Do these utility rates justify a home charger

[anjoq]

I have a tiered time of user rate plan with my utility (PG&E) and when compare all the rates my utility offers, the off peak tier 1 price is between 12 - 17 cents per kWh (based on summer and winter). In the Bay area where I work, there is ample charging at work (30A) for 8 cents / kWh. Under these circumstances does it make sense to install a home charger? Or are there convenience factors that outweigh the monetary costs.

Thanks.

 

[Tam]

...home charger...

If it works for you to charge at work, there's no need to spend money for home charger installation.

The problem might be that you might not work 365 days a year so what if you need to charge on days that you are off?

 

[ucmndd]

Look closely at the PGE EV-A rate, you may find it to be a better deal overall.

 

[anjoq]

so what if you need to charge on days that you are off?

Fair point, and I do not have enough experience to answer the question, or for that matter, other scenarios like what to do if I am not working. It is this weird additional burden we place on EV ownership. I figure I would charge at 4A at 110V, drive to a supercharger about 20 miles from home, or drive to work on a weekend to charge. The darn thing is at my home, electricians cannot give me more than 24A (30A breaker) 240V due to the rating of my incoming circuit.

Look closely at the PGE EV-A rate, you may find it to be a better deal overall.

I looked at these rates, and off-peak are lower 12-16 cents/kWh, but there are more peak hours. It may come out to be same or similar.

 

[trm2]

Go with the 240 at 24 amps, you can use the portable charger when needed at home. Nothing beats the convenience of charging at home.

 

[dhrivnak]

The convienence of home charging is huge and 24 amps would meet most needs so I would definitely install one. 110 is four times slower.

 

[gregd]

The darn thing is at my home, electricians cannot give me more than 24A (30A breaker) 240V due to the rating of my incoming circuit.

I had a similar situation. 4hrs of free charging at work, with 3hrs needed for a round trip commute. I used that most of the time, but there were still times I wanted / needed to charge at home. So I rigged up a splitter to share the dryer plug. Should have purchased a "Dryer Buddy", just for safety, but that setup worked for several years.

Eventually I realized that I really should do things right, and with the federal tax rebate on EV infrastructure expiring, I upgraded to a 14-50 outlet and OpenEVSE station. What pushed me over the edge to do it, besides the rebate, was that I discovered my house's main panel was the kind that tend to fail over time ("fail" as in "catch fire"), so the upgrade was as much about peace of mind as it was about charging the car.

One other point is that charging at 120v is less efficient than charging at 240v. So you end up paying more for the same number of charging miles when you charge at the lower voltage. I think the sweet spot is somewhere in that 24 to 48 amp range at 240v, as losses due to heating go by the square of the current, but the quicker charging lowers the total fixed overhead inefficiencies of the charger. I haven't seen an exact analysis of this, but it is clear that you really should use 240v at home.

 

[tga]

The darn thing is at my home, electricians cannot give me more than 24A (30A breaker) 240V due to the rating of my incoming circuit.

95% of my charging is on a dryer outlet at 24A - ~200miles on 12 hrs

 

[JenniferQ]

95% of my charging is on a dryer outlet at 24A - ~200miles on 12 hrs

+1 because that's where my solar is. I have the 40a at the SDGE house and that's so exxy.