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RET TECHNOLOGY

Hybrid Technology Overview
There are two main categories of hybrid architecture in use for commercial vehicles today.
Series Hybrid and Parallel Hybrid
Each type of architecture offers distinct advantages and disadvantages.

Series Architecture
All power to and from the wheels is transmitted through a pump motor or electric machine via conversion from hydraulic or electric power to mechanical power.

series


Advantages

  • Greatest potential improvement in fuel economy
  • Greatest potential reduction of CO2 emissions
  • Greatest potential reduction of maintenance expenses

Disadvantages

  • Architecture is complex
  • Design not conducive to retrofit applications
Hybrid system malfunction renders vehicle inoperable

Parallel Architecture
Power can be transmitted to the wheels simultaneously from the engine as well as through hydraulic or electric power.

paralell


Advantages

  • Performance least impacted by drive cycle
  • Most conducive to retrofit applications
  • Vehicle is still operable if hybrid system malfunctions

Disadvantages

Depending on drive cycle, may not provide the highest benefit return as compared to Series architecture.

Hybrid Propulsion Methods
Within each architecture, there are several hybrid propulsion methods that can be applied:

  1. Electric storage and propulsion
  2. Hydraulic storage and propulsion
  3. Hydrogen storage and propulsion
  4. Other – technologies currently in development or not yet discovered

Hybrid/Electric Advantages

  • Energy efficiency (10% – 32%)
  • Enhance acceleration
  • Reduced noise
  • Offers maintenance benefits
  • Emissions benefits

Disadvantages

  • Cost (60% - 80% price premium over ICE)
  • Typically requires new purchase versus retrofit
  • Battery replacement cost
  • Weight

Hybrid/Hydraulic Advantages

  • Energy Efficiency (10% -28% )
  • Enhance acceleration
  • Retrofit solutions available
  • Offers maintenance benefits
  • Emissions benefits

Disadvantages

  • Weight (though typically less than hybrid/electric)

Hydrogen (Fuel Cells) Advantages

  • Zero or low emissions energy source potential
  • $Billions$ have been committed towards a commercial solution
  • Reduces the dependence on petroleum based fuel

Disadvantages

  • Depending on source may not be zero emission
  • Commercial solution decades out
  • Lack of Infrastructure

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