Home Charging Stations Are a Real Gas (Saver)

Several new GPS manufacturers can now steer you to the nearest electric vehicle charging station while you're on the road; but, you probably don't need a GPS to show you how to "Go Home." And, let's face it; your home is the most convenient (and probably the cheapest place) for you to fill up your all-electric or plug-in electric hybrid vehicle (PEV).

charging station prewire kitEvr-Green(™) charging station prewire kit from Leviton Manufacturing Co.

You've made (or are considering making) a commitment to go "green," and one of the reasons is economic: save gas, save money. Now, you can maximize your savings and save time, too, with an electric charging station in your own home. It's true that some new PEVs will let you plug directly into a standard 110-volt outlet (called Level 1), but it may take you many hours to charge up.

The better and much quicker way is having ready access to a dedicated 220/240-volt, 40-amp circuit (called Level 2) wherever you park your car. There's no magic to it - it's as simple and inexpensive as providing the electric power to your air-conditioner, range or clothes dryer.

If you're buying a new home, talk to your builder. If you're in an existing home, talk to an electrical contractor. If you're a skilled DIYer, make sure you comply with your local electrical code and obtain all required permits.

Prewired New Homes

Some national home builders are installing prewired outlets for charging PEVs; many builders are offering them as an option. Whether you or a future buyer of your home will be using the outlet, it's a worthwhile investment. If you're in the market for new construction, be sure to take advantage of this valuable amenity.

Existing Home Installation

First, find out if your current electrical service can accommodate the extra current requirement of a dedicated circuit of up to 40 amps. This should not be a problem for homes with at least 200 amps of service. Your local power company or an electrical contractor can advise you if your current electrical service is up to snuff.

Second, find out if the power company offers any special rates for charging electric cars. Many electric utilities offer time-of-day, off-peak or other options that provide favorable rates. Some options may involve the installation of additional equipment.

Now, you will need to add a new circuit breaker to the electrical panel. Next, select a convenient location to plug in your charger and determine where and how you will run the new wiring. You can fish the wiring through the cavity walls or use an external wire management system such as Wiremold(R).

Sizing the circuit

Depending on the length of the run between your breaker box and the outlet, the electrical codes in most jurisdictions allow for the use of a plastic-jacketed (NM-B) cable using three #8 AWG insulated copper wires for a 40-amp circuit, often referred to as 8/3. The red and black wires connect to the two "hot" terminals, the white to the neutral, and a bare ground conductor is the equipment ground. Runs in excess of 100 feet should use #6 AWG copper. Don't try to save money by using aluminum -- the wire gauge requirement is thicker and the installation is trickier. It's not worth the difference.

Homes in some jurisdictions may require the use of armored (AC) or metal-clad (MC) cable. For safety reasons, MC is preferred; it has a green insulated equipment ground conductor. Others may require running the wiring cable through a conduit (metal or plastic). In such cases, cabling (UF) with four insulated wires should be used (8/4): Black and red for the "hot" conductors, white for the neutral, and green for the equipment ground. If your outlet location requires an underground feed, use the UF cable, also. In all cases, all-copper wiring should be specified to ensure maximum safety and performance.

Saving money

If a 30-amp circuit is all your charger requires, you can save on cost by using #10 AWG copper, 10/3. However, if in the future you move up to a car or charger that requires 40-amp service, you will need to reinstall your whole circuit with 8/3 copper wire.

There are other advantages from using 8/3 copper for your 30-amp circuit at the onset. Keep in mind that the farther your wiring runs from the service panel, the less voltage there is available at the outlet. So, besides the added safety of using copper and of moving up a wire size, you will also lower the voltage drop, reduce energy losses and allow your charger to work at greater efficiency. That also reduces the time to recharge your car.

Finally, if you know the configuration of the plug used by your car or the home charging station you will be using, install the proper mating receptacle at the outlet box. For outdoor installations, use an outdoor-rated receptacle and weather shield. If you're wiring for a future purchase, simply cap-off each of the conductors and screw a solid plate over the box.

The Charging Station

Several companies offer home charging units that will quickly plug-in to your new outlet. They vary in price and style, as well as voltage and amperage capabilities. Don't purchase one until you have your PEV, then check with the manufacturer for a recommendation that meets your car's requirements.

Green for Going Green

Through the end of 2011, there is a federal tax credit for 30% of the purchase and installation costs of charging equipment, up to $1,000 for individuals and $30,000 for businesses. PEV purchasers may also benefit on their federal taxes through a Plug-in Electric Drive Vehicle Credit that can range from $2,500 to $7,500 depending on battery capacity. Currently, 13 states are offering financial incentives, too. See "Plug In America" on the Web.

Depending on where you live, your local utility company may offer financial incentives for installing and using a PEV charging station. And, you should check with manufacturers such as GE, Coulomb Technologies, ECOtality, Leviton, Siemens, and Schneider, among others, to see if they meet your needs and offer any incentives.

A full explanation of what's available may be obtained from your PEV dealer. Seems like now is the time to charge into the future.

Copper Development Association Inc. assumes no responsibility or liability of any kind in connection with this publication, and makes no representations or warranties related to its use, accuracy or utility.