The long-term EV forecast has jumped by 500 percent since last year.

Oil producing countries appear to be revising their long-term forecasts for electric vehicles.

OPEC now expects EVs to account for a third of all cars by 2040 with 266 million battery-powered vehicles on the road, according to a study by Bloomberg New Energy Finance. Just one year prior to the 2016 forecast, OPEC had anticipated just 46 million units by 2040.

BNEF is even more optimistic, expecting more than a half billion plug-in vehicles by 2040. The analysis centers around the ever-decreasing price of lithium-ion battery units. If costs of batteries continue to decline at current rates, long-range electric powertrains will be more affordable than traditional gasoline or diesel powerplants in coming years.

Consistent with OPEC and BENF's predictions, the Interntaional Energy Agency has increased its 2030 EV fleet estimate from 23 million to 58 million. Exxon mobile also nearly doubled its forecast to 100 million for 2040, while BM expects the same benchmark to be hit by 2035.

"The number of EVs on the road will have major implications for automakers, oil companies, electric utilities and others," says BENF ehad of advanced transport analysis Colin McKerracher.