Sponsored

800V fast charging discussions

OP
OP

ajdelange

Well-Known Member
First Name
A. J.
Joined
Aug 1, 2019
Threads
9
Messages
2,883
Reaction score
2,317
Location
Virginia/Quebec
Vehicles
Tesla XLR+2019, Lexus, Landcruiser, R1T
Occupation
EE Retired
Didn't realize there was one in Virginia, where's it located?
Bath County

Our engineering company did an interesting one-off project for someone who is truly independently wealthy. He has a remote camp in the upper midwest with a large manmade fishing lake. We installed an off the grid solar/hydro system that pumps water into the lake during the day, and generates power via hydro at night.
How cool is that!
Sponsored

 

BigSkies

Well-Known Member
First Name
Brian
Joined
Sep 4, 2021
Threads
6
Messages
379
Reaction score
692
Location
Denver
Vehicles
R1T, Model Y
Clubs
 
Honestly, the best thing Rivian could do to improve charging speed (as measured in miles added per minute) would be to find ways to reduce the truck’s weight.
 
OP
OP

ajdelange

Well-Known Member
First Name
A. J.
Joined
Aug 1, 2019
Threads
9
Messages
2,883
Reaction score
2,317
Location
Virginia/Quebec
Vehicles
Tesla XLR+2019, Lexus, Landcruiser, R1T
Occupation
EE Retired
it's conceivable we could see pack voltages increase to 1000v - 1200v to support even higher charge rates that solid state batteries reportedly will support.
CHarIN evidently already has HPC500 and is evolving a 1500 V x 3000 A standard for trucks.
 

Trandall

Well-Known Member
First Name
Travis
Joined
Jan 13, 2021
Threads
2
Messages
1,128
Reaction score
2,064
Location
Upstate NY
Vehicles
Rivian R1T, 2023 Mach-E
Occupation
Construction Management
Some researchers in the Netherlands have what I think is a devilish clever new take on pumped storage. There is a rigid tank buried in the sea bed but open to surface pressure via a pipe. Above it on the sea floor is a flexible bladder. When there is excess generation (they are studying this for offshore wind) water is pumped from the tank to the bladder. When there is demand water from the bladder flows back to the tank through a turbine. Don't know whether this will pan out but I guess that's what the studies are to determine.
Learn something new here everyday. If their is anyone who knows hydrology it's the Dutch.
 

Sponsored

SeaGeo

Well-Known Member
First Name
Brice
Joined
Jan 12, 2021
Threads
47
Messages
5,235
Reaction score
9,677
Location
Seattle
Vehicles
Xc60 T8
Occupation
Engineer
Thus we see the main problem facing us is storage. Hydrogen in inefficient and batteries are still wicked expensive. Here in VA we are fortunate to have the particular geography to allow for a huge pumped storage facility (pump water from a lower reservoir to a higher one when there is excess and let it flow back when there is demand). It is one of few pumped storage facilities in the world because the geography doesn't exist in many places.

Some researchers in the Netherlands have what I think is a devilish clever new take on pumped storage. There is a rigid tank buried in the sea bed but open to surface pressure via a pipe. Above it on the sea floor is a flexible bladder. When there is excess generation (they are studying this for offshore wind) water is pumped from the tank to the bladder. When there is demand water from the bladder flows back to the tank through a turbine. Don't know whether this will pan out but I guess that's what the studies are to determine.
That's definitely clever!

Kauai has a (simpler) project for storing solar energy. The basically pump water uphill to a reservoir when they have excess energy, and then let it flow downhill when it's not sunny.

I'm guessing you've seen it, but energy vault is trying to make a business model of picking up blocks of stuff to store excess energy.
https://www.energyvault.com/
 
First Name
Nathan
Joined
Oct 19, 2021
Threads
0
Messages
18
Reaction score
15
Location
Idaho
Vehicles
Neon
Occupation
Employed
I'm sure there are additional safety challenges with higher voltage charging and battery storage in general. Don't really want the battery to arc weld my children into the frame in the case of an accident...
 

R1T7777

Well-Known Member
First Name
CaliSurfer
Joined
Oct 7, 2021
Threads
3
Messages
273
Reaction score
253
Location
Los Angeles
Vehicles
Chevy Bolt, Nissan Leaf
Occupation
Propagandist
What kills me in the end, even if we get to 350-400kw charging, as EVs become normal, the grid is not going to be able to absorb that type of random and unpredictable demand increase.

I guess that ties back into the chargers not being able to provide the power. Everyone will need onsite storage to smooth out the instant demand (with storage it could even be that the grid demand doesn't change, just redirects from the stationary battery to the vehicle).

But this requires a fundamental change in grid operations or charging infrastructure, or both, to fully support when evs become more widely adopted.
This is where used EV batteries could be used for on site storage to balance out peak loads.
 

JeremyP

Well-Known Member
Joined
Feb 27, 2021
Threads
5
Messages
254
Reaction score
428
Location
Grand Junction, CO
Vehicles
Toyota 4runner, BMW I3, preordered R1S
Occupation
Engineer
Xcel energy is looking at adding more pumped storage hydro about 1/2 hr from my house; its a lot of up-front cost but will last for years. Xcel has a similar system near Georgetown, Colorado that was built in 1967.

https://coloradosun.com/2022/01/24/unaweep-canyon-hydro-power-xcel/

That's definitely clever!

Kauai has a (simpler) project for storing solar energy. The basically pump water uphill to a reservoir when they have excess energy, and then let it flow downhill when it's not sunny.



I'm guessing you've seen it, but energy vault is trying to make a business model of picking up blocks of stuff to store excess energy.
https://www.energyvault.com/
 

kylealden

Well-Known Member
First Name
Kyle
Joined
Feb 25, 2021
Threads
20
Messages
1,393
Reaction score
4,254
Location
Seattle
Vehicles
Rivian R1T LE, Tesla Model Y, Zero DSR/X, '69 CJ5
Occupation
Product Management
If I'm reading the thread right, the biggest thing holding the Rivian back from, say, 350kW charging is the amperage limit on the CCS standard itself.

Is it likely that the RAN chargers will simply exceed that amperage limit (ala v3 Superchargers)? That could help explain the disparity between Rivian's fast charging claims and the observed peak rates.
 

Sponsored

Autolycus

Well-Known Member
Joined
May 2, 2021
Threads
14
Messages
2,030
Reaction score
3,116
Location
ATL
Vehicles
ICE only :(
The TVA also operates a pumped-storage plant near Chattanooga at Raccoon Mountain. It was built in the 1970s. They use it for load balancing rather than specifically as storage for renewable capture. It takes about 28 hours to fill the entire reservoir and it can produce 1652 MW for ~22 hours, so it's equivalent to ~36GWh of battery capacity? That's really big battery! :)
 
OP
OP

ajdelange

Well-Known Member
First Name
A. J.
Joined
Aug 1, 2019
Threads
9
Messages
2,883
Reaction score
2,317
Location
Virginia/Quebec
Vehicles
Tesla XLR+2019, Lexus, Landcruiser, R1T
Occupation
EE Retired
If I'm reading the thread right, the biggest thing holding the Rivian back from, say, 350kW charging is the amperage limit on the CCS standard itself.
Not really. It is the battery itself. It's (in the Large) a 135 kWh battery and to charge it at 350kW would be 2.6C which is too fast.

Is it likely that the RAN chargers will simply exceed that amperage limit (ala v3 Superchargers)? That could help explain the disparity between Rivian's fast charging claims and the observed peak rates.
Not likely, IMO. The way to charge the battery faster, given that they wanted to do that, would be to reconfigure it for charging per their patent application so that its charging load line reaches into the higher power portions of the HPC350 envelope. As configured now that load line starts at around 400 V and has a slope of probably .01 V/A so that at 500A it is at 450 V for 225 kW max. In the series configuration the load line would start at 800V and have a slope of probably 0.02V/A so that at 500A the voltage would be 900. This (450 kW) is more than an HPC350 charger can deliver but it is clear that this load line pierces the 350 kW hyperbola and that the battery, configured this way, could be charged at up to 350 kW.

I think it very unlikely that the RAN chargers will violate the CHarIN standards.
Sponsored

 
 




Top