Ask the Energy Expert: Fuel-Efficient Cars

 Each month, New Hampshire Electric Cooperative (NHEC) offers you the chance to Ask the Energy Expert. Got a question about energy efficiency or renewable energy? Send your question to energyexpert@nullnhec.com and get answers from the Co-op Energy Solutions team.

This month’s Energy Expert is Gary Lemay. Gary is a Renewable Energy Engineer at NHEC. He’s also the proud owner of a Toyota Prius plug-in hybrid car.

Q: “I am seeing more and more options for fuel-efficient cars. I’m currently in the market for a new car and wondered what you thought of the options out there for the best combination of mileage, cost and convenience.”

A: Just a few years ago, there were only one or two choices in light vehicle drive train options. About 99% of the light vehicle drive trains were gasoline-driven with a few diesel-driven options. Today there are three to five different drive train options available. We still have gasoline and diesel options that top out at a maximum of about 40 miles-per-gallon, but there are also hybrid vehicles (HEV), Plug-in Hybrids (PHEV) and all-electric vehicles (EV).

The new HEV, PHEV and EV vehicles provide many opportunities for today’s car buyer to drive more miles for less fuel, but each has been designed with unique characteristics. Car buyers need to know their driving needs and habits and match their needs to the right vehicle. Here are some considerations.

First, using electricity to power your vehicle is less than half the cost of using a gas-driven vehicle. Plus, most electricity in New England is produced locally and usually from domestic fuels. That said, if you have not planned well, you may not love your straight electric vehicle (EV) so much if it runs out of charge after 70 miles.

So what’s out there for options? Below are some definitions, benefits, and drawbacks of the various types of vehicles on the market today.

Hybrid Electric Vehicles

HEVs are powered by an internal combustion engine or other propulsion source that runs on conventional fuel and an electric motor that uses energy stored in a battery. The battery is charged through regenerative braking and the internal combustion engine and it is not plugged in to charge.

Benefits – Typically can be driven across country with refueling stops; mileage per gallon can be 50 to 100% better than conventional gas vehicles; reduced air emissions; generally lower maintenance costs; usually a longer power train and/or battery warranty.

Drawbacks – Usually, but not always, a higher initial purchase price; driving characteristics may be slightly different than conventional vehicles; sometimes they look unconventional; four or all-wheel drive vehicle options are limited.

Plug-In Hybrid Electric Vehicles

PHEVs are powered by an internal combustion engine that can run on conventional fuel and an electric motor that uses energy stored in a battery. The vehicle operates just like a hybrid vehicle but can also be plugged into an electric power source to charge the battery to a higher degree almost like a second battery. Some PHEVs are also called extended range electric vehicles (EREVs).

Benefits – Can be driven cross-country with refueling stops but can also be driven on electric alone with no gasoline usage; can be recharged at times when lower electric rates are available; blended electric and gas mileage per gallon can be another 50 to 100% better than standard hybrid gas vehicles; reduced air emissions; runs quietly; generally lower maintenance costs; longer power train or battery warranty; can be recharged with home renewable energy sources. These vehicles could be the transitional bridge between conventionally fueled vehicles and all electric vehicles.

Drawbacks – Usually a higher initial purchase price. Driving characteristics may be slightly different than conventional vehicles. Sometimes they look unconventional. Four or all-wheel drive vehicle options are very limited at the present.

All-Electric Vehicles

EVs use a battery to store the electric energy that powers the motor. EV batteries are charged by plugging the vehicle into an electric power source and they do have a regenerative drive like a hybrid. EVs are sometimes referred to as battery electric vehicles (BEVs).

Benefits: No gasoline usage; can be recharged at times when lower electric rates are available; no air emissions (except at the generator site which is usually government monitored and regulated;) generally lower maintenance costs; longer power train or battery warranty; very quiet when running; can be recharged with home renewable energy sources.

Drawbacks: Usually a higher initial purchase price and limited range. EVs have an average range of 60-80 miles per charge, making them impractical for long journeys (unless you plan your recharging stops well). In cold climates, heating and defrosting is from battery power and can reduce vehicle range. There are electric vehicles that can go 200 to 300 miles but you need to purchase the larger battery. However, the average American drives about 30 miles round trip to and from work each day, so from a commuting standpoint, an EV may be the right choice especially as a second vehicle.

Your options are growing for fuel-efficient cars, but so are your resources to learn more. Web sites to consult: greencarreports.com, pluginamerica.org, afdc.energy.gov/vehicles/electric.html