In this final progress report, we describe research results from Phase I of a technical/economic study of fossil hydrogen energy systems with CO2 sequestration. This work was performed under NETL Award No. DE-FC26-02NT41623, during the period September 2002 through August 2004.

The primary objective of the study is to better understand system design issues and economics for a large-scale fossil energy system co-producing H2 and electricity with CO2 sequestration. This is accomplished by developing analytic and simulation methods for studying the entire system in an integrated way. We examine the relationships among the different parts of a hydrogen energy system, and identify which variables are the most important in determining both the disposal cost of CO2 and the delivered cost of H2.

A second objective is to examine possible transition strategies from today's energy system toward one based on fossil-derived H2 and electricity with CO2 sequestration. We carried out a geographically specific case study of development of a fossil H2 system with CO2 sequestration, for the Midwestern United States, where there is presently substantial coal conversion capacity in place, coal resources are plentiful and potential sequestration sites in deep saline aquifers are widespread.

Proceedings of "The 10-50 Solution: Techonologies and Policies for a Low-Carbon-Future" Workshop, The Pew Center on Global Climate Change, and the National Commission on Energy Policy

Hydrogen is potentially very important for our nation's energy future. Hydrogen is one of the few widely available, long-term fuel options for simultaneously addressing energy security and environmental quality (including both deep reductions of greenhouse gases and pollutants). Use of hydrogen could transform the ways we produce and use energy. But is future large-scale use of hydrogen a foregone conclusion? Although the potential is tremendous, in the author's view, it is still too early to tell exactly how large hydrogen's role will become over the next 50 years. While a large scale hydrogen economy by 2050 cannot be considered inevitable at this point, a vigorous program of RD&D on hydrogen can be considered a prudent insurance policy against the need to begin radical decarbonization of the fuel sector within a few decades, while simultaneously addressing energy security and pollution problems. Given the promise of hydrogen, the long lead time in accomplishing transitions in the energy system, and the challenges posed by hydrogen, it is important to provide significant support now, so that hydrogen technologies and strategies will be ready when needed.

As part of the H2A effort, we are developing models of hydrogen delivery systems, for use of hydrogen as a vehicle fuel. The delivery system is defined as all the equipment between the hydrogen production plant and the hydrogen refueling station. This includes hydrogen compression or liquefaction, hydrogen storage, and hydrogen distribution in trucks or pipelines. The goals of the H2A delivery group are to: 1) develop a database on delivery system component cost and performance; 2) develop delivery scenarios for set of well defined "base cases" that span major markets and demand levels ,and 3) estimate delivery costs for these base cases. In this report for NREL contract No. SCM-2-32067- 01, we describe work related to goal 2). In particular, we have developed an EXCEL spreadsheet model of various hydrogen delivery scenarios. The spreadsheet is included as a separate file.

Presented to the Hydrogen and Fuel Cell Caucus, Washington, DC, January 11, 2005

Of all alternatives to gasoline fuels, hydrogen offers the greatest long-term potential to radically reduce many problems inherent in transportation fuel use. For example, hydrogen could enhance energy security and reduce dependence on imported oil, since it can be made from various primary energy sources, including natural gas, coal, biomass, and wastes, and from solar, wind, hydro, geothermal, and nuclear energy. Also, hydrogen vehicles have zero tailpipe emissions and are very efficient. If it is made from renewable sources, nuclear power, or fossil sources with carbon emissions captured and sequestered, hydrogen use on a global scale could produce nearly zero greenhouse gas emissions and greatly reduce emissions of air pollutants.

With recent economic, political, and social events worldwide, reliability in the energy sector is growing more valuable, and the surrounding issues are gaining visibility. Increasingly, concerns about energy supply security (and climate change) have led to proposals to shift away from oil dependence to wide use of alternative transportation fuels, such as biofuels or hydrogen. Hydrogen is of particular interest because it offers multiple societal benefits. It is often asserted that hydrogen would enhance energy reliability because it can be made at diverse scales from many primary resources. But no studies have systematically assessed reliability. There are many questions surrounding energy system reliability – especially when considering a future fuel like hydrogen. How should reliability be defined and evaluated? And would a transition to hydrogen increase or decrease reliability? This paper presents a general method to assess reliability in energy supply systems. The technique uses qualitative ratings from an expert panel regarding a set of reliability metrics. We illustrate the method by evaluating two hydrogen pathways: 1) centralized steam reforming of imported liquefied natural gas and pipeline distribution of hydrogen, and 2) on-site electrolysis of water using electricity produced independent of the grid. We found the second pathway to be more reliable, primarily due to the distributed nature of the system and the lack of hydrogen transport. The application intends to demonstrate how the method is applied, however, and the results should be regarded as preliminary. In future work, the method could be extended to compare reliability among different fuel pathways.

Hydrogen is an especially attractive transportation fuel. It is the least polluting fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewably grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional or global pollution. Hydrogen FCEVs would combine the best features of battery-powered electric vehicles (BPEVS) -- zero emissions, high efficiency, quiet operation and long life -- with the long range and fast refueling time of internal-combustion-engine vehicles (ICEVs). If fuel-cell technology develops as hoped, then hydrogen FCEVs will be a significant advance over both hydrogen ICEVs and solar BPEVs: they will be cleaner and more efficient than hydrogen ICEVs, have a much shorter refueling time than BPEVs and have a lower life-cycle cost than both. Solar-hydrogen fuel-cell vehicles would be general-purpose zero-emission vehicles, and could be an important component of a strategy for reducing dependence on imported oil, mitigating global warming and improving urban air quality, at an acceptable cost.

The development of a hydrogen infrastructure has been identified as a key barrier to implementing hydrogen as for a future transportation fuel. Several recent studies of hydrogen infrastructure have assessed near-term and long-term alternatives for hydrogen supply. In this paper, we discuss how advances in material science related to hydrogen storage could change how a future hydrogen infrastructure is designed. Using a simplified engineering/economic model for hydrogen infrastructure design and cost, we explore some potential impacts of advances in storage materials, in terms of system design, cost, energy use, and greenhouse gas emissions.

Station availability is a major concern when the deployment of an alternative fuel such as hydrogen is considered. Too few stations will make the network inconvenient, while too many will make the refueling network cost prohibitive. As a follow-up analysis to two station siting analyses completed by the authors for the California Hydrogen Highway Network, this report takes a closer look at the regional differences between the four main metropolitan areas in California: Greater Los Angeles, the San Francisco Bay Area, the Sacramento metropolitan area, and the San Diego metropolitan area. The purpose of this analysis is twofold: to generate a general model to assess hydrogen needs in different regions, and to apply the model to compare its results with the California hydrogen highways report. In the analysis that follows, average driving time to the nearest station (convenience metric) is used to determine the number of stations necessary for each region. By using convenience to determine the share of stations, regions that are less dense will be served as well as those regions with high density. The results suggest that the percentage of stations needed to meet a convenience target differs among regions depending on density. For example, a 4-min average travel time in Sacramento requires 7.2% of stations, whereas it requires only 3.3% of stations in Los Angeles. The developed equation predicts station needs as a function of population density and a desired level of convenience; if the caveats explained in the paper are observed, the prediction equation can be applied to any region.