This article either chose to
This article either chose to ignore the relevant factors resulting in lower EV sales (aka propaganda piece) or was written in ignorance of EV events that occurred in 2015 which directly resulted in lower sales. There's no information supporting a decline in EV interest.
Chevy Volt = GM announced the 2016 Volt would have a significant increase in all electric range early in 2015. This had a negative impact on 2015 Volt sales for the majority of the year. GM clearly under estimated the customers desire for a larger all electric range. GM still believes they're in the business of selling cars and have failed to realize they're now in the business of selling technology. In addition, GM did not provide inventory for the 2016 Volt nationwide. GM is only providing inventory to a few markets / cities, which prevented any kind of rebound sales late in 2015.
Leaf = first half of 2015, rumors started to circulate that the Nissan Leaf would receive an increase in all electric range. This started to impact sales. Later in the year, rumors solidified and customers became aware of a limited increase in range for the 2016 model. The 2016 model was not made available until very late in 2015 and inventory levels have been limited at best. Again, ruining any chance of a sales rebound in late 2015.
GM announced they would release the 2017 BOLT (200+ mile range EV) in late 2016. Rumors are circulating that GM is accelerating their schedules to deliver the BOLT earlier in 2016. People like myself are holding out for the next generation 200+ mile range EVs.
The current offering of EV cars were designed to only appeal to a very limited market segment. There are few people who can afford a $35K+ car and have the will to buy a small car with only 80ish miles of range in good weather. The size of that segment is unknown but it's possible the sales are reaching a saturation point and demand for 80ish mile range electric vehicles are declining. Even if this was the case, to make statements that demand for EVs are declining are not true. Give people a fully capable vehicle with 300+ miles of range for the same price as current ICE (gas) vehicles and we'll see which drivetrain people choose.