Fast Pyrolysis of Biomass

/0 Comments/in , /by

To convert residue fuels such as forest or agricultural feedstock, municipal solid wastes or tires into useful clean gas or liquid fuels, the main option today is gasification. Gasification systems – bubbling, circulating and entrained beds – produce low calorific value gases, are capital intensive, and require large plant sizes to be cost effective. They are therefore inappropriate for many residue fuels such as tires or agricultural wastes. Pyrolysis, and “rapid” pyrolysis in particular, offers a possible alternative with the following advantages:

-Lower vapor volumes which reduce emissions and capital cost.
-Elimination of the production of alkali vapors, simplifying clean-up.
-Reduced operating temperatures which minimizes the formation of poly-nuclear aromatics, in turn improving the efficacy of cracking or steam reformation prior to use in the fuel cell.
– Fast pyrolysis yields larger quantities of fuel vapor with simpler organic moieties.

[Pyrolysis involves heating in the absence of oxygen, resulting in gases, liquids and char (e.g. charcoal) in varying proportions. “Fast” heating, at lower temperature, is preferred, as it results in less char and fewer complex chemical products from subsequent reactions. Gasification, in fact, can be seen as a special case of pyrolysis, where admitting some air helps to maximize gas production over liquids and char.]

Capital and operating cost for a pyrolysis plant is directly related to heat transfer rate. Presently, most rapid pyrolysis processes use conventional entrained flow or fluidized beds which have good heat transfer rates but require small particle sizes, less than 0.08 inches, to achieve the desired residence times (less than 2 seconds) for rapid pyrolysis.

“Ablative” pyrolysis can increase heat transfer rates. The particle is abraded against the hot surface, removing reaction products and exposing fresh material for reaction.

The two ablative processes which are being developed utilize centrifugal force to achieve the required pressure on the particle to sustain ablative pyrolysis. From the operating characteristics of these processes, vortex reactor of NREL and centrifugal pipe design of Enervision Inc, it would appear that these systems cannot provide enough force on the particle to sustain ablative pyrolysis throughout the residence time of the particle. As a result large particles cannot be effectively converted.

Mechanical ablative reactors with low carrier gas requirements are under development in England and the Netherlands. From the data available, it is not obvious how easy it will be to scale these systems to commercial sizes and how effective they will be in handling a wide range of materials and particle sizes.

DynaMotive, a Canadian company which acquired rights to a fluid bed technology developed at Waterloo University, is making “BioFuel” with their BioTherm Fast Pyrolysis Technology.
http://dynamotive.com/english/units/biooil/tech.html

——- references: ———
“Principles and Practice of Biomass Fast Pyrolysis Processes for Liquids”, A.V. Bridgewater, Journal of Analytical and Applied Physics 51 (1999). (20 pages) offers a thorough review of the subject. (If you have trouble getting it, I have a low quality fax copy.)

Bridgewater has also authored a couple of books on the subject.
See: http://www.cplscientific.co.uk/press/gas-relate.html
——–

Down Stream Systems, a small company in California in the waste conversion technology business, is proposing a ” mechanical ablative pyrolysis” (MAP) unit, currently patent pending in the USA, which offers the potential for the following:

– Simplicity of design with high rates of heat transfer.
– Ability to handle a wide range of particle sizes and residue materials.
– Moderate capital cost and, therefore, the ability to site close to local sources of residue fuel.
– Minimum carrier gas requirements and low vapor volumes with associated reduction in gas clean-up costs.
– System operating temperatures, which avoid the production of alkali vapors and poly-aromatic hydrocarbons. This simplifies gas treatment for use in fuel cells.

An earlier version of the process converted 50 tons per day at a high conversion efficiency. The feedstock however, had to be finely ground. The new MAP process is designed to overcome this critical limitation. It is projected that a 50 ton per day biomass system will produce 10,000 gallons of bio-oil similar to a #2 diesel, but having somewhat less than half the energy. An appropriate site and supply of 50 ton per day of biomass for a prototype system is available.

Before installing the prototype, a series of tests will be run in a 0.5 tpd pilot scale MAP reactor. The company is seeking funding to build and install the pilot scale reactor and to perform the tests.

The pilot reactor will operate under the same conversion conditions as earlier fast acting reactors except for its unique mechanical ablation feature. The test system will be tuned until it efficiently vaporizes coarse organics. A series of tests will then be run to optimize conversion parameters, followed by steady state runs at optimal conversion settings to establish mass/energy balances, characterize the products and provide design data for the commercial demonstration. An independent consulting firm will be retained to observe the control tests and confirm process viability.

The required funding is on the order of $300,000. The company has a proposal involving equity shares in a new holding company, however they are open to other arrangements. A detailed business plan and technical proposal can be provided on request.

Contact:
Bob McChesney, Vice President
Down Stream Systems, Inc., Folsom, CA
916-989-8180 rmc@Inreach.com
323-249-5303 (at their recycling facility on Los Angeles)

http://www.downstreamsystems.com/

NxtPhase Optical I, V Transducers for High Voltage

/0 Comments/in , /by

NxtPhase Optical I, V Transducers for High Voltage

NxtPhase Corp., Vancouver BC, has developed a family of optical sensors to measure current, voltage, and power in high voltage power systems. These devices appear to be on the verge of becoming a commercial reality, and offer high accuracy, bandwidth and dynamic range. Integrated into the all-digital electronic substation measurement and control system of the future, they will help revolutionize metering, protection, and power quality management.

These optical voltage and current sensing technologies came out of two parallel independent development programs – one in the US and the other in Canada.

Current Sensor–
Honeywell applied fiber-optic gyro technology developed for demanding civil and military navigation applications to the measurement of current, and teamed with Texas A&M to produce a sensor. The first deployment was with Arizona Public Service at the Cholla Generating Station in 1997 where accuracy of 0.03 per cent has been demonstrated. Honeywell entered into a partnership NxtPhase, who has a complementary voltage technology and a similar market vision.

Voltage Sensor–
The other half of the NxtPhase story begins with Carmanah Engineering Ltd. – a successful hi-tech spin-off from the University of British Columbia (UBC). Carmanah, UBC and BC Hydro partnered to develop an integrated optic voltage sensing technology based on a unique electric field sensor called the Integrated Optic Pockels Cell (IOPC). Significant technological breakthroughs led to an extremely accurate optical voltage transducer that avoids the environmental concerns of alternative optical or conventional technologies. The first IOPC sensor was successfully deployed in 1997 at the Ingledow substation of BC Hydro.

Optical Voltage and Current Transducer–
The NXVCT combines both the optical voltage and current transducers in one instrument, over the range of transmission voltages from 69 kV to 765 kV.

Applications include:
– Accurate metering of independent power plants (The dynamic range means accuracy at 1 amp and at 100,000 amps. This can have substantial revenue implications, with the ability to measure power inflow when a plant is not producing power);
– High bandwidth monitoring of power plants, i.e. transients and harmonics; and
– High voltage power quality measurements, to diagnose equipment failures.

Very shortly a technology alliance with BC Hydro will be announced. BC Hydro will conduct field trials to test and demonstrate the devices at one of its high voltage substations to verify performance over time, and at various operating temperatures. The company is looking for customers, partners and investors. They are already in discussions with several UFTO companies and others.

For more information about the company and its products, the website is:
http://www.nxtphase.com/

Contact:
Richard MacKellar, CEO, NxtPhase Corp., Vancouver BC
604-215-9822 x 222, rmackellar@nxtphase.com

Steve Dolling, Director, Marketing
604-215-9822 x233, sdolling@nxtphase.com

———————
Further details on the technology are available:
http://www.nxtphase.com/nx3.htm

“Design Options Using Optical Current and Voltage Transducers
in a High Voltage Substation”
IEEE PES Substation Committee Annual Meeting May 1, 2000
Powerpoint presentation gives a good overview.

http://www.nxtphase.com/IEEE_substation_meeting_final_version.ppt

Here is the first page of each of two articles, and links for the pdf downloads.

“Optical Voltage Transducers for High-Voltage Applications”
http://www.nxtphase.com/NXVT.pdf

Optical methods for the measurement of current and voltage in high-voltage (HV) environments have been attracting more and more attention in the recent years. This is mostly due to the advantages that they offer over conventional instrument transformers. They provide immunity to electromagnetic interference, are typically non-intrusive, provide excellent galvanic isolation, are much lighter and, therefore, easier to transport and install. Early work on optical current and voltage sensing in the HV environment started in the 1970’s [1-5] leading to more practical and accurate systems developed in the 1980’s and 1990’s [6-13]. Also, at the commercial level, current sensing technology (both for technical and economical reasons) led voltage sensing technology. In this paper, we present results obtained using NxtPhase’s optical voltage transducer, NXVT.

Most practical optical voltage sensors use electric field sensors that operate using the linear electro-optic (or Pockels) effect. It should be noted that the sensors themselves are, strictly speaking, electric field sensors and not voltage sensors. However, various means of getting a one-to-one relationship between the voltage applied and the electric field sensed are used to derive voltage. For example the entire voltage can be applied across the electro-optic crystal, or a capacitive divider can be used to apply a well-known fraction of the voltage to be measured across an optical electric field sensors. There are advantages and disadvantages to each of these methods. Nevertheless, most successful devices in the past have used optical fibers for the transmission of light, bulk electric field sensors as sensing elements, and SF6 gas for insulation.

The NXVT introduced here combines the typical benefits of optical sensing technology with some additional features that provide further benefits to the user. For example, it does not use SF6 or oil-paper insulation, making it more environmentally friendly and much safer to use. The NXVT uses multiple miniature electric field sensors inside a high-quality post insulator, in a proprietary manner, to measure voltage with high accuracy.

———————

“Optical Current Transducers for High Voltage Applications”
http://www.nxtphase.com/NXCT.pdf

Background
Over the past 15 years, optical current sensors have received significant attention by a number of research groups around the world as next generation high voltage measurement devices, with a view to replacing iron-core current transformers in the electric power industry. Optical current sensors bring the significant advantages that they are non-conductive and lightweight, which can allow for much simpler insulation and mounting designs. In addition, optical sensors do not exhibit hysteresis and provide a much larger dynamic range and frequency response than iron-core CTs.

A common theme of many of the optical current sensors is that they work on the principle of the Faraday effect. Current flowing in a conductor induces a magnetic field, which, through the Faraday effect, rotates the plane of polarization of the light traveling in a sensing path encircling the conductor. Ampere’s law guarantees that if the light is uniformly sensitive to magnetic field all along the sensing path, and the sensing path defines a closed loop, then the accumulated rotation of the plane of polarization of the light is directly proportional to the current flowing in the enclosed wire. The sensor is insensitive to all externally generated magnetic fields such as those created by currents flowing in nearby wires. A measurement of the polarization state rotation thus yields a measurement of the desired current.

The optical current transducer being developed by NxtPhase (the NXCT) is an offshoot from the Honeywell fiber optic gyro program. Honeywell has been producing fiber optic gyros for a variety of commercial aviation applications since 1992. Extensive life and reliability testing has been carried out on the product to meet the stringent flight qualification criteria. Early on, Honeywell realized that this technology, with only minor modifications, could be applied to the field of current sensing, and a program to diversify into this area was maintained by Honeywell for several years. In late 1999, Honeywell joined with Carmanah Engineering to launch NxtPhase with the charter of commercializing the technology.

Principle of Operation
The NXCT uses the Faraday effect, but in a different architecture than the more well known polarimetric technique. The NXCT is a fiber optic current sensor and it works on the principle that the magnetic field, rather than rotating a linearly polarized light wave, changes the velocities of circularly polarized light waves within a sensing fiber wound around the current carrying conductor [1]. The effect is the same Faraday effect but differently formulated. We have found in our experience and heritage from the Honeywell fiber-optic gyroscope program that, for a variety of reasons, it is easier to accurately measure changes in light velocity than changes in polarization state. Chief among these reasons is that by using a velocity measurement scheme, we do not need to construct the sensing region from annealed fiber which is brittle and difficult to work with in a production environment.

Zero Emission Coal (Los Alamos)

/0 Comments/in , /by

(One of a series of UFTO Notes based on the recent visit to Los Alamos National Laboratory)

Zero Emission Coal

Los Alamos is working to eliminate the environmental concerns associated with the use of fossil fuel, which will continue to be an important energy source well into this century. One technology the Laboratory is developing to achieve this goal is a zero emission process for converting coal and water into hydrogen, which is then converted into electricity, with virtually no emissions of pollutants. Thirteen entities with interests in coal production and energy generation have teamed up to form the Zero Emission Coal Alliance (ZECA) which plans to commercialize this process within five years.

The Technology In the context of DOE’s “Vision 21” goal to eliminate environmental concerns from the use of coal. Los Alamos is developing technology to achieve a zero emission process for converting a coal and water slurry into hydrogen, which is in turn converted to electricity via a high-temperature solid-oxide fuel cell.

The new process builds on CONSOL’s CO2 Acceptor Process, which was piloted in the 1970’s. While still relying on cycling of calcium oxide (CaO) to drive the production of hydrogen, enhancements produce separate streams of hydrogen and CO2. The hydrogen is used to generate emission-free electricity and the CO2 is reacted with abundant magnesium silicates to be permanently sequestered as a solid, inert and stable mineral carbonate.

Hydrogen gas is produced from water and coal using a calcium oxide (CaO) to calcium carbonate (CaCO3) intermediary reaction. Through a subsequent reaction, the calcium carbonate generated by hydrogen production is converted back into calcium oxide and a pressurized stream of pure CO2. The calcium oxide is recycled to drive further hydrogen production, and the CO2 stream is ready for easy disposal.

The hydrogen is fed to solid-oxide fuel cells to generate electric power, and the ~50% of waste heat produced by the fuel cells is not truly wasted because it is reinjected into the process to drive the calcination reaction.

The already pressurized CO2 stream is reacted with magnesium or calcium silicate mineral deposits to form geologically stable mineral carbonates. (The reaction is part of the natural geological carbon cycle; therefore, all mineral end products are naturally occurring and completely benign.) The mineral sequestration process is economically viable because the CO2 stream is non-mechanically pressurized in the hydrogen production process and the carbonation reaction is exothermic (i.e., it creates energy instead of consuming it).

In addition, the types of mineral deposits needed to carry out the reaction are abundant enough to handle all the carbon associated with the world’s coal reserves. Magnesium-rich ultramafic rocks, primarily peridotites and serpentinites, are the main candidates for mineral carbonation. Deposits distributed throughout the world, though in specific concentrated areas on each continent.
——–

The Alliance
Thirteen entities from the United States and Canada with interests in coal production and the use of coal for electrical generation have agreed to contribute $50,000 each to form ZECA.

Phase I: ZECA is currently structured with an executive team headed by Jim Berson, Director of Planning and Business Development from Kennecott Energy/Rio Tinto, a technology team headed by Dr. Hans Ziock, senior scientist at Los Alamos National Laboratory, and a business team headed by Alan Johnson, President of The Coal Association of Canada. The goal of Phase I is to develop a business plan and a technical plan leading to the completion of a pilot plant in a five year time frame.

ZECA has begun to proceed with Phase I. The alliance however still welcomes the participation of additional members to ensure a broad spectrum of industry participation and expertise. As alliance members, participants in Phase I have the opportunity to help guide the work conducted under the supervision of the technical and business committees, as well as the opportunity to serve or participate on those committees at their discretion.

Additional information is available online:
http://www.lanl.gov/energy/est/zec/zec.html

for technical information:
Klaus Lackner, 505-667-5694, ksl@lanl.gov
Hans Ziock, 505-667-7265, ziock@lanl.gov

for business information:
Jim Berson, 307-687-6049, bersonj@kenergy.com
Alan Johnson, 403-262-1544, johnson@coal.ca

(I have several technical papers from Los Alamos, which I can send on request.)

ELISIMS: Detailed Simulation of Power Industry (Los Alamos)

/0 Comments/in , /by

(One of a series of UFTO Notes based on the recent visit to Los Alamos National Laboratory)

ELISIMS

“A Comprehensive, Detailed Simulation of the Electric-Power Industry: Harnessing the Los Alamos National Laboratory High-Perfomance Computing Infrastructure,”

Los Alamos is proposing to use their supercomputing capabilities to address policy analysis of utility restructuring by modeling the entire power system at an unprecedented level of detail — and breadth. Building on experience in transportation modeling**, they suggest that computer simulation at a sufficient level of detail calls for very high-performance computing: (from the abstract of a paper LA-UR-98-5920 )

——- “The electric-power infrastructure is a complex system consisting of hundreds of thousands of independent agents coupled by a dynamically constrained transmission system. Actions of the independent agents are governed by both economic objectives and constraints imposed by federal, state, and local policies. Purchasing decisions by millions of independent consumers constrained jointly by market policies and transmission-system realities will lead to unexpected emergent system behavior with potential consequences on reliability and quality.

Prior testing of energy policy is required, and this requires computer simulation. To do this at a sufficient level of detail calls for high-performance computing and the analysis and validation of emergent behavior.” ——-

The plan is ambitious: (from LA-UR-98-4952)

—— “In a nutshell, we propose to develop and deploy a comprehensive, detailed simulation of the electric industry:

– Comprehensive in that we will include the whole North American continent because that natural limit is becoming the scale of tight interconnection.

– Detailed in that we will include each significant element at the level of generators, transmission elements, varied control elements, and load distribution buses.

– Industry in that we will include the regulatory, financial, and market entities that interact with the engineering elements.

We will design a linked multi-resolution simulation hierarchy with which users may instantiate as much detail and as great a (geographic) scope as required for their particular analyses. Stability studies may require complete calculations in both scope and detail. Other studies (made cheaper by employing either the mixed resolution or a reduced scale) will be more secure with the ability to validate against the full calculations.” ——–

The goal is to capture both power flow and market dynamics together, in a way that hasn’t been accomplished before. A pilot project is underway with the California ISO to evaluate future scenarios for the structure of RTOs in the west.

A 33 page summary report (March 2000) (LA-UR-00-1572) was recently completed, which is available in pdf format:
http://w10.lanl.gov:80/orgs/tsa/tsa4/pdf/infra/elisims_report.pdf
It provides a more complete write-up of the original applications’ study and a cross-mapping to the recommendations of the DOE’s POST report (section 1.5 and Table 1 on page 11).

The program has a webpage at:
http://w10.lanl.gov:80/orgs/tsa/tsa4/infra/elisims.html

Contact:
Dale Henderson, 505-665-2151, dbh@lanl.gov
Jonathan Dowell, 505-665-9193, ljdowell@lanl.gov

—–
**The TRansportation ANalysis SIMulation System (TRANSIMS)
http://transims.tsasa.lanl.gov/

DOE Distributed Power Website

/0 Comments/in , /by

This new website just went live this morning. Looks like a good one. Happy reading!

http://www.eren.doe.gov/distributedpower/

This is the website of the DOE’s Distributed Power Program which is responsible for distributed resources’ system integration research and development. The site describes the Distributed Power Program and its activities, and provides information and current news about barriers to distributed power, policies and regulations, technical interconnection issues and upcoming events.

This unveiling was set to coincide with the long awaited release of the DOE “Barriers” study, by Brent Alderfer, Competitive Utility Strategies, which was discussed at the DOE DP Program meeting last October. (See UFTO Note – DOE Distrib Power Review & IEEE Interconnection Working Group; 12 Oct 1999.)

— Making Connections: Case Studies of Interconnection Barriers and their Impacts on Distributed Power Projects —

This study documents the difficulties faced by distributed generation projects seeking to connect with the electricity grid. The report examines the impact of interconnection issues on 65 distributed power projects. The case studies treated in the report clearly demonstrate that market barriers are real, and that they are, in part, an artifact of the present electricity industry institutional and regulatory structure designed for a vertically integrated utility industry relying on large central station generation. Given the findings, the report provides a ten-point action plan for reducing the technical, business practices, and regulatory barriers that may impede the deployment of distributed power technologies.

The full report is available for download as a pdf file: http://www.eren.doe.gov/distributedpower/barriersreport

DOE Hydrogen Program

/0 Comments/in , /by

Forwarding this announcement about the DOE Hydrogen Program website…it’s a quite comprehensive resource site on hydrogen. Note the complete proceedings from the ’98 and ’99 Program Reviews (under Information Resources).
+++++++++++

Date: Sunday, May 21, 2000 8:46 AM
Subject: [h2view] Redesigned Hydrogen Information Network website is live!

From: “Gregoire, Cathy”

The DOE Hydrogen Program website has been completely redesigned. This site contains important information on R&D advances and technology validation efforts within the US Department of Energy’s Hydrogen Program.

The web address remains the same – http://www.eren.doe.gov/hydrogen

Please note that all future notices related to the DOE Hydrogen Program, including meeting notices and solicitation announcements, will only be sent to those persons signing up on the new mailing list – this current list will no longer be used.

Action is required on your part for you to continue to receive important information. You must sign up to receive news and information (http://www.eren.doe.gov/hydrogen/registration.html)

Thank you for your interest in hydrogen.

Catherine E. Grégoire Padró, P.E.
Technology Manager, Hydrogen Program
National Renewable Energy Laboratory
1617 Cole Blvd., MS 1613
Golden, Colorado USA 80401
Tel: +1-303-275-2919
Fax: +1-303-275-2905
email: cathy_padro@nrel.gov

Amorphous Metal Motors

/0 Comments/in , /by

Here is a very new and different approach to electric motors and generators. The following summary from the company’s business plan. I am working closely with them to help them develop contacts with potential strategic partners and investors. I can send on request the complete business plan, with figures, as a Word document.

The company believes that their motors will outperform by a wide margin any of the other “new” types of motors and generators, particularly in light of the ability to eliminate gears and drivetrains.

===== Executive Summary ========

Light Engineering is introducing a patented, new and revolutionary motor/generator technology using amorphous metal materials. The use of amorphous metal leads to dramatic improvements in the performance, operating efficiencies and cost effectiveness of Light Engineering’s motor/generator. Unlike anything else in the marketplace today, Light Engineering’s motors deliver high performance, maintaining high torque over an entire speed range thus opening the door to many new applications not achievable by traditional motor technology.

Today, Light Engineering is the only developer of electric motors and generators that incorporate amorphous metals as the magnetic core material. Light Engineering has built and tested several generations of prototypes in the 5hp+ range that have now demonstrated the following advantages over conventional motors:

Significantly expanded torque/speed range
High starting torque thresholds
3x torque to weight advantage of traditional motors
4x torque to volume advantage of traditional motors
Software “scalability” with expanded frequency
High “Output Density” Generators
Significantly reduced cost of materials
Manufacturability without major capital expense

The wide performance range of Light Engineering’s motors reduces the need for mechanical gears and transmissions. Instead, software algorithms programmed into a digital signal processor responds to internal sensors, this can be done either locally or remotely over telecommunication lines. They adjust motor performance dynamically to achieve optimum operating efficiency as load conditions and user preferences change. These motors and generators are thus transformed from mechanisms that are mechanically configured to perform a specific task into intelligent platforms that provide unprecedented adaptability to the demands of their operating environment.

These motors are modular and scalable and can be incorporated into a full range of applications. For instance, in the hybrid electrical vehicle market, these motors supply the high torque required to get the vehicle moving and the high efficiency needed at various operating speeds ? all without any gears or a transmission. Light Engineering expects its motors and generators will be the technology of choice for both hybrid and fuel cell powered vehicles.

With the exceptional performance range of Light Engineering’s motors it also enables whole new classes of other products that are not practical with today’s technology. These include turbo-compressors for refrigeration, turbo-generators for stand-alone power stations, a combination starter motor/alternator for vehicles or aircraft engines and variable speed applications enabling remote control of energy consuming equipment.

The design of these motors/generators eliminates the need for Light Engineering to invest in manufacturing plants and equipment. These products will be able to quickly enter the marketplace through a combination of contract manufacturing and licensing.

Light Engineering has in place a blocking intellectual property portfolio that includes 5 issued and 4 allowed patents and has entered into a Technology Development and Licensing Agreement with Honeywell (formerly AlliedSignal), the world’s largest manufacturer of amorphous metals, sold under the trademark “Metglas” .

Light Engineering has assembled a experienced team including some of the country’s top motor designers, consultants and advisers. It leases a 12,000 square foot facility in Campbell, CA divided into offices, development laboratories and a prototype fabrication area. This “Tech Center” is equipped to design, rapid prototype, program and test the motor / generator and controller systems.

Light Engineering seeks to raise $4-5 million from the sale of a Series B Preferred Stock with the net proceeds from this offering primarily used to fund prototype development costs, hire additional staff and transition the technology from research into the first phase of commercialization.

Energy Storage Assoc Meeting Notes

/0 Comments/in , /by

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

Energy Storage Association
2000 Annual Meeting

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

OVERVIEW

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

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

+—-+—-+—-+—-+—-+—-+—-+

Flow Batteries

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

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

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

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

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

— Cellennium — also uses vanadium. This Thailand based company is developing a wide range of applications, from small to large. (http://www.vanadiumbattery.com)

+—-+—-+—-+—-+—-+—-+—-+

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

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

+—-+—-+—-+—-+—-+—-+—-+

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

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

+—-+—-+—-+—-+—-+—-+—-+

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

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

+—-+—-+—-+—-+—-+—-+—-+

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

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

+—-+—-+—-+—-+—-+—-+—-+

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

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

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

+—-+—-+—-+—-+—-+—-+—-+

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

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

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

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

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

More Battery is ALWAYS better

+—-+—-+—-+—-+—-+—-+—-+

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

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

+—-+—-+—-+—-+—-+—-+—-+

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

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

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

+—-+—-+—-+—-+—-+—-+—-+

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

Annex XV is the successor to Annex IX, and both of these are under a broad category that covers all forms of storage for energy conservation.
For details, see http://cevre.cu.edu.tr/eces

An acrobat document gives an overview (http://cevre.cu.edu.tr/eces/ax15prop.PDF) The program scope will be determined at a meeting in October, with work to begin in November.

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

+—-+—-+—-+—-+—-+—-+—-+

UPDATES:

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

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

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

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

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

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