Frequently asked questions about electric vehicles
Lane Community College is building 36 solar-powered electric vehicle charging sites for student and community use, as well as for study and research. The project was partially funded by a 2009 EWEB Greenpower grant.
We will continue to update the following most commonly-asked questions to help Eugene Water & Electric Board
customers who are considering purchasing an electric vehicle (EV).
How can I charge my EV at home?
Most electric vehicles will offer multiple charging methods. In most cases, you can use either a
normal 120-volt AC 20-amp ground fault circuit interrupter (GFCI) outlet, or have a 240-volt AC
car-charging station installed. Read
more about charging options
Do I need a home 240-volt car-charging station?
Your decision about which level of charging to set up at home will be based on the type of
electric vehicle you purchase and the distance you travel. Most vehicles will allow you to use a
120-volt GFCI 20-amp outlet, a 240-volt charging station or a commercial charging station. Read more about charging options
Who can I have install my charging station?
Primarily for safety and statutory reasons, EWEB recommends that you always use a licensed and
bonded electrician to install a car charging station. Check with the dealer or manufacturer of your
EV to find out if they have contracted with specific electricians to install charging stations.
Do I need a permit to install a car charging station?
Eugene residents should
contact the City of Eugene permit office for
specific requirements regarding permitting and inspections prior to installation or any electrical system upgrades. If you elect to
install the charging system on your own, it is still the homeowner's responsibility to ensure that the
appropriate permits have been obtained.
How long will it take to charge my vehicle?
Charging time depends on the type of charger you use, the size of your battery and how many miles
you traveled prior to charging. Read more about electric vehicle charging
Also see the graph below to estimate EV charging time per miles traveled.
What is the best time to charge my car?
The best time to charge your vehicle at home is overnight, generally after 8 p.m. and before 6 a.m.
This ensures that the electric system doesn't get overloaded at peak demand times. In addition,
charging your car overnight generally increases the likelihood that the electricity you are using
comes from renewable sources of power, such as wind and hydro.
EWEB customers currently pay the same rate no matter what time of day they charge their car.
We are studying whether it is necessary to create "time of day" rates or peak pricing as EVs
and other emergent technologies require EWEB to make capital improvements to its electric system
over the next three to five years. See EWEB's current electric rates
Our goal is to reduce the number of electrical losses and decrease our need to buy energy during
costly peak price periods so we can better serve our community in the long-term.
Learn more about
EWEB's energy future
Where will I be able to charge my EV when I'm away from home?
There are many public charging stations in Eugene, including two at EWEB's riverfront headquarters
location and two at our Roosevelt Operations Center. See a list of charging station maps
When I plug my car in, my fuse (or circuit breaker) trips off. What's going on?
Fuses generally blow (or circuit breakers trip) when the amperage on a circuit exceeds
the rated capacity. Have a licensed electrician look at your panel and your charging station
needs to determine whether you need to upgrade a circuit, or upgrade your electric service
to a higher amperage rating. Please note that a dedicated circuit is recommended for
How do I charge my car at home if I am a renter?
If available, you can use a standard 120-volt GFCI outlet in your garage or
near where you park your electric vehicle. A dedicated circuit is recommended.
If you do not have an available and safe outlet where you park,
you will need to look for public charging stations. There are many public charging stations in Eugene, including two at EWEB's riverfront headquarters
location and two at our Roosevelt Operations Center. See a list of charging station maps
How much will it cost to have my charger installed?
Plug-in vehicle charging equipment installation costs can vary greatly depending on the
configuration of the home and electrical circuitry, local code requirements, and the
type of equipment installed. Contact a licensed electrical contractor for a cost estimate.
How much will it cost to charge a car in my home?
It depends on how far you drive the car, the car's efficiency (similar to miles-per-gallon in gas cars) and the
cost of electricity.
EWEB has three electric rate
tiers that increase in cost as more energy
is used. Therefore, the cost to charge the car is more expensive if you fall in a higher tier.
Review your monthly bill to determine which how much electricity you are using and
which tier this falls within.
You can estimate your costs on a per-mile basis. Most electric vehicles have an
efficiency between 3 to 4 miles per kilowatt-hour. Also taking tiered electric rates into consideration,
the costs for your electric vehicle may range from 1.8 cents to 3.4 cents per mile.
If you drive 10,000 miles per year, your electric bill could increase by $180 to $340
per year. However, this increase would be offset by not paying for gasoline.
See the graph below to estimate how much it will cost to charge your electric vehicles based on
How does the cost of charging an electric car compare with a gas-powered car?
The cost-comparison depends on a number of factors. For illustrative purposes, let's assume that you
have a fairly efficient gas-powered vehicle that gets 30 miles per gallon. At $3 per gallon, your
fuel cost is 10 cents per mile. Based on the previous example, the cost of an electric vehicle ranges
from 1.8 cents to 3.4 cents per mile. Therefore, if you drive 10,000 miles per year, it would cost
between $180 and $340 a year to power an electric vehicle, and about $1,000 per year to drive a
30-mile-per-gallon gas-powered vehicle (at $3 per gallon).
What is the life-cycle cost of an electric vehicle compared to an internal combustion engine vehicle?
The total cost of ownership of an electric vehicle using current technology is typically less than an
internal combustion engine vehicle. This is true if gasoline prices stay at or above $3 per gallon and
you own the electric vehicle for more than 10 years.
The cost of electricity is much lower than
gasoline. EVs will also likely have lower maintenance costs. The internal combustion engine has
hundreds of moving parts that require oil, coolant and filter changes every 3,000 to 5,000 miles.
An electric vehicle motor will generally require one yearly check up to top off brake fluids and
lubricate bearings. EV owners may need to replace their battery during that 10 year
period, depending on the
type of battery.
How much will my electric bill increase if I host a Level 2 charging station
at my business?
Commercial (or non-residential) accounts are charged for both energy and demand. Energy is the
kilowatt hours (kWh) used during each meter reading period (about four weeks).
Demand is the largest 15 minutes of energy used in the building during each meter reading period.
Demand is presented as kilowatts (kW) and represents one 15-minute period in the meter reading
period when the building's energy use was highest (demand-period). Both fees should be considered
to determine the cost of hosting an EV charging station on a commercial account.
A Level 2 charging station can use up to 7 kilowatts (kW) to charge one EV. (For two EVs, charging
could be 14 kW.) If an EV charges during the building's demand-period, there will be an
additional demand cost. If an EV is charged at a time when it will not increase the demand,
the cost will only be the energy (kWh) rate.
Unfortunately, without smart meters, EWEB does not know when your demand-period occurs. For many
commercial customers, the demand-period occurs during the late afternoon in the summer, and in the morning in the
winter. To host a charging station without increasing the monthly demand cost, charging would need to occur
when the building's electric use is low. For many commercial accounts, the best time to charge an
EV and avoid increasing the demand fee is overnight.
Because of the demand fee, the exact cost for EV charging on a commercial account is difficult
to answer. The minimum cost to charge an EV on a commercial account is the energy used (kWh)
multiplied by the energy rate. If the EV was charged any time but the demand-period, and demand was unaffected, the energy cost
is the total cost of the EV charge.
However, if the EV was charged during the demand-period just one time in a meter reading period,
it could increase the building's monthly demand, and demand charges would increase. As you can see in the
example below, the demand fee can greatly affect the cost of operating an EV. The following example
uses EWEB's 2011
medium general service rates for commercial customers.
Energy charge (minimum cost)
Energy used (kWh) x energy rate = energy charge
Example: 7 kWh* x 4.5 cents = $.315 or 32 cents
Demand fee (will increase if EV is charged during demand-period)
Demand charge x demand (kW) = demand fee
Example: $6.13 per kW x 7 kW = $42.90
|In this example, charging any time, except the demand-period,
costs 31.5 cents. Charging one time during the demand-period cost $43.22 dollars.
The example above used a building where the EV was mixed with other electrical loads and the demand
increase could be avoided if charging occurred any time but the demand-period. If the charging
station is the only load on the meter, there is no way to avoid the demand being increased.
Of course, the more EVs charged during a meter reading period, the more the demand cost
can be spread across a number of EV charges.
Currently, the residential
rate structure only has an energy (kWh) charge. However, if you compare
commercial energy rates with residential energy rates, you will see that residential energy
rates are higher. One reason for this difference is residential energy rates have an
assumed demand component included in the rate, whereas the commercial rates separate
energy and demand. EWEB also pays a demand fee when purchasing wholesale power. In the future, a
Time of Use (TOU) rate structure could be adopted to manage utility (peak) demand costs and provide
customers a price signal when prices are higher. As you can see, prices are higher when a
demand component is included.
more about energy and demand rates on commercial accounts
Will the electric grid be able to support the extra demand caused by electric vehicles?
One of the challenges of preparing for an increased electric vehicle adoption rate is that it is not
yet clear how large the market for EVs will be, or how fast it will grow. During early market development,
when the number of plug-in electric vehicles is relatively small, we do not anticipate
any significant system-wide impacts to the electricity grid or electricity supply.
It will be important to evaluate and learn from our experience during these early years,
to plan for potential future impacts.
As the number of plug-in electric vehicles grows and we learn how customers are charging
their vehicles, we'll be able to better determine the impact to the electricity grid. Avoiding
EV charging during times of high wholesale prices will be an important policy objective.
We may determine that it is necessary to reinforce the distribution system in neighborhoods that have
large numbers of plug-in vehicle owners and faster, higher-voltage charging systems.
EWEB is committed to making the necessary upgrades as quickly and efficiently as possible.
What is the predominant source of electricity that I'll be charging my car with?
EWEB's primary source of electricity is hydropower, which is fossil-fuel free.
EWEB also generates and purchases wind power for use by EWEB customers.
EWEB's source of
electricity isn't carbon-free, however. Two-thirds of our electricity comes from the federal
Bonneville Power Administration. Most of that power is hydroelectricity, but BPA also purchases
power on the wholesale market that sometimes comes from natural gas and coal-fired power
plants in the Western United States, especially during peak demand periods (generally,
5 to 9 a.m. and in the early evenings).
Plugging your car in overnight ensures that you are
charging your vehicle at times when the percentage of wind, hydro and other renewable energy
output is at its highest in the region.
I was told EWEB will take energy from my battery. Is that true?
Initially, only "one-way" charging stations will be available. In other words, your EV
will draw power from the electrical grid but will not have the
capability to feed power back into the grid. However, utilities are researching the potential
benefits and feasibility for allowing for electric car owners to sell excess vehicle
power back to the utility while plugging into charging stations. There are numerous technical,
economic and process questions to be addressed, but the concept has potential.