Yes, they're really cool. I own one. Zero emissions and all that. There's one problem. They won't save the world by themselves.
There are many problems to overcome. One of the major advantages of crude oil and gasoline is that they are liquids. They are relatively easy to transport over great distances.
They also have really high energy density. The best EV batteries as they currently exist have 1/150th the energy density of gasoline. This means that in order to store the same energy as a gallon of gas you would need the volume equivalent of 150 gallons. Now multiply that times 13 or so (the average car's fuel tank size).
The second most obvious problem is that the electricity used to charge your EV has to come from somewhere. Most power generation in the world is still from fossil fuels. Carbon based fuels make up the lion's share at about 83%. Non-carbon fuels make up the rest. Things are improving in this regard, but they aren't happening nearly fast enough to slow the worst effects of climate change.
We need to make the wholesale switch to renewable energy like yesterday you say. Yes, that's obvious, but it's not so easy. In order to do this it would take something like 70 times the entire green buildout from 2010 to 2021, which equates to 43,000 terawatt-hours worth of solar panels and wind turbines.
This would present many obvious technical challenges. I'm not saying it can't be done. It would just be really hard--and very expensive. The problem with this is not installing this many solar panels and wind turbines. It's producing this many.
Also, in order for solar panels and wind turbines to be effective the sun has to shine and the wind has to blow. Most parts of the world are not well suited for either of these. A good example is Germany. They have invested heavily in greentech, but unfortunately for them their geography is not well suited for either wind or solar.
The United States is blessed with a geography that supports both forms of energy generation in the Great Plains and southwest respectively. It is, in fact, arguably the best positioned advanced economy for a green energy buildout.
The other major problem with renewables is that the electricity they generate must be stored somewhere or it's lost. Electricity is produced as it's consumed and where it's consumed. This concept is called dispatchability.
On a hot summer day in the southwestern United States when electricity demand is high from air conditioning this is not as much of a problem when everyone's solar panels are producing or in the plains states when the wind is blowing. But what about at night? In the winter? Obviously, there needs to be a way to store the energy for times when the sun's not shining and the wind's not blowing. Enter battery storage. Perfect solution, right? Not so fast. The scale required to balance the energy requirements for something like a city would require batteries on the order of megawatt-days worth of power. With the best scalable battery technology out there it is currently 6 times more expensive than a natural gas power plant, and that's not counting the cost of production or distribution.
Furthermore, it would take the ability to store months' worth of electricity to get a country like the US off of fossil fuels for times when the solar and wind power aren't generating enough to meet demand. There is simply not enough lithium on the planet for the US (let alone the entire world) to achieve this goal.
The one ray of hope at the moment as I see it is nuclear power. Unfortunately, in the past 30 years or so nuclear's share of global power generation has slowed considerably. The accidents at Chernobyl and Fukushima certainly didn't help its reputation any. But the fact is that advances in nuclear power have made it extremely safe. Thorium reactors
, for example, operate at much lower pressures and produce much less radioactive waste than traditional nuclear reactors. So maybe a future of nuclear energy and electric cars? Maybe not.
Complex Supply Chains
Building cars is extremely complicated. Traditional cars have from 15,000 to 25,000 different moving parts sourced from thousands of suppliers all over the world, Furthermore, in recent decades companies have moved to a just-in-time inventory model that has for the most part made them more profitable, but also susceptible to disruption as evidenced by the recent chip shortage. Electric cars have even more complex supply chains in that they require many more raw materials sourced from even more countries. Conventional vehicles require a lot of manganese and copper, but EVs require even more. Plus a whole lot of other materials.
There are many problems to solve to mitigate the worst aspects of climate change, and we have already begun implementing a lot of the solutions. EVs are a very small part of this and will remain so given all of the problems I have outlined above.