gergg wrote:True....I live near Atlanta, will drive the Leaf approx 15,000 miles/year, my house has great South facing area with little shading.
O.K. That's the main information we need. The U.S. Government has maintained a database of solar insolation for the past 40-odd years and they have nice resources to help you calculate the electricity production you might expect. The simplest calculator is PVWATTS
. I put in the data I used for MY array into your location to see how your insolation compared with mine and it looks like your annual production predicted by PVWATTS is about 12% better than it predicts for us here in Virginia (assuming your roof points directly South and your roof pitch is 8:12 (33.69 degrees) elevation). My array is 9.87 kW and you can see the performance I have been getting by clicking on the link below in my signature. You can scale from my numbers by adding 12% and also adjusting for size to see what a similar system would do for you. (Note that your production only scales 12% on an ANNUAL basis, not month-to-month. For instance, in June, our systems are predicted to produce the same amount, since your temperatures are hotter. In the wintertime, your numbers are much better, however.) Note that if your roof pointing is within about 15 degrees of the boresight I used, then the annual production numbers are within about 1 percent or so of being accurate.
As far as cost of the array goes, I paid about $4/W installed, but I did the installation myself. If you pay someone to do it, you might expect to pay $6/W to $8/W installed.
As far as powering the LEAF, 15,000 miles at about 4 miles/kWh (wall) comes to 3750 kWh/year consumption to run the LEAF. Using PVWATTS for your location (again, assuming roof is directly South and 8:12 pitch) and using a DC to AC derate factor of 0.85 (open for some debate, it may be a little higher
), I calculate that you will need an array size of 2.5 kW to produce the same amount of AC electricity that your LEAF would consume. At $6/W installed, that comes to about $15,000 before any tax credits and about $10,500 assuming you can still get a 30% Federal tax credit. Of course if you want to do more than just power your LEAF, you can go much larger.