# Forums

## Average kWh per year for 12,000 miles per year?

I'm working on the plans for a solar array on my property to fully power my house and future electric cars. What I'd like to know is what the average amount of power consumption is on an average driven Tesla. Of course we're dealing with approximations but I figured a 100kWh battery pack does around 300 miles so .33kWh/mile x 12,000 = 4,000kWh per year. When I asked someone at Tesla in an email he relied exactly as follows... "I would say 12,00 is a good average to use." When pressed for 1,200 or 12,000 I never got a reply. So what is it, about, 1,200, 4,000, 12,000 kWh expected yearly use on a 12,000 mile/year Tesla?

Thank you!

Best,
Gene

spgraff | May 22, 2017

I had a 8.5kW system of solar panels (Sun Power) in the back of my house (Which is all electric except for heating in the winter) in 9/16. From the curb, one cannot even tell that my panels supply over 100% of my power needs. As a result of the over capacity, the utility has given me a credit of 1600 kWh so far. I can apply the kWh bank from the utility to charging my Model 3. The 1600 extra kWh represent almost 10,000 (9045) free miles of driving in my Model 3 assuming 4.24 miles/kWh.

Hope to be free of gasoline completely with the Model 3, which will be powered mostly by the sun (...pretty cool!!!... :) )

My HVAC system is about 14 yrs old and I hope to replace it with an all electric ductless system. It is supposed to save approximately 30% on my electric bill (more power for the car) Do you know anyone that had this done?

Thanks,
Stephen

SUN 2 DRV | May 22, 2017

Gene, your original math is right. Rule of thumb is 3 miles per kWh. But there can be material variance depending on your driving style and average weather conditions. In 82k miles my average consumption is 328 Wh/mile, heavy foot, California weather. Keep in mind there's about a 20% additional loss due to charging efficiency issues.

jordanrichard | May 22, 2017

i too have a S85, but live in CT, nit a heavy foot and my life time avg is also 328. That is after 79,000 miles.

gene | May 22, 2017

Thank you for all the replies everyone. That extra 20% is especially good to know! I wonder where the Tesla dealer got the "12,00" number from but that's neither here nor there. My daily driver is a 700hp C7 Z06 and my wife drives a newer Tahoe. We're using a lot of gas now but it will be the last gas [hopefully!] we ever use. I'm looking forward to running 9 seconds in the quarter mile powered by the sun on my property. :)

Thanks again!

Best,
Gene

UnshodBob | May 23, 2017

I used 3855.4 kWh to go 12,528.7 miles from when I got my car until my first service appointment. That's about 308 wh/mile average. This is real-world driving in SoCal mostly, so warm temps, lots of traffic, city/highway/freeway and flatland/mountains/deserts, but also several long trips to central California, Phoenix and (more recently) as far as Colorado Springs and Denver. My lifetime average energy use is about 301 wh/mile over 21,000+ miles.

rxlawdude | May 23, 2017

We have 52,000 miles in 21 months on my 70D, and charge at home more than 90% of the time. I drive about 90 miles every weekday, and consumption is about 700-900kW/month. We have a 6.6kW solar array, and the car pretty much eats every kWh the solar produces.

barry | May 28, 2019

Don't use battery capacity to calculate usage.
"a 100kWh battery pack does around 300 miles" is inaccurate as not all of the 100kWh is used.
And, the energy economy is the same regardless of battery size for a given model. Temperature and driving conditions and driver behaviors will, however, impact values.
The lifetime numbers provided by owners like UnshodBob should be helpful. I'm sizing a solar system now in anticipation of a Model 3 driving 20,000 miles/year and think I'll build out for an extra 5,000 kWh to cover most of it.