Re: Musk obviously has staff to pay his bills and thus never actually sees them ...
"@Naughtyhorse - you seem to be majoring in stupid yourself, and providing no evidence to the contrary. The difference in power draw between peak and off peak is well documented at over 50,000MWh, using 1/3rd of that for 8 hours per day (overnight, off peak) would be enough to drive over 30% of the cars in the country."
Cept of course you cant determine when people will run out of juice (it's kinda the point of the whole article, you know if you read the words!) so by your measure when your tesla goes flat, you have to park up until around 23:00 then fill up with off peak amps. What a cool idea! CONGRATS etc etc you just made noddy cars an even worse idea!
"DC power lines have been in use since the 1930's when the Swedes worked out how to do what Edison couldn't. There's nothing new or magical about them, we use them to transfer power between France and the UK, and between the UK and Ireland."
DC power lines have been in use since considerably before 1930 - by roughly 50 years! yes we use them to control transfer of power internationally - but (read my post) it is only economic if you are transferring MASSIVE amounts of power from 1 point to one other point - or interconnecting 2 grids that fun at different frequencies, or are not in phase and cannot be practically synchronised. Not from 1 point to many (you have to build a lot of substations) for DC this is vastly more expensive than AC. you can't charge a car at transmission voltages (due to insulation issues), and you cant efficiently transmit at charging voltages (due to I squared R issues - z0 may be lower, but it aint zero) so you need to 'transform' voltages - for this you need a transformer :-), sadly they only work with AC, so you take your transmission level DC, chop it to AC (you use a ton of REALLY expensive thyristors to do this) transform the ac down to a charging voltage, and rectify that (admittedly using cheaper thyristors this time - just a few tens of thousands of dollars) and you add in a shedload of reactive compensation to deal with all the narsty harmonics this generates. (this is what we had to do in Qatar when i built one of these a few years back - so just maybe i might have the vaguest inkling as to what i am on about)
"Feeding power back in to the grid is also a well known technology, it is used by owners of PV panels for example. The idea of EV drivers setting an amount of power they can afford to return to the grid and getting a higher rate for that is far from fanciful."
Okay, we'll ignore the protection issues this raises, like the UK regulator :-), plus it really would take me too long to explain. take it from me it is a VERY BAD THING! something we will all get to appreciate in a few years time, when network availability drops through the floor. due to the massive drop in fault tolerance introduced into the system.
Yes it is entirely technically possible to do this, if ill advised, given the assumptions on load flow that underpin all current (lol i made a pun!) protection schemes. What is so outrageously stupid about this suggestion is;
current and foreseeably projected EV projects are all on a knife edge regarding the amount of per stored in the batteries. The idea that people in any significant numbers will have sufficient quantities of power to consider returning any to the grid is laughable. And you know those uber expensive dc-dc substations i told you about - you just made them a shitload more expensive (metering CT's and comms equipment).
technically when the price of gas goes up a cent overnight, i could go down to the gas station and sell the petrol out of my tank back to them, and make a tidy profit!
now i wonder why THAT never happens?