Thermoelectrics Could Give PHEVs Help In Heating And Cooling

One of the biggest challenges the automakers face in the design of plug-in hybrid electric vehicles (PHEV) is the heating and cooling of the passenger compartment. Conventional vehicles draw heat generated from inefficient operation of the internal combustion engine into the passenger compartment.

PHEVs and EVs don't generate much waste heat, especially when they are operating for short trips. Maintaining a constant warm or cold temperature draws a significant amount of energy from the vehicle and will quickly drain the battery packs. Current designs use large battery packs to cover the "cost" of heating and cooling. The use of larger battery packs increases the vehicle's weight and cost.

New thermoelectric semiconductor technology that can provide either heating or cooling, depending upon the direction of the applied current, may solve this problem. GM and Ford are both developing thermoelectric-based heating and cooling systems which may provide more efficient climate control and reduce the size of the battery packs in PHEVs and EVs.

Unlike conventional heating systems, which rely on centralized components with high electrical resistance, thermoelectrics can be placed in different areas of the car and generate warmth in zones around individual passengers. A thermoelectric heating system could use between one-sixth and two-thirds of the power that a conventional heating system uses, based on the number of passengers in the vehicle. Automakers estimate that thermoelectric climate control could be in vehicles by 2012, regardless of the vehicle type. Such systems would reduce the need for a conventional compressor for air conditioners, reducing the vehicle's weight and improving fuel economy.


Photo Credit: Gabriel Fernandez