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Summary This paper compares the relative cost of long-distance, large-scale energy transmission by electricity and by gaseous and liquid carriers (e-fuels). The results indicate that the cost of electrical transmission per delivered MWh can be up to eight times higher than for hydrogen pipelines, about eleven times higher than for natural gas pipelines, and twenty to fifty times higher than for liquid fuels pipelines. These differences generally hold for shorter distances as well. The higher cost of electrical transmission is primarily due to lower carrying capacity (MW per line) of electrical transmission lines compared to the energy carrying capacity of the pipelines for gaseous and liquid fuels. The differences in the cost of transmission are important but often unrecognized and should be considered as a significant cost component in the analysis of various renewable energy production, distribution, and utilization scenarios.

Direct hydrogen fuel cell electric vehicles (FCEVs) produce only water as a byproduct, thereby eliminating tailpipe carbon and criteria air pollutant emissions associated with internal combustion engine vehicles (ICEVs). However, in order to achieve economic parity with ICEVs, technological challenges must be overcome to lower system cost. The U.S. Department of Energy (DOE) monitors estimated fuel cell (FC) system cost and tracks progress towards milestones by techno-economic analysis based on demonstrated laboratory technologies for a next-generation 80 kWnet automotive FC stack for light-duty vehicles. The findings of the 2017 automotive FC system cost analysis are summarized, including the baseline system characteristics and specifications and the results of Design for Manufacture and Assembly (DFMA®) analysis of system manufacturing across a range of annual production rates. The highest volume predictions, for 100,000 and 500,000 units per year, result in a total system cost of $50/kWnet and $45/kWnet, respectively. The assumptions and methodology of the DFMA® analysis of the 2017 baseline FC system were validated by comparison with the FC system in the commercially available Toyota Mirai. One prospective pathway for decreasing system cost to $30/kWnet needed for cost competitiveness with ICEVs is outlined.

Liquid hydrogen (LH2) truck delivery and storage at dispensing sites is likely to play an important role in an emerging H2 infrastructure. We analyzed the performance of single phase, supercritical, on-board cryo-compressed hydrogen storage (CcH2) with commercially-available LH2 pump enabled single-flow refueling for application to fuel cell electric buses (FCEB). We conducted finite-element stress analyses of Type 3 CcH2 tanks using ABAQUS for carbon fiber requirement and Fe-Safe for fatigue life. The results from these analyses indicate that, from the standpoint of weight, volume and cost, 2-mm 316 stainless steel liner is preferred to aluminium 6061 alloy in meeting the required 15,000 charge-discharge cycles for 350–700 bar storage pressures. Compared to the Type 3, 350 bar, ambient-temperature H2 storage systems in current demonstration FCEBs, 500-bar CcH2 storage system is projected to achieve 91% improvement in gravimetric capacity, 175% improvement in volumetric capacity, 46% reduction in carbon fiber composite mass, and 21% lower system cost, while exceeding >7 day loss-free dormancy with initially 85%-full H2 tank.

In this study, the Design for Manufacture and Assembly (DFMA®) cost analysis methodology is used to examine several possible proton exchange membrane (PEM) automotive fuel cell (FC) bipolar plate (BPP) manufacturing approaches to help prioritize R&D needs in achieving the U.S. Department of Energy (DOE) BPP 2020 cost target of $3/kWnet (1). This paper provides: 1) an overview of BPP cost projections including automotive Original Equipment Manufacturers' (OEM) costs compared to DOE's 2020 target, 2) a comparison of three BPP base material selections (stainless steel (SS), carbon composite, and flexible graphite), 3) a list of manufacturing issues and limitations of metallic plates, and 4) identification of multiple pathways utilizing a roll-to-roll 2-D cell manufacturing approach inspired by Nissan (2). Sensitivity analyses are conducted to define a pathway to lower cost BPP assemblies for SS by postulating specific criteria (material cost, power density, etc.) to achieve the DOE BPP cost target.

A techno-economic analysis was conducted for metal–organic framework (MOF) adsorbents, which are promising candidates for light-duty vehicle on-board natural gas and hydrogen storage. The goal of this analysis was to understand cost drivers for large-scale (2.5 Mkg/year) MOF synthesis and to identify potential pathways to achieving a production cost of less than $10/(kg of MOF). Four MOFs were analyzed with four different metal centers and three different linkers: Ni2(dobdc) (dobdc4– = 2,5-dioxido-1,4-benzenedicarboxylate; Ni-MOF-74), Mg2(dobdc) (dobdc4– = 2,5-dioxido-1,4-benzenedicarboxylate; Mg-MOF-74), Zn4O(bdc)3 (bdc2– = 1,4-benzenedicarboxylate; MOF-5), and Cu3(btc)2 (btc3– = 1,3,5-benzenetricarboxylate; HKUST-1). Baseline costs are projected to range from $35/kg to $71/kg predicated on organic solvent (solvothermal) syntheses using an engineering scale-up of laboratory-demonstrated synthesis procedures and conditions. Two alternative processes were analyzed to evaluate the cost impact of reducing so...

Techno-economic analysis (TEA) plays a critical role in assessing the cost of a technology relative to the current market, in identifying high impact areas for research and development investment, and in informing relevant stakeholders. In this chapter we discuss three main topics: (1) an overview of TEA, its processes, methods, and considerations for developing a good TEA framework; (2) description of the U.S. Department of Energy's H2A Production Model which is used for evaluating their portfolio of hydrogen production research; and (3) a synopsis of currently published H2A case studies illustrating the application of techno-economic analysis to hydrogen production technologies. These technologies include polymer membrane and solid oxide electrolysis, photo-electrochemical, methane steam reforming, coal gasification and use of biomass (via gasification or bio-derived liquids) and solar thermal routes to hydrogen. From the analyses comparisons between various technological approaches can be made in terms of costs, implementation, investment and versatility.

Low cost, durable, and selective membranes with high ionic conductivity are a priority need for wide-spread adoption of polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). Electrolyte membranes are a major cost component of PEMFC stacks at low production volumes. PEMFC membranes also impose limitations on fuel cell system operating conditions that add system complexity and cost. Reactant gas and fuel permeation through the membrane leads to decreased fuel cell performance, loss of efficiency, and reduced durability in both PEMFCs and DMFCs. To address these challenges, the U.S. Department of Energy (DOE) Fuel Cell Technologies Program, in the Office of Energy Efficiency and Renewable Energy, supports research and development aimed at improving ion exchange membranes for fuel cells. For PEMFCs, efforts are primarily focused on developing materials for higher temperature operation (up to 120 °C) in automotive applications. For DMFCs, efforts are focused on developing membranes with reduced methanol permeability. In this paper, the recently revised DOE membrane targets, strategies, and highlights of DOE-funded projects to develop new, inexpensive membranes that have good performance in hot and dry conditions (PEMFC) and that reduce methanol crossover (DMFC) will be discussed.

Steady-state and time resolved IR spectroscopy have been used to characterize vibrational spectra and relaxation dynamics of the antisymmetric CN stretching band of tricyanomethanide (TCM) in solutions of water, heavy water, methanol, dimethyl sulfoxide, formamide, and the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4]. The vibrational energy relaxation times for tricyanomethanide in these solvents are longer than those previously reported for dicyanamide, another CN containing anion, in the same solvents. Results of ab initio calculations of the vibrational frequencies for tricyanomethanide depend on the method used and compare favorably with experimentally measured values for IR-active and Raman-active bands. Proton and electron affinities were also calculated.

Vibrational spectra and energy relaxation lifetimes are reported for the protonated acidic species hydrazoic acid (HN3) and the azide (N3-), thiocyanate (NCS-) and dicyanamide (DCA) anions in imidizolium and phosphonium ionic liquids (ILs). The vibrational spectra and dynamics for the anions in phosphonium tetrafluoroborate and dicyanamide ILs are similar to those previously reported for imidizolium ILs, which resemble the behavior in aprotic molecular solvents such as dimethylsulfoxide. The results are different for hydrazoic acid. In water, methanol and other protic solvents the energy relaxation time is shorter for the azide anion than its protonated and neutral counterpart, hydrazoic acid. In ILs, however, the anion relaxation times are faster than the acid, indicating that the intermolecular interactions are different for acids and anions in ILs compared to conventional molecular solvents.

Small anions in polar solvents are benchmark systems for fast vibrational energy relaxation (VER) due to the Coulombic effects that promote solute-solvent interactions. In order to investigate the effects of solute charge and solvent isotope effects on vibrational spectra and dynamics, infrared pump-probe studies have been used to determine VER (T(1)) times for the pseudohalide acids, XNCS and XN(3) (X = H, D), in protic solvents, H(2)O, D(2)O, CH(3)OH, and CD(3)OD. These results are compared with the well-studied azide and thiocyanate anions. Solvent isotope effects of the vibrational frequency shifts of azide and for VER rates of both azide and thiocyanate are similar to those for the hydro- and deutero-protonated species in water. VER times are longer for HN(3)/H(2)O, HN(3)/CH(3)OH, and DN(3)/CD(3)OD (T(1) = 2.3, 5.6, and 3.7 ps, respectively) than for the corresponding anions in solution (0.8, 3.0, and 2.1 ps), which is consistent with the idea that ions relax more quickly than neutrals. But the times measured for DN(3)/D(2)O, HNCS/H(2)O, and DNCS/D(2)O (T(1) = 1.2, 1.5, and 4.4 ps, respectively) are shorter than for the corresponding ions (2.3, 2.7, and 22.0 ps). Fast VER for DN(3) in D(2)O is attributed to strong coupling to nearby solvent bands and/or to Fermi resonances that promote intramolecular vibrational relaxation. For the HNCS and DNCS, the faster rates can be understood by recognizing that the charge displacements are similar to those for the anion.

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Time-dependent wave packet quantum scattering (TWQS) calculations are presented for HD(+) (v = 0 - 3;j(0)=1) + He collisions in the center-of-mass collision energy (E(T)) range of 0.0-2.0 eV. The present TWQS approach accounts for Coriolis coupling and uses the ab initio potential energy surface of Palmieri et al. [Mol. Phys. 98, 1839 (2000)]. For a fixed total angular momentum J, the energy dependence of reaction probabilities exhibits quantum resonance structure. The resonances are more pronounced for low J values and for the HeH(+) + D channel than for the HeD(+) + H channel and are particularly prominent near threshold. The quantum effects are no longer discernable in the integral cross sections, which compare closely to quasiclassical trajectory calculations conducted on the same potential energy surface. The integral cross sections also compare well to recent state-selected experimental values over the same reactant and translational energy range. Classical impulsive dynamics and steric arguments can account for the significant isotope effect in favor of the deuteron transfer channel observed for HD(+)(v