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Posted by admin at 9:30AM on 9/17/2011 with tags: , , , , , , , , , , ,

Currently, the car with the best gas mileage reaches about 50 miles a gallon. So, it came as a huge shock to the automotive industry when General Motors announced last year that their new electric-drive Chevy Volt would reach an EPA-rated 230 miles per gallon. But so far, journalists, industry experts and even the EPA are still at a loss to fully explain GM’s math.

The Chevrolet Volt is a plug-in hybrid electric vehicle, designed to run on electricity until its battery level drops. After that, a gasoline engine kicks in to power the car. According to GM, the Volt’s battery-only range would be about 40 miles, and the gasoline engine would have about 40 mpg.

How did GM reach this inflated figure? According to Motor Trend, GM used a proposed EPA measurement system that converts a vehicle’s kilowatt hours (kWh) to an equivalent in miles per gallon. Since GM predicted the Volt would consume 25 kWh per 100 miles, they calculated 230 miles per gallon. The EPA has since shied away from GM’s claims, officially rating the Volt at 37 kWh per 100 miles and announcing it had “not tested a Chevy Volt and therefore cannot confirm the fuel economy values claimed by GM.”

Journalists questioned the 230 mpg claim because the actual figure can change drastically depending on how the Volt is driven. For instance, CNN predicts that if a driver goes 300 miles with a fully charged battery, the fuel economy would actually be about 62.5 mpg. Edmunds.com found that with the battery depleted the car averaged 31.1 mpg.  Edmunds ultimately called the Volt’s performance “seriously subpar when compared to the mid-40s mpg that a standard hybrid typically provides.”

Analysts say GM’s figures also overlook recharging and initial costs. GM has said 8 kWh are needed to travel 40 miles, which the Department of Energy says will cost around 88 cents per charge. While these costs may appear modest, reviewers like Edmunds.com question the overall value since the Volt is far more expensive than other hybrids.

Ultimately, GM and other EV manufacturers need to justify the high price tag of their vehicles by providing buyers measurable fuel savings and a return on their investment. But, even the CEO of GM has questioned the Volt’s lasting value, saying it will be “an old, old technology and old news” in just five years.

PHOTO: GM-Volt.com

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According to a new study by psychologists at Germany’s Chemnitz University of Technology, drivers who regularly worry about an electric vehicles’s (EV) battery level don’t maximize their vehicle’s potential. The study found that worried drivers overcharged their EVs on a regular basis. However, the study didn’t address how overcharging can lower the vehicle’s battery life and potentially strain electric grids.

Feeling like you’re about to be stranded because your car runs out of juice is known as “range anxiety” in the EV business. The study at Chemnitz found drivers experienced range anxiety about once per month, and researchers proposed that feeling could worsen if there were no nearby public charging stations. EV manufacturers have long tried to dismiss consumers’ worry about insufficient mileage between charges. Then again, when new battery-electric cars like the Nissan Leaf lose power unexpectedly, range anxiety may be well founded.

The researchers discovered most drivers needlessly recharged their vehicle with 20 percent or more power left in the battery. This finding is important because frequent charging can overwhelm the electric infrastructure, which is already threatened by electric vehicles.

Experts estimate that EVs consume about a third of the power of a house, and warn that adding electric cars to a residential area could overwhelm transformers and even cause blackouts. A public charging network would ease drivers’ nerves, but would add an additional burden to the grid. EVs draw their power from a system that is not prepared to meet the increased demand.

Overcharging can also degrade EV’s battery at a higher rate. Fast charging a Nissan Leaf, for example, can decrease the battery life much faster than slow charging at home. And, replacing a dead EV battery isn’t cheap: a recent article from the UK states that a new battery pack could cost over $30,000.

With the harm overcharging can ultimately bring to their vehicles and the electric grid infrastructure, EV drivers unfortunately have more to worry about than just their range.

Image by Salvatore Vuono

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  • Electric vehicles aren’t “zero-emissions” as advertised. Sure, EVs may have no tailpipe emissions, but when an EV plugs in, where does the energy come from? The fact is, almost 50 percent of our nation’s electricity is produced by coal. According to one new study, half of an EV’s lifecycle greenhouse gas emissions are produced during the manufacturing and shipping phase.
  • Alternative vehicle fuels aren’t just better for the environment, they’re better for your health. In some states, vehicle emissions constitute the largest source of air pollution like smog and ozone, which can lead to respiratory and other health issues. That’s why the American Lung Association promotes alternative fuel use.
  • Current technology cannot affordably harness enough renewable energy power to meet electricity demand. Also, while wind and hydro power are considered by some to be viable energy sources, researcher and author Vaclav Smil contends that these two sources could only supply a small portion of future energy demand. Together, all renewable energy sources only constitute 8% of current worldwide energy supply, according to Smil’s book.
  • Biofuels, such as ethanol, are not feasible future energy sources. With the challenges that global food supply is currently facing, we can no longer afford to use food as vehicle fuel while other alternatives are available. Many experts have linked redirected food supply used for producing corn-based ethanol to rising tortilla and livestock feed prices. “Ethanol is taking a larger and larger share of [corn] production,” says one agricultural economist.

To learn more about the differences between alternative fuels, view our Alternative Fuel Fact Briefs online.

PHOTO SOURCE: Project Seed

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Posted by admin at 5:08PM on 6/24/2011 with tags: , , , , , , ,

A recent British study has questioned the environmental benefits of plug-in electric vehicles (PEVs) and has gone so far as to claim they may be dirtier than gasoline vehicles. While this statement may baffle those who have seen automakers’ touting “zero emissions” EVs (view our June 2nd post about Nissan), the study goes on to say that nearly half of an electric vehicle’s emissions are produced during the manufacturing process, before the car has ever been driven. EVs require multiple batteries to operate – batteries that greatly increase the amount of energy needed and pollution created by the factory.

Of course, the other portion of EV emissions is created when the vehicle’s battery is charging. Since much of the world’s electricity is sourced from dirty sources such as coal, the EV’s emissions are simply being transferred from the road to the area around the power plant.

One place this study’s findings might be (indirectly) tested is in Australia where PEV manufacturer Tesla is attempting to break the national record for the longest road trip by an electric vehicle with its all-electric “Roadster.” It will be recharged along the way with renewable energy sources such as solar, hydro and wind to illustrate the low emissions capabilities of the vehicle. Critics of the project, such as automotive expert and editor of New Zealand’s sardonic Dog and Lemon Guide Clive Matthew-Wilson, say that the car isn’t as environmentally conscious as Tesla would have you believe. “Burning coal to make electricity to power an electric car creates more pollution than if you simply powered the same vehicle using petrol [gasoline],” Matthew-Wilson said.

This study was among the first to complete an analysis of  the energy-intensity of producing batteries when calculating EV life-cycle emissions. Given that this and other recent studies have targeted EVs’ green credentials lately, shifting from gasoline to mass production of EVs may be too ambitious for now – which only furthers the case for using American-made, clean-burning alternative fuels like autogas and natural gas.

To make the way for a true clean energy future with PEVs, America would need to overhaul its energy grids and greatly expand renewable energy use. The disparity between EVs’ actual contribution to lowering emissions and EV proponents’ dream of what it could be does not mean we’re stuck with gasoline in 2011– autogas is right here, right now.