DOE H2A Delivery Analysis
Hydrogen delivery is an essential component of any future hydrogen energy infrastructure. Hydrogen must be transported from the point of production to the point of use and handled within refueling stations or stationary power facilities. The scope of hydrogen delivery includes everything between the production unit (central or distributed) and the dispenser at a fueling station or stationary power facility.
In order to begin the task of hydrogen analysis, the H2A Analysis Group has developed three H2A delivery models: Delivery Carriers Components, Delivery Scenarios Analysis, and Refueling Station Analysis. All models follow the H2A approach to economic parameters, transparency, color coding, and model layouts.
The following H2A delivery analysis tools are available through this site.
- Delivery Components Model
- H2A Delivery Components Model Version 2.0
- H2A Delivery Components Model User's Guide
- H2A Delivery Carrier Components Overview Version 1.0
- H2A Delivery Scenario Analysis Model (HDSAM) Version 3.0
- H2A Delivery Scenario Analysis Model Version 3.0 (HDSAM 3.0) User's Manual
- H2A Refueling Station Analysis Model (HRSAM) Version 1.1
All H2A delivery models contain macros that are necessary for proper operation. Because Microsoft Excel has a macro security option (to either accept or deny macros), your computer needs to be configured for these macros to run. Macro security needs to be set at either medium or low. If you are running Excel 2003 with a medium security setting, a dialog box asking if you want to run macros will appear each time you open a spreadsheet that contains macros (such as the H2A Delivery Models). With a low security setting, the macros will be allowed to run automatically. In Excel 2007 with a medium security setting, a shield will appear at the top of the screen each time you open the models. You must click on "options" and "enable content" for the macros to run. To access the Excel macro security option, use the following menu tree: Tools > Macros > Security.
Overview of H2A Delivery Analysis
There are three broad delivery pathways: gaseous hydrogen delivery, cryogenic liquid hydrogen delivery, and novel solid or liquid hydrogen carriers. The liquid and gaseous pathways transport pure hydrogen in its molecular form via truck or pipeline. A carrier is a material that carries hydrogen in a form other than free hydrogen molecules. Carrier pathways transport hydrogen via truck or pipeline and require the return of spent fuel for reprocessing.
To date, H2A delivery analysis has focused on liquid and gaseous pathways using currently available technologies. Future analysis will investigate emerging and longer-term options for hydrogen delivery. Detailed, comprehensive analysis of the potential cost and performance of future delivery technologies and systems will be required to better understand their advantages and disadvantages for both the transition to and long-term use of hydrogen as a major energy carrier.
H2A Delivery Components Model
In H2A delivery analyses, hydrogen delivery is defined as the complete set of equipment and processes used to move hydrogen from the point of production (larger central plant or small distributed production unit) to the nozzle of a dispenser. The feedstock, scale, and process used to produce hydrogen are outside the bounds of delivery; so too is the operation of the hydrogen-fueled vehicle.
Within the bounds of the delivery system, hydrogen is conditioned to permit bulk transport as a compressed gas or as a liquid; shipped via a bulk transport mode (e.g., transmission pipeline or truck) to a terminal where it may be further conditioned, stored, or transferred to a local distribution mode; and delivered to a refueling station where it is dispensed onto vehicles.
The H2A Delivery Components model focuses on components required to deliver liquid hydrogen or compressed hydrogen gas from a central production plant or distributed production unit to the nozzle of the dispenser. At this point, novel storage and delivery technologies, such as hydrogen carriers, are not modeled. The components that are modeled in Version 2.0 of the tool are listed below.
- Truck—compressed hydrogen gas tube trailer (2700 psi)
- Truck—liquid hydrogen tanker
- Compressor (single-stage or multi-stage units)
Bulk Storage Components
- Compressed gas tube
- Bulk liquid tank
- Geologic/underground cavern
Transmission/Distribution Interface Components
- Pipeline to gas terminal (with either geologic or liquid storage for plant outages and demand surges)
- Pipeline to liquid terminal (with either geologic or liquid storage for plant outages and demand surges)
- "Pure" liquid H2 terminal (with either geologic or liquid storage for plant outages and demand surges)
- "Pure" gaseous H2 terminal (with either geologic or liquid storage for plant outages and demand surges)
Refueling Station Components
- Daily storage (either in low-pressure vessels or as components of cascade charging system)
Integrated Refueling Station
- Gaseous (containing integrated compressor, cascade compression/dispensing, and storage)
- Liquid (containing integrated storage, vaporizer, and cascade compression/dispensing)
The model is written as a Microsoft Excel spreadsheet with a separate tab for each of the delivery components. The model calculates the cost contribution of each component within the delivery infrastructure to the $/kg cost of delivering hydrogen. This cost contribution is based on inputs provided by the user describing the amount of hydrogen to be delivered and basic capital and operating costs for the component.
Version 2.0 contains default values that represent currently available (2005) technologies and costs. These parameters can be changed by the user to simulate advancements in technology and changes in other costs.
Using the H2A Delivery Carriers Components Model
Hydrogen carriers have been under intense investigation for their potential to meet the DOE on-board storage goals. Potential alternative hydrogen carriers include metal hydrides, chemical hydrides, high-surface-area carbon sorbents, and liquid-phase hydrocarbons. While these alternative hydrogen carriers have the potential to provide on-board storage, they may also be used to improve the efficiency and cost of hydrogen delivery to refueling stations. Certain hydrogen storage technologies may not meet all of the requirements for use on-board vehicles but may be viable for hydrogen delivery because delivery components have less restrictive requirements than on-board storage regarding their volumetric and gravimetric capacity.
A hydrogen carriers' model was developed in Microsoft Excel to evaluate the cost associated with various carriers' delivery pathways. It serves as a tool to examine the cost of components associated with different pathways (liquid truck, solid-state truck, pipeline, etc) in which various carriers can be used for hydrogen delivery, to establish which components contribute significantly to the delivery cost, and to provide ranges for the characteristics of each component. The model has been developed in the H2A tools format and incorporates many of their features. The model contains macros that are necessary for proper operation.
H2A Delivery Scenarios Analysis Model
Like other H2A-developed tools, the Hydrogen Delivery Scenario Analysis Model (HDSAM) uses an engineering economics approach to cost estimation. For a given scenario (discussed below), a set of "components" (e.g., compressors, tanks, tube trailers, etc.) is specified, sized, and linked into a simulated delivery system or pathway infrastructure. Financial, economic, and technological assumptions are then used to compute the levelized cost of those components and their overall contribution to the delivered cost of hydrogen. Version 2.0 contains default values that represent currently available (2005) technologies and costs and current population and infrastructure characteristics. These parameters can be changed by the user to simulate advancements in technology and changes in other costs or relevant characteristics.
As in the H2A Delivery Components model, hydrogen delivery is defined to include the entire process of moving hydrogen from the gate of a central production plant onto a vehicle. Thus, delivery includes all transport, storage, and conditioning (e.g., compression, liquefaction, or for hydrogen carriers, hydrogenation/reprocessing of spent material) from the outlet of a centralized hydrogen-production facility to and including a refueling station that compresses, stores, and dispenses the hydrogen. Hydrogen delivery could also include compression, storage, and dispensing of hydrogen produced on site at a forecourt (e.g., distributed production). The current version of HDSAM (V2.0) does not model distributed production scenarios or hydrogen carrier pathways. Future versions of the model will include these options.
HDSAM draws upon the engineering economics calculations in the H2A Delivery Components Model. In effect, many of the "component" spreadsheets (or tabs) within the Delivery Components Model are embedded in HDSAM, which links them into appropriate combinations to define a delivery pathway, size the individual components consistent with a scenario's demand estimate, and calculate the cost associated with delivering a given quantity of hydrogen via the specified pathway.
The user defines a scenario by selecting a market type (e.g., urban, rural interstate, or a combination of the two); specifying its size, location (either a generic urbanized area of defined population or any of over 400 urbanized areas contained in a drop-down menu), and the market penetration of hydrogen-fueled vehicles in the total population of light-duty vehicles; selecting delivery modes for bulk transport from a production facility to a city gate and for local distribution; specifying a type of storage for plant downtimes and surge demands; and indicating a desired refueling station size.
Market size can vary from an urbanized area of 50,000 people to one of over 20 million people, and from an interstate highway segment of 10 mi. to 300 mi. (1000 mi. for pipeline delivery). Market penetration can vary from 1% to 100%. Bulk transport can be via gaseous tube trailer, liquid hydrogen truck, or gaseous pipeline. Local distribution is generally via the same mode; however, for bulk transport via pipeline, local delivery may also be accomplished by any other mode.
Storage for plant outages and surge demands can be in geologic formations or as liquid hydrogen, and refueling stations can range from 50 kg to 6000 kg of hydrogen dispensed per day. Thus, delivery scenarios are combinations of (a) markets, (b) market penetrations, (c) delivery modes, (d) downtime storage, and (e) refueling station size, with an associated set of assumptions about market demand and infrastructure.
In reality, however, delivery scenarios are even more variable. The user can define a scenario further by changing such default values as the distance from a central production facility to the edge of the urban area, the average fuel economy of hydrogen and conventional light-duty vehicles, the city's rates of motorization (e.g., vehicles per person) and vehicle utilization (e.g., miles driven per vehicle per year), financial assumptions, and the characteristics and cost of any component in the delivery pathway.
Within HDSAM, user selection of a delivery mode invokes an associated chain of delivery "components" or processes required to satisfy market demand. For example, if the user selects liquid hydrogen truck delivery (with liquid storage for plant downtimes and demand surges) for a given market, penetration rate, and refueling station size, the model calculates not only the number and cost of the trucks required to deliver the fuel to refueling stations, but also the cost of appropriately-sized liquefiers, pumps, vaporizers, dispensers, truck loading facilities, and storage vessels at terminals and refueling stations. Collectively, these steps or "components" are known as a pathway.
The figure below illustrates three broad liquid hydrogen pathways contained in Version 2.0 of the model. Note that because delivery is broken down into bulk transmission and local distribution—each of which can be by a different mode—loading, conditioning, and storage activities normally associated with a terminal or depot can be located anywhere between the production plant and the city gate. In Pathway 1, they are co-located with production; in Pathways 2 and 3, they are at the city gate.
Version 2.0 of the model contains a revised demand profile that is used to calculate average and peak demand. Storage needs are computed to satisfy peak summer demand (e.g., the first five minutes of the peak hour of the peak day) as well as scheduled maintenance and other plant downtimes. Equipment sizing versus storage needs is optimized within the model—that is, components are sized so that their total cost (capital and operating cost of equipment and associated storage) is minimized.
H2A Refueling Station Analysis Model
Researchers at Argonne National Laboratory (ANL) have developed the Hydrogen Refueling Station Analysis Model (HRSAM), which calculates the cost of hydrogen refueling as a function of various fueling station capacities and design configurations. HRSAM is an abbreviated version of HDSAM that focuses solely on near term refueling station costs. HRSAM incorporates the significant design aspects of refueling stations, including the size and cost of capital equipment, and the costs of operation and maintenance. Default values for model inputs are based on early market data, but they can be modified by a user to evaluate different refueling options. Station design parameters that are particularly significant to operators are highlighted in a separate easy-to-use interface; these parameters include annual projections of station utilization, the number of hoses a station has, the number of consecutive fills a station can complete, and the modes of hydrogen delivery the stations accepts. Users can also specify economic inputs, such as rate of return and debt-to-equity ratio. Using discounted cash flow analysis, HRSAM then outputs the annual and cumulative cash flows, cost of refueling per kilogram of hydrogen, years required to break even on investment, total capital investment, and land area a given station requires.