Globally, electric-vehicle sales make up only about 1% of sales. In the US, three vehicles are driving the growth of the market, such as it is: the Chevy Bolt, the Nissan Leaf, and the Tesla Model 3 — all mass-market cars.
Leaf sales should remain predictable: this is a car that's been around for years and recently got a big update. I'd expect it to post something like 10,000-15,000 in unit sales for 2018.
The Bolt has been an unexpected success story; at a stretch, it could hit 50,000 in total 2018 sales, assuming GM wants to make that many and demand continues to grow.
The Tesla Model 3 is the wildcard. Demand on paper is crazy high, over 400,000 pre-orders. But Tesla's ability to deliver the vehicle is woeful. Full production likely won't arrive until mid-2018.
That means less than 200,000 Model 3 deliveries in 2018. So the meat of the US EV market will add up to only about 250,000 — roughly a 1.5% share on the mass-market level (Tesla's share of the luxury market, at roughly 100,000, could be added to that).
Analysts will point to a wildcard factor of more affordable EVs on the road inspiring more sales, a virtuous cycle. I'll believe it when I see it. The overall market dynamics are pointing more toward a consolidation than growth, as flat 2018 sales will constrain EV expansion.
Growth, growth, growth for EVs in a juiced sales environment isn't a good thing; it would be better if we saw a few years of sales at a solid level, indicating consistent demand.