As you can see, there are lots of variations here... so, lets break it down a bit:
(sorry about the long post, this is a compilation of things I've said, heard, and run into)
First off, read the FAQ: (
FAQ: Home Tesla charging infrastructure Q&A)
Before starting, determine how much power you would be drawing, this number drives the size of the cable, breakers, and possibly main house supply.
- If installing a NEMA 14-50 outlet, you will need a 50 Amp circuit,
- If installing the HPWC, You can choose how much power the HPWC will use after installation (from 12A [15A breaker) to 80A (100A breaker). Most want to install it at 80A, but if your car doesn't have dual chargers, you cant use that much anyway)
- Note: this can be useful in cases where you just cant get a 50A circuit in your hose for whatever reason, (your media room is just drawing too much power and the local electrical company wont run a larger service?), you can install the HPWC (and call it a LPWC), set it to whatever you can get, and use that...perhaps not the best charging, but safer than installing something too large for your service.
- if installing another outlet type or another type of EVSE (much less common) you would need the correct side for whatever you are installing (*check the docs)
So, the pieces needed for any install would be:
- House main power supply (is there enough available amps to install the EVSE at the preferred setting without upgrading the service?). Hopefully this is yes, but it is something to check.. your electrician should be checking this when quoting.
- If not, you will have to increase the side of your service to the house, this can cost a significant amount of money.
- Unless you are COMPLETELY comfortable with working on home services, DO NOT attempt this yourself!
- Panel size / load: is there enough available amps on the panel to install the EVSE. (this is often the same as above, but some houses have multiple panels/sub panels, feeders, etc...).
- If you need a new service, you probably need a new panel as well, but you might need a new panel even if your service is large enough. for example, if you don't have enough free slots for breakers, or if your panel was undersized.
- These can easily cost a few thousand dollars, though there it totally depends on the size and complexity of the job.
- Breaker for the EVSE circuit:
- Assuming you have enough power, and your panel has space, you will need a dedicated breaker for this. the cost of the breaker itself can run from $20 to $200 depending on your panel and takes a couple of minutes to snap in. (for me, a 100A breaker is about $70 at Lowes.)
- Wire to the EVSE
- This is usually a larger part (often the largest largest part) of the install costs. this can be done in conduit, or installed behind a wall, or buried (in the case of it running across a yard), all depending on local codes, EVSE size, and your physical environment.
- Cable that will support 100A can run more than $5 / foot, with pretty high install charges (so, a 50' run could be > $250 just in electrical cable)
- Running in conduit, while adding to the cost of materials, can sometimes actually end up cheaper by reducing install time, but it has an industrial look that might not fit your environment (or it might be just what you are looking for)
- Even short runs will usually take an hour or so by the time everything is done... long runs can add days of work, especially if trenching and refilling is needed.
- If trenching, make sure to call the number for your area that will come out and tell you where underground utilities are... this is often free, and is ALWAYS better than hitting a gas line with your shovel.
- This may be another place you can save money, if your electrician is willing to work with you, (some are, some are not) you might be able to do the trenching, or the work of mounting the conduit and pulling the cable, and leave them with just coming in for 30 minutes and doing the connections and testing them.
- DONT try to save money by using a smaller size cable than what is needed, if anything if in doubt, go up a size. If you don't know the right size, check first (and don't ask the hardware store guy) the FAQ linked above has some wire sizes in it, but wire sizing (and type) is dependent on a number of factors including the length of the run, if it is being buried, or in conduit, etc... Again, if in doubt, get an electrician.
- EVSE mounting / physical installation
- for many installations, this is simply screwing a metal box to the wall, no biggie, but if your installation is outside, or if you have specific requirements such as a post or enclosure to mount the outlet / EVSE in/on, it can be much more complex.
- This is something you may be able to save some money on and do yourself, or get a handyman to do the work at $50/hour instead of $125/hour.
- Nearby Electrical Shutoff/Lockout
- If the EVSE circuit size is more than a certain point (60A I think?), Most electrical codes require a nearby box that allows cutting the power to the circuit and locking it so that anyone working on it does not get shocked. Some people feel this can be the circuit breaker, some disagree pointing out that most circuit breakers do not lock. If you are putting in a HPWC instead of a 14-50 outlet, this is something to keep in mind. These boxes can run from $100 to several hundred, and installing them could add a few hundred (or more) to the cost of the installation. (if you are not sure, check with your local electrical inspectors).
- EVSE electrical connection / outlet.
- Next, you have to actually connect the EVSE or outlet to that wire you ran. if installing a 14-50 outlet, this is fairly easy and should not add significant time. if installing the HPWC, (especially if the electrician is not familiar with it) it could add an hour for the electrician to work through the docs and settings and put it together. (hopefully not, but don't be surprised if so).
- Local Permits
- Depending on your area, you might have to get a permit. Some people recommend skipping this step as it is often a pain in the rear (and sometimes you fail the inspection and have to fix something), I recommend that you DO get a permit and inspection just to make sure (there are also significant liability, insurance, and resale issues if you don't, see the FAQ again). This is not a simply an outlet that you are installing, it is easily enough power to burn down the house (and worse, your car) if done wrong! If using an electrician, they should take care of this, but if they don't mention it, ask. often the cost of permit(s) are not included in the initial quote and you may have to pay them separably. if the electrician says they don't need a permit, check the internet for your local government to see if it isn't needed, and if it IS needed, and the electrician is NOT getting it, get another electrician!
- Around here, permits cost about $90, but that differs dramatically in different areas, and some electricians will charge for the time to get the permit and be there for the inspector, so know those costs as well (the are sometimes not included in the quotes either).
For simple installations, which are probably most of them, you don't have to worry about most of the above adding to your cost, but you should be aware that ALL of these steps need to be considered when figuring out the cost, even though many of them end up being zero.
The cost (if using an electrician) should be based on these factors and their hourly rate, so if you are getting a high cost, ask for the breakdown or sit down and discuss the quote with them and see if it makes sense. if the electrician is saying it will cost 2,000 to install a simple 14-50 outlet, that sounds high, but it might not be if it includes upgrading your panel to handle the 50A circuit, or running 50' of cable. also, in some places, electricians use a "book" price... i.e., something like $500 + $50/foot for a 14-50 outlet, no matter how easy (or hard) this is. if you get quoted a book price and it doesn't feel right (sometimes book prices can end up being WAY more than is needed), ask about getting a per hour quote, they might not do it, but it's worth asking.
If you plan on (or are even just considering) doing the work yourself, my recommendation is to still get a few quotes for it. if you find that everyone is recommending replacing the panel or upgrading the house's service. consider letting them do the work. If they come back and just quote running the wire and installing a plug or EVSE, you can more easily consider doing it yourself if you are comfortable enough with it.
I've heard it recommended that you don't tell installers you are installing an EVSE for quotes as they might jack up your price. Personally I don't agree with that, the load calculations for a dryer plug are different from those for an EVSE, which could lead to your having problems later, and in most cases I am sure they will figure it out when you are point to a spot in the garage that is no where near thir laundry <grin>. Not telling them you are getting a "Tesla" might make sense though. (note: I've never heard of this causing a problem, but misleading the professionals who are doing high power electrical work in your house is not the best plan.) If you think you are getting padded quotes, get more of them and/or check out the installers on something like Angie's List.
And finally, don't let anyone push you into doing the work yourself if you are not comfortable with it. Yes, in many cases it is VERY EASY to do this, but these voltage/amperage levels can easily kill you or burn down your house. Its not worth the risk if this isn't something in your comfort zone.