model to calculate net present value cost-benefit of various storage technologies in various applications. Alan Collinson,
Regenesys, the National Power spin off, has announced their first commercial scale project (120 MWH, 15 MW) at a power plant in the UK. This is one of the prominent “flow” battery technologies discussed several times before in UFTO Notes. Notably, they have qualified it to provide blackstart, in addition to energy management, arbitrage, and frequency and voltage regulation. They also have an initial agreement with TVA to the first N American installation.
Tokyo Electric is getting good results with their advanced sealed Sodium-Sulfur battery. A key to safety is an innovative self-shut down mechanism where an inner tube expands if heated (by the reactions that would result from a leak) and blocks the ceramic electrolyte. A 6 MW, 48 MWH system has been operating since mid 1999, for load leveling and ancillary services.
AutoCap reported on the advantages of charging battery cells individually, greatly extending the expected life of batteries in large systems. When an entire string of cells are charged in series, due to variations some cells are overcharged and some undercharged. They’ve developed a system with an isolated charger, and a cell selector device that monitors and charges one cell at a time. This applies only to the maintenance charging, not the heavy recharging cycle after a discharge.
New Supercapacitor — there are countless stories around about ultracaps or supercaps. Many use low voltage aqueous electrolyte concepts, with extremely high surface area electrodes made of very porous materials, and utilizing the double layer effect. Though they can deliver unheard of capacitance in small packages (farads instead of microfarads), these cells have problems with high impedance and self-discharge. To reach any useful working voltage, cells must be put in series, and run into additional issues to do with voltage balance. According to tests of an 11,000 Farad unit at EPRI PEAC, a Russian company has a breakthrough concept involves an asymmetrical design, which solves these problems, and can deliver very high discharge rates over a wide temperature range, with high specific energy.
From the website:
“JSC ESMA electrochemical capacitors utilize a polar cell and aqueous electrolyte. The negative electrode is made of an activated carbon material having high surface area, where electric energy is accumulated at the electric double layer. The positive electrode is made of nickel hydroxide and designed for high charge/discharge rate. This combination of electrodes provides a 4-5 times increase in specific energy over capacitors designed with both electrodes made of a carbon material. The maximum operating voltage of the cells ranges from 1.3 to 1.6 V depending on the capacitor type and its operating mode. The capacitor is prismatic in shape, with a case made of plastic. It has a resealable safety valve in its cover to release gas during improper use when a certain value of excess pressure is reached. JSC ESMA capacitors have been designed to remain in service even if the operating voltage level is exceeded. Capacitor operating characteristics do not degrade if the capacitor is operated under an excessive voltage level over a short time. The capacitors can withstand a short circuit current caused by improper handling.”
Emitter Turn-Off Thyristor (ETO) is a new solid state switch developed at Virginia Tech that promises great improvement over GTOs and IGBTs. It is a hybrid based on the GTO and MOSFET. It is much smaller and simpler, it uses less drive power, and it is 10 times faster — it can turn off 3000 amps in 2-3 microseconds, vs. 30 for present devices. This speed will enable switches that can react to faults in time to safely turn off rather than relying on fusing. Virginia Tech is actively looking for licensees to commercialize the ETO. (I have pdf copies of the full paper and the patent application.)
Zinc Bromine Flow Batteries (ZBB & Powercell) Powercell’s standard unit is the PowerBlock, 100kW/100kWh, in one self contained package complete with power electronics, is in production. ( ZBB Technologies Inc. in Wisconsin is developing a larger utility scale version, with DOE funding. Two 400 kWh demonstration units are being installed on Detroit Edison’s system this Fall. Though based on the same original work at Exxon years ago, the two programs have important design differences.
Active Power, following on their very successful IPO, has a deal with Caterpillar, who is selling systems under the name CAT 250. This is a 250 KVA, 12 sec system. A price of $250-325/KVA was mentioned. Active Power has also recently built active harmonic filtering into the package. Duke Power reported on a demo installation at one of their customer sites.

Magnet-Motor (Germany) reported on their use of 2KWH/150 KW flywheels on public buses, ever since 1988. Company website:

Several programs are working on flywheels using superconducting magnetic bearings: the Shikoku Research Institute, Chubu Electric with Mitsubishi, and Boeing Phantom Works. This last one appears to have some resemblance to the earlier work at Argonne that was supported in part by ComEd. It is funded under the DOE Superconductivity Initiative.


Distributed Power Strategies and Business Opportunities
Sept 25-27,2000, Washington, DC

One of dozens of conferences on distributed power, this one had some big names and a high level of international participation, but no big announcements or new insights. As usual, the networking opportunities were at least if not more valuable than the sessions.
Ake Almgren, CEO of Capstone, was co-chair, with Mark Fallek of DTE Energy. In his opening remarks he noted that DG and central station plants are both needed, it’s not an either-or situation. DG can be thought of as another way to “distribute” power, not to “generate” it. Central station plants have a very long lead time, and difficult siting requirements. Also, T&D costs contribute as much as $4-500/KW to the price of power, which DG can avoid. Fallek cited some future global market estimates for DG of $38 billion/year. Premium power, now a $50 billion market, is growing at 30%/yr, suggesting $500 billion in 15 years.
Bob Shaw, who single-handedly invented venture capital in new energy technology, and who helped start many of the notable companies now making headlines, gave a perspective that was extremely bullish on DG and renewables, but a bit alarmed about the “bubble” situation. He is convinced that DG really will take over from central station power, sooner rather than later. DG is a perfect case of a “disruptive technology”. The engines built by US automakers every year are equivalent to the capacity of the entire US generating system. So, an industry 1/10 the size of Detroit could replace that system in a mere 10 years. The fact that VCs and Wall Street see energy technology as the “next big thing” is making capital available to this sector as never before, but it is also leading to unsustainable valuations that could become problematic. The paper is available online: I also have a copy of the powerpoint presentation, which provides some additional material.
“First, Second, or Third Coming??”
Is DG just a replay of one or two previous episodes, or very different this time? Shaw clearly espoused the latter view, but others were less convinced. In the 60’s, a midwestern gas company pushed a “total energy” concept based on reciprocating engines; maintenance problems and the poor suitability of recips to baseload operation proved the undoing. In the 80’s, the PURPA QF provisions led to a swarm of packaged cogen installations; QF contracts have all but faded from the scene. Shaw maintains that today’s convergence of developments is really different. Robert Swanekamp, editor of Power Magazine, took an extreme contrarian position that DG is a non-event, and that 1/2 of the large CCGT’s on order will be cancelled as a power glut emerges. He said he had no knowledge of the disruptive technology argument, but that didn’t stop him from dismissing it. (He was probably the only person present who hadn’t heard about Clayton Christensen’s ideas and their relevance to DG. See UFTO Note 19 April 1999; or
Technologies — there were a dozen or more presentations by companies: makers of fuel cells, stirling engines, and microturbines; power electronics, internet-based controls and energy management; and O&M.
Barriers — reports on the EEI and IEEE interconnection efforts; an excellent overview of competitive, institutional, regulatory and financial obstacles by Nat Treadway, (for a similar presentation, see

Energy Storage Assoc Meeting Notes

Here are some notes from the recent meeting of the ESA, here in the SF
bay area. The ESA website will be posting additional information.

Energy Storage Association
2000 Annual Meeting

“Cleaner, Greener Power through Energy Storage”
6-7 April 2000
Pleasanton, CA


Finally, energy storage appears to be breaking through, across a broad front. There are about 100 MW of pending purchases for systems in the US, and a comparable amount in Europe. This new success isn’t limited to one technology either, but is spread across many different ones, from flywheels to SMES to advanced Pb Acid to “flow” batteries. Applications range from small to large, from local UPS/power quality to grid support systems.

This meeting had as its theme the environmental implications of storage, noting the synergies with renewable power (e.g. to improve its dispatchability and application), and how storage also can improve the environmental performance of conventional plants.


Flow Batteries

Flow batteries in particular are emerging strongly; four companies presented different chemistries and product niches.

In these systems, two electrolytes flow through a reactor, which is similar to a fuel cell, on either side of an separator membrane. When a voltage is applied across the reactor, the electrolytes change state and become “charged”. The “charged” electrolytes pass out of the reactor to be stored in tanks. Just like a conventional rechargeable battery, the process can be easily reversed. The “charged” electrolytes flow back through the reactor and electricity is produced. The technologies are environmentally benign, modular, comparatively easy to site, and separate the power rating from the energy storage capacity. They also appear to be free of the charge/discharge management issues that most battery chemistries suffer from, i.e. they can be fully discharged, and have no standby self-discharge losses (i.e. when the circulating pumps are turned off). Manufacturing and material costs are relatively low, and system costs will drop as the number of installations increases.

— Regenesys — Large Scale Utility Energy Storage — sodium bromide and sodium polysulphide electrolytes. An “electricity warehouse” reference design is based on 120 MWh with 10 hour discharge, max rated output 14.75 MW. Other configurations (5 – 500 MW) are possible. First plant at advanced stage of planning on a power station site in the UK. The first N. American “follow-on” installation is in advanced discussions. A transportable/containerised unit is suggested at 20 MWh, 2MW. (

— Pinnacle VRB Ltd — Renewable and Remote Applications — vanadium (in various charge states). Invented at Univ of New South Wales, Australia. Licensed to Sumitomo and Mitshubishi in Japan. Sumitomo has developed collapsible storage tanks that can go through doors and manholes, enabling installation in existing structures. (High time-of-day rate differentials make diurnal peak shaving attractive.) Installation at SDGE as part of EPRI DR test program. A unit at a park hostel in Australia is 20 kw/120 kwh, part of a remote power system. Another on King Island is 100kw/1800 kwh supports a minigrid and drastically reduces diesel fuel and operating costs. (

— Powercell — Zinc-Flow™ uses zinc bromide and polybromide solutions. Their standard unit is the PowerBlock, 100kW/100kWh, in one self contained package complete with power electronics. It is on the market, to date mostly through Williams Energy, and the company is ramping up production to meet the demand. (

— Cellennium — also uses vanadium. This Thailand based company is developing a wide range of applications, from small to large. (


Keynote Address: * Renewables, Distributed Generation and System Reliability in a Restructured Electric Supply Industry – Gregg Renkes, The Renkes Group, Ltd.

Renkes was staff to Senator Murkowski for many years, and directly involved in many of the congressional hearings on the energy industry. He gave a detailed view of how the players line up in Washington, particularly as to how the elections will impact restructuring legislation in the near future. Starting from a historical perspective (cold war, White House and Congress controlled by opposite parties), he uses various clues to how Gore and Bush’s views on energy will play out (in the closest race in recent history), and concludes they’re very similar. The current administration’s proposal, and what’s been done in Texas both point to restructuring, market mechanisms to deal with emissions, renewable standards, etc. In Congress, there’s also more agreement than disagreement, and the states’ speed on restructuring is pressuring Congress to do something sooner rather than later, regardless of election results. Grid reliability, and shortages expected this summer are high profile reasons for action. Overall, conditions are looking increasingly positive for distributed power, renewables, and storage application.


* Energy Storage and Renewable Energy, BPA’s Perspectives
Mike Hoffman, Bonneville Power Administration

BPA is espousing an “EnergyWeb” concept, and see storage as an important element alongside distributed generation and renewables. In conjunction with wind, for example, storage can make it possible to dispatch wind power in the large flat blocks during peak demand, and displace carbon-based generation in the process. Wind power could also be bid into hour-ahead and week-ahead markets if the storage system has a high enough discharge rate. Customer side storage becomes relevant if there are demand charges–and retail access. Larger system configurations depend on local market structures. On the transmission system, storage presents many potential benefits, no one of which is enough by itself to justify the cost, but taken together could do it. Storage will be easier to site than new lines; it can help with congestion management, increase transfer capability, and replace contingencies. Transportable systems would overcome fears of stranded investment. Fast systems (e.g. SMES) can help with stability.


* IBERDROLA’s Technology Demonstration Centre
Jesus Garcia Martin, IBERDROLA

This center supports the generation and other business units of Iderbola, one of the four large utilities in Spain. The only such facility in Spain, it evaluates and tests new technology, does technology transfer, and tries to reduce the time it takes to introduce new technology. In renewable energy, they have PV arrays, fuel cell demonstrations (one with Ansaldo in Italy is a molten carbonate), studies in biomass, thermal solar, wind and hybrid systems. There is also have a 2 MW battery storage system, operating for the last 4 years.


* Power Quality Management as a Green Technology; Imre Gyuk, DOE

Storage is important for reliability and economic competitiveness, and it also plays a role as a green technology, by virtue of its ability to increase the potential of (intermittent) renewable energy sources by making them more dispatchable, and, for example, reducing/optimizing use of diesels in off grid or microgrid settings.


* Flywheels for Renewable Energy and Power Quality Applications
Don Bender, Trinity Flywheel Power

(There was also a tour of Trinity’s plant nearby.) As lower tech flywheel (i.e. steel) systems are opening the market, high speed carbon composite systems are making steady progress, though they’re taking longer than anticipated. There’s been a lot of hype over the last 10 years, and only a small number of contenders are still around. Programs were underfunded, and had too much of a component, not system, focus. Also, requirements for vehicular applications were too severe for the first step.

Trinity’s “electromechanical battery,” as they like to call it, uses a 9 inch diameter rotor. Turning at 40,000 rpm, it will deliver 50 kW for 20 sec. Other configurations offer 100kW/15 sec to 250kW/3 sec, and 700kW/5 sec. Installed on a DC bus to add or remove power as needed, it can deliver energy, or power or both, from a compact package – power density (of the motor/generator and power electronics) starts at 5 kW/kg. The state of charge is always precisely known from the rotational speed. The balance of plant has turned out to be a bigger challenge than originally expected, and the power electronics have very special requirements. Flywheels should have an advantage for short duration power quality applications. Safety concerns have been addressed by a collaboration among most of the developers. You need either containment or rotor integrity, not both. Trinity has focused on rotor integrity, through extensive overspeed/burst testing.


* Battery Energy Storage for Residential Photovoltaic Systems
Bill Brooks, Endecon Engineering

Over 75% of the 299 PV systems installed under CEC Emerging Renewables Buydown program in the first two years of the program include some amount of battery storage. (Even higher percentage among residential projects). The CEC Buydown does not apply to the battery portion of the systems. (even though several attempts were made to include batteries). Battery options are generally preferred and actually help sell the PV system by providing firm backup power capabilities. Batteries are here to stay in this market.

Most appropriate battery for this market is the Valve-Regulated Lead-Acid (VRLA) battery. Advantage—Low maintenance, good performance Disadvantage—Higher cost, intolerant of high temperatures or improper regulation voltages.

Enclosures need very little ventilation. Best if placed in garage or in an outdoor enclosure (in shade and/or conditioned to prevent high temperatures). Building inspectors are unfamiliar with reviewing battery installations; their requirements vary from plywood boxes to explosion-proof enclosures with four-hour fire ratings. Very few batteries or battery enclosures have listings or recognitions by testing labs. PV is blazing the way for a whole series of backup power options for residential and commercial customers.

The Trace 5548 Power Module has a5.5kW ac rating, 44-60V dc input, 120Vac output — Batteries and controls all in the same cabinet, up to 12 kWh in storage cabinet.

More Battery is ALWAYS better


* Utility Evaluation and Demonstration of Dispersed Subsurface
Compressed Air Energy Storage, Dale Bradshaw, Tennessee Valley Authority

A 300 MW CAES site got pretty far in the planning stages in the early 90’s, but the plant was never built. Now TVA is considering a smaller scale system (10-20 MW; 6-10 hours) to be used close to the customer to help relieve transmission congestion. The compressed air field would consist of 3-4000 ft of 5-foot diameter gas pipe, laid out in any pattern convenient for the site, e.g. under a farmer’s field. The CT’s would always be available, even if the storage was exhausted, and while using the compressed air, plant output would not be sensitive to ambient air temperature, and would be a low cost source of spinning reserve, with rapid hot or cold start. Operating cost benefits compared with a CT become significant under higher gas prices.


* Lithium Ion Batteries for Energy Storage Applications
Jim McDowall, SAFT America
Lithium Ion is not just one kind of battery, but refers to a whole family of battery materials and chemistries, with a wide range of characteristics. First proposed in 1990, and first shipped in 1993, they are now in 1/2 of all portable devices. Saft and others have been working on a large scale version for EV applications. Lithium is the lightest metal and offers the highest voltage. With no water present, there’s no problem with electrolysis during charging. SAFT’s battery has lithiated cobalt oxide as the positive electrode, lithium intercalated in graphite as the negative electrode, and the electrolyte consists of LiPF6 salt in an organic solvent. Lithium-Ion batteries must be protected from high temperature (they’ll burn over 150 deg C), overcharge, overdischarge, and over voltage. Therefore each cell must have its own built-in electronic monitoring and control. The batteries provide good cycling, high power, and deep discharge. They’re in pilot production and should be available commercially in 3 years. Though the initial cost is high, this will be very dependent on volume (as with so many new technologies). Life-cycle cost should eventually match Lead-Acid batteries.

* Molten Salt as an Energy Storage Medium
Hugh Reilly, Sandia National Lab

The Solar II plant, closed down over a year ago, used molten salt to transport heat from the tower to heat exhangers, making steam for power generation. Adding 2 large storage tanks effectively decoupled the collection of energy from the generation of electricity, with 105 MWhr of storage, at 97% efficiency, and thus enabling anytime dispatch of solar electricity. The salts solidify at 430 deg F, so the “cold tank” must be kept above that temperature. A new plant using this approach, “Solar Tres”, is under construction in Spain by a consortium that includes Boeing and Bechtel.


* Annex XV: Energy Storage and Renewable Generation: The New Opportunity
John Boyes, Sandia National Lab
The International Energy Agency (IEA), which is an offshoot of the OECD, sponsors a series of research programs and working groups. For a complete list, see “Implementing Agreements” at

Annex XV is the successor to Annex IX, and both of these are under a broad category that covers all forms of storage for energy conservation.
For details, see

An acrobat document gives an overview ( The program scope will be determined at a meeting in October, with work to begin in November.

The objective is “to move storage systems towards commercial market implementation, via the mechanism of technology and applications demonstrators. Whilst it is beyond the scope of Annex 15 to implement an actual demonstration project, it is fully intended that much of the necessary groundwork will be covered within the project to make a demonstration project the next logical step in electrical energy storage system market development.”



Jon Hurwitch – His firm Switch Technology has merged with RK Sen to form Sentech

Evonyx – Ian Grant is new to ESA and a new employee of Evonyx, announced a major investment by Niagara Mohawk in their company. Evonyx has a new type of Zn-Air battery which can be recharged or physically refueled with solid plates or tapes. They forsee applications from AAA size to multi-MW. (

Trace (Trace Technologies and Trace Engineering) announced their merger with Xantrex.

Brad Roberts explained that Omnion had been acquired by S&C Electric, and that they were filling commercial orders for the PQ2000.

Anthony Price and Joe Iannucci observed that lots of money has been spent on reducing the cost of storage technology, nothing has been spent on increasing its value, e.g., integrating it with renewables.

Steve Eckroad summarized recent developments at Golden Valley Electric, Fairbanks, where they’re in the last stage of bidding for a major BESS. There are 3 finalists- ABB, GE and Siemens, each teamed with a particular battery. An award is expected in September.