An Historical Overview of the Vanadium Redox Flow Battery Development at the University of New South Wales, Australia

 

by

 

Maria Skyllas-Kazacos

School of Chemical Engineering & Industrial Chemistry,

University of New South Wales, Sydney, NSW, AUSTRALIA 2052

 

 

INTRODUCTION.

 

The Redox Flow Cell is an electrochemical system which allows energy to be stored in two solutions containing different redox couples with electrochemical potentials sufficiently separated from each other to provide an electromotive force to drive the oxidation-reduction reactions needed to charge and discharge the cell. Unlike conventional batteries, the redox flow cell stores energy in the solutions, so that the capacity of the system is determined by the size of the electrolyte tanks, while the system power is determined by the size of the cell stacks. The redox flow cell is therefore more like a rechargeable fuel cell than a battery (see Figure 1). 


 


Figure 1: Redox flow cell concept with separate energy conversion and energy storage

                 Components

 

While the Redox Flow Cell concept has been around for close to 30 years with several systems evaluated by various groups around the world, only the Regenesys systems developed by National Power in the UK and the Vanadium Redox battery pioneered at UNSW (1 - 42) have reached commercial fruition. The Regenesys system (43) uses the sulphide/polysulphide redox couple and the bromine/bromide couple in the in the negative and positive half-cells respectively. Like all other redox cells that use two different solutions in each half-cell, the Regenesys system suffers from cross-contamination of the electrolyte solutions with the resultant need for complex solution chemistry maintenance regimes to avoid capacity loss. The UNSW Vanadium Redox Battery (VRB) on the other hand, uses the same element in both half cells, thus eliminating any problems of cross-contamination.

 

THE UNSW VANADIUM REDOX BATTERY (VRB).

 

Of the redox flow cells developed to date, the vanadium redox flow battery, or VRB system, pioneered at the University of New South Wales, Australia, has shown the greatest potential with high energy efficiencies of over 80% in large installations and long cycle life. As illustrated in Figure 1 above, the Vanadium Redox Flow Battery employs the V(V)/V(IV) and V(III)/V(II) redox couples in sulphuric acid as the positive and negative half-cell electrolytes respectively. The charge-discharge reaction occurring in the vanadium redox cell are:

 

At the positive electrode:

                                                          discharge

VO2+  +  2H+  +  e  ç===è     VO2+   +  H2O                 E°   =  1.00V

                                                           charge

 

At the negative electrode:

                                                               charge   

V3+   +   e-   ç=è   V2+                   E°  =  -0.26 V

                                                              discharge

 

The standard cell potential E° (cell) is 1.26 Volts at concentrations of 1 mole per litre and at 25°C, but under actual cell conditions, the open-circuit cell voltage is 1.4 Volts at 50% state-of-charge and 1.6 Volts at 100% SOC.  Typically, the electrolyte for the vanadium battery is 2 M vanadium sulphate in 2.5 M H2SO4, the vanadium sulphate (initially 1 M V (III) + 1 M V (IV)) being prepared by chemical reduction or electrolytic dissolution of V2O5 powder. 

 

The basic components of the redox cell are illustrated in Figure 2.

 


 

 


Figure 2: Basic Components of VRB cell stack

 

 

Features and Advantages of the VRB:

 

Most of the advantages of the vanadium battery are thus due to the use of the same element in both half-cells which avoids problems of cross-contamination of the two half-cell electrolytes during long-term use.  This means that the electrolytes have an indefinite life so that waste disposal issues are minimised.

 

Other advantages of the VRB include:

 

·        High energy efficiencies between 80 and 90% in large installations.

·        Low cost for large storage capacities.  Cost per kWh decreases as energy storage capacity increases, typical projected battery costs for 8 or more hours of storage being as low as US$150 per kWh.

·        Existing systems can be readily upgraded and additional storage capacity can be easily installed by changing the tanks and volumes of electrolyte.

·        Capacity and state-of-charge of the system can be easily monitored by employing an open-circuit cell.

·        Negligible hydrogen evolution during charging

·        Can be fully discharged without harm to the battery

·        All cells fed with same solutions and therefore are at the same state-of-charge

·        No problems of cross-contamination therefore solutions have indefinite life.

·        Long cycle life

·        Easy maintenance.

·        Can be both electrically recharged and mechanically refueled

 

Vanadium Battery Research,  Development and Demonstration Projects at UNSW

 

Initial work on the Vanadium Redox Battery (VRB) at UNSW began in 1984 where it was taken from the initial concept stage through the development and demonstration of several 1-4 kW prototypes in stationary and electric vehicle applications over a 15 year period at UNSW. While other researchers had previously proposed the use of vanadium redox couples for redox cell applications, this was previously believed to be impractical due to the very low solubility of V(V) compounds which would have restricted the concentration of the vanadium electrolyte to less than 0.2 moles per litre, this being much too low for practical use. The UNSW breakthrough came when it was discovered that highly concentrated V(V) solutions could be prepared in sulphuric acid by the electrochemical oxidation of V(IV). By oxidising a 2 M vanadyl sulphate solution, it was possible to prepare a highly concentrated 2 M V(V) solution which, unexpectedly, did not precipitate over a reasonable temperature range. This meant that reasonable vanadium solution concentrations could be achieved for a practical systems. A further milestone in the UNSW R&D program, was the development of a low cost process for producing vanadium electrolyte from the vanadium oxide raw material. The low solubility of the oxides meant that simple dissolution could not be used in electrolyte production, so electrolytic and chemical reductive dissolution processes were developed at UNSW to overcome this major hurdle.

 

As part of the UNSW R&D program since 1984, a wide range of research projects were undertaken, these covering:

·  basic electrochemical studies of vanadium compounds in a range of electrolytes to determine the kinetics and mechanisms of the vanadium redox couple reactions (1-9);

·  kinetic studies of V2O5 thermal decomposition reaction over a wide range of temperatures and solution compositions to establish the stability limits of the vanadium electrolytes (10,11);

·  kinetic & mechanistic studies of V2O5 powder leaching to optimise electrolyte production (12);

·  electrocatalysis of graphite electrodes for increased cell performance (13-15);

·  studies of electro-osmosis and diffusion processes of ions across ion exchange membranes (16-24);

·  mathematical modelling of shunt currents and pumping energy losses in bipolar cells (25);

·  thermal modelling of redox cells under a range of operating conditions and environmental temperatures to predict cell temperature fluctuations (26);

·  V2O5 powder dissolution studies for a range of reducing agents (27);

·  studies of alternate electrolytes and complexing agents for vanadium redox couples (28,29);

·  state-of-charge monitoring methods for redox cells (30,31);

·  conducting plastics and electrode activation studies (32-36);

·  chemical regeneration of vanadium redox couples - kinetic studies of regeneration reactions (37).

·  stabilisation of supersaturated vanadium solutions using precipitation inhibitors (38,39).

 

In addition to the above research projects, UNSW also led the world in the construction and demonstration of VRB systems in field trials, including design and installation of the first ever VRB used in a demonstration Solar House in Thailand (Figure 3 and ref 40), an emergency back-up system for submarines (Figure 4) and the world’s first vanadium battery powered electric golf cart (Figure 5 and ref 41).

 

 

Figure 3: Vanadium Battery powered Solar Demonstration House in Thailand

 


 


Figure 4: Emergency Back-up Battery for Submarines (sponsored by Australian Dept of

                     Defence)

 

 

Figure 5: UNSW vanadium battery powered electric golf cart

 

A unique feature of the VRB is its ability to be recharged both conventionally or with mechanical refueling by exchanging spent solutions at suitable refueling stations as illustrated in Figure 6. This concept has attracted enormous interest and enthusiasm from the community and from government and industry groups over the years and a world-first vanadium battery powered electric golf cart, sponsored by Pacific Power was commissioned and field tested by our group at UNSW in 1995/96.

 

 
 

Figure 6: VRB refueling station
 

 

VRB Commercialisation

 

The UNSW Vanadium Redox Battery technology is currently being successfully commercialised in a range of stationary applications such as wind, solar and load-leveling installations around the world and the demand for these systems is growing rapidly in North America, Japan, Europe and Australia.

In 1993 licenses for the VRB were issued by UNSW to Thai Gypsum Products in Thailand for Solar House applications, as well as to Mitsubishi Chemicals and Kashima-Kita Electric Power Corporation in Japan where a 200kW/800kWh load-leveling demonstration system was installed in 1997 (44).  The UNSW VRB technology was sold to the Australia listed company Pinnacle VRB in 1998 and extensive commercialisation activities are currently underway to manufacture, sell and install VRB systems in a wide range of stationary applications around the world.

 

In 1999, Pinnacle VRB entered into a new licence agreement with Sumitomo Electric Industries (SEI) who had been evaluating the UNSW VRB technology for several years and have built a 450 kW/ 1 MWh vanadium redox battery load leveling demonstration system at the Kansai Electric Power Plant in Japan (Figure 7), as well as several other VRB systems for wind energy storage and other stationary applications (45, 46).

  

 

Figure 7: SEI Substation Demonstration System Load leveling DC 450kW x 2h

 (Ref:  http://www.sei.co.jp/sn/0105/p1.html)

 

 

The wind energy storage facility delivered by SEI to  the New Energy and Industrial Technology Development Organization and The Institute of Applied Energy is illustrated in Figure 8. The VRB was constructed next to the wind power generator of Hokkaido Electric Power Co., Ltd., where it is used to store wind power and stabilize the output shift of wind generation. Operation started in March 2001. The advantage of the VRB for wind power output stabilisation is the very high cycle life of the VRB compared with other battery systems. In fact, SEI have reported more than 16,000 charge-discharge cycles with a 25 kW VRB stack, or up to 8 years projected life. After 8 years, it is possible to replace the membrane and extend the life of the system even further. This means that the replacement costs of the VRB would be significantly lower than other types of batteries.


 

 


Figure 8: SEI Wind Power Generation Output Stabilization AC 170kW x 6h

(Ref: http://www.sei.co.jp/sn/0105/p1.html).

 

Another Canadian company McKenzie Bay, has recently announced plans to establish a wind power systems supply and installation company based on the VRB technology and are currently undertaking design and feasibility studies for a vanadium battery electrolyte manufacturing plant in Canada to supply these and other projects. Pinnacle has also licenced the VRB technology to the Canadian listed company Vanteck VRB for the African continent and a 250 kW VRB system was recently commissioned by Vanteck in conjunction with the South African utility, ESCOM.

 

A new 250 kW/2 MWh VRB installation for the USA has also just been announced by Pinnacle. The installation, which will be modular and relocatable in design, will be used by PacifiCorp to supply peak power capacity (charging in the off-peak hours) and provide end of line voltage support (supplying up to 250 kVAR of reactive power) in a remote area in southeastern Utah. The stored energy and voltage support available through this VRB unit will allow PacifiCorp to maintain reliable electric service in the area while deferring the need to build a new substation. Because the unit will be portable, it can be moved to another location as needed in the future.

 

Electric Vehicle Applications

 

The development of a suitable power source for electric vehicles is regarded as a top priority by most government and environmental groups everywhere as a means of addressing the serious health concerns associated with high levels of urban air pollution experienced by all major cities around the world. The benefits of the Vanadium Redox system for electric vehicle applications can be summarised as follows:

·        Refuelling in five minutes by exchange of electrolyte at a specialised refuelling station allows 24 hour operation of buses, taxis, fork-lift trucks and other vehicles (not possible with any other type of battery system).   

·        Electrolyte fuel is recharged in the refuelling station using renewable energy or off-peak grid power and is re-used continually

·        Simpler, safer, more efficient and much lower cost than gaseous Hydrogen Fuel Cells

·        Convenient integration into conventional IC engined fleets – refuelling points may be sited alongside diesel or petrol pumps

·        Subject to local market conditions complete Redox fuel systems could be installed for fleet operators and electric fuel could be sold at below equivalent cost for gasoline or diesel

·        Silent, emission free operation in electric urban vehicles

 

The main drawback of the VRB for electric vehicle applications, however, is its relatively low energy density compared with nickel metal hydride or lithium batteries. The energy density of a redox flow battery is related to the concentration of the redox ions in solution, on the cell potential and the number of electrons transferred during discharge per mole of active redox ions. In the all-vanadium redox flow cell, the present energy density is 25 Wh/kg, this being based on a maximum vanadium ion concentration of 2 M or less for wide temperature range operation. This concentration represents the solubility limit of the V(II) and/or V(III) ions in the sulphuric acid supporting electrolyte at temperatures below 5 oC and the stability of the V(V) ions at temperatures above 40 oC.

 

More recent studies at UNSW has shown that vanadium concentrations of up to 3M can be achieved with addition of precipitation inhibitors that can stabilise supersaturated vanadium solutions. This allows the energy density to be increased to around 35 Wh/kg. Electrolytes of up to 3 M vanadium have been demonstrated in the UNSW electric golf cart (48) and even higher  concentrations could be achievable with temperature control. If the energy density of the VRB could be doubled to 50 Wh/kg, a wider range of mobile applications will emerge for the VRB. Further research and development is being undertaken at UNSW to enhance the energy density of the VRB by:

¨      In-situ chemical regeneration of the vanadium redox couples

¨      Improved stabilising agents

¨      Alternative supporting electrolytes

 

These improvements have already led to considerable commercial interest in the VRB for mobile applications and it is anticipated that new joint ventures between Pinnacle VRB and other groups will see the VRB in a range of off-road and on-road vehicles in the not too distant future.

 

Other work that is being undertaken includes the development of a gelled vanadium battery in which the electrolytes are immobilised with suitable gelling agents. Gelled electrolyte batteries have potential application in hybrid electric vehicles where the required capacities of 15-20 minutes can be achieve. Recent studies at UNSW (42 ) have shown that gelled vanadium electrolytes of up to 4 M concentrations can be cycled in a cell with reasonable efficiencies.

 

CONCLUSIONS

 

With high energy efficiencies of over 80% and a cycle life of greater than 16,000 cycles, the Vanadium Redox Flow Battery that was pioneered at the University of New South Wales has been shown to be superior to any other battery system currently available. Commercial installations have already been completed in several parts of the world for a range of stationary applications and full-scale manufacture has begun in Japan.

 

The unique feature of “instant recharge” by mechanical refuelling, also allows many benefits and much greater flexibility for electric vehicle applications so that market acceptance can be more readily achieved. VRB users would thus have the convenience of being able to either recharge their vehicles at home at night, or refuel any time of the day, the same way that they currently fill their tanks with gasoline or petrol. Unlike petrol, however, the vanadium solutions are never consumed, but can be recharged indefinitely.  The spent solutions could thus be stored at the refuelling stations for recharging at night with off-peak electricity. The VRB recharging stations would thereby act as load-levelling systems, so that the need to build extra power stations to meet the increased power demand from electric vehicle charging would be deferred.

 

The current energy density of the VRB would permit its use in buses and a range of off-road vehicles where mechanical refueling would allow 24 hour use. Further improvements in energy density, however, should also see the VRB gaining acceptance for electric passenger vehicles in the not-too-distant future.

 

REFERENCES

 

1.       "A study of the V(II)/V(III) redox couple for redox flow cell applications", E. Sum and M. Skyllas-Kazacos, J. Power Sources, 15, 179-190 (1985).

2.       "Investigation of V(V)/V(IV) system for use in positive half-cell of a redox battery", E. Sum,            M. Rychcik and M. Skyllas-Kazacos, J. Power Sources, 16, 85-95 (1985).

3.       "New all-vanadium redox cell", M. Skyllas-Kazacos, M. Rychcik, R.G. Robins, A.G. Fane and      M. Green, J. Electrochem. Society, 133, 1057-1058 (1986).

4.       "Evaluation of electrode materials for all-vanadium redox flow cell", M. Skyllas-Kazaocs and           M. Rychcik, J. Power Sources, 19, 45-54 (1987).

5.       "Efficient Vanadium Redox Flow Cell", M. Skyllas-Kazacos and F. Grossmith, J. Electrochem. Soc., 134, 2950-2953 (1987).

6.       "Characteristics of new all-vanadium redox flow battery", M. Rychcik and M. Skyllas-        Kazacos, J. Power Sources, 22, 59-67 (1988).

7.       "All-vanadium redox battery", M. Skyllas-Kazacos and R.G. Robins, US Pat. No. 4,786,567, 1986.

8.       "Characteristics and Performance of 1 kW Vanadium Redox Battery", M. Skyllas-Kazacos, D. Kasherman, R. Hong and M. Kazacos, J. Power Sources, 35, 399-404 (1991).

9.       "Electrochemical Behaviour of V(V)/V(IV) Redox Couple at Graphite Electrodes", S. Zhong and M. Skyllas-Kazacos, J. Power Sources, 39, 1-9 (1992).

10.   "Electrolyte Optimization of Vanadium Redox Cell" by M. Kazacos, M. Cheng and M.        Skyllas-Kazacos, J. Appl. Electrochem., 20, 463-467 (1990).

11.   "Thermal Stability of Concentrated V(V) Electrolytes in the Vanadium Redox Cell",  M.Skyllas-Kazacos, C. Menictas and M. Kazacos, J. Electrochem. Soc., 143, L86-L88, April, 1996.

12.   "Vanadium Compound Dissolution", M. Skyllas-Kazacos, M. Kazacos and R. McDermott, Sth. African Patent No. 88/9244.

13.   "Chemical Modification and Electrochemical Behaviour of Graphite Fibre in Acidic Vanadium Solutions", B.T. Sun and M. Skyllas-Kazacos, Electrochem. Acta., 36, 513-517 (1991).

14.   "Modification of Graphite Electrode Materials for Vanadium Redox Flow Cell Applications - Thermal Treatment", B.T. Sun and M. Skyllas-Kazacos, Electrochimica Acta, 37, 1253-1269 (1992).

15.   "Chemical Modification of Graphite Electrode Materials for Vanadium Redox Flow Battery Application - Part II:  Acid Treatments", B.T. Sun and M. Skyllas-Kazacos, Electrochimica Acta, 37, 2459-65 (1992).

16.   "Preparation and Evaluation of Composite Membrane for Vanadium Redox Battery Applications", S.C. Chieng, M. Kazacos and M. Skyllas-Kazacos, J. Power Sources, 39, 11-19    (1992).

17.   "Modification of Daramic Microporous Separator for Redox Flow Battery Applications", by S.C. Chieng and M. Skyllas-Kazacos, J. Membrane Science, 75, 81-91 (1992).

18.   "Permeation Selective Separators and Processes for making such Separators", J. Chieng, M. Kazacos and M. Skyllas-Kazacos, PCT Patent Appl., Sept. 1992, AU9200491.

19.   "Characterization of Novel Composite Membrane for Redox Flow Battery Applications", T. Mohammadi and M. Skyllas-Kazacos, J.Memb.Sci. 98, 77-87 (1995).

20.   "Preparation of Sulphonated Composite Membrane for Vanadium Redox Flow Battery Applications:, T. Mohammadi and M. Skyllas-Kazacos, J. Membrane Sci, 107, 35-45 (1995).

21.   "Use of Polyelectrolyte for Incorporation of ion-exchange groups in composite membranes for vanadium redox flow battery applications", T. Mohammadi and M.Skyllas-Kazacos, J. Power Sources, 56, 91-96 (1995).

22.   "Water Transport Study Across Commercial Ion Exchange Membranes in theVanadium Redox Cell", T. Mohammadi and M. Skyllas-Kazacos, J. Power Sources, 133, 151-159 (1997).

23.   "Evaluation of Chemical Stability of Some Membranes in Vanadium Solution", T. Mohammadi & M. Skyllas-Kazacos, J. Applied Electrochemistry, 27, 153-160,  (1996).

24.   “Modification of Anion-exchange Membranes for Vanadium Redox Battery Applications", T. Mohammadi and M. Skyllas-Kazacos, J. Power Sources,  63, 179-186, 1996.

25.   “Design and Development of Vanadium Redox Battery Prototype”, M. Skyllas-Kazacos, M. Kazacos, P. Wegner and R. Burford, SERDF Project, Final Report, NSW, Office of Minerals and Energy, January, 1991.

26.   “Design of Vanadium Battery for Remote Area Solar Energy Storage” Simon Ting, Honours Project Thesis, UNSW, 1988 (supervised by M.Skyllas-Kazacos)

27.   "High Energy Density Electrolyte for Vanadium Redox Battery",  M. Kazacos and M. Skyllas-Kazacos, South , African Patent, 94/9140, September, 1995.  International Patent Appl. No PCT/AU94/00711, November, 1994.

28.   "All-vanadium redox battery with additives", M. Skyllas-Kazacos, Patent Appl. No. PCT/AU88/00472, Dec. 1988.

29.   "Evaluation of NH4VO3 Derived Electrolyte for Vanadium Redox Flow Battery", C. Menictas,        M. Chen and M. Skyllas-Kazacos, J. Power Sources, 45, 43-54 (1993).

30.   "State-of-Charge of Redox Cell", by M. Skyllas-Kazacos, M. Kazacos, J. Joy and B.G.     Madden, Patent Appl. No. PCT/AU89/00252, June 1989.

31.   "Vanadium charging cell and vanadium dual battery system", M. Skyllas-Kazacos, M. Kazacos and R. McDermott, Patent Appl. No. PCT/AU88/00473, Dec. 1988.

32.   "Performance of carbon plastic electrodes in vanadium redox cell", by M. Kazacos and M. Skyllas-Kazacos, J. Electrochem. Soc., 136, 2759-2760 (1989).

33.   "Fabrication and Activation Studies of Conducting Plastic Electrodes in Acidic Vanadium Solutions" by S. Zhong, M. Kazacos, R.P. Burford and M. Skyllas-Kazacos, J. Power Sources, 36, 29-43 (1991).

34.   "Conductive Carbon-Polypropylene Composite Electrodes for Vanadium Redox Flow        Battery", V. Haddadi-Asl, M. Kazacos and M. Skyllas-Kazacos, J. Appl. Electrochem. 25, 29-33 (1995).

35.   Carbon-Polymer Composite Electrodes for Redox Cells", V. Haddadi-Asl, M. Kazacos and M. Skyllas-Kazacos, J. Applied Polymer Science, 57, 1455-1463 (1995).

36.   "Flexible Conducting Plastic Electrode and Process for its Preparation, V. Haddadi-Asl,      M. Kazacos and M. Skyllas-Kazacos, US Patent No. 5,665,212, Sept, 1997.

37.   "Studies of Chemical Regeneration of Vanadium (V) for Vanadium Redox Battery", M. Abdus Samad and M. Skyllas-Kazacos, in Proceedings 9th Australasian Electrochemical Conference, Wollongong, February 1994, pp 65-1 to 65-4.

38.   "Stabilised Electrolyte Solutions, Methods of Preparation Thereof and Redox Cells and       Batteries Containing Stabilised Electrolyte Solutions" M.Skyllas-Kazacos, Aust Patent No 696452, Dec 1998, US Patent No. 6,143,443, 7 Nov, 2000.

39.   “Evaluation of Precipitation Inhibitors for Supersaturated Vanadyl Electrolytes for the Vanadium Redox Battery”, M. Skyllas-Kazacos, C. Peng and M. Cheng, Electrochemical and Solid State Letters, 2, 121, 1999.

40.   "Improved PV System Performance using Vanadium Batteries", R. Largent, M. Skyllas-      Kazacos and J. Chieng, Proceedings IEEE, 23rd Photovoltaic Specialists Conference, Louisville, Kentucky, May 1993.

41.   "Status of the Vanadium Battery Development Programme", C. Menictas, D.R. Hong, Z.H. Yan, J. Wilson, M. Kazacos and M. Skyllas-Kazacos, Proceedings, Electrical Engineering Congress, Sydney, November 1994.

42.   “Gelled Electrolyte Vanadium Battery” M. Skyllas-Kazacos, Provisional Patent Application,  PCT /AU01/00923,  27 July, 2001.

43.   “Electrochemical Apparatus for Energy Storage and/or Power Delivery Comprising Multi-Compartment Cells” R. Zitto, PCT/GB93/02110, October, 1993.

44.   “Vanadium Redox Flow Battery with Resource Saving Recycle Ability. I Production of Electrolytic Solution for Vanadium Batteries from Boiler Soot”, M. Nakajima, M. Sawahata, S. Yoshida, K, Sato, H. Kaneko, A. Negishi and K. Nozaki, Denki Kagaku, 66, 600, 1998.

45.   “Development of a Redox Flow Battery System”, N. Tokuda, T. Kumamoto, T. Shigematsu, H. Deguchi, T. Ito, N. Yoshikawa and T. Hara, SEI Technical Review, No 45, Jan. 1998

46.   “Feature Article: Redox Flow Batteries” SEI News, http://www.sei.co.jp/sn/0105/p1.html

47.   Sir John Samuels, EFuel Technologies, Private Communication, October, 2001

48.   “Small-scale Laboratory Testing and Golf-Cart Trials of  3 Molar Vanadium Electrolyte”, C. Menictas and M. Skyllas-Kazacos, Report to Pinnacle Mining NL, Feb 1998.