Commuter Charging

110 V Charging: Available at Home and Everywhere

Any ordinary outlet will do. Most electric cars come with a cord that can be connected to any ordinary outlet. The maximum charging rate varies a little depending on the capabilities of the circuit being used, but in general one gets about 4.5 miles for every hour of charging. Suppose you drive 50 miles a day, and can plug in your car overnight (about 11 h). You’re all set. If you drive 35 miles a day and can charge through a 110 V outlet at work, that will also meet your daily need.

What if you have to park on the street, at a spot that changes from day to day, and you can’t charge at work? Some EV owners are able to use a public charger under these circumstances. Although it may cost a bit more than home charging, it may also provide a parking space in neighborhoods that have few. For many people, however, reliance on public charging stations is inconvenient if they do not live or work near one. One of the goals of EV advocacy groups is to develop charging solutions for residents that cannot reliably park near an outlet. This problem requires additional infrastructure development.

How much does home charging cost?

Let’s assume you drive a car with an electric range of 200 miles, and you’re an average driver, with a mix of low and high speed driving (EV fuel economy is far less at 75 mph than at 45 mph, just as it is with a regular gas car). In the summer you are likely to get 4-5 miles for each kwh (kilowatt-hour) of juice. In the winter this figure drops to around 3 miles/kwh.

There are some inefficiencies in charging, but about 90% of the juice flowing through your electricity meter makes it into the car battery. So, for 200 miles of range, and assuming an average of 4 mi/kwh your battery will need 50 kwh and this pulls about 55 kwh through your electricity meter. In Durango, CO this costs you about $3.41 if you have time-of-day metering and are able to charge during off-peak hours. (All EVs are set up specify charging time if you allow them to; they’ll make sure your battery is fully charged when you next need it regardless). In Cortez and Farmington the marginal cost of residential electricity is higher. An electrical 200 mile fill-up there will run you about $5.50. In either case, far less than filling a gasoline car.

220 V Charging: Requires some special hardware

220 V Charging at Home

Almost all households have some 220-240 V circuits for heavy loads (electric range, electric dryer, and so forth). Such households are suitable for installing a 220 V charger; these cost $500-$1000 for the hardware, and you probably want to hire an electrician to install it (labor is in addition to the hardware cost).

There is a magic asterisk for this installation, however. If your electrical panel (which houses the circuit breakers for the house) is already full, the panel might need to be upgraded, at significantly greater expense. For that, you’ll have to get a quote from an electrician. Another possibility is that running the wires from the panel to where you wish to charge could be physically difficult (often it is not hard).

The good news is that subsidies are often available for this expense. For example, in La Plata and Archuleta Counties, Colorado, La Plata Electric Association will subsidize the installation of a Level 2 (that is 220-240 V) charger in your home, to the tune of around $1000. Contact LPEA for the specifics of the latest installation offers (lpea.com/electric-vehicles-evs). Farmington and Cortez utilities do not have car charging rebates at this time (Dec 2019). Coloradoans are eligible for state grants for the installation of multi-family residential or business chargers (In SW Colorado, visit FourCore.org for assistance with applying).

Public 220 V Charging

The 220 V level of charging, which Tesla calls “destination” charging, makes up the vast majority of public charging stations, as well as most of the home chargers. For example, in the Four Corners area there are currently (Nov 2019) 35 public sites where one can charge one or more cars. Thirty-three of these sites house level 2 or destination chargers. There are usually several chargers at each site (up to 20). The number of these sites is increasing very rapidly. Many of them do not charge for the juice, though most of them require a free app to hook up. See Plugshare.com for the localities of these chargers; the list improves weekly.

Like most sites, Plugshare.com wants you to sign-in and get their (free) app, but that is not required. Just enter an area code or city name, and it will show you a current map of the charging stations. If you get the app and sign in, it will often (not always) tell you which of the chargers are in use right now (and warn you about ones that may be out of order). Plugshare also allows registered users to leave reports of their experience at public chargers. This is very handy if you’re traveling to an area and you want to see recent updates on how the charger is working, and if you may have to wait to use it. In November 2019, it’s unusual to have to wait for a charger. Progress needs to continue to ensure public fast-chargers are available in growing numbers as the numbers of EVs on the road continues to grow.

220 V Charging Port Types

One item displayed on the Plugshare site is which type of charging port is present. Non-Tesla owners generally (see next paragraph) need to go to those charging stations that have “J-1772” connectors, though adapters for non-Tesla owners to use Tesla destination chargers are available online for about $230 (2019 price). Tesla owners have some additional choices, especially if they have purchased adapters which allow them to use J-1772 connectors. A Tesla comes with a Tesla Destination connector, and can hook up to any Tesla Destination plug without further ado. With an appropriate adapter, Tesla owners can also hook up to a J-1772 plug.

With a different adapter, Tesla and non-Tesla owners can hook up to a 220-240 V outlet known as a NEMA 14-50. The importance of the latter is that RVs at campgrounds with electric hookups normally have NEMA 14-50 240 V outlets. There are many of these publically available, especially during the summer when almost all campgrounds are open. For example, in the Four Corners area there are at least 52 NEMA 14-50 outlets available for electric car charging. EV owners with a quiver of adapters can find a tap in almost every town (although I’ve seen some pretty steep fees for the privilege at campgrounds, as charging may tie up a campsite).

For fast charger connector types, see Road Trip Charging.

Prices of Public Charging

Public chargers vary wildly in the price they charge for electricity. Many are free, but some charge $20 or more for a fill-up. Keep in mind public chargers have three major expenses they can recoup only by charging for the electricity. One is space: parking spaces are precious and expensive in urban places. Often the rate you will pay for a charge is less than the cost of paying a parking meter. Another big expense is installing the requisite electric lines and chargers. If the sidewalk needs to be dug up and underground electric lines extended and installed, this expense can be tens of thousands of dollars. The final cost is the smallest of the three: the electricity. In most cases, the institution that owns the land (the hotel, electric utility, car dealer, and so forth) has installed a charger to promote their business, and understands that very few users will be paying for electricity initially. As electric cars increase in popularity, one expects rates to become more standardized, but for now, the charging stations are an expense that often does not profit the sponsoring business. However, even at $20 a fill-up, electric charges compare favorably with the cost of a gas fill-up.

How many miles of additional range do you get with a Level 2 charger?

That varies with car and charger. A good rule of thumb would be 25 miles for each hour of charging. Some of the faster ones get up to 70 miles per hour of charging. At the low end (25 additional miles/h), such a charging rate is sufficient for recharging most cars’ batteries overnight. Thus most people rely on a Level 2 charger to fully restore their car’s battery while they sleep. Even a 300 mile range can be restored overnight. But let’s say you need to drive to Salt Lake City tonight, and you have a BEV, not a PHEV or HEV (See EV Types). For that, you need a fast charger, which is explained with the Road-trip Charging button.