In fairness to the Nissan Leaf, the Chevy Volt, and other plug-in vehicles, we've got to cut them some slack and recognize that the first-generation of almost any major innovation often has plenty of room for improvement.

With plug-ins, we've got a class of vehicles that can help reduce greenhouse gases and protect the atmosphere. By driving these vehicles, the incentive for consumers is supposed to be that we will save all that money we would have been spending on gasoline.

The problem, of course, is that the plug-ins generally cost $8,000 to $20,000 more than comparable gasoline versions, according to the Detroit News, and it can take years or decades to recoup the higher initial cost.

Consequently, the government subsidizes these vehicles by tossing you an additional incentive to buy them while hoping that you don't actually do the math. A report from the Union of Concerned Scientists (UCS) did the math and it's not encouraging.

UCS says that electric vehicle drivers can save $750 to $1,200 a year compared with operating a compact gasoline vehicle that gets 27 miles per gallon fueled by gas at $3.50 per gallon. Any "savings" that is supposed to materialize from electric vehicles is negligible since you basically have to drive the same car for 10 years or more just to break even.

And it gets worse. The Los Angeles Times says the savings depend on how much a local utility charges for electricity and, like gasoline, that varies widely from one region to another. The range of savings requires charging on the lowest-cost electricity plan and that may require consumers to switch from their current rate plan to a more advantageous one, often limiting charging time to night hours dictated by the utility.

When it comes to pollution, UCS says that charging an electric vehicle (EV) in the cleanest electricity regions (NY, California, Pacific Northwest, Alaska) yields global warming emissions equivalent to a gas-powered vehicle that achieves over 70 mpg.

But more than one-third (37 percent) of Americans live in regions where an EV has emissions equivalent to a gas-powered vehicle that achieves 41-to-50 mpg.

Eighteen percent of us live in regions where an EV has the same emissions of a gas-powered vehicle getting 31 to 40 mpg, and the Rocky Mountain grid region has the highest emissions intensity, meaing an EV is no better than a gas-driven vehicle achieving 33 mpg.

Who knows? Maybe all that doesn't matter to the people who want to be the first on their block to own an EV. For now, it's an uphill climb since EVs total sales last year were 17,425, which is less than 0.1 percent of the U.S. market. That means whoever is the first on your block will probably have those bragging rights for a long, long time.