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 an H2A delivery scenario analysis model. The model follows the H2A approach to economic parameters, transparency, color coding, and model layouts.
- H2A Delivery Scenario Analysis Model Version 2.0 (Register for Model Tool Download)
- H2A Delivery Scenario Analysis Model Version 1.0 (Register for Model Tool Download)
- H2A Delivery Scenario Analysis Model Version 2.0 Users Guide (guide forthcoming)
- H2A Delivery Scenario Analysis Model Version 1.0 Users Guide (PDF 228 KB )
The H2A delivery analysis model contains macros that are necessary for proper operation. Since 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 automatically be allowed to run. 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.
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 as 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 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.) are 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 (i.e., 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 which compresses, stores and dispenses the hydrogen. Hydrogen delivery could also include compression, storage and dispensing of hydrogen produced on site at a forecourt (i.e., 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 (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 persons to one of over 20 million, 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 percent. 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 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 further define a scenario 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 (i.e., vehicles per person) and vehicle utilization (i.e., 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 which is used to calculate average and peak demand. Storage needs are computed to satisfy peak summer demand (i.e., the first five minutes of the peak hour of the peak day) as well as scheduled maintenance and other plant downtimes. Equipment sizing vs. storage needs are 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.