May 202016

2013-nissan-leafby Kim Slack

At a recent meeting of Sustainable Belmont, Kim Slack was part of a panel discussing the benefits of electric vehicles (EVs). The following is his summary of that discussion.

Of the many reasons to consider an all-electric car, two key factors are low operating costs and the health of the planet.

Low operating costs.

Electric vehicles (EVs) are more energy-efficient than gas-powered automobiles. Electric cars can travel up to 115 miles on the energy contained in a gallon of gas, according to the Environmental Protection Agency (EPA) miles-per-gallon-equivalent measure (MPGe), which is the average distance traveled per unit of energy consumed.

I did a recent personal study. Driving my Nissan Leaf electric vehicle for 1,000 miles saved me more than $30 over driving our 30 mpg gas-powered Honda Fit. This was based on gas priced at $1.90/gallon, and electricity at $0.19/ kilowatt-hour (kWh), and the cost of gas and oil changes during that 1,000-mile test period. Unless gas prices dip below $1.14 and stay there for months, the electric vehicle is more economical than a gas car. This comparison also includes gas and oil changes, but omits longer term maintenance costs associated with gas cars such as timing belts, valve adjustments, transmission fluid, spark plugs, air filters, and muffler and exhaust pipes. Insurance costs are comparable.


Comparing the manufacture, operation, and disposal of electric cars, the Union of Concerned Scientists estimates that EVs on average produce 50% less greenhouse gases than similarly sized gas-powered vehicles, over a lifespan of 162,000 miles. This assumes that, as is the case in New England, most electricity used to charge the battery is not produced with coal. Charging directly with rooftop solar reduces emissions even more.

Health of the planet.

Burning fossil fuels such as gasoline contributes to global warming. Unfortunately, the carbon dioxide that is released from our tailpipes stays in our atmosphere for hundreds of years—so our grandchildren and their children will have to adapt to a significantly different climate, one that scientists believe will have scarcer food and more extreme weather.

The US Department of Energy estimates the transportation sector generates 40% of atmospheric greenhouse gases. Electric vehicles offer a way to reduce that and are readily available on the market. Meanwhile, government and industry are making investments to encourage more EVs, from tax credits and charging station infrastructure to automotive innovation.

Not all electric vehicles are all-electric.

Some electric cars rely on gas engines for backup, some don’t. All-electric cars (like the Nissan Leaf and Tesla) use a large battery pack, typically 24 kWh-plus capacity. They have a range of 65 to 75 miles before recharging, depending on driving conditions. Batteries recharge in 12 hours or more on a 110-volt outlet, or about half that time on a 240-volt outlet. For daily commutes within the range of the battery, or other predictable driving routines, these cars can work well as second cars. Or the EV can be your only car if you turn to car-sharing services and rentals for longer trips.

Plug-in hybrids (like the Chevy Volt) use a combination of battery and gas power, first running on electricity until the battery is depleted, then switching to gas backup. The larger the battery capacity, the more emission-free driving time. For instance, the Volt has an 18.4 kWh capacity battery, about three-quarters the size of all-electric vehicles. On the other hand, the 4.4 kWh plug-in Toyota Prius can go 15 to 20 miles on battery alone before switching to its gas engine. These cars are good where driving patterns are unpredictable, or for accommodating the occasional long drive.

Other hybrids.

Non-plug-in hybrids (including other models of the Prius) use electric and gas motors in tandem to reduce gas consumption. The primary motor is gas, but it idles on electric power. Battery capacity for the regular Prius is 1.3 kWh. Such cars reduce emissions less than all-electric or plug-in vehicles do, but at highway speeds of 50 mph are better than most gas-only vehicles.

Suffering from range anxiety?

Because battery size and charging times limit the distance the car can travel, adjusting to these constraints takes a bit of effort. One way to manage the transition prior to purchase is to record your daily routine distances and add an extra 30% buffer. Then match your normal range to the vehicle options. Most EVs warn drivers when the battery is low, and will show nearby charging stations in their navigation systems. Belmont citizens on average drive 20 miles a day. An electric vehicle would not disrupt most of our driving habits, especially as a second vehicle.


Scott Miller, a Belmont resident and one of the panelists at the Sustainable Belmont event, is eastern region vice president of sales of ChargePoint, a national firm that installs and manages charging stations.

According to Miller, charging times vary depending on the car and the type of connection. Many cars today can charge in less than 6 hours, and on some connections in as little as 30 minutes. Ordinary household 110-volt outlets can charge a car in 12 to 16 hours. Adding a faster 240-volt home charging station may cost $1,000 to $2,000, depending on the distance from your garage or parking spot to your electrical panel.

Purchase price.

Retail prices for new EVs cover a large span, depending on the model. The small Mitsubishi i-MiEV lists for about $24,000, and a BMW i3 for $44,000. The Tesla S goes for over $70,000, but cheaper models are on the drawing boards. Tax credits for buying a new EV in 2016 are a $7,500 federal credit (for batteries with 5 kWh capacity or more) and $2,500 Massachusetts credit (on most EV models). Check with the IRS and Massachusetts Department of Revenue about specific conditions before buying.

Because gas prices are currently low, the demand for efficient models is less, depressing the cost of electric vehicles and presenting bargains for consumers, especially on low-mileage used vehicles. At this writing, three-year-old Leafs with 20,000 miles or less list for $10,000-$12,000. Other models to check are the Ford Focus EV, Ford C-Max (plug-in), and Chevy Volt.

How long do batteries last?

Nissan warrants their batteries for seven years, typical for other vehicles as well. New Leaf batteries cost about $4,000. Discarded batteries are re-used in less intense environments and can ultimately be recycled, recovering most of their elements for other uses.

Business benefits.

ChargePoint’s Miller noted that strategically placed charging stations could help attract drivers to business districts. The batteries charge while the drivers shop or dine. Individual charging units can be free or accept payments, and may have set time limits. Lexington Center has a few; so does the Watertown Arsenal Mall. Across the region, some employers provide charging stations, as do some MBTA parking garages, including Alewife Station. Miller said hundreds of charging stations are becoming available in eastern Massachusetts. He added that the state currently covers half the cost of the station, to encourage both private and municipal providers.

The future is electric.

Electric vehicles represent the immediate future in personal transportation. They reduce emissions, have low operating costs, and are fun to drive. They’re perfect for the distances most Belmontonians drive. Kick gas, and go electric.

Kim Slack lives in Belmont and is a member of Sustainable Belmont. In addition to driving an EV, he commutes on his bicycle. He recently installed solar panels to further reduce his reliance on the grid.


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