1. Task1 Study of System Evaluation

1.1 Research and Development Goals

The aim of surveys and studies at Phase II for Task-1 Systems analysis is to study an optimal scenario for introduction of hydrogen energy and formulate a strategy for its introduction. With short- and medium-range plans in view, therefore, efforts should be exerted to identify promising technologies and research and development tasks based on the results of assessing the energy consumption, environmental impacts and economical efficiency of various hydrogen utilization systems, including those designed to use hydrogen produced not only from renewable energy sources but also from fossil energy resources.

Major items of the FY1999 survey and study plan included: 1)a study of systems, specifically the primary evaluation of promising systems in terms of energy consumption and economical efficiency; 2)the collection and examination of necessary data for checking the performance of the promising systems and assessing their costs; 3)the formulation of a plan for analyzing the lifecycle assessment (LCA) of the promising systems; 4)a study on suitable methods of assessing the economical efficiency of the hydrogen energy systems covered by the WE-NET Project; and 5)surveys in Europe that are helpful in formulating a hydrogen energy introduction strategy of Japan.

Also a research coordination council was organized and held to coordinate research activities under the WE-NET Project in general and to facilitate surveys and studies involved in Task 1 in particular. This report summarizes the results of the FY1999 plan.

1.2 Results in FY1999

(1) Study of Systems

<1>Assessment of By-product Hydrogen Supply Systems

We assessed the capacity and economical efficiency of systems for supplying soda-electrolysis by-product hydrogen and coke-oven by-product hydrogen that are considered promising sources of hydrogen supply from short- and medium-range points of view. The assessment found that 1.36 GNm3 of soda-electrolysis by-product hydrogen (in about 40 production sites in Japan) and 10.16 GNm3 of coke-oven by-product hydrogen (similarly, in about 20 production sites) are made yearly. This means that an annual by-product hydrogen supply capacity of 11.52 GNm3 (or 147.1 PJ (petajoules)) is available now.

In assessing the economical efficiency of the systems, we examined two cases of soda-electrolysis by-product hydrogen supply. One assumed that hydrogen would be transported to hydrogen supply stations in the vicinity of the production factory by pipeline and then filled into the Metal hydride tanks of vehicles. The other postulated that hydrogen would be compressed and filled into high-pressure containers (at 20 MPa) and then transported by tractor-trailer to hydrogen supply stations where compressed hydrogen would be filled into the Metal hydride tanks of vehicles through a pressure-reducing valve (since hydrogen could be fed into the Metal hydride at a pressure of 0.99 MPa or less, the portion of hydrogen remaining in emptied high-pressure containers would be around 5%). The findings indicate that the cost of hydrogen gas supply at hydrogen supply stations will be \34/Nm3-H₃ in the former case and \45/Nm³-H₃ in the latter case which uses tractor-trailers for transportation of hydrogen, assuming that the distance of delivery to the hydrogen supply stations is 50 km.

The economical efficiency of supplying coke-oven by-product hydrogen (The by-product hydrogen production site was supposed to be in Shikoku.) was also assessed in two cases. One assumed that hydrogen would be transported as high-pressure gas to hydrogen supply stations in the vicinity of the production factory by pipeline, while the other assumed that hydrogen produced in Shikoku would be transported to Tokyo in the form of liquid hydrogen. In the former case, it was found, the cost of gaseous hydrogen supply at hydrogen supply stations would be \40/Nm³-H₃ when the size of hydrogen production was set at 120 tons/day, or \58/Nm³-H₃ when the size of production was set at 1.2 tons/day. In the latter case which involved long-distance transportation of liquid hydrogen, the cost of liquid hydrogen supply at hydrogen supply stations would be \55/L (liter)-LH₃ (\71/Nm³-H₃ in gaseous hydrogen equivalent) when the size of hydrogen production was set at 120 tons/day. Should the size of production be reduced to one tenth, the cost would increase to \66/L-LH₃, according to the assessment. From now on, our efforts will be focused on finding the advantages of different hydrogen supply methods in terms of energy consumption, environmental impact and cost by assessing these methods in each of prospective demand sectors, such as vehicles, large-scale power generation and small-scale, distributed (on-site) power generation, under equal conditions using the distance of transportation as a parameter. The methods covered by the assessment will include three systems: One produces hydrogen at a large installation and transports and supplies it in the form of liquid hydrogen; another produces hydrogen also at a large installation but transports it in the form of high-pressure gas and supplies it in a liquefied or compressed form; and the other produces hydrogen at a small, distributed installation such as methane (Natural gas) reforming station and supplies it in a liquefied or compressed form.

<2>Assessment of Stand-alone Wind Power/Fuel Cell Combined Power Generation System on Remote Islands

At present, remote or outlying islands mostly rely on diesel power generation for electricity supply. A preliminary study was conducted to assess the economical efficiency of a stand-alone wind power and fuel cell combined power generation system that replaces diesel power generation by wind power generation and stores part of electric energy produced by the wind power unit in the form of hydrogen through water electrolysis and uses it as fuel for power generation by the fuel cell unit whenever wind conditions are unfavorable. The findings indicate that an estimated cost of power generation by the combined system ranges from \56/kWh (with an alkali fuel cell unit) to \67/kWh (with a phosphoric acid type fuel cell unit). Reportedly power generation by existing installations on remote islands costs somewhere between \50/kWh or over because of high transportation costs for diesel fuel. From the results of the preliminary study, it is expected that the stand-alone wind power and fuel cell combined system will have sufficient economical competitiveness against the existing diesel power generator system as its power generation cost will be equal to or according to circumstances about half of that of the existing system. Since wind power potential largely depends on the situation of the installation site, we will more closely examine the performance of the proposed combined system at selected sites from the next fiscal year in an effort to more accurately estimate its power generation cost. It is expected that the cost of the system will be further cut back through reductions of the wind power plant cost and the improvement of fuel cell efficiency.

<3>Survey on Possibility of Using Wooden Biomass

With the cost of carrying out forestry residues (the cost of transporting wood in the form of chips) in Japan set at \23,000/ton (at a water content of 10%) and with the calorific value of wood per ton set at 0.45 TOE in oil equivalent, we estimated the cost of wooden biomass energy at \51,000/TOE. As kerosene retails at some \45,000/ton (based on the 1998 record), the estimation indicates it is uncertain whether the biomass energy will have sufficient competitive abilities in the heating and hot water supply sectors of the energy market under the present conditions.

(2) Collection and Examination of Data

Concerning fuel cells which are considered to be among key technologies in facilitating the use of hydrogen, surveys were conducted on the available quantities of platinum and fluorine resources and on the cost of manufacturing polymer electrolyte membrane fuel cell stacks.

It was found that world total platinum reserves (ultimate recoverable reserves) are 100,000 tons, or approximately 300 years in terms of R/P (the ratio of reserves to production) at the present rate of consumption. The R/P, even when calculated on the basis of proved reserves, would reach 100 years. Assuming that the amount of platinum required for automotive fuel cells is 10 g/vehicle and that one third of motor vehicles in service in the world are powered by fuel cells, the platinum requirements for this purpose would account for 2.3% of ultimate recoverable reserves. The requirements could be met sufficiently if the platinum is recycled like the one which is now used as a catalyst in the exhaust gas purifiers of conventional vehicles. Meanwhile, the R/P for fluorine at the current consumption rate was estimated at 90 years, indicating that there is no problem with the availability of fluorine resources. However, it was found that the world community depends on South Africa for most of its platinum requirements and on China for most of its fluorine requirements. This means that underground deposits of these materials are unevenly distributed among regions of the world.

In the survey on the trend of fuel cell stack cost, it was estimated from the results of analyses by fuel cell manufacturers that the cost of these stacks would decrease from $6,300/kW at present to $200/kW in the years ahead. A cost analysis of individual stack components found that platinum and membrane materials alone would cost about $18/kW based on the present performance of fuel cells (as estimated with the power generation density and platinum requirement of the catalyst set at 1 W/cm2 and 0.4 mg/cm2, respectively, and with the effective area and power generation density of the membrane set at 75% and 0.5 W/cm2). As the cost of existing engines is reported to be in a range of tens of dollars per kW, these survey findings indicate the need to further cut back the cost of fuel cell stacks through the improvement of their performance. Among future topics of survey, we are planning to examine an acceptable cost range of fuel cell stacks by comparing them with existing engine-powered vehicles in the next fiscal year.

(3)Formulation of Plan for LCA Analysis of Promising Systems

A plan for future lifecycle assessment (LCA) from fiscal 2000 onward was formulated, following a study and a decision on system boundaries, the method of dealing with their allocation and the concept of data characteristics. In fiscal 2000, the plan calls for an analysis of many conceivable fuel cycles that may be helpful in formulating an appropriate scenario for the introduction of hydrogen energy. In fiscal 2001, efforts will be focused on LCA, including the evaluation of systems at the manufacturing stage.

(4)Study on Methods of Economical Efficiency Assessment

As a result of classifying available methods for assessing the economical efficiency of energy systems when they are put on the market, it was found that conversion into the current value is desirable in assessing systems with a relatively long service life which are covered by the WE-NET Project. Based on this finding, we decided to use a current value method with a standard stipulating the adoption of systems that are found profitable. In predicting future reductions of system cost, we found it desirable to use an estimation method based on the principle that the effect of mass production be calculated with a running curve (that are defined as C=a・P-b, hereupon C means cost and P means product quantity) while that of technological innovation be considered to show a downward movement from the running curve. This method enables us to estimate a future system cost in connection with each of these effects.

(5)The Examination of Hydrogen Introduction Scenario in Advanced Countries of Western Europe

- Western Europe depends on the import from the outside of Western Europe for petroleum and the natural gas though it is not as much as Japan. Especially, petroleum depends on the import for about 80%. After 2005, the decrease in output of the North Sea oilfield is anticipated, and it is afraid of the rise in the petroleum price, though it promotes the alternative energy sources. For example, the TES (Transportation Energy Strategy) project is started up in the industrial-government complex in Germany and it starts the selection of the petroleum alternative source for energy the car.

- In the current state, 1995, the renewable energy demand in Western Europe nations (EU 15 country) is 337TWh in the amounts of the electric power consumption, which is 14% of the electric power, and 38.7Mtoe in heat consumption. However, it is predicted that the renewable energy demand increases in each of 675TWh, 80Mtoe in 2010. The expansion of the demand for the biomass is large with eight times in the electric power and with twice in heat. And the solar heat is assumed to 15 times though the amount is absolutely little.

- The method transforming to hydrogen from intermittent energy of wind power facilities has a possibility to form initial market as a system that is tied up with fuel cell in Western Europe as well as other countries and regions. According to Latest announcement, European commission set goal of the share of renewable energy as 12% of primary energy. Thus such system will be more important than yet be.

1.3 Research and Development Task in Future

The hydrogen introduction scenario is required to construct the future hydrogen energy society that WE-NET advocated. In addition to a technical development scenario, the hydrogen introduction scenario should be made including the hydrogen introduction scenario (goals) and the schedule of hydrogen supply and demand, infrastructure construction, relaxation of regulation and enlightenment etc. which are needed to achieve the hydrogen introduction goal. Making the hydrogen introduction scenario is effective and useful for achieving WE-NET phase II research and development efficiently and starting phase III research and development smoothly. So, we will make the first draft of hydrogen introduction scenario as the highest priority subject in the fiscal year 2000. After making the hydrogen introduction scenario, we will make the hydrogen introduction strategy on the basis of the scenario to perform our WE-NET research and development effectively and assure the achievement farther more. The scenario will be brushed up annually as researches progress on LCA etc.,.

And the evaluation of the environment performance, energy efficiency and also economic efficiency of the hydrogen system technology in the life cycle is necessary in making the hydrogen introduction scenario and also hydrogen introduction strategy. Then we are planning to carry out fuel cycle analysis in next fiscal year and LCA after next fiscal year.