The funny thing is, this isn't new technology. There were electric cars that compared evenly or even favorably to gas cars in both cost and performance from the very beginning. Over time, the gas monopolies were able to shut out the competition by building infrastructure faster and generally just having more money resources available to promote the vehicles that consumed their product.
Electric cars are not more expensive because they are more expensive to make. I built one. I was part of a team in high school that built the first student-made electric vehicle in the state of Georgia, an electric go-kart. We went on to be the second team in Georgia to complete a conversion of a full sized vehicle. We were not supported with funds by the school district or the state, we raised money by putting on a dinner theater and by doing presentations to our local Lions and Kiwanis and Rotary clubs. We got a company that manufactures electric motors to donate a motor, and we bought everything else and built it ourselves. We bought an old Ford Ranger at a junkyard with the money from the dinner theater, and stripped it down to the rails in our workshop, and then did a complete conversion on it. We built a battery compartment under the truck bed that housed sixteen lead acid boat batteries, and retrofitted the transmission linkage to accept the output from the electric motor.
The final product was astoundingly good, for a truck built by kids with no engineering experience. It was a real vehicle, capable of reaching and maintaining interstate speeds, with a range of 100 or so miles on a charge. And we did it in less-than-ideal circumstances, with a total cost of about $6,000, including the donated engine and all the tools and supplies we had to buy.
Sure, we used cheap lead-acid batteries, and we paid for it in performance. If we had been able to get our hands on modern nickel-hydride or lithium ion batteries, we could have easily tripled our benchmarks for range and acceleration, and come in weighing far less. If our budget had been $8,000 instead of six, we would have been able to do that. And these days, those batteries are not as expensive as they were back in 1999 when this all was going down.
So yeah, the technology exists and is not hard to use, and it's not prohibitively expensive. Car companies are not building electric cars for other reasons than that. We did a lot of research at the time on the subject, and we actually got to talk to some car company executives and engineers and designers, and from what we heard it seems that mostly it's because it would require a huge investment up front in order to convert existing production plants to build a totally different kind of car, and they're skittish about making that investment because they don't have enough solid evidence that the new cars would sell at a rate that would turn over the investment quickly enough. And the reason they don't have enough evidence is because the only electric vehicles being made are generally boutique models that don't move a lot of units, because they're created and marketed as a special product, because no one has invested in large-scale production.
There's also the problem of infrastructure. The roads are well-equipped to handle gasoline cars, but charging stations for EVs are still rare in most parts of the country. And there's the other problem with charging stations: charging takes time. A person can stop for gas and get right back on their way, but if you stop to charge your EV you've probably got at least an hour or two to kill. So the idea of charging facilities that are similar in nature to gas stations is not really how it would need to work - the charging station would be better in a parking lot at the mall, or at popular tourist destinations or local entertainment. Stop and see a movie, come out and your car is ready.
And that brings us to the only real technological barrier - range. A fully electric vehicle is completely capable of most everything a person could need a vehicle for. Except long-distance travel - gas vehicles are 100% better for that. Various schemes for resolving this problem have been attempted: regenerative braking, wireless charging on the move, etc. We experimented with a setup with small electric brush motors on each axle which served as mini-generators and pumped electricity back into the battery array. We got a small boost in range in our paper calculations, but in reality it was highly inefficient, and the extra weight canceled out the positive effects, so we scrapped the idea.
Anyway, all that was to basically agree that it's unlikely that existing large car manufacturers are going to take the Tesla patents and dive into the EV market full steam. It's way too much of a risk for them still. But there's the possibility that some outsider will use this stuff to start a new company, and build their own factory, and make cheap mass-produced EVs. It's totally possible.
