Thermoelectrics: Making Heating and AC Systems for PHEVs More Efficient and Practical
Image courtesy of crazytales562 via flickr
Once merely the province of mechanics and ambitious car hackers, PHEVs are finally set to enter the mainstream in 2010 when several of the big automakers roll out their first models. Yet amidst all the excitement and anticipation that this has generated -- to which we, among many other blogs/commentators, have fallen victim to -- it has become easy to overlook an obvious fact: that PHEV adoption isn't likely to gather steam until several obstacles, including the higher sticker price, are sufficiently addressed. Writing for Technology Review, Kevin Bullis has identified one of the biggest potential headaches: building energy-efficient heating and AC systems. As he notes, conventional heating systems are horribly inefficient and -- because they derive energy from the heat generated by a car's internal combustion engine -- probably wouldn't work in PHEVs; they also add a few thousand dollars to a PHEV's price tag. Since these run on electricity -- and therefore don't generate excess heat -- their batteries will need to be tapped to provide the heat needed, potentially draining them of thousands of watts -- a serious problem for anybody driving in cold weather (let alone freezing). In the case of AC, hot weather typically causes the electric range of PHEVs to fall, thus limiting the quantity of watts that can be harnessed to provide the cooling.
The most promising technology being worked on to tackle this issue is thermoelectrics: semiconductor devices that provide either heat or cooling depending on the direction of the underlying electric current. Companies like GM and Ford are even considering the use of nanotechnology in a bid to further drive down costs and boost efficiency. Unlike heaters, they can be installed at various points in the car -- even in the driver's headrest -- providing a more effective, targeted means of heating/cooling passengers.
The benefits in terms of energy savings could be significant: As Bullis explains, thermoelectric systems would save anywhere from 1,500 (if the car is full) to 3,800 watts (for an individual driver) over ordinary systems. While these systems are likely to miss the first wave of PHEVs, automakers are ramping up efforts to ensure they make it into the next wave, projected to appear in 2012.
Via ::Technology Review: Heating Plug-in Hybrids (news website)