# When Will I Be Able to Do This?



## tarbe (Apr 7, 2007)

Plug my all electric car into a socket at my house and charge it completely off my solar panels?

Just need the correct inverter and enough ooomph, right?

Anyone doing this already?

I could save my 46 mpg VW diesel for the longer (>50 mile) trips.



Tim


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## Jim-mi (May 15, 2002)

Actually that would be very easy to do . . . . .

But I would suggest you be in your 'LazyBoy' recliner when you hear the 'upfront' cost of the system..........

Many days I could do that with my system------BUT not all the time . . the 'dead' of the winter . .no wind no sun . . . . 

More importantly at this *time* I do not know of an electric vehicle that would work for me . . .or that I could afford...........


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## artificer (Feb 26, 2007)

Not for a very long time, unless you have more money than you can use.

The Nissan Leaf has a 24kwhr battery, and the Chevy volt has a 16kwhr battery. I'll use these as a basis for charging.

5hrs of charging per day. 75% charge efficiency.

24kwhrs would need 6.4kw of solar panels, while the leaf needs 4.3kwhrs.

Your car needs to be connected to the solar system during the middle of the day, or you need to store the charge in batteries, which will charge the car's battery when you get home. With house batteries, your charge efficiency just dropped a lot with the dual charging, so add more panels. One solution is to have a two quick change battery packs. Swap out the 500-1000lbs of batteries after each charge.

Cost is going to be a lot. Even at $1/watt, you're talking over $5k just for the solar panels. Installed prices are probably going to be closer to $5/watt with batteries. You could end up spending half again what the car cost, just for solar.

The better solution is to plant rape or oil sunflower, and press it for oil. Convert to biodiesel, and burn that in the VW. (as long as the VW isn't the 2009 or newer... auto regen of particulate filter will kill the engine)

Just how much is that warm fuzzy feeling going to cost you?

Michael


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## SolarGary (Sep 8, 2005)

artificer said:


> Not for a very long time, unless you have more money than you can use.
> 
> The Nissan Leaf has a 24kwhr battery, and the Chevy volt has a 16kwhr battery. I'll use these as a basis for charging.
> 
> ...


You don't need the batteries if you don't mind grid-tied systems. Just set up the system large enough to support your house and the car. The excess during the day goes to the grid and you get credit for it whether your car is there or not.

My 2.1 KW PV array does 15 KWH on a nice day, so based on that it would have to grow by about (24/15)(2.1) = 3.3 KW to provide the extra to fully charge the car on a sunny day. Not all days are sunny, but you probably also don't use the full charge every day?

Depending on subsidies and all, I suppose you might add the 3.3 KW of PV for about $5000?

Don't know what the Leaf gets in miles of range for the 24KWH, but if its 300 watt-hours per mile, it would be 80 miles. For a 25 mpg gas car at $4 per gallon, that's worth about $13 per day, or nearly $5000 a year. That's unrealistic, but if you average 40 miles per day, its still $2300 per year -- pretty good return on a $5000 investment with very little maintenance?

I'm seriously thinking about expanding my PV array to cover our remaining house power use and the addition of a plug in hybrid -- thinking about the Prius plug in, which has short electric range, but its about right for us.

Gary


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## artificer (Feb 26, 2007)

Gary, I was assuming off-grid, which is probably a bad thing to do. Even with grid-tie, the economics are still out there. The Leaf costs $35k for 73 miles of range (US). Thats $10k more than a hybrid, and $20k more than a 31mpg honda civic. (edit: $17k for 2012 Prius) So, $25k or $15k more to go electric, using your $5k for the panels/grid-tie inverter/installation. At $4/gal and 31mpg, you have to drive 194k miles or 116k miles before you start to see any savings. If you already have a plugin hybrid, its a sunk cost, so it makes more sense.

Still... you have to drive 53 miles every day for the Leaf, or 31miles/day for the hybrid for the economics to work out on a stricktly cost basis. The less you drive, the less sense an electric vehicle makes, unless fuel prices double.

If you look at a plug in hybrid, like the Toyota Prius, I can't understand what the attraction is. $32k up front price with only a 10 mile electric range. At $4/gal and 50mpg that 10 miles only costs $0.80 a day. Even if you drive it every day, you only spend $300/year on fuel. The Honda Civic would cost $471/year in fuel to run. Thats 36 years of running, before you cover the extra cost of the hybrid.

My numbers are a bit muddled, but you get the idea. In a straight economic equation, I haven't seen where an electric car is cheaper than a gas/diesel car. They'll give you warm fuzzy feelings of saving the planet, but I don't see the numbers as an argument for them. 

Just got back from a 2,500 mile vacation trip with the Jetta TDI pulling a trailer. 30mpg, and did I mention a trailer? As far as I know, most hybrids will not let you tow something, unless its a SUV. Yet one more reason we went with diesel over hybrid.

Michael


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## nadja (May 22, 2011)

Oh what most people overlook on run time on those neato squito cars, is what if it is raining and dark ? Oh you need to turn on your wipers and lights too. Maybe add a little cold to the talk and turn on your heater. If you have one.


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## tarbe (Apr 7, 2007)

I have two VW diesels, but only run max 5% bio in them as they are 2009 and 2012 (Jetta Wagon and Touareg). 

It's not about a warm fuzzy feeling of saving the planet for me. It is about contingencies and independence. I don't see an economic payout on the solar that is compelling.


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## Jim-mi (May 15, 2002)

I'll say again; an electric that will fit me (bum leg) and that I can afford.
I have ridden in a Prius . . very nice . . .
But now with the bum leg I can't even get in one . . . .
The Tesla is really really nice but I'm a little over one hundred thousand short for it.

Last week I hauled many many bags of Cyprus mulch in the back of my veggie oil fueled Chev diesel truck . . . . . .
Can't haul *stuff* in those little things that you have to shoe horn your self into....
Yes I have given lots of thought to a VW TDI

Thanks Michael for all you figures.
That just helps keep me knowing that the "warm fuzzy feeling" of a plug in electric is a long way off for me...........................


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## SolarGary (Sep 8, 2005)

Jim-mi said:


> I'll say again; an electric that will fit me (bum leg) and that I can afford.
> I have ridden in a Prius . . very nice . . .
> But now with the bum leg I can't even get in one . . . .
> The Tesla is really really nice but I'm a little over one hundred thousand short for it.
> ...


You might try the Prius V -- I tried one in the showroom and its noticeably roomier in the front seat. The back end is also bigger for hauling stuff.

Gary


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## SolarGary (Sep 8, 2005)

artificer said:


> Gary, I was assuming off-grid, which is probably a bad thing to do. Even with grid-tie, the economics are still out there. The Leaf costs $35k for 73 miles of range (US). Thats $10k more than a hybrid, and $20k more than a 31mpg honda civic. (edit: $17k for 2012 Prius) So, $25k or $15k more to go electric, using your $5k for the panels/grid-tie inverter/installation. At $4/gal and 31mpg, you have to drive 194k miles or 116k miles before you start to see any savings. If you already have a plugin hybrid, its a sunk cost, so it makes more sense.
> 
> Still... you have to drive 53 miles every day for the Leaf, or 31miles/day for the hybrid for the economics to work out on a stricktly cost basis. The less you drive, the less sense an electric vehicle makes, unless fuel prices double.
> 
> ...


Hi Michael,
The Prius is not recommended for even a light trailer -- one of my few complaints about it. If I want a sheet of plywood I have to use the big car.

The plug in Prius works out well for our particular living situation -- our round trip into town is just within its 15 mile electric range. The rest of the time we are on long highway drives, and the nice thing about the plug in Prius is that the highway mpg is the same as the regular Prius -- this is not at all true with some hybrids -- e.g. the chevy volt. Since we do more highway than city driving so its important for us to have good mpg on the highway when in gasoline mode.

I need to go back and check the numbers, but you do get the federal tax credit on the plug in Prius plugin (not the full $7500, but something), and the plug in model comes standard with more "stuff".

For me carbon emissions are important, and if I can get close to dollar payback over the life of the car, I'd be onboard as long as there are carbon reductions. This is one thing that steers me away from diesels in that the 10% higher BTU content of the diesel fuel also means about 10% more carbon -- 2.9 ton/yr Prius vs 5.0 ton/yr Jetta diesel.

Gary


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## WisJim (Jan 14, 2004)

We have a VW Golf converted to electric and it has about a 30 mile range. Further than that we use the Ford Ranger pickup that gets 25 to 30 mpg. The Golf is charged from our PV/wind system, and of course we don't wait until the battery is fully discharged before recharging it, so most of the time it doesn't take too long to charge it. We had noticed that we seldom drive more than 50 or 60 miles a week, so an electric car with a modest range works well for us. And the car is home most days so it is convenient to charge from the wind and solar.


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