National Renewable Energy Laboratory

Advanced Heavy Hybrid Propulsion Systems

Technical Targets

The objective of technical target setting is to identify and quantify vehicle, subsystem, and component-level research and development technical targets that will enable industry to meet the goal of the Advanced Heavy Hybrid Propulsion System (AH2PS) project—to double the fuel economy of a commercially viable vehicle. As many combinations of technical targets could enable us to meet our goals, NREL is seeking the solution that has the lowest associated R&D effort and life cycle cost.

Researchers at NREL are working with AH2PS industry teams to identify heavy hybrid vehicle system requirements with a cascading approach to set technical targets (Figure 1). The AH2PS project has goals for vehicle-level performance, cost, and reliability requirements. These requirements are cascaded down to the vehicle powertrain and component level and technical targets are set within commercial viability constraints. Thus, a given set of targets will be vocation specific and linked back to an actual vehicle system.

Cascading diagram depicting the vehicle requirements used to set technical targets for AHHPS. We must ask the question of whether the current technology using existing commercial constraints of vehicle level performance, cost, and reliabiliy requirements, allow us to meet our goals and if not these are the factors we use to set technical targets. These targets are cascaded down to the vehicle powertrain and component levels and technical targets are set within these commercial viability constraints.

Figure 1 - Cascading of vehicle requirements to set technical targets