OK, let's play from the top.
You've got a 100A panel and, yeah, I do get it, there may not be much room in the beast. But there's a caveat: Putting in a 200A panel might not be as expensive as you think. The State of New Jersey, for one, actually subsidizes the cost of larger panels (and/or the drop from the power pole to carry the extra current) if the purpose is to charge a BEV. Um. That's you, but you live in New York. Let me do a quick web search.. You might want to read through this and see if any of it applies to you:
Alternative Fuels Data Center: Electricity Laws and Incentives in New York
Next: In general, there's two main ways to charge a Tesla, at least if you want to sleep well at night:
- Charge it with a Mobile Connector. That the whatsit that comes in a fabric bag that can go in the trunk, but can also be semi-permanently mounted on a wall. It's about $250 or so and about $15 for each of the plethora of adapters that one can get for it. The cable length.. let me go get mine and measure it.. is about 18 feet. Important point, and there will be a quiz later: The maximum current this thing can do is 32A, period.
- Charge it with a Wall Connector. Cool, nice: Cable's pretty long, you mount it in the garage somewhere and go to town. It can do up to 48A of charge current. Costs about $475 these days.
Next: There's the car. If you have a Standard Range Tesla (something less than 300 mile range), max current that car can suck down will be 32A, max. It can do less, of course, but 32A is max is what you get. If you have a Long Range or Performance Tesla, then that car's max current is 48A.
Next, let's talk about costs for
new installations. This may or may not be you, but let's cover the bases.
First: if you're putting in something like a NEMA14-50 socket, you'll need, first, a high quality socket, not that $BS they sell at Home Depot. That's a couple hundred. And, if you're doing this to code, you'll need a GFCI for that socket, given that we're talking garages, damp, and all that. That's also close to a couple hundred smackers. Add to that the cost of the mobile connector and, ta-da! turns out that it's
cheaper to put in a Wall Connector, which has its own built-in GFCI. (Note: Running the appropriate length wire, of the correct gauge, is about the same for both.)
Let's hit the famous NEC 80% rule: Max current on a circuit for a
continuous heavy load is 80% of the circuit rating. Got a 120 VAC 15A circuit with a breaker to match? Max current is 80% of that, or 12A. Want to have a 48A load @ 240 VAC? Then the
circuit rating (i.e., the size of the breaker/wire) has to be 60A minimum, since 80% of 60A is 48A. You don't mess with this rule: Violating it results in house fires, Which You Really Don't Want To Do.
Now for the easy one. Say you've got a 120 VAC 15A socket in the garage; usually, those have a single breaker hooked to it. Max power that can be drawn is 120 VAC @ 12A (that 80% rule again) which is 1440 W. Your Model Y gets about 280 W-hr/mile, so your charge rate is 1440W/(280W-hr/mile) = 5.1 miles of charge per hour. There's two problems with this rate:
- 5.1 miles of charge per hour for a car that's plugged in overnight from, say, 6 p.m. to 8 a.m. (14 hours) is 72 miles. Um. That's not a lot.
- In cold weather, down in the teens or something, the car has to warm up the battery before it'll take a charge. The power to do that is pretty blame close to that 1440W; I've seen a Model 3, in cold weather, charge at 1 mile of charge per hour, or even zero. (It's a big battery, got a lot of surface area, so it needs at least a couple kW to get the thing warm. Once warm, it's OK.)
So, 240 VAC is cool. What you say you have: A duplex 15A breaker on 240 VAC. Hm. Wonder what kind of socket you've got, there, one sec.
(Above is courtesy of Wikipedia's NEMA connector page.)
So, I'm a-guessing that, if the drier installation was Done Right, you've likely got a NEMA6-15 socket, that being the only 240 VAC @ 15A socket that's out there. (The breaker current rating, the current rating of the wire in the wall, and the socket are
supposed to match. Take no wooden nickels.) And, as it happens, Tesla does sell a NEMA6-15 adapter for the Mobile Connector.
So: 240 VAC @ 12A (remember the 80% rule) gets you 2.88 kW.
Charge rate, according to Tesla: 10 miles of charge per hour. In 14 hours, that'll get you 140 miles. Which is 2X better than that 120 VAC socket.. but it's still not wonderful.
Say what you
really want is that if you plug your car in, near empty, when you get home at night, it'll be charged up to 80% of max (which is normal for NIMH batteries). Suppose you've got a 320 mile range car: 80% of that is about 260 miles. Say you plug it in when its got 40 miles left, so you need 220 miles of charge in 14 hours. That's a charge rate of 220/14 = 15.7 miles of charge per hour. Looking at Tesla's Charge Rate graph, you'd likely want a NEMA10-30 or NEMA14-30 socket and a 30A drop to the socket.
But, at this point, you're talking new construction, since you don't have any socket like that. And pulling wire for that and putting in a new socket probably calls for an inspection.. and it's GFCI city. Conclusion: If you can stick a 30A 240VAC breaker in your box, you do that, put in a Wall Connector to connect to it, and continue on your way.
Finally: There's this thing called a Load Calculation that electricians do. It's a National Electric Code Standard. The electrician looks at your panel, looks at the square footage of your house, the loads caused by the appliances (and
not the drier that's not there) and comes up with a number of How Many Additional Amps your panel can support. You tell the fellow that you'd like 30A if possible; you might get surprised if he tells you, "60A is no problem."
And check and see if there's some subsidy for putting in a bigger panel for these purposes.
Got any further questions? Ask 'em.
