Energy & Environment

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

CHARGING UP

Recharging NEVs and longer-range EV cars is more time-consuming than simply refilling a fuel tank; a bulk charge rate (up to 75 percent battery capacity) takes four hours, and a complete battery recharge takes eight to 10 hours, at 10 to 15 cents per hour. (Recharging bike and scooter batteries takes less time.) At work, a few solar-electric panels in the parking lot would be all you need to recharge your EV's batteries for the evening commute home. Most EVs plug into a standard 110-volt wall socket for overnight charging. Larger EVs or ones with high-voltage battery packs may require a 220-volt outlet.

Savvy EV owners add a time-of-use (TOU) meter to their home utility meter to lower the rate for EV recharging. A TOU meter records power usage within two distinct time periods: peak (between 11 a.m. and 7 p.m.) and off-peak (from 7 p.m to 11 a.m.). Most homes pay a flat rate for electricity for a 24-hour period, but a home with a TOU meter pays two rates: a higher one for peak use and lower one for off-peak use.

Since most EVs are recharged overnight, TOU metering is an ideal arrangement that significantly reduces the cost of recharging daily. In the United States, says Paul MacCready of Aerovironment, a company specializing in electric and hybrid vehicle systems. 6 million EVs could be recharged from utility electricity overnight without the construction of a single new power plant.

The cost of installing a TOU meter ($150 to $200) pays for itself in about a year's time. Many states now also offer significant rebates to offset the cost of installing grid-tied renewable energy systems. The Database of State Incentives for Renewable Energy ( www.dsireusa.org ) lists programs by state. Homeowners can take advantage of these savings and use the clean electricity produced from the sun or wind to recharge their electric vehicle.

EV charging stations are popping up throughout the country to assist with opportunity charging. A dedicated parking space designated with a sign, with a charging box mounted on a pole serves this function. Both 110- and 220-volt sockets are available. The electricity consumed is so miniscule, most charging stations offer the service for free. In Switzerland, EVs may pull into a streetside parking spot, plug into the meter at the curb, and deposit coins for parking and electricity. In California, the Sacramento Municipal Utility District shades its parking lot with solar-electric panels, which provide power for its mixed fleet of EVs.

RSS | Comments | E-mail | Print