Solar panel for recharging

[Steve Brown]

A great accessory would be a solar panel which can be mounted on the roof and/or hood of the car to recharge the battery while the car is parked in the sun all day. This would be great for commuters in California and other states where the sun shines bright most days. A 500 watt solar panel would provide 4 kW hrs during an 8-hour shift. That could extend the electric range of the Volt by 20 miles. Plus, solar energy is free and generates zero emissions.

[hermant]

A 500 watt solar panel gets me thinking. How large in square feet, how heavy in pounds, and how expensive would a solar panel have to be to generate 500 watts?

Based on COTS (commercial off the shelf) panels, 80 watts can be generated by a 30 pound panel with a surface area of 6.9 sq ft. That means that 500 watts would require 6.25 panels, a weight of 187.5 pounds, and cover 43.125 sq ft. That's a square with over 6 and a half foot sides! I suppose you could cover the entire top of the car (roof, hood, trunk) will solar panels and get close to that much area. You'd lose one passenger worth of carrying capacity due to the additional weight but that might be acceptable.

However, assuming that you paid around $500 for each panel, you'd be out $3125. If this arrangement did generate 4kWH per day (best case scenario), that would save about 40 cents per day in grid power. That yields an ROI of 7812.5 days or about 217 years. I think we should encourage worksites, malls, grocery stores, etc. to just install metered electrical outlets in their parking lots.

[Jackson]

Believe me, an on-board solar array is one of my fondest dreams, but it just doesn't make sense at the moment. My hope is that research into multi-junction, or Indium Gallium (or something so far unthought of) will produce cells with conversion efficiencies above 60%, inexpensively enough to be worth doing. Cost analyses don't look promising, but we all know someone who would do it anyway. Eventually, costs might come down for the rest of us.

Solar cell research currently trends in two disparate directions: $ per watt, period; which doesn't care about efficiency (2% efficient is fine if you want to cover the back of a billboard, and it costs less than paint). The other is high performance, regardless of cost. Because of the lack of area on a vehicle, main-drive recharging panels would have to fall into this category. Don't hold your breath, waiting. But maybe someday ...

[Steve Brown]

The above points are well taken.

How about a DC charging port on the Volt, so people can set up their own solar panel arrays at home? A DC charging port would obviate having to convert the output of solar panels to 120 VAC, eliminating the energy losses and expense that would entail.

[Texas]

Please refer to the following threads that deal extensivily with this subject. There are calculations and reasons why solar on the surface (SOTS) is such a great idea. Benefits that far outweigh the amount of power the cells generate. The benefits of new and interesting functionality. Enjoy:

http://gm-volt.com/forum/showthread....highlight=sots
http://gm-volt.com/forum/showthread....highlight=sots
http://gm-volt.com/forum/showthread....highlight=sots


And even much more here in the old forum:

http://gm-volt.com/volt-discussion/?...opic=76&page=1


After reading all of these references are you now a SOTS fan? I know I am. If you live in a sunny area and drive less than around 6 miles a day you would not only never have to deal with gas but you wouldn't even have to plug in! However, that is just the tip of the iceburg when it comes to SOTS.

[Steve Brown]

I like the idea of solar carports in parking lots, charging the batteries of cars parked under them. Imagine coming back to your car and finding that not only is the battery charged for the trip home, but the car is not the oven it would have been if exposed to the sun all day. That will save additional energy that would have been used by the air conditioner to cool the car down to a tolerable temperature. On a sunny day, a single carport could provide the 8 kilowatt hours of energy to bring the Volt battery up to full nominal charge, so you could drive up to 40 miles to work and 40 miles home without using gasoline.

To make this happen, the Volt should have a DC charging port, a connector to plug in a direct current source of power. That would enable the solar cells to feed energy more or less directly into the Volt's battery, eliminating the waste of energy that would occur, and expense of inverters, if the direct current from the solar cells has to be converted to 120 VAC.

[Texas]

I like the idea of solar carports in parking lots, charging the batteries of cars parked under them. Imagine coming back to your car and finding that not only is the battery charged for the trip home, but the car is not the oven it would have been if exposed to the sun all day. That will save additional energy that would have been used by the air conditioner to cool the car down to a tolerable temperature. On a sunny day, a single carport could provide the 8 kilowatt hours of energy to bring the Volt battery up to full nominal charge, so you could drive up to 40 miles to work and 40 miles home without using gasoline.

To make this happen, the Volt should have a DC charging port, a place to plug in a direct current source of power. That would enable the solar cells to feed energy more or less directly into the Volt's battery, eliminating the waste of energy that would occur, and expense of inverters, if the direct current from the solar cells has to be converted to 120 VAC.

You can check out a good discussion on charging stations here on this thread:

http://gm-volt.com/forum/showthread....light=carports

Sometimes the search function can be used to determine if topics have already been hammered on. This way we won't have so many separate threads all on the same subject. It will help keep things connected. There are a lot of really good ideas floating around this forum. Please check it out.

[Steve Brown]

Texas has told me in so many words to shut up and use the search engine, but my idea of having a connector to charge the Volt's battery from a source of direct current has not been mentioned in threads he linked to, and the idea needs to be considered by GM.

[Texas]

Texas has told me in so many words to shut up and use the search engine, but my idea of having a connector to charge the Volt's battery from a source of direct current has not been mentioned in threads he linked to, and the idea needs to be considered by GM.

Sorry I didn't include the thread that talked about direct dc/dc input. Here it is:

"Yes, I have an official GM solar charging station at my house. When I drive my Volt home I will plug it in and my solar panels will provide most of the energy. Green today. Seriously, it's much easier to go green when you are just charging batteries. You can go from your roof mounted solar panels to your inverter to the Volt's charger to your battery or there will probably soon be the option to go from your solar panels to a DC to DC power supply that will directly feed the batteries. Much more efficient if you are charging during the daylight hours. Anyway. Go green and install solar on your house today! I think the concept is just too simple for most people to grasp. Solar - battery - motor. Yawn.
"


http://gm-volt.com/forum/showthread....t=power+supply


Of course you are free to say as you like. I just think it's more useful for other readers if we keep things organized. Why start chipping away at the wheel when it's almost finished? The search engine is our friend. Cheers.

[timanderson]

I completely agree with you! nothing can beat solar energy, if utilized in a meaningful manner.I tried it once but the service provider charged me a fortune and the end product was bad. I am now going to consult http://www.classiccarports.com/ on my friend's suggestion. He too has got solar carport installed recently and is quite happy with the product as well as the maintenance facility being offered to him by the company. I read that Classiccarports have 30 year history of providing commercial sales, service and repairs and offer customized according to our needs.