Posts

EEStor Ultracapacitor and Ultrabattery

/0 Comments/in , /by

There have been so many breakthrough battery claims, but here’s one that might deserve a careful look. The specs are impressive, and the entire manufacturing process has been thought through using processes and equipment already proven in a large-scale commercial operations. The founders bring a wealth of experience as senior technology managers in large companies and startups. The company has maintained a very low profile for several years, and I first talked to them in early 2003.

The claim is for systems at 1/2 the cost of lead-acid (per kwh), and 1/10 the weight. Specifically, they quote a product which at 400 pounds will deliver 52 kwh. Discharge (and charge) rates are at "electronic" speed, and would be limited only by the sizing of the drive circuits and external systems. Thus power ratings can be as high as needed. Selling price would be $3200 at modest production rates, and eventually down to $2100 in high volume.

Here are some specs the company is claiming:

                                          present   longterm
   Energy density, Wh/L        606        1513
   Specific energy, Wh/kg      273         682
   Price, $/kWh                        61           40

The company intends to pursue a licensing model, after building their own assembly line to prove out the technology and seed the market.

The technology is basically a parallel plate capacitor with barium titanate as the dielectric. With it’s extremely high permittivity, barium titanate has a long history in capacitors, but one known for high leakage, voltage breakdown and temperature sensitivity. EEStor has confronted these drawbacks head on, and has measurements on prototypes to support their claims.

The product is a ceramic-based unit fabricated with integrated-circuit techniques. The design is based on proprietary technology and there is a patent pending for the production process. There are no corrosive, hazardous, or explosive materials used in manufacturing this product, making this a totally green technology. Also, since it is ceramic, it can be fully charged and discharged using ultrahigh currents and at electronic speeds repeatedly with no degradation to the original specifications. Samples have been rapid-cycled over 1 million times, with no change of any kind. Operating temperature is -40 to +85 deg C.

Until now, electrostatic capacitors have not been considered for energy storage applications because of their low energy density characteristics. Capacitors applied to storage are based upon electrochemical and electrolytic capacitor technologies, which possess higher energy densities. EEStor’s development proposition changes that premise by eliminating the inherent weaknesses of electrostatic technology for storage applications.

A number of major companies have said they would issue a purchase order quickly if specs are met.

The company is currently seeking equity investment of $3.5 million. A business plan is available.

Contact Richard D. Weir, President and CEO
    EEStor, Inc. Cedar Park, TX
    512-258-5669   dick_weir@eestor.us

Firefly Re-invents the Lead Acid Battery

/0 Comments/in , /by

In early May, Caterpillar announced the formation of a new spin-off company called Firefly Energy Inc., whose purpose is to complete the development and commercialization of a dramatically improved lead acid battery technology. The entire research program, people and technology have been transferred out of CAT into the new startup after several years of in-house research. CAT will remain as only a partial investor once there is new financing.

Attempts have been made before to re-invent the lead acid battery, without much success. Prominent among them, Electrosource/Horizon and Bolder Technologies, both of whom ran into obstacles in cost, performance and manufacturability that couldn’t be overcome. . (In Dec 2001, Bolder was acquired out of bankruptcy by Singapore based GP Battery. In Feb 2003, Eagle-Picher announced a new joint to produce the Horizon battery.)

Firefly has high expectations that they’ve got it right. In fact, key personnel from those previous efforts are involved, along with an all star cast of battery industry veterans.

Firefly’s claims include: 1/4 the weight (eliminating 80% of the lead), double life expectancy, 7x charge rate, and manufacturing that is compatible with existing lead acid battery production facilities. It should cost no more than current lead-acid batteries, making it a small fraction of the cost of nickel metal hydride and lithium technologies. Cycle life, even at 80% depth of discharge, is several thousand cycles, one or two orders of magnitude better than conventional lead acid, on a par with the advanced technologies. Two main problems of lead acid, sulfation and corrosion, are all but eliminated. Heat dissipation is excellent, even at the greatly increased charge and discharge rates.

One of the keys to these improvements is a substrate material for the plates that no-one thought to try before. Highly porous, it provides for thousands of times more “cells”, or locations where the reaction can take place. Fourteen patents are already in process, with more to come.

The company plans to license the technology, and to manufacture with partners that already have production lines, co-branding new products that will be priced at or below leading batteries on the market.

They are raising an initial seed round now, with a $2 million “A” round to follow immediately.

http://www.fireflyenergy.com/

Contact:
Ed Williams, CEO
303-440-4920, ewilliams@fireflyenergy.com

Bipolar NiMHydride Battery

/0 Comments/in , /by

Electro Energy, Inc. (EEI) has developed a new type of rechargeable nickel-metal hydride (BP Ni-MH) battery using a bipolar configuration. A combination of unique materials, a design, and a production process make possible a lower cost technology which out-performs present commercial nickel-metal hydride and lithium polymer batteries in both power and energy.

A key advantage of a bipolar format is that the current path is the shortest possible. In a series arrangement, current passes directly through the separator, across its entire area. This eliminates the need for lugs and cell interconnections, with the additional internal resistance, sealing problems, and structure they bring.

The classic bipolar design (similar to most fuel cell stacks) involves a stack of metal plates, each with an anode applied to one side and a cathode to the other. For batteries, the problem of sealing the edges has proven difficult. EEI’s solution is to make each cell a stand-alone sealed flat wafer. The wafer cells are stacked up to make a higher voltage package.

EEI has developed and patented both the design of their battery and the production process for its manufacture. Prototypes exist and have been tested extensively. The US Air Force is evaluating units for use on F16 (and NAVAIR for the F18) jet fighters (1/3 the weight and volume of what they’re using now).

Conventional Ni-MH rechargeable batteries represent a $3 billion market currently, and EEI expects to dominate that and other markets, because their battery will deliver more energy and power per unit volume and per unit weight, at lower cost. Cycle life is in excess of 1000 cycles in deep discharge use, and over 12,000 cycles at 40% discharge. Cost will be 1/2 that of Li -Ion, and there are no toxics substances. The technology will be very competitive in the applications requiring high voltage and power, e.g. hybrid vehicles.

The company is seeking equity investment, having received over $15 million in government and other grants, particularly from DOD and DOE. A full business plan is available.

Contact: Mike Eskra, President & COO
Electro Energy Inc, Danbury CT
203-797-2699 meskra@electroenergyinc.com
http://www.electroenergyinc.com

Cell Details
As a departure from classic cylindrical or prismatic battery packaging approaches, EEI’s is a flat, wafer, bipolar design for the nickel-metal hydride chemistry. Individual flat wafer cells have outer contact faces with one positive electrode, a separator and one negative electrode. The contact faces serve to contain the cell and make electrical contact to the positive and negative electrodes. The the two electrode faces are completely sealed at the edge to contain the potassium hydroxide electrolyte. To make a multi-cell battery, identical cells are stacked one on top of each other such that the positive face of one cell contacts the negative face of the adjacent cell resulting in a series-connected battery. Power is taken off at the ends of the cell stack. An outer container holds the cells in compression and provides structural integrity for the stack.

This design has several advantages. The need for conventional terminals, tabs, current collectors, and cell containers is eliminated. Use of available space is maximized, with the headspace for tabs and terminals required in conventional cells eliminated. The path that current has to move within the electrodes and from cell to cell is minimized, since the current flows out on the entire surface of the electrodes. Battery impedance is reduced, making this design particularly effective for high rate, power applications. The wafer stack has excellent thermal management properties. Cells act like cooling fins, conducting the heat out to the side. Compared to conventional cylindrical and prismatic packaging designs, there is considerable reduction in cost, weight, and volume.

EESAT’02 Electricity Storage Conference

/0 Comments/in , /by

The Electric Energy Storage Applications and Technologies Conference (EESAT 2002) was held in San Francisco April 15-17, 2002. Ever hopeful for the promise of storage, sponsors point to growth in markets, increased focus on reliability (supply crises and terrorism), and advances in technology. Evidence includes the increasing number of demonstration projects, and estimates that more than 100MW of advanced, distributed energy storage is being installed in North America this year, and another 100MW in Europe and Japan.

Session titles were:
– Overview of Electrical Energy Storage Applications & Technologies
– Multi-megawatt Applications
– Advanced Battery Applications
– Power Electronics and Conversion Systems
– Design and System Studies
– Flywheel Applications
– Capacitor and Super Capacitor Development and Applications
– High Speed Flywheel Development
– Battery Development and Applications

The website has the agenda with the complete list of papers.
http://www.sandia.gov/eesat/
It also provides the agenda from EESAT 2000*. I have the CD of the papers, if you want any of them. The 2002 papers should be available shortly to attendees, and I will supply them as well.
*(29 Oct 2000 UFTO Note – Travel Reports)

The ESA newsletter provides a helpful summary of the conference:
http://www.energystorage.org/archive/Newsletter_May_2002.pdf

And while we’re on the subject, have a look at this comprehensive technology overview:
http://www.re-focus.net/mar2002_4.html

Not on the agenda, but noteworthy: A new lobbying and educational group has formed; the Energy Storage Council promotes public policy that supports energy storage as a key dimension of the electricity value chain. This is the brainstorm of Jason Makansi, former editor-in-chief of McGraw-Hill’s Power magazine. Membership information and a white paper can be found on the website:
http://www.energystoragecouncil.org

Flow Batteries
Perhaps the biggest news is the progess that large scale “flow” batteries are making, both technically and commercially, for large scale systems (100 kw and up). Recall that there are several competing electrochemical schemes. A comparative assessment of flow batteries was provided in a paper by C. Lotspeich based on work done for an E-Source report.

– Regenesys- sodium bromide and sodium polysulphide (ufto note Sep’99)
– ZBB & Powercell – zinc bromine
– Vanteck & Sumitomo/Reliable Power – vanadium redox
– Plurion – cerium vanadium MSA

Except for the zinc bromine, they offer freedom to size a system’s power (kw) and capacity (kwh) separately (either aspect can be added to over time), by adding either cells or electrolyte storage.

Regensys is building their first N American installation at TVA. It will be 12 MW/120 MWH.
http://www.regenesys.com

ZBB’s demonstrations of a transportable system are proceeding well, in collaboration with Detroit Edison. This is 200kW/400kWh battery system, on a 40 ft trailer. The application is grid support. http://www.zbbenergy.com/

Powercell may be revived from bankruptcy. Too soon to tell. Word is that some of the former management team is trying to put it back together.
http://www.powercell.com/

Vanteck has resolved its corporate problems and has a field trial underway in S Africa for a 250 kw/520kWh system. The vanadium technology boasts very high power delivered over milliseconds or slower discharge over days. They’ve also announced a commercial order from Pacificorp. http://www.vanteckvrb.com/

Reliable Power is Sumitomo Electric Intl (SEI)’s presence in N America for SEI’s vanadium battery systems. (SEI is one of the original licensees of the patents.) Size range is 100kw-3MW. UPS *and* peakshaving. Peakshaving earns$ day in and day out, while the UPS sits and waits to deal with a power glitch. Very high power for 3 sec… 3 MW, or 1.5MW for an hour. Meanwhile, Sumitomo has a number of fully commercial systems in operation in Japan.

Plurion, a brand new arrival on the scene, made its public debut at the conference. Its chemistry is based on cerium and vanadium in a “mixed electrolyte” with methanesulfonic acid (MSA). They claim cheaper longer lasting electrodes and membranes, greater simplicity, and lower cost. The system requires neither nafion or precious metal catalysts. Electrolyte management is said to be simpler than in other systems, requiring no ongoing cleanup treatment. Remarkable in the current investment climate, the company raised $14 Million recently, and is on schedule with an ambitious development plan. The technology was developed by Electrochemical Design Associates, Inc (Berkeley CA), and EDA is doing most of the ongoing technical work. http://www.e-d-a.com/ [I have press releases and their powerpoint presentation that I can provide on request.]

Flywheels, Capacitors, Other Batteries

Progress continues on many fronts, with commercial or near commercial applications taking hold. Systems studies examined grid support and ancillary services, microgrids, and identifying best applications and key variables to cost effectiveness.

Nickel Hydrogen Battery Ready for Commercialization

/0 Comments/in , /by

UFTO first reported on this technology almost 6 years ago, and issued updates in Oct ’96 and Jan ’98.
================================
UFTO Bulletin #16 December 18, 1995

Nickel Hydrogen Batteries have been used in space for decades, and are known for extreme reliability. Ergenics Inc. has basic patents for a “segmented Ni H battery” concept that should make it practical for terrestial uses. They’re building a prototype for ARPA for a military hybrid vehicle, and can make them as small as a laptop computer battery.

It uses metal hydride to store the hydrogen outside the battery cell, thus eliminating self-discharge, most if not all safety concerns, and heat transfer issues. Most important, it’s low pressure, unlike usual Ni H batteries, which require a high pressure tank. A key advantage over Ni metal-hydride batteries is long life because the hydride is isolated from corrosion producing chemicals of the battery cell. …. The company … [hasn’t] yet focused on applications in UPS and utility storage systems. This may turn out to be quite competitive with the other forms of storage that everyone is working so hard on, and it could be an opportunity for a strategic technology edge. Call me for more info.
================================

Now at long last, a new company, ElectraStor, has licensed the Ergenics technology, made substantial improvements, and is positioned to manufacture it, initially in their own pilot production facility. The plan is then expand manufacturing, and/or to sublicense the technology and manufacturing know-how worldwide. Originally focused on hybrid vehicle batteries, ElectraStor is also now addressing applications in stationary electric power storage, where a convincing case is made for major cost and performance advantages, particularly in applications requiring high power and quick response.

Here is a portion of ElectraStor’s Executive Summary:

ElectraStor LLC owns a breakthough rechargable low pressure Nickel-Hydrogen “fuel cell battery” technology. This technology has been extensively validated and is ready for commercial production. Serious discussions are ongoing with substantial corporations and government agencies worldwide, including the FTA, Siemens, Fiat, MAN, the Italian government, DaimlerChrysler, Altra, Mercedes EvoBus and others. The Company is raising US$12M to fund a profitable pilot plant, bring the company to profitability, and perform R&D on new products.

Advantages of ElectraStor NiH Batteries: Phenomenal “life of the vehicle” cycle life, zero self-discharge, extraordinary tolerance to overcharge and over-discharge, 100% depth of discharge capability, low cost, low-pressure, high specific power, no maintenance, all-weather operation and a high degree of safety compared to competition. ElectraStor batteries have two to five times the specific power of NiMH and lead acid products and have specific energy comparable to Li-ion and Li-polymer products, while offering far greater tolerance to high mechanical, thermal and electrical stresses.

The Technology: ElectraStor NiH batteries combine a bipolar fuel cell stack with a closed loop supply of low pressure hydrogen stored in a segmented hydride with a limited supply of oxygen stored in a nickel hydroxide, which is regenerated using electricity during recharge. Because it separates hydrogen storage from the wet aspect of the battery, the chemical reaction is only a catalyst and no longer causes degradation of the battery parts, as remains the case in the NiMH design. This enables the ElectraStor battery to be cycled almost indefinitely without degradation or failure.

Intellectual Property: ElectraStor holds an exclusive, worldwide, sub-licensable license to technology developed by Ergenics, together with any and all improvements and extensions to this technology. The patent portfolio is extensive, broad and deep. R&D is ongoing, both by Ergenics and ElectraStor, and further patents are in the immediate pipeline.

Time to Market: The NiH battery is ready for production. ElectraStor has teamed with the FTA and the Belcan Corporation (the largest engineering and technology services organization in Ohio, with revenues over $400M) to construct the pilot plant. The plant will be up and running at full capacity within seven months of funding. The plant’s flexible manufacturing line will produce batteries both for electric and hybrid vehicles as well as a variety of further mobile and stationary applications.

Validation of ElectraStor Technology: Testing is ongoing, both by independent third parties and by our Corporate and Government partners, including the City of Pittsburgh, Mass., the Federal Transit Authority (FTA), the Italian Government, Siemens, Fiat, MAN, DaimlerChrysler and others.

http://www.electrastor.com
(this website will be updated by mid December)

Please contact me for more information and appropriate introductions.

On-Line Transformer and Battery Monitoring

/0 Comments/in , /by

Serveron Corp. launched itself in February as the industry’s first provider of full time monitoring services for T&D equipment. Starting with the gas-in-oil sensors developed by a predecessor company, Micromonitors, Serveron offers a complete solution, from instrumentation, to on-line monitoring, to (condition-based) maintenance scheduling and asset management, to risk management. The company also has comprehensive monitoring technology for station battery systems. The complete suite of applications also covers tap changers, arresters, bushings and breakers.

Large Power Transformers:
Note some alarming facts about the T&D infrastructure, and large transformers in particular. The fleet is “graying” — the average age of units now in use is 35 years. Hartford Steam Boiler has data showing an exponential increase in serious failures: 1% of large transformers (1,000 transformers in the US alone) will fail this year, and the failure rate will rise to 2% by 2008.

The average cost of such a unit is $2-3 million and lead time for new ones can exceed a year or more, so a major failure has very significant implications. An early target — powerplant step-up transformers. Any event that could take part or all of a plant’s capacity off-line for a long time becomes even more crucial in today’s climate.

In addition, major savings can be realized with true condition-based maintenance. Since monitoring and diagnostics have not been readily available or cost-effective, utilities now perform maintenance on arbitrary schedules, but estimates are that 30% to 50% of that work is unnecessary. Finally, capital equipment replacements can be prioritized and scheduled in ways that specifically minimize physical and financial risk.

Serveron’s TrueGas™ analyzers monitor the levels of volatile dissolved gases in the insulating oil in large transformers and other oil-filled equipment. Over the life of a transformer, fault gases form due to the degradation of the insulating materials or from the presence of thermal or electrical faults. The type and concentration of these gases are primary indicators of transformer condition and types of faults.

TrueGas analyzers are the only instruments available today that detect and separately analyze trace levels of all eight fault gases. Other instruments detect only a subset of these gases or provide only combined gas data that may not accurately predict equipment failures.

Since serious problems evidence themselves only hours to days before a failure, realtime online measurements and analysis are critical. Test procedures that involve the periodic drawing of samples and sending them to a lab just can’t do the job.

Serveron’s on-site equipment and Web-based analysis software provide continuous monitoring during actual operations, and thus early identification of transformer conditions that require maintenance or that could lead to catastrophic failure of the equipment.

The company will also integrate other sensor data into the system, such as electrical, thermal and mechanical (e.g. acoustic/vibration) parameters.

Battery Systems:
All power plants and T&D substations have large banks of batteries which provide back-up power required for startup and for graceful shut down in the event of an unplanned outage or equipment failure. There can be 50 to 70 truck-battery-sized cells in each bank, for a total of tens of thousands of individual battery cells in an average utility, at hundreds of remote locations. Inspection and maintenance is a major cost, as these systems must function when called upon. (In nuclear plants, they also have to be available, or the plant may have to shut down.)

Serveron’s CellSense™ monitors provide continuous measurements of all key physical and electrical parameters needed to characterize the condition of all individual cells as well as the battery system as a whole. CellSense™ instruments monitor the batteries on-site, and graphical data can be viewed from any remote location using a common browser to access Serveron’s secure web site. With CellSense™ monitoring, battery maintenance and inspection can be reduced from a monthly to an annual activity.

I have a company powerpoint presentation (400kb) that I can send on request, and more information is available on the company’s website:

http://www.serveron.com/

Contact: Jim Moon, CEO 541-330-2350 jim.moon@serveron.com

Technology Transfer Opportunities – Wright Laboratories

/0 Comments/in , /by

UFTO

PROPRIETARY

Final Report

Technology Transfer Opportunities in the Federal Laboratories

Wright Laboratories

U.S. Air Force

Dayton OH

February 1998

Prepared for:

Utility Federal Technology Opportunities (UFTO)

By:

Edward Beardsworth

Consultant

This report is part of a series examining technology opportunities at National Laboratories of possible interest to electric utilities

 

Contents:
page
1. Summary
1 Overview & Organization
3. Technologies & Programs

This report is proprietary and confidential. It is for internal use by personnel of companies that are subscribers in the UFTO multi-client program. It is not to be otherwise copied or distributed except as authorized in writing.

Summary

This report details findings about technology and technology transfer opportunities at the Wright Laboratories that might be of strategic interest to electric utilities. It is based on a visit to the lab in June 1997 and subsequent contacts, as part of the UFTO multiclient project.

Background

Noting the tremendous scope of research underway in the research facilities of the U.S. government, and a very strong impetus on the government’s part to foster commercial partnering with industry and applications of the technology it has developed, the UFTO program has been established as a multi-client study of the opportunities thus afforded energy utilities and their many subsidiaries.

Air Force Research Laboratory

In a major reorganization just put into effect in mid 1997, all the Air Force R&D activities were brought together into one single entity called the Air Force Research Laboratory.

From the AFRL website: http://www.afrl.af.mil/

———————

The mission of the Air Force Research Lab is to lead the discovery, development, and transition of affordable, integrated technologies for our air and space forces — to keep our Air Force "the best in the world." Our mission is executed by our nine technology directorates, located throughout the United States; the Air Force Office of Scientific Research; and our central staff. Our partners include universities and industry, with whom we invest almost 80% of our budget, and our customers include the Air Force major commands, who operate and maintain the full spectrum of Air Force weapon systems. We are a full-spectrum laboratory, responsible for planning and executing the Air Force’s entire science and technology budget: basic research , applied research, and advanced technology development. The work is done at facilities all across the country (Wright-Patt, Kirtland, Brooks, Edwards, Eglin, Tyndall, Bolling, Hanscom, Rome).

The AFRL is made up of more than 6400 government people, which includes over 1500 military and over 4800 civilian personnel. We have about 3500 scientists and engineers, of which over 800 have PhDs.

———————

Budgets and staffing of research groups and facilities are relatively stable over time, as the Air Force regards its research capability as vital to the conduct of its overall mission, and takes a long view of its future technological needs.

• Technology Transfer

The Air Force, like all of DOD, has a strong commitment to Tech Transfer, and like DOE and other agencies,has a wide latititude of contracting mechansims and ways of working together with private industry and academia. One of the primary motivations for working with the commercial sector is to enhance the capabilities of private industry so as to lower costs to the Air Force of the high-value manufactured items they need.

The AFRL operates Tech Connect, the main point of contact for tech transfer for the entire Air Force. It provides search and contact services and facilitation.

In addition, each operating location (not just labs) have their local point of contact or ORTA (Office for Research and Technology Application).

To contact TECH CONNECT

Call – (937) 656-2530 Toll Free (800) 203-6451 FAX (937) 656-2138

Web site — http://tto.wpafb.af.mil/tto/techconn/index.htm

Wright Labs Overview

Wright Laboratories, located at Wright Patterson Air Force Base, Dayton OH, is oldest and largest of the Air Force research laboratories, with a history stretching back to 1917.

Wright Labs is headquarters for a number of Directorates (e.g. armament, avionics, flight dynamics, etc.).

Propulsion Directorate http://www.pr.wpafb.af.mil/

One of these, the Propulsion Directorate, has the highest relevance for utilities.

The Propulsion Directorate’s work has many potential non-aerospace and commercial uses in:

– Materials and Materials Application
– Measurement and Sensing
– Modeling and Visualization
– Energy and Power

With an annual budget of about $150 Million, and about 300 mostly technical and scientific personnel, its technical divisions are:

Division – Office Symbol (Primary Site/Secondary Site)

– Power Division – AFRL/PRP (WP)
– Propulsion Sciences and Advanced Concepts Division – AFRL/PRS (Edwards/WP)
– Turbine Engine Division – AFRL/PRT (WP)
– Rocket Propulsion Division – AFRL/PRR (Edwards)
– Integration and Operations – AFRL/PRO (WPAFB/Edwards)

Principal Point of Contact: Kristen Schario, 937-255-2131, scharika@wl.wpafb.af.mil

Power Division http://www.pr.wpafb.af.mil/divisions/prp/prp.html

The Power Division plans, formulates, manages and executes research, exploratory and advanced development programs in energy conversion and storage, and power generation, transmission, conversion, and thermal management. This includes electrical, mechanical, thermal, and fluid power for aircraft, missile, terrestrial, and special Air Force applications.

Technologies & Programs

Covered in this report:

Page
• More Electric Aircraft (MEA) 4
Power generation
Power systems and distribution components
Passive components – Capacitors
Power electronics/motor drives
• Ground Power 4
Remote Small Scale (10-120 watts)
Cryogenic Lightweight Deployable (1-4 MW)
• Turbine Compressor Research Facility 8
• Electronics Cooling
• Mechanical Testing of Electrical Machinery
• Silicon Carbide High Power Electronics
• Superconductors, Cryogenic Power Electronics
• Batteries 4
• Lubrication Technology 4

• More Electric Aircraft (MEA)

Contact: Maj. Michael Marciniak, 937-255-6226, marcinma@wl.wpafb.af.mil

The Air Force has a major effort on the "More Electric Aircraft" (MEA), from which many "dual-use" applications arise. As with the more electric ship and tank, the PNGV hybrid/electric vehicle efforts share many common requirements and opportunities.

The goal of MEA is to replace hydraulic and pneumatic systems, which account for more than 1/2 of all downtime and failres of fighter aircraft, with electrical ones. A wide range of technologies are involved, including actuators, electronics cooling, motor/alternators, supercapacitors, batteries, power system controllers, and high power semiconductor devices.

The MEA will require a highly reliable, fault tolerant, autonomously controlled electrical power system to deliver high quality power to the aircraft’s loads. Also, reliable high power density motors and motor drives ranging from a few horsepower to hundreds of horsepower will be required

Military aircraft have numerous subsystems powered by one or more sources of secondary power: hydraulic, pneumatic, electrical and mechanical. Secondary power is typically extracted from the main engines mechanically by a driven shaft and pneumatically by bleeding the compressor. Mechanical power is distributed to a gearbox to drive lubrication pumps, fuel pumps, hydraulic pumps and electrical generators. Pneumatic power typically drives air turbine motors for engine start systems and environmental control systems. Electrical power and hydraulic power are distributed throughout the aircraft for driving subsystems such as flight control actuators, landing gear brakes, utility actuators, avionics, and weapon systems.

Recent and projected advancements in aircraft electrical power system and component technologies have resulted in renewed interest in the MEA. For example, hydraulically driven actuators would be replaced by electric motor driven actuators, gearbox driven fuel and lubrication pumps would be replaced by electric motor driven pumps, and a pneumatically driven compressor for environmental control would be replaced by an electric motor driven compressor. Studies on two different military fighter aircraft have shown that the MEA concept provides significant reliability, maintainability and supportability payoff.

There are four major technical thrusts in the roadmap: (1) power generation, (2) power systems and distribution components, (3) passive components, and (4) power electronics/motor drives

Power Generators — Independent Power Units (IPU)

A High Reliability Generator was developed from a conventional 400 Hz Variable Speed Constant Frequency (VSCF) system to a dual output (270 VDC and 400 Hz) system capable of supporting the near-term MEA.

The Switched Reluctance Starter/Generator program developed the preliminary design for a 375 KW, 270 VDC switched reluctance starter/generator in which the electrical machine is integrated internally with an advanced gas turbine engine.

A smaller 250 KW unit was built and tested to demonstrate the critical technologies. The switched reluctance starter/generator system offers a robust, high temperature, fault tolerant solution for the environmental demands of the turbine engine and the performance demands for the MEA.

Feasibility is based upon recent advancements in power electronic component technologies, high temperature wire insulation, and high temperature, high strength magnetic materials. The power electronic inverter is essential to the system since it provides the means to excite and process power to and from the unit. An Electro-Magnetic Interference (EMI) filter will reduce unwanted frequency components.

These systems are directly applicable to ground applications. In fact, Allied Signal is the contractor, which no doubt contributes to their civilian microturbine program.

In another development, an internally integrated 375 KW Starter/Generator for large aircraft enginees will include the critical step of eliminating the engine gearbox and aircraft mounted accessory drive. Integration into the gas turbine engine is enabled by high strength, high

temperature permanent magnet materials (cobalt-iron) and reliable high temperature wire insulation.

Power Systems and Distribution Components

The MEA will need a highly reliable, fault tolerant, autonomously controlled electrical power system to deliver high quality power from the sources to the load.

There are several challenges in designing an electrical power system for a MEA. Total onboard power requirements will be much greater, ranging as high as 1-10 MW per aircraft. It adds substantial amount of high power dynamic motor loads which could impact power quality. Most of these loads will have a low input impedance "capacitive" EMI filter which could present an in-rush current problem. Some MEA loads such as flight control actuators could provide regenerative energy back to the power distribution system.

Most important, these loads are flight critical, and loss of power to these loads could result in the loss of the aircraft. Thus, the performance and integrity of the power distribution system becomes a critical network which links sources to loads.

Presently, the Air Force has two programs for power systems and distribution components for the MEA.

– Power Management and Distribution for More Electric Aircraft (MADMEL) program
– Remote Terminal utilizing 270 VDC Solid State Power Controller program.

Future programs include development of: (a) high current (>50 ampere) intelligent power controllers and contactors that provide control, protection, and status feedback. (b) smart, overcurrent, differential current, and ground fault protection systems, (c) arc detection circuits to trigger protection devices in the event of an arc. (d) highly reliable and rugged connectors and interconnect components.

Passive Components – Capacitors

— Contact: Sandra Fries-Carr, 937-255-6016, carrsj@wl.wpafb.af.mil

State-of-the-art aircraft capacitors are considered to be the weakest link in power electronic systems. They are also large, heavy and lossy. This is a real concern for the MEA since 100s to 1000s of capacitors will be required for filtering and energy storage. The Air Force is pursuing several organic and inorganic capacitor technologies under contract that promise improvements in reliability, size, weight, and electrical and thermal performance.

Foster-Miller Corp. was awarded an SBIR contract to examine the application of PBZT polymer film for capacitors. This film demonstrated dielectric strengths as high as 100,000 Volts/Mil and low dissipation factor at high temperatures (up to 300*C). A follow-on SBIR contract to Foster-Miller further developed the PBZT film to make highly reliable, high energy density capacitors with operating temperatures to 300*C.

Westinghouse Science and Technology Center was under contract to develop and demonstrate high temperature (>200*C) AC and DC filter capacitors using a FPE polymer film from 3M Corporation. The capacitors were tested with a Variable Speed Constant Frequency (VSCF) generator system and demonstrated over 2000 hours of trouble free operation at 225*C.

Olean Advanced Products, Division of AVX Corporation is under contract to develop multilayer ceramic capacitors with increased operating temperature (up to 300*C) and reduced dissipation factor over a wide frequency and temperature range. Ceramic capacitors offer tremendous volumetric density compared to other capacitor technologies.

Wright Labs, in-house, is using low temperature RF sputtering to make very thin film ceramics (600 angstroms) which can be put directly on a circuit board.

Ultra high energy density pseudo capacitors have been developed, demonstrating energy densities over 11 Joules/gram and possibly as high as 30 J/g. An inexpensive device about the size of a quarter, weighing 6 grams, is rated at 5 farads at 5 volts. These are use in burst power and other aircraft and civilian applications, and can be stacked to the 1 KV level.

Diamond Thin Film Capacitors

The Air Force is conducting an in-house research program to investigate the possibility of using diamond-like carbon and polycrystalline diamond films as dielectric materials for capacitors. Diamond has the highest thermal conductivity of any material known and a very high dielectric strength, electrical resistivity and operating temperature capability. Wright Labs has made thin films using microwave plasma-enhanced chemical vapor deposition that have very stable performance over a wide temperature range. Capacitors continue to work well at 600 deg C, with a power density of 7 Joule/gram.

The Air Force has recently awarded several contracts to investigate other promising dielectric materials and construction techniques for capacitors. This includes silicon carbide, barium titanate, and multi-layer diamond capacitors.

Power Electronics and Motor Drives

— Contact: Clarence Severt, 937-255-6235

Advancements in power semiconductor devices, capacitors, and integrated circuits for control has enabled high density, reliable power electronic and motor drive systems that are essential for the MEA. These include generators, battery chargers, DC to AC inverters, and DC to DC converters, and motor drives, which provide the interface between the electrical power system and the motor.

To date, the Air Force has focused on MOS Controlled Thyristor (MCT) switching device and the MCT driver. Future work will center on Application Specific Integrated Circuit (ASIC) technology for motor drive controls and the development of advanced drives for induction, permanent magnet, and switched reluctance motors.

In September 1986, the Air Force awarded a contract to the General Electric Corporate Research and Development Center to develop a high power MCT device. At that time, GE had only demonstrated a small MCT device capable of a few Amps and a 200 Volts. The objective of this contract was to develop and demonstrate a high power device (with several orders of magnitude increase in power handling capability) that would be applicable to aircraft power conditioning. The goal was to develop a 150 Ampere 900 Volt device capable of high speed operation (200 nanosecond turn-on and 1 microsecond turn-off capability), low forward voltage drop (1 Volt) and high temperature capability (>200*C junction temperature).

Later in the contract, an integrated circuit driver chip was developed that provides an interface between logic control signals and the gate of the MCT. This program was successful in meeting its goals, and several hundred first generation MCT devices and driver circuits were produced, with significant performance improvements as well as size and weight reductions when compared to bipolar junction transistor technology available at that time.

A second contract was awarded to GE to make the MCT an acceptable and preferred device for military weapon systems such as the MEA. This contract is focused on advanced hermetic packaging, radiation hardening, and symmetrical voltage blocking for AC applications. Also improvements to the MCT are being investigated which offer improvements in peak current turn-off capability and current density.

———————————————————-

• Ground Power

Remote Small Scale (10-120 watts)
— Contact: Tom Lamp, 937-255-6235, xxxx@wl.wpafb.af.mil

The Air Force has over 80 remote sites in Alaska that need ultra high reliability power sources in the 10-30 watt range, for sensor systems, to 120 watts. Most are equipped with thermoelectric generators (TEG) that operate on propane, with some photovoltaic. The transportation costs run to $30-40 per pound of fuel, so the low efficiency of TEG, typically about 5%, is obviously a concern. Requirements are unattended operation, low health and safety risk to local population and Air Force personnel, and low environmental risk. Installation must be quick, by heliocopter drop-in. Weather conditions are very extreme.

But for the social outcry that would result, RTG’s are the obvious best choice (radionuclear thermal generators–as used on space missions). Other mature technologies include batteries, fuel cells, wind and engines, none of which meet the objectives.

Other choices are Stirling, Thermionic, Thermophotovoltaic, and AMTEC, all of which are small scale heat-to-electricity conversion devices with higher efficiency than TEG.

Stirling is under development by NASA for slightly larger systems (350 watts), and DARPA is funding some work on TPV and AMTEC ( a 500 watt compact system for the Army).

For the Alaska sites, the conclusions are that AMTEC and Stirling are the best candidates. Work is underway to develop prototype systems, building on the work done for space power systems. Commercial applications could include gas metering, navigation stations, weather monitors, and cathodic protection.

Cryogenic Lightweight Deployable (1-4 MW)
— Contact Jerry Beam, 937-255-6226

The Air Force needs lightweight deployable power plants to support, as one example, ground based radar (GBR) systems. Conventional technology and it’s supporting infrastructure is larger and heavier than wanted, and one of the Air Force’s key goal is to reduce the "logistics tail" whenever possible. A study showed that the conventional GBR plant with 5 semi-trailers and 140 cubic meters in volume, could be reduced to 2 trailers by the use of a superconducting cryogenic power generator. Since the radars already need cryogenic support, this is not an additional requirement, and the size and efficiency gains are significant. A prototype system will be tested in 2000, and could be in the field by 2005.

• Turbine Compressor Research Facility (CRF)
— Contact: Mark Reitz, 937-255-6802

The CRF is a major facility for conducting tests and evaluations of full scale multi stage and single shaft fans and compressors for gas turbine engines. Extending over four buildings, it is capable of 30,000 hp at speeds to 16,000 rpm, and 15,000 hp from 16 to 30,000 rpm. It can create steady-state and transient phenomena on full size test articles under conditions that are similar to those of actual operation. It has been used for many advanced turbine development programs to evaluate fans and core compressors.

Solar Turbines, Inc. is developing gas fired turbine engines for cogeneration and industrial drive applications in industry, under a CRADA with DOE’s advanced turbine program. The compressor for this engine is now under test at the CRF to identify any possible design deficiencies. This is the first major commercial use of the CRF.

• Electronics Cooling
— Contact John Leland, 937-255-2922

Cooling of power electronics is particularly important as systems become more compact and powerful. Anticipating cooling requirements up to 600 W/sq cm, a number of initiatives at the Lab include:

— testing performance of heat pipes in aircraft-type environments, e.g. under acceleration and vibration. Contact Kirk Yerkes, 937-255-6241
— integration of direct spray cooling into a 270 V 400 A single phase inverter, leading to a reduction in size of 10X. Direct immersion, jet impingement and flow boiling are also receiving attention. Contact Brian Donovan, 937-255-6241
— Venturi flow cooling is another technique under consideration

• Mechanical Testing of Electrical Machinery
— Contact Tim Young
— Characterization of soft magnetic materials at higher speeds and temperatures encountered in IPU’s
— Windage in generators can become a significant power loss (as much as 30-40%) at high RPM due to viscous air losses.

• Silicon Carbide High Power Electronics
— Contact: Clarence Severt, 937-255-6235

Compared with silicon, Silicon Carbide semiconductors have 3 times the band gap, and a operating temperature range reaching 4-600 deg. C, compared with 125 deg. C for silicon. It also has higher breakdown strength, which can mean thinner devices. Also, increased circuit efficiencies can reduce heat loads as much as 5X.

The main obstacle to using SiC in power electronics is the difficulty in making it without defects. "Micropipes" form too easily as the material is built up by vapor deposition.

The Air Force program has focused on development of high quality semiconductor grade material, improving on both wafer size and defect rates, for an aggressive development effort for power electronic devices. They have set a goal to demonstrate a 100-amp 600-V 572 deg F SiC switch by the year 2002.

For the power industry, discussions were well along with EPRI last year on possible cofunding of several device programs, but EPRI backed out. No new initiatives have come forward since.

——press release by CREE Research, one of the key developers in this program——–

Cree Unveils New Product Offerings for Silicon Carbide Wafers 40% Reduction in Micropipe Densities on Silicon Carbide Material

(Durham, NC May 27, 1997) Cree Research Inc. [NASDAQ: CREE] today announced that it has made tremendous progress in its efforts to reduce micropipes within its silicon carbide (SiC) material. Cree will now offer its 4HN type SiC wafers with reduced micropipe densities (MPD) and graded to three categories. The low grade will have a maximum of 30 micropipes/cm2, which represents a reduction in MPD of 40%. A new select grade will be added, which will have a range of 31 to 100 micropipes/cm2. In addition to Cree’s low and select grades, the standard grade will have a range of 101 to 200 micropipes/cm2. This represents a reduction in MPD of 50%.

Christer Ovren, Director of Silicon Carbide Device Development at Asea Brown Bovari (ABB), commented that "Cree continues to lead the world in making lower micropipe substrates available for the research and development of next generation devices. This latest advance is another step forward in maturing the manufacturing process for silicon carbide technology." ABB has purchased SiC wafers from Cree for a number of years.

These reduced micropipe densities are a result of Cree’s continuous commercialization of its SiC material technology. Cree expects this technology breakthrough to enable SiC material for more applications and improve device performance of existing applications. North Carolina based Cree Research, Inc. is the world leader in the development of silicon carbide-based semiconductors which have potential advantages in certain optoelectronic, RF and microwave, power, and high temperature applications. Cree owns outright or licenses exclusively 40 patents related to its process and device technology.

————————————————————————-

• Superconductors, Cryogenic Power Electronics
— Contact: Charles Oberly, 937-255-4814

As noted above, cryogenic systems can have dramatically improved efficiency, size reduction, and performance as compared with standard counterparts. Power conversion efficiency of an alternator/motor, for example, can reach 99%, including the refrigeration needed, compared with 92% for conventional copper based components. Wright Lab is developing both the high temperature SC materials and designs for generators, motors, actuators and power transmission lines.

Perhaps less well recognized, cryogenic cooling (i.e. to liquid Nitrogen temperatures) dramatically improve the performance of standard commercial solid state electronic components. Devices such as MOSFETS exhibit significantly reduced heating and faster switching. Ceramic capacitors have lower losses and higher capacitance when cooled.

• Batteries
— Contact Steve Vukson 937-255-7770, Dick Marsh

Aircraft battery systems are a major concern, particularly in regard to weight, reliability and maintenance. For example, vented NiCd battery maintenance costs are $3000/yr for each battery, amounting to $1/2 billion over a 20 year period. Wright Labs has developed a maintenance-free sealed NiCd cell technology, which uses low cost separator materials and which they’ve married with a microprocessor-based smart charger. These new systems will eliminate all scheduled maintenance costs, and also to save another $1/2 billion by reducing flight mission interruptions.

The bulk of the Lab’s battery program budget is devoted to advanced lithium polymer technology, doing work in molecular engineering in cooperations with Cornell, Berkeley and other academic institutions. The program has demonstrated prototype rechargeable lithium batteries with energy densities above 80 W-Hr/kg.

Thermal batteries are a special class of one-shot primary batteries used in weapons systems to deliver a large burst of power, very reliably, after waiting as long as one or two decades. Sandia National Lab is also well versed in this technology. ( –Would this have a useful role to play in nuclear power plant emergency systems?)

• Lubrication Technologies
— Contact Bob Wright, 937-255-4230, wrightrl@wl.wpafb.af.mil

This separate branch provides field support, development and advanced technology research. Their services to the Air Force include comprehensive testing facilities, bearing systems development, lubricant testing, magnetic bearings, etc.

For lubricants, increasing operating temperatures and longevity of lubricants are ever present goals. Some state-of-the-art compounds (polyphenyl ethers) have higher temperature capability but cannot be used below 40 deg. F, an obvious limitation for tactical systems. Others (perfluoro ethers) perform extremely well over a wide temperature range, but degrade quickly leading to corrosion. The overall paradigm is shifting from use of bulk oils to vapor phase lubricants, soft magnetic materials, and expendable coatings, although conventional ester lubricants are still foreseen to be the mainstay of aviation lubrication for some time to come. Meanwhile, integration of on-engine (on-line) oil condition diagnostics is an important theme. Off-line diagnostics are effective, but not optimal. This is a vital issue, as lubricant systems are implicated in 1.5 aircraft losses per year.

Magnetic Bearings — The Lab has a major development program, foreseeing big opportunities in engines to do active rotor dynamics control, increase temperature, do active control of compressor stability and blade tip clearance, and to have less logistics and better real time diagnostics.

On-line spectrometer — The Lab is sponsoring development of a very small infrared spectrometer for on-line oil analysis. The device measures the condition of the basestock and additives, and can detect the presence of unwanted contaminants, such as water, fuel, glycol, or wrong oil type.

——————–

"RULER" — Remaining Useful Life Evaluation Routine — off-line test system measures antioxidant levels in lubricants quickly and accurately by "voltammetric analysis". Results enable operators to determine remaining useful life of lubricants in less that a minute. RULER System consists of an "RULER" — Remaining Useful Life Evaluation Routine — off-line test system measures antioxidant levels in lubricants quickly and accurately by "voltammetric analysis". Results enable operators to determine remaining useful life of lubricants in less that a minute. RULER System consists of an instrument with probe, R-DAS (RULER Data Acquistion Software) pre-installed on a desktop or laptop computer. RULER System cost about $15,000. Proprietary solvents are used in the tests.

The RULER was originally developed at the University of Dayton Research Institute for Wright-Patterson Labs, for quick tests on aircraft oils between missions. It is manufactured by Fluitec Ltd., based in Dayton, OH with operations in Brussels. RULER customers cover a large range of industries world wide in oil, additive, manufacturing plants, power generation, aerospace and fleets. It’s applied to turbine, hydraulic, synthetic, working fluid, IC engine, and even biodegradable oils.

Contact: Lawrence Contreras, Fluitec, 937-223-8602, lcontrerasjr@juno.com

Battery Market Studies from Sandia

/0 Comments/in , /by

Battery Market Studies from Sandia
Aug 14, 1997

Sandia has issued two new reports on markets for batteries:

——————-
“Photovoltaic Battery and Charge Controller Market and Applications Survey”, Hammond, Turpin, et.al, SAND96-2900, December 1996

Surveys were conducted with PV system integrators, battery makers, and PV charge controller makers, to a) quantify the market for batteries shipped (in 1995), b) quantify market segments by type and application, c) characterize controllers used in PV systems, d) characterize operating environments for storage components in PV systems, and e) estimate the market in the year 2000.

In 1995, worldwide shipments for PV batteries totalled $300 million, with a U.S. accounting for just over 10%. In either case, system integrators account for no more than 14% of batteries sold for PV.

——————-
“Battery Energy Storage Market Feasibility Study”, Akhil and Kraft, SAND97-1275/1 and SAND97-1275/2, July 1997. (The first, 1275/1, is a short version of 25 pages. The second, 1275/2, is the long version, with about 200 pages, which will be available sometime in September.)

The purpose of this study was to quantify the energy storage market for utility applications by surveys of electricity providers, battery storage system vendors, and others. Specifically, goals were a) to gather perceptions in the battery energy storage (BES) and utility industries on desired features and comparison with other storage options; b) to estimate BES markets through the year 2010; and c) to provide Sandia and DOE with inputs to the Energy Storage System Program effort.

——————-
Reports can be obtained through NTIS or directly from Sandia. Send requests to Imelda Francis, 505-844-7362, fax 505-844-6972, or: igfranc@sandia.gov.