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FlyinLow

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Feb 5, 2018
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Only one question.. solar? Adding solar to a model 3 can make it very competitive with $18000 cars when you consider TCO over 10 years and residual value, even without tax credits. I know it's tough for someone buying an $18k car to have that kind of but picture view. The more miles you drive the better the value as well and the more valuable the solar can be as an investment.

Why? Because adding a solar power system to a house will cost more than the car in many cases. A Model 3 I can buy this year is a minimum of $44,000 before taxes and a medium sized solar system putting out 6kW for an all electric house (3 br, 2 bath, five person family) and that only covers about 60% of the needed electricity for this house with optimal south facing roof. Solar City quoted me $40,000 for this system.

This was my case. I chose not to invest in solar because of the fact that a system covering my whole roof would take 15 years to break even and is only warrantied for 20 years for the systems I've seen. I don't need a new roof, so a Tesla solar tile roof would be an unnecessary cost. Car charging and Winter in PA both negate any Net Metering that is advertised as cost mitigation. A large solar array would be an emotional purchase that my local realtor tells me will decrease the value of my house because it will be "ugly."

Additionally, anyone I've known who was buying the $18,000 commuter car is likely not interested in an up front investment of $44k for a Model 3 and an additional $40k up front for solar.

The reality is that in PA just North of Pittsburgh, the 15 year Total Cost of Ownership for the $18,000 car with oil changes and gasoline is WAY less than buying a Model 3 now and adding solar to my house. I would venture a guess that a plug in hybrid like the Volt or Prius is still much too expensive to justify buying new if cost per mile is my only concern.

When we figure out how to make a desireable electric car that costs the same new as a Corolla or Civic (less than $20,000) the the EV revolution will be in full swing.

That being said, I enjoy my used Model S that I charge using a 120V/15A standard plug in my garage. It works wonderfully and I am anxiously awaiting the near future where battery technology and cost for electric cars and solar will make sense for the masses.
 
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VT_EE

Active Member
Apr 22, 2017
2,025
2,421
Maryland
Why? Because adding a solar power system to a house will cost more than the car in many cases. A Model 3 I can buy this year is a minimum of $44,000 before taxes and a medium sized solar system putting out 6kW for an all electric house (3 br, 2 bath, five person family) and that only covers about 60% of the needed electricity for this house with optimal south facing roof. Solar City quoted me $40,000 for this system.

This was my case. I chose not to invest in solar because of the fact that a system covering my whole roof would take 15 years to break even and is only warrantied for 20 years for the systems I've seen. I don't need a new roof, so a Tesla solar tile roof would be an unnecessary cost. Car charging and Winter in PA both negate any Net Metering that is advertised as cost mitigation. A large solar array would be an emotional purchase that my local realtor tells me will decrease the value of my house because it will be "ugly."

Additionally, anyone I've known who was buying the $18,000 commuter car is likely not interested in an up front investment of $44k for a Model 3 and an additional $40k up front for solar.

The reality is that in PA just North of Pittsburgh, the 15 year Total Cost of Ownership for the $18,000 car with oil changes and gasoline is WAY less than buying a Model 3 now and adding solar to my house. I would venture a guess that a plug in hybrid like the Volt or Prius is still much too expensive to justify buying new if cost per mile is my only concern.

When we figure out how to make a desireable electric car that costs the same new as a Corolla or Civic (less than $20,000) the the EV revolution will be in full swing.

That being said, I enjoy my used Model S that I charge using a 120V/15A standard plug in my garage. It works wonderfully and I am anxiously awaiting the near future where battery technology and cost for electric cars and solar will make sense for the masses.
I have serious doubts about the competency your realtor if they think solar panels will devalue your house. Nobody I have ever talked takes that view. Of course a bad installation may be detrimental. I made sure my panels were put up in a way that was pleasing to the eye with no conduit running on top of the roof. Totally agree that the Model 3 doesn’t compete on price with Honda Civics and such, but that is an apples to oranges comparison. Model 3 should be compared to the BMW 3 series on price. The drive and amenities are far superior to any Civic class car.
 

FlyinLow

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wayner

Active Member
Oct 29, 2014
3,812
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Toronto
Additionally, the most efficient charge rate for Tesla lithium ion batteries is about 25A, so that is the rate most people are using for home charging. This will fill a Tesla from empty to full in about eight hours.
I realize this was done a few months ago but this is a very good post.

One quibble though - I doubt that most Tesla owners charge at 25A , unless they don't have HPWCs. I would think that anyone that has a HPWC is going to charge at a much higher current. If the HPWC can charge at 80A then why not charge at that rate? That's what I do and I am guessing that is what most folks with HPWC's do as well. And most times that I am charging I am only adding 10-20kWhs.
 

FlyinLow

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Feb 5, 2018
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I realize this was done a few months ago but this is a very good post.

If the HPWC can charge at 80A then why not charge at that rate? That's what I do and I am guessing that is what most folks with HPWC's do as well. And most times that I am charging I am only adding 10-20kWhs.

Charging at the most efficient rate could be helpful if I was going to be utilizing solar to charge my car. Why waste preciously acquired juice?

Another reason to charge at 25A is that I may not want to run the required wire size to charge faster than that in an existing structure. Wire that is 6 gauge and larger is somewhat hard to bend and will be a bear to route through walls. Search for the car charging outlet chart for all options that are out there.

Additionally, if I care about efficiency and cost at all like so many people talk about here, then less waste equals a lower cost per mile to drive. Likely this is merely academic though, because future proofing a charging set up is always a good idea. Run the larger wire, set up a robust charging solution with a junction box close to the charger if possible to allow for future upgrades.
 
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wayner

Active Member
Oct 29, 2014
3,812
1,385
Toronto
I like solar - I have 10kW of panels on my roof - but it isn't necessarily practical to be charging from your solar panels as most people work during the day and their car will not be at home during peak solar production time, at least not on most weekdays. But since most jurisdictions use net metering or something similar the point is kind of moot since you are not really directly using the energy that you produce. That is even less desirable with the plan that I am on since I am able to sell my solar power for about 3-4X the amount that I pay for power.

When it comes to charging I used government incentives that were available to pay for 50% of charger installation costs and 50% of a charger. That helped to defray the costs, but even if those were not available I would have wanted the full capability of an 80A/240V charger at home. I rarely actually need to charge my car that quickly, but it is good to have the option and, like you set, it future proofs your house. But it is becoming less necessary as I now have seven SCs within 45km of my home.
 

nwdiver

Well-Known Member
Feb 17, 2013
7,743
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United States
I realize this was done a few months ago but this is a very good post.

One quibble though - I doubt that most Tesla owners charge at 25A , unless they don't have HPWCs. I would think that anyone that has a HPWC is going to charge at a much higher current. If the HPWC can charge at 80A then why not charge at that rate? That's what I do and I am guessing that is what most folks with HPWC's do as well. And most times that I am charging I am only adding 10-20kWhs.

I have a 80A HPWC and charge @ ~20A for the reason @FlyinLow stated... it's more efficient. If I don't need a charged car for another 14 hours why burn the extra electrons to get it charged in 2?

The ironic part about EVs and Solar is that for most areas it's still better to export during the day then use off-peak energy to charge at night. You're likely displacing much dirtier energy during the day and using much cleaner energy at night. In the mid-west there's often surplus wind at night that is either used or wasted.... don't think there's ever excess wind during the day...
 

tpham07

Active Member
Mar 21, 2017
1,965
2,202
Rhode Island
I have a 80A HPWC and charge @ ~20A for the reason @FlyinLow stated... it's more efficient. If I don't need a charged car for another 14 hours why burn the extra electrons to get it charged in 2?

The ironic part about EVs and Solar is that for most areas it's still better to export during the day then use off-peak energy to charge at night. You're likely displacing much dirtier energy during the day and using much cleaner energy at night. In the mid-west there's often surplus wind at night that is either used or wasted.... don't think there's ever excess wind during the day...

I said this same exact thing and racked up a lot of disagrees and hate in the model 3 thread. The charging speed difference between 32A and 48A to me doesn't warrant the cost of a wall connector. Only buy a wall connector for the convenience, not speed.
 
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nwdiver

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Feb 17, 2013
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Only buy a wall connector for the convenience, not speed.

I do still think it's worth the investment to get a HPWC. There's also a durability issue. A HPWC is going to hold up much better under daily use than a UMC. I've killed 2 UMCs in ~5 years.... though I'm sure being limited to 32A will help with longevity.
 

tpham07

Active Member
Mar 21, 2017
1,965
2,202
Rhode Island
I do still think it's worth the investment to get a HPWC. There's also a durability issue. A HPWC is going to hold up much better under daily use than a UMC. I've killed 2 UMCs in ~5 years.... though I'm sure being limited to 32A will help with longevity.

i agree with that. im only regretting my purchase because im moving out of my house and the thought of having to pull the wall connector out of the wall and hide those wires so the next person doesn't kill themselves and sue is just exhausting haha. my charging needs would've have been met appropriately with a UMC. and i have a gen1, so its 40A.
 

nwdiver

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Feb 17, 2013
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United States
i agree with that. im only regretting my purchase because im moving out of my house and the thought of having to pull the wall connector out of the wall and hide those wires so the next person doesn't kill themselves and sue is just exhausting haha. my charging needs would've have been met appropriately with a UMC. and i have a gen1, so its 40A.

If you really want to take your HPWC with you just abandon the wires in place; De-terminate them from the breaker and cap them with electrical tape or wire nuts. The only way for someone to get hurt then would be to be digging around in the panel; in which case they should be a 'qualified person'.
 

tpham07

Active Member
Mar 21, 2017
1,965
2,202
Rhode Island
If you really want to take your HPWC with you just abandon the wires in place; De-terminate them from the breaker and cap them with electrical tape or wire nuts. The only way for someone to get hurt then would be to be digging around in the panel; in which case they should be a 'qualified person'.

Yeah thats the plan, even rewiring with a nema 6-50 has been considered too since the wires are already there. would just have to swap to a 50A breaker instead of the 60A i have. Still a PITA though :)
 
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RFernatt

Solar/EV Owner/Enthusiast
Oct 13, 2016
645
3,363
Eastern Panhandle, West Virginia
...A Model 3 I can buy this year is a minimum of $44,000 before taxes and a medium sized solar system putting out 6kW for an all electric house (3 br, 2 bath, five person family) and that only covers about 60% of the needed electricity for this house with optimal south facing roof. Solar City quoted me $40,000 for this system.

I know every house and installation can be different, but that is just a crazy figure for a general 6kW system. I would definitely get more quotes.

Last fall I installed an 11.3kW system using premium all black Panasonic panels warrantied for 25 years at 90% rated production with parts and labor coverage, a SolarEdge 11.4kW inverter with a 25 year warranty, and premium racking for less than $33K soup to nuts. Installation was done in 1.5 days and there is no exposed conduit or wiring. Subract the 30% tax credit that it was under $23K net. This system is sized to provide 100% of the power for a 2 br, 2 bath, 2 person all electric house, two electric cars (when my M3 gets here), and all electric lawn equipment. No power bill and no fuel purchases (just Supercharger costs for occasional trips).

I do volunteer work with Solar United Neighbors (SUN), a non profit that helps organize "co-ops" (group buying) for solar installations in multiple states. We use $2.75-$3.00/watt as a rule of thumb for most installations understanding that upgraded equipment, challenging roofs, ground mounts, or special circumstances could be more.

 
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FlyinLow

Enjoy the journey
Feb 5, 2018
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Great info on solar costs. My quote from SolarCity did seem a bit high. Incentives are nice, but I look at the cost and don’t count on subsidies to justify a purchase.
When I commit to installing a solar system I’ll need to do a lot more research and get multiple quotes.
 

roblab

Active Member
Jul 15, 2008
3,394
2,445
Angwin (Napa Valley) CA
I do still think it's worth the investment to get a HPWC. There's also a durability issue. A HPWC is going to hold up much better under daily use than a UMC. I've killed 2 UMCs in ~5 years.... though I'm sure being limited to 32A will help with longevity.

Amazing! I've charged almost entirely with my UMCs, 3 years for both my Ses. Never had a problem.

When wifey got the 3, we were charging two at once, so cut them both down to 24 each on one hundred amp box, in case the spare water heater kicks in. Hey, I've got all night. It's not a lot slower than 32 if you're asleep.

I never could see the value of "fast charging" (80 amp) when you're sleeping.
 

nwdiver

Well-Known Member
Feb 17, 2013
7,743
9,958
United States
Amazing! I've charged almost entirely with my UMCs, 3 years for both my Ses. Never had a problem.

Have you checked? Still kinda worked but it got a tad warm... Tesla agreed so they sent me a new one. ~3 years later the replacement is now having the same problem...


Screen Shot 2018-08-16 at 5.44.23 PM.png
 

voyager

Member
Apr 28, 2009
922
467
Amsterdam, Netherlands
There is another way of looking at electric cars...
It is something Elon Musk himself already referred to: EVs are like big appliances.

Requires to do some out-of-the-box thinking. I mean this literally: outside that boxy thing that’s parked upfront.
Instead of 'car'... think: personal-mobility appliance or Auto-Mobile...

Sleek, lightweight and versatile, it may be as disruptive for personal mobility...
as THE ‘appliance’ in personal communication, the smartphone.
On paper it comes down to this:

2%2BBIG%2Bsev%2Bvs%2Bi-Pace.jpg
 

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