By all accounts, the electric vehicle industry appears to be a market on the brink of mainstream adoption, yet sales and growth rates continue to fall short of projections. So what is missing to take EVs to the mass market?

As with any emerging technology, there are a number of questions that are preventing potential buyers from signing on the dotted line. Price is naturally a concern for a customer base still climbing its way out of the Great Recession. According to Pike Research's annual Electric Vehicle Consumer Survey, the optimal price for EVs to attract buyers is around $23,000, but currently there is not a model available today priced under $30,000.

"It's not that potential car buyers reject the idea of being green. Most love the idea -- until it involves the hassle and substantial expense of installing a home charger on top of paying a substantial price premium over an equivalent non-electric car. And then there is planning for range limits," said a recent article in the Detroit Free Press that also touches on an important point.

Perhaps just as inhibiting as cost and range limitations are the questions surrounding how customers will actually use their EV once they drive it off the lot.

Yet, the resolution of these deterrents is only half of what must be done for successful mass market adoption. The other half involves the infrastructure supporting the use of these vehicles, namely the charging vendors and utility companies that will establish the charging points, supply the energy to power EVs, and calculate and send bills for payment.

Without thinking through the end-to-end, car-to-cash process in terms of how owners will charge and pay for the energy consumption of their EVs, consumers will continue to be hesitant to buy, regardless of the purchase price.

Right now there is relatively little infrastructure in place for consumers to confidently use an electric vehicle in the same way they would a traditional car. While there is certainly a segment of the population that will adopt of EVs for their environmental benefits, the majority of car buyers will stick with their gas-powered vehicles until EVs can offer the same freedom and convenience they enjoy now.

At the end of 2011, there were nearly 5,000 charging stations in the United States; by 2017, Pike Research estimates that number will grow to be 1.5 million. As a result, the EV charging industry is a bit like the Wild West.

Today there are more than 50 different vendors producing charging station technology, each looking to stake their claim and make their name in the industry. At the same time, there is a variety of different charging locations and billing scenarios they must support. Most people are familiar with the idea of charging their EV at home, which would be added to their utility bill, but what if they were to charge at someone else's house? That could be billed similarly to a mobile roaming charge.

Other scenarios might include an employer offering subsidized payments as a benefit to employees, or fuel stations selling electric charging through a point of sale or subscription model. And somehow all of these different charges have to end up on a single bill.