Unintended consequences are always a big factor in any new thing. Both lithium and rare earth materials must be mined and refined and this leads to pollution. China is the big source for both of these items and has an abysmal record when it comes to pollution. It is only a matter of time before the "green" activists point out the consequences of going electric. This will drive the cost of the raw materials up or make them unavailable.
On the other hand a battery that better utilizes it's raw materials is to be welcomed because it uses fewer raw materials although it seems that the more efficient a battery becomes the greater it's safety risks and hence potential for widespread adoption.
EV cars will only be a practical alternative to good old gasoline when they can go as far as the driver can, so more like 1000 miles is needed than 300. Until then they will remain only a novelty, a city car for those that can afford to have multiple vehicles, and have enough money to not even care about the extra money spent to be using an EV. An EV has more in common with a boat or a motorcycle than a gasoline powered car. If Envia indeed lives up to it's claims, although I'll admit skepticisim, there certainly are a lot of other markets that would use this battery technology other than EVs, so I hope their business plan is not banking on EV sales to survive. As for the use of "biological batteries", we have that now, it is call a bicycle.
TJ - While the grid runs a little more to the edge in the northeast, line maintenance is a big cause of problems there.
Moving from Texas to Virginia 9 years ago, I was shocked at how poorly the line right-of-ways are maintained. Back home the power companies thought nothing of removing any trees even remotely threatening to lines; here they are content to carve a little path through the trees. The rest of the states up here are about the same.
The gyroscopic effect can be delt with by making the axis of rotation vertical. That allows you to drive in circles all day long. Gimbal mounting allows you to go up and down hills. San Fracisco would be an extreme case.
We have our own well. All the water that we use goes through a heat exchanger first. That is how I air condition our house. The slight increas in water temperature keeps the plumbing from sweating and it also takes some of the load off the water heater.
Around 1950 there was a flywheel powered bus, the Oerlikon Gyrobus. Also, the Joint European Torus at Culham Lab uses a huge flywheel, the peak pulse is not far off the whole UK National Grid power. Modern flywheel design is much faster, a light composite wheel with great tensile strength. If the axis is vertical with compliant mountings, gyroscopis moment is not problem. However I think the total energy storage is not that high.
My money would be on algae derived oil, produced in sunny places and easily stored and shipped using existing infrastructure. The CO2 from burning it has been absorbed from the atmosphere in growing it, so there is no net CO2 production.
If somebody figured out how to make an on-board fuel reformer that would convert fuel, butanol or ethanol for instance, into hydrogen, or make a fuel cell that efficiently used molecular fuel directly, you could have the advantages of our fuel infrastructure plus the advantages of electric cars. You could "gas" up at a service station in a few minutes with fairly safe, liquid fuel in a few minutes, and drive hundreds of miles.
This is a great development and will speed the day we can have a 'commuter vehicle' that is all electric.
As far as hydrogen infrastructure, that's the big problem. Fuel cells will NEVER work because of this. The dollars needed to build a hydrogen infrastructure would never be recovered. Hydrogen is a boondoggle that is used by politicians to distract from real solutions.
Far better to use a fuel for which the infrastructure exists now: Biodiesel. With new algal production methods, we could replace all of the liquid fuel needed for transportation in this country with biodiesel. The infrastructure exists, the engines exist. What we need is the political will. The EROI on biodiesel is very high and this combined with technologies like we see from Envia would make us energy independent within 5 years. The solutions are there. We are held back only by corporate and political manipulation.
Fly-wheels are a horrible idea. They are extremely heavy and if you move their axis of rotation even by a few degrees the amount of force exerted on the unit would tear it apart. Fly wheels were considered for trains that stop frequently. The idea was to store some of that energy on a flywheel and reuse it. Obviously even on its intended use it's still far-fetched. Water when in freezes it decreases in density causing it to burst most vessels it's stored in. Water is great energy storage for heating and cooling. Sun to water heat transfer can be 80%+ for heating and with water evaporative process an extremely high amount of heat can be moved with relatively cheap water pumps. HVAC power systems on the other hand are less than 10% efficient and the colder the process the less efficient. You are speaking about a system that is barely 2-5% efficiency. Batteries on the other hand can have efficiency of between 30-70%.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.