EV Charging Power Factors

[FionaZuppa]

Swappable battery packs?

consumer handling of a ~50kAhr high voltage batt ?? it will not be feasible to have highly trained well paid "batt station" folks to swap out your EV batt, and a standard batt frame/size will likely never come as the makers compete for their customers.

swappable batts may have a economics issue. lets say all 250million vehicles use 1batt pack during sunlight hours, now for night all 250million need to be swapped. thats good, but come morning you now have 500million dead batt packs. you need at least 2x in-use batt packs to be able to rollover into the next day. so at any given time you need to charge 500million EV batt packs during the daytime !! run the math, thats surely is a problem for the grid even if you stagger the charging over a ~8hr day. all that is a 1:1 need, you need even more batt packs to account for batt pack failures, etc.

a post mentioned nuke power. that can add some dwell time to allow physicists/chemists/engineers (<-- the folks who make stuff) to find a better solution. nuke power has limited uranium available. however, a tokamac is on the horizon , and as soon as tokamac comes online all of this solar batt talk will be dead.

 

[gadfly56]

consumer handling of a ~50kAhr high voltage batt ?? it will not be feasible to have highly trained well paid "batt station" folks to swap out your EV batt, and a standard batt frame/size will likely never come as the makers compete for their customers.

swappable batts may have a economics issue. lets say all 250million vehicles use 1batt pack during sunlight hours, now for night all 250million need to be swapped. thats good, but come morning you now have 500million dead batt packs. you need at least 2x in-use batt packs to be able to rollover into the next day. so at any given time you need to charge 500million EV batt packs during the daytime !! run the math, thats surely is a problem for the grid even if you stagger the charging over a ~8hr day. all that is a 1:1 need, you need even more batt packs to account for batt pack failures, etc.

a post mentioned nuke power. that can add some dwell time to allow physicists/chemists/engineers (<-- the folks who make stuff) to find a better solution. nuke power has limited uranium available. however, a tokamac is on the horizon , and as soon as tokamac comes online all of this solar batt talk will be dead.

Breeder reactors would cover it past the likely lifespan of technical civilizations on this planet. And/or thorium based liquid fluoride salt reactors. Back in the late 60's early 70's Oak Ridge had a demonstration reactor run for about 20,000 hours before the program was scrapped. Big plus for these is they could burn the high-level waste everyone is so worried about.

 

[FionaZuppa]

Breeder reactors would cover it past the likely lifespan of technical civilizations on this planet. And/or thorium based liquid fluoride salt reactors. Back in the late 60's early 70's Oak Ridge had a demonstration reactor run for about 20,000 hours before the program was scrapped. Big plus for these is they could burn the high-level waste everyone is so worried about.

... and put all the nukes where ?? coastlines are limited, and you unfortunately cannot protect them. recall that when oil dies so does aircraft unless a synthetic fuel can be engineered.

 

[gadfly56]

... and put all the nukes where ?? coastlines are limited, and you unfortunately cannot protect them. recall that when oil dies so does aircraft unless a synthetic fuel can be engineered.

Thorium reactors are walk-away safe.

 

[FionaZuppa]

Thorium reactors are walk-away safe.

no they are not. they have self melt-down controls, but that alone does not make them safe. an aircraft diving into one is an issue, etc.

and TH is also limited resource, but in breeders it could allow ~1k year period to make better solutions. this 1k year is only to replace electrical consumption. however, the existing write-ups from various univ's do not address the additional energy needed to make new products that will disappear when oil dies, etc.

but yes, agree, TH breeders is plausible.

 

[GeorgeB]

It's harmful to the battery to charge with ripple. It's only tolerated for engine starting battery charging since you don't charge those from AC on a regular basis.

I've not seen a new automobile with a GENERATOR in perhaps 50 years. 3 phase alternators are standard on everything but lawn-tractor type products and maybe small motorcycles which use the starter as a generator to recharge the battery.

Or is the point that ripple from 3 phase is low enough as to be insignificant?

 

[retirede]

I've not seen a new automobile with a GENERATOR in perhaps 50 years. 3 phase alternators are standard on everything but lawn-tractor type products and maybe small motorcycles which use the starter as a generator to recharge the battery.

Or is the point that ripple from 3 phase is low enough as to be insignificant?

I was thinking the same thing.

 

[FionaZuppa]

I've not seen a new automobile with a GENERATOR in perhaps 50 years. 3 phase alternators are standard on everything

 

[jaggedben]

And unaffordable. There is only so much cost savings to be had on scale up. It would be cheaper to buy an NG fueled whole house generator and run it when the sun doesn't shine than to get a large enough solar plant with backup batteries to manage the same feat.

It should be said that if the solar is installed primarily to be a grid-tied system then the additional cost of installing backup power using batteries is the cost that should be compared. No doubt what you say is still true, for now, leaving aside incentives.

 

[gadfly56]

It should be said that if the solar is installed primarily to be a grid-tied system then the additional cost of installing backup power using batteries is the cost that should be compared. No doubt what you say is still true, for now, leaving aside incentives.

Fair enough.

 

[Electric-Light]

I've not seen a new automobile with a GENERATOR in perhaps 50 years. 3 phase alternators are standard on everything but lawn-tractor type products and maybe small motorcycles which use the starter as a generator to recharge the battery.

Or is the point that ripple from 3 phase is low enough as to be insignificant?

Yep. Three phase rectified AC has significantly less ripple never drops to zero.

Charging from AC in the context of my earlier post; I meant using a portable charger to charge from a wall outlet. You only do this when you run into a problem of some kind. So those car battery chargers are usually just a transformer and diodes. This kind of charger will reduce battery life if you're charging things that are regularly charged from an outlet. So electric car charger would be expected to have a way of reducing ripple.

Getting close to 1.6kW of charging power available from a 20A and keeping battery ripple level under check at the same time means PFC is not option. Therefore, you can assume EV charger is nearly perfect PF.