80khw battery in an average model s * 300000000 million cars / (3,911,000,000,000 kwh energy use in the in all of 2015 [2] / 365 days per year) = 2.239 times as much storage in cars on the road versus energy usage which seems pretty doable. Also, it also gets better because as car batteries age and their storage / weight goes down, you can replace them with new ones and put the old ones in grid storage locations where weight / storage does not matter and run them till they are literally dead.

[1]: about a little less than 1 per person (just rough estimating here)

[2]: https://en.wikipedia.org/wiki/List_of_countries_by_electrici...

1. We need to eventually switch our winter gas heaters to electric which while helping balance summer vs winter electric usage, electric heating isn't as efficient and we have to increase the outside air a lot more in the winter than we have to cool it in the summer (for most people at least).

2. I forgot to add in the extra electric demand needed to power the cars which is currently powered by oil.

So, heat pump efficiency vs temperature only tells part of the story. With good insulation you will almost always need more cooling in the summer than heating in the winter outside of the arctic circle.

Ground source heat pumps have a typical efficiency of about 400%. You're moving heat from the ground to your house rather than heating up the air, so you get considerably more useful energy out of the system than you put in.

https://en.wikipedia.org/wiki/Geothermal_heat_pump

Ground heat-pumps are being championed as a cost effective replacement for keeping houses warm. They provide a 4:1 heat:electricity ratio so have lower running costs than gas. They can also be attached to sun panels and can work with storage heaters (heat the water when the sun shines, use it when it doesn't).

Unfortunately pumps are expensive and very invasive to install in existing houses - you need to dig gardens up to lay the pipes and installation for an average house is about 15-20k EUR ($17k-$23k).

(They’re special for several reasons. A big one is that they have huge thermal mass, so your heat pump can operate at whatever time of day you want. This means you can optimize for electric rates vs outdoor temperature. Heat pumps, unlike gas boilers, are considerably more efficient when it’s warm out.)

However, I do expect cost improvements. Even if the cost to make a battery is constant when measured in joules, PV is getting cheaper and can supply more joules for less money.

It's too far out to say if electric cars/dynamic grid/renewable energy will revolunatize our planets energy usage since we are very entrenched in the current system (and anyone claiming anything beyond 5 years underestimates how fast shit changes IMO) but I am seriously excited about these changes with how much the economics have been improving for a clean energy society.

While Apple Pay itself is only about four years old, contactless payment has been fairly standard in the UK for about 10 years, and chip and pin is over 20 years old.

[1] https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Sta...

In 2 decades there will be hundreds of millions of electric cars in the world which currently do not exist. This is a huge increase in battery power even with battery technology not changing in the next 2 decades.

I was more thinking along the lines of larger 'industrial' scale capacitors, but I'm not sure if there are fundamental barriers physical that can't be overcome to make such devices a sensible route to pursue?

Right, but our ingenuity and understanding of the physics may well not be perfect. Didn’t Moore’s law continue on well past it’s sell-by-date?

Our understanding of gravity is pretty much the same as Newton's in how we can utilize it. We know its not perfect but that doesn't change the reality. And ironically, battery chemistry is better understood than gravity.

I suspect anyone from Newton’s day would be surprised to see an A380.