Solar-powered interior cabin heater?

[RobbW]

Time for my annual "The Colder Months Draw Nigh" bout of questions. In this round, what I am wondering is if there is any type of solar-powered contraption I can use to minimally (or maximally if possible) heat the interior of my Meepster while it sits outside in the frigid cold for 8 hours while I'm at work? I'm envisioning a flexible solar panel that I can unroll and place on the roof of my iMiEV. This would in turn power an interior cabin heater that could keep the inside of my Meepster nice and toasty warm all day long. Or at the very least, minimally warm the inside so it isn't so damn freezing cold when I leave work at the end of the day. Alternatively, I wouldn't mind permanently installing solar PVs on the roof (or wherever is most feasible) to power an internal heater for the winter (and maybe an A/C unit for the summer?).

 

[JoeS]

Geeks do math

Without doing the math, I suspect it would be more efficient to put a black blanket over the car rather than try to actively power some type of heater with a flexible solar panel which, for the size of an i-MiEV roof, would be about 100W. For example:

http://www.amazon.com/Flexible-Sola.../B010CL6KPK/ref=sr_1_3?ie=UTF8&qid=1441401998

Accounting for inefficiencies in both energy absorption and power conversion, I think you'd be lucky to get 25W usable out of this thing while you're at work ... which I suspect won't do diddly to heat the insides of your i-MiEV in your winter climate.

A few more sweaters, longjons, insulated boots, and personal powered body heaters sound like a better investment. Hmmm, what about a black car cover?

Didn't you say you were going to be able to be plugged into the grid while at work? With a Remote or maybe even a small 120vac space heater on a timer, you should be all set...

 

[PV1]

I've thought about this, too. With my white paint, my roof stays cool almost year round. What I do is park facing south. The large windshield allows most of the interior to be as warm as 80 F even when it's about 20 F outside. Of course, air below the armrests is frigid. Maybe take a solar panel and power a fan to blow the cold air from the floor up towards the dash?

(It's hard to think about the cold after waxing the car in 85 F shade.)

As for rooftop solar, Grape Solar makes 100 watt panels that are semi-flexible. You should be able to fit 3 of them on the roof. If you can get 30 watts a piece, 90 watts should be enough to keep a pair of heated floormats warm. That, combined with direct solar heating, should keep the interior comfortable. Of course, this is all for nothing if the car is in the dark for an hour before you leave.

 

[Don]

Without doing the math, I suspect it would be more efficient to put a black blanket over the car rather than try to actively power some type of heater with a flexible solar panel. . . . .

I was thinking the same thing

Passive solar heating. Instead of putting up the silver panels covering the windshield to keep out the summer heat, lay a pair of black panels on the dash and let the sun shine through the windshield and heat up the black panels and thereby warm the car's interior . . . . a little bit

Don

 

[Phximiev]

You need an "anti-Budge" cover. Made from a material to hold heat in rather than repel it.
Perhaps, like a plug-in electric blanket fit to the car?

 

[genec]

Get a large dog and keep it in the car. A large dog gives off the same amount of heat as a 100 watt light bulb.

 

[PV1]

Get a large dog and keep it in the car. A large dog gives off the same amount of heat as a 100 watt light bulb.

:lol: Yeah, but your windows will have water running down them from the vapor .

Actually, a laptop doing some heavy crunching made a noticeable difference in temperature in 45 minutes. I tried this the other night with my laptop doing work for the Clean Energy Project and SETI@Home.

 

[jray3]

I think that a south-facing parking spot with clear sky views is the best idea thus far. The interior is dark enough that I wouldn't expect any added black material to make much difference. For those of us with plug-ins at work, I've been meaning to test the range of my pre-heat remote!
Beyond that, we'd get into remote start fueled heater discussion or a big thermos full of hot water, like the Prius coolant bottle that's been discussed before.

 

[GdB]

This looks like a good heating option for the miev, if we could get a salvage one from a crashed ??? EV.
https://cleantechnica.com/2017/09/2...acturer-ptc-cabin-heating-tech-improve-range/

How hard is it to get access to the battery high voltage?

 

[jray3]

This looks like a good heating option for the miev, if we could get a salvage one from a crashed ??? EV.
https://cleantechnica.com/2017/09/2...acturer-ptc-cabin-heating-tech-improve-range/

How hard is it to get access to the battery high voltage?

Borg-Warner is trying to pull a fast one there, as PTC 'ceramic' heater grids have been the standard heater in DIY EV conversions for 20 years. It is much faster to heat the airstream than to heat a water reservoir that then heats the air. Though all electric resistance heaters are 100% efficient, the slow response of an electric water heater and heat energy that gets 'abandoned' in a reservoir full of hot water that resumes cool-down every time you shut down the car would make direct heating more efficient.

Most efficient of all would be a heat pump, especially one that pulls heat from the motor/inverter cooling loop, which besides scavenging a few Btu, would make the drivetrain run more efficiently as well while allowing that little radiator do double duty. A regular air-source heat pump should be easy to implement on any vehicle with air conditioning. (Just add reversing valves.)

 

[Aerowhatt]

I think that a south-facing parking spot with clear sky views is the best idea thus far. The interior is dark enough that I wouldn't expect any added black material to make much difference.

This is the best option for solar heating. To greatly increasing the effect fabricate some custom insulation panels for the rear and rear side windows (perhaps front side windows too). This could be an external or internal solution depending on your preference. Keep the windshield nice and clean too. Aim the car windshield to the southwest (or for maximum exposure for whatever time of day you plan to leave the parking lot). Best case, you could get into an uncomfortably warm car in cold weather.

Material for the panels could be that reflective bubble sheet plastic material. Silver side to the interior of the vehicle!

Aerowhatt