Feasibility of Thermoelectrics for Waste Heat Recovery in Conventional Vehicles

Thermoelectric (TE) generators convert heat directly into electricity when a temperature gradient is applied across junctions of two dissimilar metals. The devices could increase the fuel economy of conventional vehicles by recapturing part of the waste heat from engine exhaust and generating electricity to power accessory loads. A simple vehicle and engine waste heat model showed that a Class 8 truck presents the least challenging requirements for TE system efficiency, mass, and cost; these trucks have a fairly high amount of exhaust waste heat, have low mass sensitivity, and travel many miles per year. These factors help maximize fuel savings and economic benefits. A driving/duty cycle analysis shows strong sensitivity of waste heat, and thus TE system electrical output, to vehicle speed and driving cycle. With a typical alternator, a TE system could allow electrification of 8%-15% of a Class 8 truck's accessories for 2%-3% fuel savings. More research should reduce system cost and improve economics.

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  • Corporate Authors:

    National Renewable Energy Laboratory

    1617 Cole Boulevard
    Golden, CO  United States  80401

    Department of Energy

    1000 Independence Avenue, SW
    Washington, DC  United States  20585
  • Authors:
    • Smith, K
    • Thornton, Matthew
  • Publication Date: 2009-4

Language

  • English

Media Info

  • Media Type: Print
  • Pagination: 24p

Subject/Index Terms

Filing Info

  • Accession Number: 01140721
  • Record Type: Publication
  • Report/Paper Numbers: NREL-TP-540-44247
  • Files: TRIS
  • Created Date: Sep 25 2009 12:11PM