General > General Technical Chat
“Battery EV” vs “Hydrogen Fuel cell EV”
<< < (8/68) > >>
Marco:

--- Quote from: nctnico on November 12, 2021, 02:41:02 pm ---No. You'd need 30% to 40% of the parking spaces

--- End quote ---

If our government had been pro-active and nationalized the fibre installation and combined it with charging installation even 100% would have been relatively cheap. If the sidewalk is opened up any way, installing a power cable and concrete pits every 5 meter with a power connection into which charging points can be installed at some future date costs basically bugger all. Then you can slowly build out the charging infrastructure, all the way upto 100%, just by lifting pavers and putting a charger in the pit.

Shoulda, woulda, coulda.
tom66:

--- Quote from: nctnico on November 12, 2021, 02:41:02 pm ---
--- Quote from: tom66 on November 12, 2021, 01:09:53 pm ---For charging on the street, a typical EV with a 40kWh battery will need to charge about once a week to cover commuting uses.  So we do not need a density of chargers to match the number of cars. What we do need is dedicated on-street parking bays with EV chargers, about 10-20% of all spaces on a given street should consist of these.

--- End quote ---
No. You'd need 30% to 40% of the parking spaces AND solve the problem that people don't occupy a charging point unnecessary. Are you going to wake up at 3:00 in the morning to move your car so the beighbours can charge theirs? The reality is that the current BEVs are not yet evolved to a point where they are real alternatives for cars that run on fuel or hydrogen. It takes another revolution in battery technology to increase the capacity / weight ratio and charge speed. The only charging infrastructure that makes sense financially due to resource sharing is to have superchargers like/at gas stations and charge there within a few minutes. Charging at home / in the street is a temporary crutch and will dissapear again after 10 to 20 years from now.
--- End quote ---

Don't know where you get 30-40%, even 20% would be on the high end.

Average odo for someone in Europe is 12,000 km/year (7,500 mi/year.)  Average EV gets about 4-5 km/kWh,  say 4 km/kWh to be a pessimist.  An on-street charger can manage 7kW.  So for a year's charging you need 3,000 kWh or 428 hours of charging.  There are about 8,700 hours in a year, so the average EV needs to spend about 5% of its life plugged in.  And since cars spend about 95% of their time parked, it seems crazy to say that there wouldn't be a time in that 95% where the car could not be charged (and only half of those need to be at public chargers, because the other half will charge their majority of electrons at home.)

The big challenge is making sure everyone doesn't hog the resources e.g. at night, so you'd want to scale the resource by 2x or so, to account for peak time usage (getting home at 6pm and looking for a charger.)  Plus you'd want workplace chargers, supermarket chargers, gym chargers, etc. so that people can opportunity-charge whenever their car is parked up.  The 12,000km/year usage would use about 8.2kWh/day, so Monday-Sunday uses 41kWh.  Are we really saying in that time that no one could spend 5 hours of that week with their car hooked up?  I don't believe it.  All a matter of making sure that people can opportunity-charge.
rstofer:

--- Quote from: nctnico on November 12, 2021, 03:09:02 pm ---@Wraper: You are making the mistake assuming that everyone has a driveway AND wants to plug in the car every time they park it / enjoy unplugging it before use.

--- End quote ---

Oddly, that's exactly what I do and have done so for the last 8 years.  A partially charged battery is, well, partially charged - kind of range limiting.
rstofer:
I have yet to see an EV alongside the road with a dead battery.  Yes, range anxiety is a real thing but it can be handled.  I recently gave away my Chevy Silverado (pickup truck) and now the two of us share the EV.  Somehow, it all works out.  There is something of a requirement that a retired EE drive an EV.  There's so much magic in these vehicles!

Covid has had some offshoots:  Everything we need is delivered.  Fast food, groceries, beer...  The delivery charge is worth it to me just to avoid having to walk through some of the grocery mega-stores.  Even Costco delivers and that's usually a really big deal.  Worth every dime to have somebody else fill the cart, pass through checkout and deliver it to my doorstep.
rstofer:

--- Quote from: tom66 on November 12, 2021, 03:45:44 pm ---
--- Quote from: nctnico on November 12, 2021, 02:41:02 pm ---
--- Quote from: tom66 on November 12, 2021, 01:09:53 pm ---For charging on the street, a typical EV with a 40kWh battery will need to charge about once a week to cover commuting uses.  So we do not need a density of chargers to match the number of cars. What we do need is dedicated on-street parking bays with EV chargers, about 10-20% of all spaces on a given street should consist of these.

--- End quote ---
No. You'd need 30% to 40% of the parking spaces AND solve the problem that people don't occupy a charging point unnecessary. Are you going to wake up at 3:00 in the morning to move your car so the beighbours can charge theirs? The reality is that the current BEVs are not yet evolved to a point where they are real alternatives for cars that run on fuel or hydrogen. It takes another revolution in battery technology to increase the capacity / weight ratio and charge speed. The only charging infrastructure that makes sense financially due to resource sharing is to have superchargers like/at gas stations and charge there within a few minutes. Charging at home / in the street is a temporary crutch and will dissapear again after 10 to 20 years from now.
--- End quote ---

Don't know where you get 30-40%, even 20% would be on the high end.

Average odo for someone in Europe is 12,000 km/year (7,500 mi/year.)  Average EV gets about 4-5 km/kWh,  say 4 km/kWh to be a pessimist.  An on-street charger can manage 7kW.  So for a year's charging you need 3,000 kWh or 428 hours of charging.  There are about 8,700 hours in a year, so the average EV needs to spend about 5% of its life plugged in.  And since cars spend about 95% of their time parked, it seems crazy to say that there wouldn't be a time in that 95% where the car could not be charged (and only half of those need to be at public chargers, because the other half will charge their majority of electrons at home.)

The big challenge is making sure everyone doesn't hog the resources e.g. at night, so you'd want to scale the resource by 2x or so, to account for peak time usage (getting home at 6pm and looking for a charger.)  Plus you'd want workplace chargers, supermarket chargers, gym chargers, etc. so that people can opportunity-charge whenever their car is parked up.  The 12,000km/year usage would use about 8.2kWh/day, so Monday-Sunday uses 41kWh.  Are we really saying in that time that no one could spend 5 hours of that week with their car hooked up?  I don't believe it.  All a matter of making sure that people can opportunity-charge.

--- End quote ---

Opportunity charging at a supermarket or other public place also makes you a target for <insert something bad here>.  I can see places of employment because many are behind fences but I'm certainly not going to charge right next to an ATM machine.

Were I still working, I would have been the guy building out multiple charging stations for our employees.  As we were essentially an engineering division of some 10,000 employees (far less in later years), how many stations would I need?  10% of current headcount?  We had enough incoming power (115kV 28MVA easily) but I would have had to dig up a lot of pavement to get the 12kV over to a dedicated substation (or several) to provide 240V for the chargers.  It would have been a monster project but the company would have just considered it a cost of doing business.  Charging would have been free.  I don't know what it might cost but I know I would take a flogging every day for a) it isn't done yet and b) it costs too much.  Such is the life of a project manager.

I suppose we could play 'musical plugs' and require employees to share time on the charger but these folks cost a LOT of money.  We wouldn't even consider it!

All of that charging would be during 'on peak' hours...
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod