Fraunhofer Institute for Manufacturing Engineering and Automation IPA in Stuttgart researchers recently created a new film-based panel heater for electric vehicles (EV), according to recent reports.
Worth noting up front, is that according to the researchers, the new panel heater is more effective than conventional electric heaters, especially on shorter trips.
Since EVs don’t produce nearly as much ambient heat as combustion engines do (which is where much, or all, of the heat in conventional cars comes from), running the heater in an EV can be a real battery drainer. As such, heaters that can be used in EVs — that are more energy efficient than currently used designs — possess great potential applicability.
The new heating panel idea is based around a film coated with a thin layer of conductive carbon nanotubes. This film is then attached to inner door trim and generates heat there when electricity flows through it — working essentially the same as a conventional electric resistance heater (think of a coil stovetop), with flowing electricity encountering resistance and creating heat.
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In conventional electric resistance heaters, the conductive material usually used is copper wire—embedded in silicone mats, for example. The Fraunhofer solution offers several advantages:
While the copper wire heaters currently available are relatively bulky and take up quite some installation space, the film heater consists of a layer of conductive material with a thickness of only a few micrometers. It can be flexibly applied to the most various surfaces and contributes to saving energy and costs due to its low weight. The CNTs themselves have a low heat storage capacity, as a result of which the generated heat is directly released into the environment.
As opposed to the wire-based variant, the heat is evenly distributed here over the entire surface of the film, which considerably increases efficiency. When the driver switches the heating off, the material cools down just as quickly. Such fast response times are ideal for short distances such as urban trips. The desired heating output can be infinitely adjusted by the user. Even isolated defects do not impair functionality. In wire-based heating systems, for example, even minor breaks in the metal can lead to failure.
The new film was applied by the researchers via division into small modules, which are then individually glued to the door.
The project manager at Fraunhofer IPA, Serhat Sahakalkan, explained: “Slight creases arise at the curvatures, which change the spacing of the electrodes. Even heat distribution would then no longer be ensured.”
The researchers involved are currently working to simplify the approach, so that the film can simply be “sprayed” on — which would make the technology more economical.
Heating with electricity is a huge issue. We have millions and millions of homes which burn fossil fuels for winter heating, and all of these homes are going to need to be converted over to electric heat. Most of these homes are not conducive to inexpensive insulation techniques. Capes, for instance, often require sprayed foam or resheathing the entire house. This can cost many tens of thousands of dollars.
Almost nobody heats their home with electric base-board heaters anymore – because it is *too expensive* at our current electricity rates. Geothermal won’t work for many, and it is also very expensive – out of reach for normal folks. We really need to think about public ownership of our renewable energy utilities and electric rates that are fixed by the government at or near zero. Otherwise, half of us will freeze to death.
Anything that involves carbon nanotubes doesn’t sound like it’s going to be economically feasible for awhile… Plus, how does this compare to the efficiency of heat pump systems already being used in some EVs (such as Leaf)? I’ve always heard that a heat pump is always more efficient than resistance heating, which makes this nanotube tech pretty useless for saving energy.