Search NASA⌕ Search

SEARCH · Search NASA

Results for “medium-duty vehicles”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

80 records · Page 5

Enabling Seamless Integration of EV Charging Infrastructure with Weak Electric Grids

Widespread adoption of Electric Vehicles (EVs) for light, medium, and heavy-duty applications has gained significant interest. Based on ownership and user preferences, light duty and local delivery medium-duty EVs are typically connected to grid distribution networks whereas larger medium duty and heavy-duty EVs are typically connected to distribution or even sub-transmission networks. Challenges with at-scale EVs and charging infrastructure supporting them include interoperability, distribution network upgrades, surge in demand charges, power quality issues, voltage stability, etc. Based on real-world data, steady-state and dynamic assessments of light-duty EV charging with a focus on DC Fast Charging (DCFC) for weak distribution grids is presented. Three main areas of contributions in this paper include - steady state and dynamic power quality measurements and assessments using real world data, transient assessments of light duty EV integration with weak distribution networks (IEEE 13 node feeder system) under grid-connected and microgrid modes, and formulation of an intelligent charging decision algorithm to enable an impact-minimal charging.

actionable intelligence↗

Spatial and Temporal Analysis of the Total Cost of Ownership for Class 8 Tractors and Class 4 Parcel Delivery Trucks

The medium- and heavy-duty transportation sector is experiencing rapid changes in powertrain technology innovation, with recent announcements of battery electric and fuel cell electric trucks being offered. The economics of these alternative powertrain vehicles are uncertain and difficult to compare directly. This analysis seeks to provide a rigorous, techno-economic analysis of all of these alternative powertrain vehicles within the same analytic framework. Specifically, this report evaluates the total cost of ownership (TCO) of six different truck powertrain technologies (diesel, diesel hybrid electric, plug-in hybrid electric, compressed natural gas, battery electric, and fuel cell electric) for three different truck vocations (Class 8 long haul [750-mile range and 500-mile range], Class 8 short haul [300-mile range], and Class 4 parcel delivery [120-mile range]), for three different time frames (2018, 2025, and Ultimate).

08 HYDROGEN↗

Deep Electrification Analysis: The Role of the U.S. Power Grid for Sustainable Transportation

This project attempts to quantify the size of electric generation for the entire nation to transition from a fossil fuel based transportation sector to a zero GHG emission-based energy source. The scope of this analysis is limited to decarbonizing the transportation sector, leaving the remaining sectors, such as power (for those that are still fossil based), industry, and building sectors, for later phases of study. The study year for this analysis is 2050, with expected escalation in transportation services and naturally occurring evolutions in the electric power sector and the entire economy. This analysis uses the projections of the Energy Information Administration’s (EIA’s) Annual Energy Outlook (AEO 2020) Reference Case for study year 2050 [EIA/AEO2020] as a base-case. The transportation sector is disaggregated by the following modes and classes: (1) on-road (divided into light-duty, medium-duty, heavy-duty vehicles), (2) aviation, (3) maritime, and (4) rail. The decarbonization case was based on only 2 pathways: (1) electrification of on-road transportation except for 30% of heavy-duty vehicles, and (2) power-to-liquid for the remaining transportation modes. The study estimated for 11 US regions what the additional wind and storage capacities requirements are to replace the fossil-based fuels with renewable wind capacity. Considered were the utilization of the existing idle capacity particularly during the load valley at night and any additional new generation capacity in EIA projections for the reference case. To balance the additional wind capacity required significant energy storage capabilities which were estimated in terms of power capacity (GW) and energy capacity (GWh). The paper further characterizes the energy requirements by a relation of power capacity to duration, allowing the analyst to gain insights into what the best technology portfolio might be to meet the new balancing or flexibility needs.

24 POWER TRANSMISSION AND DISTRIBUTION↗

MC Formula Protocol for H35HF Fueling (CRADA Final Report)

The National Renewable Energy Lab (NREL), Frontier Energy, and the industry partners worked together to help SAE J2601-5 develop an H35 high-flow (HF) medium-duty (MD) and heavy-duty (HD) fueling protocol. The team upgraded NREL's hydrogen filling simulations (H2FillS) model to accommodate an MC Formula fueling (t-final) table generation capability by leveraging NREL's high-performance computing system. Based on protocol boundary conditions (e.g., allowable maximum flow rate, range of storage system size) set by SAE J2601-5, the team generated the fueling tables and then validated the reliability of those tables by installing them on NREL's HD dispenser and ZBT's H35HF dispenser and then performing H35HF fueling experiments. Through the validation process, this team certified that the fueling tables generated were reliable to install in commercial H35HF dispensers and then performed H35HF fueling of commercial MD/HD vehicles.

08 HYDROGEN↗

Natural Gas Vehicle Basics

Natural gas powers about 175,000 U.S. vehicles and more than 23 million vehicles worldwide.1 Natural gas vehicles (NGVs) are a good choice for high-mileage (high fuel-use) fleets - such as buses, medium- and heavy-duty trucks, and refuse vehicles - that are centrally fueled or operate within a limited area or along a route with natural gas fueling stations. The advantages of natural gas as an alternative fuel include its domestic production, established distribution network, relatively low cost, and emissions benefits.

alternative fuel↗

Electric Vehicles for Fleets

Electric vehicles (EVs) can fulfill many daily driving needs, making them a great solution for fleets. They offer several benefits and can fill roles in light-duty, medium-/heavy-duty (MD/HD), and even off-road applications. The unique fleet environment presents considerations beyond those that consumers must address before going electric. For example, fleet managers must understand the impacts of charging multiple vehicles while maintaining fleet operations. Larger MD/HD vehicles bring additional factors to consider.

ADVANCED PROPULSION SYSTEMS↗

MC Formula Protocol for H35HF Fueling

A publicly available and verified high-flow fueling protocol for H35 medium-duty (MD) and heavy-duty (HD) hydrogen-powered buses and trucks does not exist. This could lead to transit agencies needing to select suppliers for purchase of new fleet vehicles, and to multiple providers responding with incompatible vehicle designs in the future. With the expansion of MD/HD vehicles using 35 MPa storage, there will be a need for publicly accessible H35HF stations, and these will require the use of a standardized prescriptive fueling protocol. The development of a fully tested and validated H35 high-flow (H35HF) MC Formula fueling protocol for MD and HD buses and trucks can provide guidelines to design H35 stations and vehicles, enable other manufacturers and vehicle original equipment manufacturers (OEMs) to enter this space, and ultimately accelerate to popularize the hydrogen market.

ADVANCED PROPULSION SYSTEMS,ENERGY PLANNING, POLIC↗