EESAT’02 Electricity Storage Conference

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.
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:

And while we’re on the subject, have a look at this comprehensive technology overview:

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:

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.

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.

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.

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.

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. [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.

Biomass Cofiring

A couple of UFTO utilities have expressed an interest in biomass cofiring, so I followed up with Sandia and also found some other resources also which you may find useful.


First, the new National Energy Technology Lab website for global climate change has a lot of information on the subject:


The 1995 UFTO report on Sandia had this brief summary on the Combustion Research Facility (CRF) that Sandia operates at its Livermore CA site…

“Over 1000 Sandia employees are located in facilities in Livermore California, and operate several special facilities, one of which is the Combustion Research Facility, the only one of its kind in DOE. Can handle industrial scale burners to 3 million BTU/hour. It is a “user facility” and outside visitors and users are encouraged. Partnerships with industry include GM, Cummins and Beckman Instruments and many others. Developed a number of specialized flame/combustion observational, measurement and diagnostic techniques. Provided fuel blending strategies to midwest utilities to meet SOx requirements. The Burner Engineering Research Laboratory is a user facility for industrial burner manufacturers.”


The CRF “Multifuel Combustor” website is currently under construction:


The CRF continues to be a significant contributor to combustion science, and in particular has amassed a major database of the combustion characteristics of over 50 different biomass fuels, most recently in the context of cofiring with coal. This work has been funded mostly by DOE, and includes information on emissions, carbon burnout, ash, and corrosion/deposition.

They’re also doing extensive computer modeling of coal, biomass and coal-biomass cofiring combustion. The coal modeling is under EPRI sponsorship, so that work is available to EPRI members. The dedicated biomass boiler modeling (stokers, etc.) is publicly available. The intellectual property issues associated with the coal-biomass cofiring are currently being sorted out, but it will be at least available to EPRI members and possibly to everyone.

For addition information, contact:

Larry Baxter 925-294-2862;
Sandia National Labs, Livermore, CA


Larry has generously supplied a copy of a brand new overview paper. Here are the first couple of pages. I have the complete 8 page overview as a (100k) Word document, which I can send on request. Larry has a more detailed article that he is willing to send to interested parties. Also, see below for some earlier reports, and a link to an upcoming American Chemical Society meeting session.



Larry Baxter, Allen Robinson, Steve Buckley and Marc Rumminger Sandia National Labs, Livermore CA

March 2000

This document presents guidelines for cofiring biomass with coal in coal-fired boilers. These guidelines are based on the results from pilot- and commercial-scale tests using a variety of biomass fuels and coals. Guidelines are offered in each of six general areas of major concern when cofiring biomass with coal: (1) fuel preparation and handling; (2) pollutant emissions; (3) ash deposition and deposit properties; (4) fuel burnout; (5) corrosion; and (6) fly ash utilization. For each of these areas, a brief statement of the issue and a brief guideline are summarized. More detailed information can be found at the cited website and in the references.

Summary of Cofiring Guidelines

We believe the following guidelines are generally valid, but there are specific instances where each of them is not valid. The discussions in the literature and web site provide the background to determine when such instances arise.

Fuel should generally be prepared and transported using equipment designed specifically for that purpose rather than mixed with coal and simultaneously processed.

Wood-coal blends generally reduce NOx emissions. This reduction is traced to lower fuel nitrogen content and higher volatile yields from biomass. SOx is nearly always reduced proportional to the reduction in total fuel sulfur associated with combining biomass with coal.

Deposition rates from blends of coal and biomass vary strongly with the type of biomass fired. Most wood-coal blends reduce both the rate of deposition and the difficulty managing the deposits. Some biomass-coal blends, in particular high alkali and high chlorine fuels, severely increase deposition problems.

Complete conversion of the carbon in biomass fuels requires that the fuel be processed to small particle sizes and be moderately dry. Particles generally need to be less than 3 mm (1/8 inch) to completely combust. Fuels that pass through a quarter-inch screen are generally dominated by particles less than 1/8 inch. High moisture contents (greater than 40%) and high particle density both significantly increase the time required to completely combust the particles.

Fuel chlorine and alkali concentrations should be limited to less than one fifth of the total fuel sulfur on a molar basis to avoid corrosion problems. This limit should be applied to the fuel composition as fired through any single burner except in the rare case of rapid and complete mixing of in the furnace.

Fly ash from wood-coal cofiring generally does not significantly degrade fly ash performance as a concrete additive. However, strict interpretation of current standards for inclusion of fly ash in concrete preclude mixed ashes, including biomass-coal ashes. Fly ash from many herbaceous fuels may negatively impact concrete properties.


Concerns regarding the potential global environmental impacts of fossil fuels used for power generation and other energy supplies are increasing in the U.S. and abroad. One means of mitigating these environmental impacts is increasing the fraction of renewable and sustainable energy in the national energy supply. Traditionally, renewable energy sources struggle to compete in open markets with fossil energy due to low efficiencies, high cost, and high technical risk.

Cofiring biomass with coal in traditional coal-fired boilers (subsequently referred to as cofiring) represents one combination of renewable and fossil energy utilization that derives the greatest benefit from both fuel types. Cofiring capitalizes on the large investment and infrastructure associated with the existing fossil-fuel-based power systems while requiring only a relatively modest investment to include a fraction of biomass in the fuel. When proper choices of biomass, coal, boiler design, and boiler operation are made, traditional pollutants (SOx, NOx, etc.) and net greenhouse gas (CO2, CH4, etc.) emissions decrease. Ancillary benefits include increased use of local resources for power, decreased demand for disposal of residues, and more effective use of resources. These advantages can be realized in the very near future with very low technical risk. However, improper choices of fuels, boiler design, or operating conditions could minimize or even negate many of the advantages of burning biomass with coal and may, in some cases, lead to significant damage to equipment. This document reviews the primary fireside issues and guidelines for implementing coal-biomass cofiring.

Fuel Characteristics

The biomass fuels considered here range from woody (ligneous) to grassy and straw-derived (herbaceous) materials and include both residues and energy crops. Woody residues are generally the fuels of choice for coal-fired boilers while energy crops and herbaceous residues represent future fuel resources and opportunity fuels, respectively. Biomass fuel properties differ significantly from than those of coal and also show significantly greater variation as a class of fuels than does coal. As examples (see Figure 1 and Figure 2), ash contents vary from less than 1% to over 20% and fuel nitrogen varies from around 0.1% to over 1%. Other notable properties of biomass relative to coal are a generally high moisture content (usually greater than 25% and sometimes greater than 50% as-fired, although there are exceptions), potentially high chlorine content (ranging from near 0 to 2.5 %), relatively low heating value (typically about half that of hv bituminous coal), and low bulk density (as low as one tenth that of coal per unit heating value). These properties each affect design, operation, and performance of cofiring systems.


Published papers available on cofiring:

Robinson, A., Baxter, L. L., Freeman, M., James, R. and Dayton, D. (1998) “Issues Associated with Coal-Biomass Cofiring,” In Bioenergy ’98Madison, Wisconsin.

Robinson, (1998) “Interactions between Coal and Biomass when Cofiring,” In Twenty-Seventh Symposium (International) on Combustion Combustion Institute, Boulder, CO, pp. 1351-1359.

Baxter and Robinson (1999) In Biomass: A Growth Opportunity for Green Energy and Value-added Products, Vol. 2 (Eds, Overend, R. P. and Chornet, E.) Elsevier Science, Ltd., Oxford, UK, pp. 1277-1284.

Baxter and Robinson (1999) “Key Issues When Cofiring Biomass with Coal in pc Boilers,” In Pittsburgh Coal Conference Pittsburgh, PA.

Baxter, Robinson, and Buckley (2000) “The Potential Role of Biomass in Power Generation,” In Biomass for Energy and Industry: 1st World Conference and Technology Exhibition Seville, Spain, to be presented.

Baxter, (1997) “Biomass-Coal Cofiring: Imperatives and Experimental Investigations,” In 3rd Biomass Conference of the Americas Montréal, Ontario, Canada.

Baxter, (2000) “Cofiring Biomass in Coal Boilers: Pilot- and Utility-scale Experiences,” In Biomass for Energy and Industry: 1st World Conference and Technology Exhibition Seville, Spain, to be presented.

Buckley, (1997) “Feasibility of Energetic Materials Combustion in Utility Boilers: Pilot-scale Study,” In 1997 Spring Meeting of the Western States Section of the Combustion Institute Sandia National Laboratories’ Combustion Research Facility, Livermore, CA.

Junker, (1997) “Cofiring Biomass and Coal: Plant Comparisons and Experimental Investigation of Deposit Formation,” In Engineering Foundation Conference on the Impact of Mineral Impurities on Solid Fuel Combustion Kona, HI. Robinson, A., Baxter, L. L., Freeman, M., James, R. and Dayton, D. (1998) “Issues Associated with Coal-Biomass Cofiring,” In Bioenergy ’98Madison, Wisconsin.

Robinson, (1997) “Fireside Considerations when Cofiring Biomass with Coal in PC Boilers,” In Engineering Foundation Conference on the Impact of Mineral Impurities on Solid Fuel Combustion Kona, HI.

Robinson, (1997) “Ash Deposition and Pollutant Formation when Cofiring Biomass with Coal in PC Boilers,” In EPRI Coal Quality Conference Kansas City, MO.

Robinson, (1997) “Pollutant Formation, Ash Deposition, and Fly Ash Properties When Cofiring Biomass and Coal,” In Engineering Foundation Conference on the Economic and Environmental Aspects of Coal Utilization Santa Barbara, CA.


1998 Tech Review — Sandia Combustion Research

-Coal and Biomass Combustion
-Cofiring Biomass and Coal to Reduce CO2 Emissions from
Coal-Fired Utility Boilers
-Thermal Conductivity of Ash Deposits Formed in Utility Boilers
-Mineral Matter Evolution during Coal Char Burnout


1997 Tech Review — Sandia Combustion Research

Scroll down to — “Coal and Biomass Combustion”

-Carbon Burnout Kinetic Model Developed for Pulverized Coal Combustion;
-Ash Deposit Property Analysis
-Pollutant Formation and Ash Deposition When Cofiring Biomass and Coal
-Formation of Ash Deposits in Biomass-Fired Boilers
-Combustion Properties of Biomass Pyrolysis Oils


AUGUST 20-24, 2000
Washington DC.

Division of Fuel Chemistry:

· 1990 Clean Air Act Amendments: A 10-Year Assessment
· Inorganics in Fossil Fuels, Waste Materials, and Biomass:
Characterization, Combustion
· Waste Material Recycling for Energy and Other Applications
· Fossil Fuels and Global Climate/CO2 Abatement
· Solid Fuel Chemistry
· Chemistry of Liquid and Gaseous Fuels

IEEE DistGen Stds update

IEEE SCC21 P1547 Web Site Available:

(The first is the html home page, the second one is simply an archive file log.)

The site includes a P1547Background file, a P1547MeetingPattern file explaining meeting logistics, and folders for past and ongoing notices, agendas and minutes. (Meeting minutes “annexes” are not available electronically.)

The January 2000 meeting (Albuquerque NM) minutes have just been posted at the “archives” site. <>

The next meeting is April 26-27, 2000 hosted by Cutler-Hammer in Pittsburgh PA Next after that is June 7-8, 2000, hosted by Capstone Turbines in Los Angeles

Contact is: Tom Basso, 303-384-6765,

(For additional background, see:
UFTO Note – IEEE Stds for DR Interconnection, 09 Jul 1999)


In related developments: (February 10, 2000)

Sandia’s PV News: IEEE Interconnection Standard For Utility-Intertied Photovoltaic Systems Is Approved

An IEEE-sponsored working group has developed an interconnection standard that will simplify the process of interconnecting photovoltaic systems with an electric utility. Photovoltaics (PV) is a solar-electric technology that uses solid-state solar cells to convert solar energy to electric energy. Not only does this standard vastly simplify PV interconnection, but it is the first IEEE standard of its kind for allowing utility interconnections of non-utility-owned distributed generation equipment. The unique aspects of this standard include tightly-defined requirements for the interconnecting hardware that can be tested by an independent test laboratory such as Underwriters Laboratories. This removes former barriers to PV use throughout the country.

John Stevens, Sandia National Labs, chaired the working group, which included about 25 members representing the utility industry, the PV industry, PV inverter manufacturers and PV researchers. The effort was sponsored by IEEE Standards Coordinating Committee 21 (SCC21). It required a little over three years from initial announcement of the project to final approval by the IEEE Standards Board. Its value is that it provides a standard that PV interconnection hardware can be designed to, thus removing the requirement for specialized hardware for different utility jurisdictions. The standard includes very specific requirements for systems of up to 10kW, but it covers systems of all sizes. The IEEE PV interconnection standard, identified as IEEE Std 929-2000, is known informally as IEEE 929.

The standard actually applies to the PV inverter, the device that converts the PV dc energy into utility-compatible ac energy. Similar inverters are used in other distributed generation systems such as fuel cells and microturbines. Many of the requirements for interconnection that are described in IEEE 929 might also be adopted for these other technologies.

IEEE 929 provides guidance for operating voltage and frequency windows, trip times for excursions outside these windows, requirements for waveform distortion, as well as defining a non-islanding inverter. An important parallel effort was performed at Underwriters Laboratories where a test procedure, UL 1741, was written that will verify that an inverter meets the requirements of IEEE 929.

In support of the IEEE 929 process, several development projects were completed at Sandia that addressed interconnection issues. The performance of several inverters operating in parallel when a utility line is de-energized was characterized to better understand the potential for unintended operation during a utility outage (“islanding”). A control scheme was developed to assure that islanding doesn’t happen. A test was developed to allow testing of single inverters to identify the presence, or lack, of an adequate anti-islanding scheme. Several specific tests were performed at the request of some electric utilities to examine such issues as ferroresonance with inverters under fault conditions and response of inverter protection schemes to the non-sinusoidal waveforms that are sometimes associated with abnormal conditions on utility systems.

This working group was an outstanding example of people with different backgrounds working together toward a common goal — simplifying the interconnection procedure. IEEE SCC21, which is chaired by Dick DeBlasio of NREL, has sponsored numerous PV-related standards since its inception in the late 1970s.

For further information on this PV interconnection standard
contact John Stevens,
Sandia PV Projects (505) 844-3698 (phone) (505) 844-6541 (fax)

CERTS – New DOE Prog in Elec. Reliability

The Consortium for Electric Reliability Technology Solutions (CERTS) has been tasked by DOE to undertake a major new $2.5 million program in electric power system reliability research and technology development. (Congress re-established a budget for Transmission Reliability research in FY 1999, in DOE’s newly renamed “Office of Power Technologies” (OPT), formerly called the Office of Utility Technologies, under Deputy Assistant Secretary, Dan Adamson.)

The members of CERTS include:
Lawrence Berkeley National Laboratory (LBNL)
Edison Technology Solutions (ETS)
Oak Ridge National Laboratory (ORNL)
Pacific Northwest National Laboratory (PNNL)
Power Systems Engineering Research Center (PSERC)
Sandia National Laboratories (SNL).
The program is an important element in DOE_s response to the recommendations and findings of the SEAB Task Force on Electric System Reliability final report. (See UFTO Note, Oct 8, 1998, or go to:

PSERC is a group of universities that have formed a cross-disciplinary team dedicated to solving the challenges arising from power system restructuring. It’s worth a visit to their website at:

CERTS organizers are committed to a high degree of involvement by stakeholders. In particular, there will be a Technical Advisory Committee (see below), and numerous opportunities to participate in the research itself. A website is in preparation to provide public access to program details and developments.


Joe Eto, LBNL, Program Office Manager for the Consortium, 510-486-7284

Phil Overholt, DOE/OPT, T&D Reliability Program Manager, 202-586-8110

Introduction and Overview–(excerpted from CERTS proposal)

The U.S. electric power system is in transition from one that has been centrally planned and controlled to one that will be increasingly dependent on competitive market forces to determine its operation and expansion. Unique features of electric power, including the need to match supply and demand in real-time, the interconnected networks over which power flows, and the rapid propagation of disturbances throughout the grid pose unique challenges that are likely to be exacerbated in the future. As the physical events of 1996 and the market events of 1998 demonstrate, the reliability of the grid and the integrity of the markets it supports are integral to the economic well-being of the nation.

The Consortium for Electric Reliability Technology Solutions (CERTS) was formed to develop and commercialize new methods, tools, and technologies to protect and enhance the reliability of the U.S. electric power system under the emerging competitive electricity market structure.

CERTS organizes its activities under four major areas: (1) Reliability Technology Issues and Needs Assessment; (2) Real Time System Control; (3) Integration of Distributed Technologies; and (4) Reliability and Markets. The first area encompasses strategic planning; the remaining three areas involve research and technology development. (See individual projects described below).

CERTS Organization

LBNL operates a Program Office for CERTS with day-to-day responsibilities for managing CERTS projects and activities acting under direction from the Management Steering Committee.

ETS operates a Commercialization Office for CERTS with responsibilities for preparing commercialization plans and, when appropriate, implementing commercialization activities for CERTS projects and activities.

CERTS is also working with DOE to create a Technical Advisory Committee, consisting of 10+ industry stakeholders and experts to review the activities of the consortium and provide guidance on research direction.

FY 99 activities for DOE include work in five areas

1. Grid of the Future

The first year of a two year planning study to identify emerging gaps in reliability technology R&D. In the first year, CERTS will lay the groundwork for the development of a federal R&D roadmap by preparing six white papers, which will be the basis for industry-wide stakeholder workshops on: (1) alternative scenarios for the future of the electric power system, including a detailed articulation of the technological assumptions underlying each of these futures; (2) assessment of the technology and control R&D needs for widespread integration of distributed resources; (3) recent reliability issues review, including in-depth analysis of technological and institutional aspects of recent reliability events (e.g., summer 1996 WSCC events; winter 1997 northeast ice storms; winter 1998 San Francisco outage, etc.); (4) review and assessment of the current structure of U.S. bulk power markets and provision of reliability services (including 1998 price spikes in mid-west and west, and absence of meaningful opportunities for demand response); (5) assessment of the technology and control R&D needs for real time system control; (6) assessment of the treatment of uncertainty in planning and operational models.
2. Distributed Technologies Test Bed

The first year of a major multi-year effort to design and ultimately, with industry and other stakeholder partners from industry, operate an in-field distributed technologies test bed. The objective of this work is to develop and demonstrate the technologies and control strategies needed to support widespread integration of distributed resources into the grid.

During the first year, CERTS will: (1) specify the information needed to conduct system simulation studies of distributed technologies, assemble available information, and develop a plan for additional laboratory bench tests to gather missing information; (2) conduct simulation studies of the different scenarios of distributed technology penetration using available data and models to evaluate distribution system reliability impacts and identify micro-grid control issues; and (3) develop a multi-year demonstration plan for a distributed technologies test bed.

3. Reliability Market Monitoring, Design, and Analysis

The first year of a multi-year effort to improve the design and operation of markets for the provision of reliability services in a restructured electricity industry. An integrated set of data development, simulation, and design activities will provide both immediate and longer-term benefits to emerging competitive markets.

During the first year, CERTS will: (1) collect data on ancillary services market compliance for the CA ISO and evaluate alternative user interfaces for using these data; (2) use these and other data to examine the performance of the market and, where warranted, suggest directions for fundamental changes in the design of these markets; (3) use experimental economic methods and other methods to simulate the performance of both current and proposed market designs; and (4) analyze customer-side technical requirements for provision of reliability services

4. Smart VAR Management System

Develop and demonstrate a software tool that will allow system operators to measure, communicate, and process real-time data to perform a VAR analysis of the WSCC grid and provide system operators with voltage profiles and reactive reserve margins at key substations. Had this tool been available, the 1996 outages on the Western grid could have been prevented.

During the first year, CERTS will develop, prototype, and field-test hardware and software that can be integrated with current energy management systems to provide operators with necessary information, contingency simulation, performance tracking, and report generation on voltage and reactive reserve margins.

5. Distributed Control

The first year of a multi-year effort to develop and demonstrate the appropriate role for distributed controls in management of the operations of regional power systems. During the first year, CERTS will initiate a demonstration of the ability and comparative performance of autonomous reasoning agents to maintain power system reliability compared to conventional centralized control methods.

Inverters – State-of-the-Art

Sandia’s Energy Storage Program has published a new report on power conversion systems which gives a comprehensive overview of the various design approaches, the current state of the art, and recommendations for future development (specifically targeting cost reduction).

The abstract appears below. I also have an electronic copy of the Executive Summary, which I can provide on request (specify RTF or HTML format).

To request copies, contact:
Imelda Francis, 505-844-7362, Fax 505-844-6972,

Technical contact:
Stan Atcitty, 505-284-2701,

“Summary of State-of-the-Art Power Conversion Systems
for Energy Conversion Storage Applications”

Sandia National Labs, SAND98-2019, September 1998


The power conversion system (PCS) is a vital part of many energy storage systems. It serves as the interface between the storage device, an energy source, and an AC load. This report summarizes the results of an extensive study of state-of-the-art power conversion systems used for energy storage applications. The purpose of the study was to investigate the potential for cost reduction and performance improvement in these power conversion systems and to provide recommendations for future research and development.

This report provides:
– an overview of PCS technology,
– a description of several state-of-the-art power conversion systems
and how they are used in specific applications,
– a summary of four basic configurations for the power conversion
systems used in energy storage applications,
– a discussion of PCS costs and potential cost reductions,
– a summary of the standards and codes relevant to the technology,
– recommendations for future research and development.

Substation Power Quality System

Sandia is developing a proposal for a Substation Power Quality System (SPQS) project and needs industry input. Attached below are the text of a powerpoint presentation and a list of questions. There hasn’t been much involvement yet from utilities, so UFTO companies are especially encouraged to respond directly to Sandia with comments. The central question now appears to be: “Are utilities or large end users interested in a substation level power quality system?”. (There will also be a presentation at the PowerSystems World ’98 conference in Santa Clara, CA on Nov. 11.)

The DOE Energy Storage Systems Program at Sandia has been working with industry and other laboratories for several years on storage systems for substation power quality applications.

Over the last three years, DOE and Sandia worked closely with Public Service of New Mexico on a project with the intent of developing and demonstrating a substation power quality system. Industry partnerships were to be formed for the development phase, and a demonstration site was chosen at Sandia. Recent market downturns coupled with turmoil in the electric utility industry prevented the completion of this project. The DOE Energy Storage Program is still committed to working with industry on the development and testing of substation level, mid-voltage power quality systems.

The system as currently conceived would operate at the 12-15 kV, 2-6 MVA level. It would correct power quality problems originating upstream of the substation in the transmission line system or downstream in adjacent distribution system feeder lines. Open questions exist regarding the required ride-through time, technology to be employed, and the location for such a demonstration. This is anticipated to be a three-year project. The intent is to form a cost shared partnership to design, construct and field a system in this power range.

Sandia is very interested in obtaining comments on the Utility and Electricity provider industry interest in such a project, and feedback from energy storage system suppliers on the technology available for this type of system.

————-(text of powerpoint vugraphs)——–
Substation Power Quality Project

Dean Rovang, Abbas Akhil, John Boyes
Sandia National Laboratories, Albuquerque, NM

(Oct. 7, 1998, ESA Fall ’98 Meeting, Atlanta, GA)

— Why Are We Here?
Discuss the ESS/SNL perspective on a Sub-station Power Quality System (SPQS)
Past motivation and future expectations
History of project at SNL with PNM
SNL’s performance expectations for PQ system
Obtain industry perspective
Industry perspective on SPQS market
Industry needs of system performance:
Power level, ride through, footprint
Describe SNL’s expectations for further work
Competitive, cost-shared proposals
RFI followed by RFP

— Past Motivation
PNM’s experience with large hi-tech customers in their service area
Traditional UPS solutions did not solve all PQ problems
PNM was seeking a utility-level solution
SNL advocated a SMES solution at a mid-voltage level
SNL Superconductivity Program
Preliminary thinking indicated 1 – 2 second ride through was adequate

— Project History
PNM and SNL formed an Industrial Advisory Board (IAB)
Primarily semiconductor manufacturers
Define system performance requirements
1 – 2 second ride through was thought to be adequate
“Baseline” PQ system concept with 2 second ride through
12.47 kV, 22.4 MVA
SMES system size was 42 MJ

— Other IAB input
Cost must not only be competitive, but aggressively competitive
Not UPS, limited ride through
It protects entire load, people expect lower $/kVA
Demonstrate device at someone else’s facility
Some factors motivated rethinking project scope
Cost estimates of $17 million for baseline system
4 second sag recorded at customer site

— Revised Baseline system was proposed
SNL advocated idea of “meaningful yet supportable” demonstration
6 MVA size: matches SNL loads
Split-bus concept at Substation 41
Use battery to reduce cost and meet ride through requirements
SNL and PNM pursued CRADA for demonstration at SNL site
CRADA package was prepared but not executed
Project canceled

Mid-voltage level is the next logical step in the evolution
of PQ systems
Industry wants to develop SPQS technology
Provides vehicle for Utilities to deliver Premium Power
Whole facilities and multiple customers can be protected
in a Premium Power Park concept
Utility will have control of PQ system at the substation level
Short power interruptions can be corrected at one place
Voltage sags are not always corrected by existing systems
Economy of scale

— Substation Power Quality System:
Correct voltage sags/swells and momentary outages from transmission lines or
adjacent feeder lines

— SNL Expectations for Future SPQS
Interconnection voltage: 12 – 15 kV
System power: 2 – 6 MVA
Ride through options:
2 – 8 seconds for voltage sags
up to 30 seconds for 3rd re-closer requirements
1/4 cycle switch time
Storage technology insensitive
Turnkey system
Modular design, outdoor installation
Self-contained energy storage module(s) – eliminate need for building
Minimize footprint

Demonstration preferred at customer site; alternately at SNL
Innovative power conversion and system design
Prefer not paralleling existing small systems to meet performance
Encourage formation of user/supplier consortia
Cost-sharing of 50-80% by industry
SNL contribution expected to be $1.5-2.0 M over 3 years
Time to demonstration – 3 years
Place contract in FY99
System build FY00
System installation and testing FY01

Questions For The Utility/Electricity Provider Industry

1. Are Power Quality solutions at the substation location
useful to you?
2. What voltage(s), in mid-voltage range, are of interest?
3. What is the minimum power level of interest?
4. What power quality events should this system address?
5. What ride through time should this system be capable of
6. What problems would this system create that must be addressed
in the design phase? Reconnection? Siting? Safety? Control?
Maintenance? Etc.?
7. What type of sites would benefit from this system?
8. Are there any potential sites in your system?
9. Are you interested in hosting the site?
10. Do you see the need for this system now? In the near
term (1-3 years)? In the long term (>3 years)?
11. What would be a cost goal for such a system?

Questions for the Power Quality System Industry

1. Are the technical specifications in the ballpark?
2. Is the schedule estimate in the ballpark?
3. What are the technical issues in the proposed system?
4. Are the power electronics for the mid-voltage specification
ready for commercialization? If not what is the state of
the art?
5. What are the cost drivers of a mid-voltage Power
Quality system?
6. Who should perform the system integration function?

Questions for All

1. What kind of partnerships/consortia/collaborations could
be formed to pursue this system? Cost Sharing? Intellectual
property rights? Project responsibility? Etc.?
2. What other information is necessary for your company to
participate in this project?
3. What other information is necessary to start this project?
4. Other questions or comments:

___ Indicate if you would like emailed summaries of ESA meeting discussion
and future communications on the SPQS project.

Please Return to: John D. Boyes, Sandia National Laboratories
Telephone: (505) 845-7090 Fax: (505) 844-7874

Sandia: Critical Infrastructure

Energy and Critical Infrastructures
(Notes from UFTO visit to Sandia 12/97.)

Sam Varnado, Director
Energy and Critical Infrastructure Technology Center

Sandia is at the forefront of the big wave of attention currently being paid to “critical infrastructure surety” as it impacts national security. (Surety means “assurance”, and encompasses safety, integrity, authenticity, security, reliability, and technology.) Coming at the issue from a long background in systems analysis in the nuclear energy and weapons programs, they’ve emerged as a major player. Their experience in probabilistic risk assessment (PRA) is seen as directly translatable to infrastructure systems analysis. Since it is impractical to define threats, the approach is “consequence based”, as a means to determine why and where protections are required. It begins by identifying consequences that must be avoided, and then finds the system failure modes that could lead to them.

Sandia supported the President’s Commission on Critical Infrastructure Protection (PCCIP), which has an extensive website ( featuring the complete text of their major report issued in October 1997. An Interim Group is continuing the Commission’s work. Also, the National Security Council is heading another interagency group that is drafting a Presidential Decision Directive to assign responsibility for the different infrastructures to the different agencies (due to be released soon).

The PCCIP report identifies the electric power grid as one of the most critical infrastructure sectors, notably in terms of the high degree of interdependence and interconnectedness of power with all the other sectors: telecommunications, finance and banking, oil and gas distribution, transportation, and vital human services (e.g. banking depends on information systems which depend on power). The power grid is very susceptible to physical and cyber threats, the latter especially in light of the increasing role of computers in the hardware, markets and financial dealings of the industry.

There is also a high degree of concern over the uncertain implications of utility industry restructuring. The transition from regulated rate based monopolies to competitive energy markets will most certainly impact reliability of service and vulnerability to disruption. Existing reliability models are not capable of accurately reflecting the issues that will arise.

Safety and Reliability of Nuclear Systems

Nestor Ortiz, Director, Nuclear Energy Technology Center,

For the DOE Nuclear Energy Program, there is research in Plant Lifetime Improvement, Aging of Reactor Components, and Instrumentation and Control Upgrade.

Sandia developed and maintains several noteworthy PRA codes. To mention some of them:
– MELCOR is used internationally and by the NRC. Modeling fully integrated engineering systems, it simulates the propagation accident to consequences. (U.S. utilities use MAP).
– CONTAIN is a research and design certification tool for containment systems
– RADTRAD design basis dose calculations for NUREG 1475. Revised baselines may eliminate the need for some equipment and maintenance procedures.

¥ Loss of Off Site Power (LOSP)
Of particular note, Loss of Off Site Power (LOSP) studies have led to major concerns over the potential impact of restructuring. In the PRA safety analysis of a nuclear power plant, the probability of loss of offsite power (i.e. power on the grid) is a very important factor. Plant safety systems are stressed by LOSP events, contributing over time to increased probabilities of malfunctions (e.g. resulting in higher probabilities of a loss of coolant accident).

While grid reliability has generally been excellent (

At the same time, Sandia has extensive experience and has developed a Generic Network Reliability Analysis Toolset, which is extremely effective for analysis telecomm networks. However, preliminary efforts to investigate the applicability of this model indicate that it is not immediately extensible to networks with direction and capacity constraints inherent in bulk power grids.

Contact Dennis Berry, 505-844-0234,

Electricity Interdependencies – Estimating Economic Risks

Sandia has surveyed existing economic risk models to see if they can be usefully applied to estimate impacts of electric power disruptions.
– Lifeline LLEQE — effects of earthquake, for insurance
– FEMA – consequence assessment tool
– Electric Sector — 44 different models
– NDAC – telecom

They chose ENERGY 2020, the most recent incarnation of the Dartmouth (“Club of Rome” and FOSSIL 89) systems dynamic modeling approach, which has been used by EPA to analyze effects of green house gases on the electric system. It is “agent-based” and adaptable, and is available for free.

It feeds into REMI, a commercial (expensive!) dynamic regional macro-economic model. In preliminary runs with the Texas grid study results, it showed clearly that regions could experience permanent loss of jobs and increased costs. Future work will include use of Sandia’s own ASPEN model, an agent-based simulation of the US economy.

Contact Diane Marozas, 505-844-5504,

Impacts of Storage on National Grid Reliability

Storage on the power grid can be seen in several different lights: 1. as a source of peak supply; 2. as a load and demand-side management option, and 3. as a means to render renewable generation more reliable from a systems operation perspective. Sandia has just completed an initial scoping study relating the 3rd option, to develop recommendations for how modeling methodologies need to be enhanced in order to address the question. In particular, the NEMS model could be used for such analyses with some modifications. (NEMS is DOE/EIA’s general equilibrium model of the national energy system. It’s Electricity Market Module doesn’t currently have the capability to model storage on the national grid.)

“Modeling of Battery Energy Storage in the National Energy Modeling System”,
SAND97-2926, Dec 1997

Contact Paul Butler, 505-844-7874,

Vital Issues Panel

Sandia uses its own “Vital Issues Panel” methodology to identify strategic issues in areas of national importance, particularly where there is a potential for Sandia to make contributions from its technological capabilities. Topics have included Global Climate, Environmental Security (i.e. the environment as a national security issue (e.g. effluents used aggressively, destabilization potential in Eastern Europe, terrorist targets, etc.) Infrastructure has been examined in two case studies, Critical Issues and Vulnerabilities in the Electric Sector, and separately, Vulnerabilities of the North American Power Grid.

Critical Issues and Vulnerabilities in the Electric Sector

To study vulnerabilities associated with the Electric Sector, Sandia convened a panel of experts representing the electric utility sector(April 1997). The group and identified critical issues and discussed how technology can help address those issues. They determined the top eight most critical issues arising from industry restructuring. In priority order, they are:

– Management and ownership of data streams
– The importance of consumer choice
– Competitive market pricing systems that will determine the mix of options
– Environmental issues
– State/federal role in collaborative and strategic research
– Integration of the national electric grid
– Incentives for keeping distribution systems up to date
– Accelerated retirement of a significant amount of generating capacity.

The panel also discussed the past, present and future of utility R&D, and ranked federal and private R&D spending priorities:
– Federal: Integration of the national grid and environmental issues
— Private: Importance of consumer choice, management and ownership of data streams, and environmental issues.

A concern remains whether the utility participants were sufficiently representative of the industry, and whether they – or the industry – appropriately estimate the importance of broader security issues, as compared with individual business concerns (e.g. with data ownership and dividing of system responsibilities). The Sandia team is anxious to have greater involvement from the industry in these efforts.

The discussions are summarized in the report: SAND97-1659, August 1997
Contact Arnie Baker, 505-284-4462,

North American Power Grid (NAPG)

In April and June 1997, panels attended by stakeholders from government, industry and academe discussed vulnerabilities associated with the NAPG. The first panel was tasked to develop a mission statement and to define criteria by which risks and threats could be identified and prioritized. The second panel identified and defined categories of risk to the NAPG and assessed their relative importance, based on the groundwork laid by the first group.

The overall results:

–Criteria: Likelihood, Consequence, Timeframe, Cost/Benefit

–Risks: In rank order of importance
– Unrecognized risks embedded in new technologies and operating structures
– “Tragedy of the Commons” *
– Physical Threats and non-natural disaster
– Shorter time horizons driven by cost reduction
– Reliability and liability implications of reregulation
– Cyber threats

*”Tragedy of the Commons” (a term originated by Garrett Hardin his classic 1968 article in Science Magazine), is the idea that no single actor has enough concern for the whole system, but each has the ability and self-interest to overtax available resources. In the context of the power grid, obligation to serve and cooperation are being replaced by competition and opportunism.

A partial outline of the results are available at:
It hasn’t been decided yet whether the report will be released outside Sandia, in view of proprietary information it contains.

Center for System Reliability

Contact Robert Cranwell, 505-844-8368,

Sandia technologies and expertise:
Modeling, simulation, optimization, maintenance strategies, network reliability/vulnerability, risk management, sensitivity/uncertainty analyses, human factors/human reliability, life-cycle cost analysis, software reliability, prob. risk assessment.

Applied to:
Power Generation, telecommunications, transportation, health care, equipment

Sandia has done analyses for many large corporations, e.g., design for reliability; predict and optimize impact of upgrades; optimization of spares inventory, etc.

Reliability Analysis Software Packages
Reliability enters into every phase of a product life cycle, from concept to design to production and operation to phase-out. Sandia has developed computer models to support the entire reliability engineering cycle.

WinR –Over 100 copies sold, available on a commercial basis from Sandia (they’re looking for a vendor). PC based reliability modeling and analysis provides a “dashboard” showing status of system components and performance.

Arramis – PRA for larger systems

WinR-PdM — Predictive Maintenance — combine real time sensor data with WinR for a dynamic view of component aging and overall system reliability. Demo at Allied Signal on a flexible manufacturing system

CRAX — The CassandRA eXoskeleton (CRAX) is a new reliability analysis tool that is being developed at Sandia National Laboratories to support the Materials Aging and Reliability Program (another key capability at Sandia is the detailed understanding of the physics of aging phenomena–fatigue, fracture, corrosions, etc., which have myriad and complex implications for systems reliability).

There are three major elements to CRAX:

Analysis Engine (Cassandra)
User Interface (Tcl/Tk GUI)
Physical Model (User Supplied)

The Cassandra uncertainty analysis engine consists of a number of software routines which permit the user to select a variety of methods for including uncertainty in their analyses. Cassandra is CORBA compliant and platform independent permitting easy interface with many of the new engineering design and analysis software packages. Existing uncertainty analysis techniques include a variety of Monte Carlo and analytically based approaches. The specific methods are constantly being updated and improved.

In addition to the CORBA interface structure, access to the Cassandra uncertainty analysis engine is also available via a Tcl/Tkgraphical user interface. There is also an effort to permit this interface to be accessed through a WWW browser. This will greatly aid in access to the analysis software within the using community.

The final element of CRAX is the physical model. A major decision early in the development of CRAX was the decision to not include any physical modeling tools. Rather than develop a new modeling tool (e.g. finite element model or fault tree tool) it was decided to let the engineer rely on the existing tools that they were comfortable with and had confidence in. While not the ideal situation in terms of analysis speed, it was felt that for the engineers to become comfortable with incorporating uncertainty into their deterministic models, we did not want to stretch their belief system too far. Hence the reliance on existing, deterministic analysis tools and the reference to CRAX as an exoskeleton. Within CRAX is the capability to either recompile the existing software into the tool, thereby significantly increasing computational efficiency, or rely on ‘hand-shaking’ between the CRAX program and the existing software. TheTcl/Tk GUI handles either of these situations very easily.

David G. Robinson; 505-844-5883,

Strategic Surety & Risk Management

Contact Laura Gilliom, 505-844-9104,

(Surety means “assurance”, and encompasses safety, integrity, authenticity, security, reliability, and technology.)

(The following discussion is extremely sketchy–intended only to bring identify some of these subject areas and to highlight Sandia’s involvement and expertise.)

This program addresses itself to the state-of-the-art of “surety”, bringing together many of Sandia’s core capabilities. It’s overarching goal is to bring risk and reliability analysis from its current statistical foundations to become a predictive capability. “Consequences” are the starting point, as mentioned earlier, and “interdependencies” are a major theme. The work proceeds by combining what is done at the level of engineering design codes with analyses of scenarios for risk.

Risk Management is broadly defined as a management tool that encompasses these different but closely related activities:
1. Identification of hazards associated with a technical system
2. Determination of the risks (consequences and likelihoods) of those hazards.
3. Reduction of risks to acceptable levels through appropriate design and control measures.
4. Thorough documentation of the above 3 activities.
5. Continuing reevaluation to improve the system or solution.

At Sandia, several hundred professional staff apply these activities in 8 major areas :
– Environment and environmental restoration
– Information systems
– Nuclear Reactors
– Physical Security
– Production and Manufacturing
– Transportation
– Waste Management
– Weapons

To realize benefits of overlapping interests, these staff participate in an internal organization of risk professionals at Sandia, called Sandia’s International Institute for Systematic Risk Studies (SIIRS, or “scissors”).

–High Integrity Software
Abstract Synthesis Transformation — make short pieces of code that are “provably correct.”
Software Event Execution Reliability (SEER) involves a math overlay to be sure that sequences occur correctly.

–Information Assurance- Cryptography
Most methods of cryptography involve the use of a key and function. Sandia has developed a new approach to split the function, so no one person can have everything.

Sandia is the only DOE lab allowed to do R&D on cryptography, primarily for use and control of nuclear weapons. They have a major crypto library which is widely licensed.

–Devices–safe and secure. Doing new research to have confidence in the behavior of a system when a “chip makes a decision”.

–Authentication Center of Excellence (ACE) for banking, devices and software…physical tokens of authenticity; smart cards and highly secure smart card readers–systems for the Defense Department. (Think about SCADA systems and how susceptible they are to outside interference and control!)

–Information Warfare assessments–information and physical security. Imagine the havoc of an all out cyber war, i.e. an attack from an enemy country or syndicate, not just hackers.

–Auctions – imagine a new player who wants to disrupt it–gray areas between gaming the system and dishonesty….not just an issue of terrorists, but of businesses vulnerable to other players. How can bids/contracts be authenticated and when and how can they be disowned or repudiated?

Sandia’s PV News: Possible Procurement for Remote Power

(Forwarding note about renewable funding source…)


Subject: Sandia’s PV News: Possible Procurement for Remote Power
Date: 18 Mar 1998 16:54:03 -0700


Last year, the Congress passed legislation, as follows:

“Federal buildings/ Remote power initiatives — The House and Senate each included proposals intended to direct the Department (of Energy) to identify and pursue near term opportunities to exploit the strengths of solar and renewable energy technologies. The conference agreement includes both initiatives and provides $5,000,000 for these activities. The Department is directed to provide the House and Senate Committees on Appropriations with a program plan which includes a funding profile, and criteria for awarding proposals. All proposals must include a cost benefit analysis. The Department may approve only proposals that have verifiable, favorable cost benefits over a period of not more than ten years. Cost benefits shall be based exclusively on actual monetary costs and savings.”

As part of its response to this legislation, the Department of Energy issued a procurement through its State Energy Program office for up to $1.2 million in cost-shared projects, with the Department’s share being 25% of the cost, awarded in the form of a grant. The proposals that were submitted total substantially less than the available funds, so the Department is considering reissuing the procurement. The Department has asked for our assistance in publicizing this opportunity. In particular, we feel that the renewable energy industry may bring projects that would meet the procurement requirements to the attention of the states.

It is our understanding that the procurement requires that proposals be submitted through offices of state government, but does not require state matching funds. All matching funds could be provided by a private party for a privately-owned project as long as the state were willing to participate in proposing the project to the Department.

We would like feedback on whether there is sufficient interest in these projects to justify reissuing this call for proposals. Also, we are interested in feedback on the content of the statement of work below. Note, however, that the ten-year cost/benefit period is a requirement of the legislation. Please reply to this e-mail or via the phone numbers listed below.

The complete procurement may be found at

Only 6.52 is proposed to be reissued.

Total Funds: At least $1.2 million Estimated number of projects: 12 or more
Match: 300%; higher leveraging encouraged

In much of the developing world, and portions of the U.S., the costs of electricity transmission and distribution systems are prohibitive. As a result, large amounts of electricity, heating and cooling is provided by comparatively expensive and polluting diesel equipment or gasoline. In many cases renewable energy technologies are cost-competitive, but underutilized because of lack of consumer acceptance or reliability. This solicitation focuses on applications of renewable energy for remote energy needs, to demonstrate cost-effective, modular technologies as reliable, easy to operate, and easy to maintain.

Projects Requested in FY 1998:
Grants are available for design, purchase and installation of renewable energy technologies including solar hot water (SHW), where they would displace or avoid the use of diesel fuel or gasoline.

Examples of remote applications could include island mini-grid systems that supplement or displace existing or planned diesel/gasoline generation, or end-of-line systems or off-grid applications that could not be cost-effectively served by line extensions. All projects must monetary cost/benefit ratios over an analysis period of 10 years or less. They must also include an estimate of avoided or displaced fossil fuel generation, and an estimate of the number of similar applications that might be possible. Projects that demonstrate new products or applications that have a significant future market potential are desired. Examples could include products that also renewable energy technologies like PV and SHW systems that combine heat and electricity services, or projects that demonstrate new applications like telecommunication services for off-grid or remote areas.

Evaluation Criteria:
Value in demonstrating a viable application of renewable energy that can be replicated at other sites, including the number and size of potential applications. (30%)
2) Technical quality of plans for system design, operation and maintenance. (20%) 3) Cost sharing above the 300% match requirement. (20%) follow-up plans for disseminating results and lessons learned within the State, and/or nationally. (10%) 5) Demonstration of new technology or applications to advance consumer acceptance and/or reliability, for example building integration, or new types of services for an area. (10%) 6) Value of displaced diesel or other fossil fuel generation and other


Sandia PV Projects
(505) 844-3698 (phone)
(505) 844-6541 (fax)

Sandia is a partner in the National Center for Photovoltaics (NCPV). Work performed at Sandia National Laboratories on behalf of the NCPV is funded by the U. S. Department of Energy, Office of Photovoltaic and Wind Technology, James Rannels, Director.