cwerdna
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Rocky Mountain Institute and Evgo fleet and tariff analysis (relates to DC FCing)

Tue Apr 11, 2017 10:45 pm

Thanks to a post on https://www.facebook.com/groups/rav4ev/, from http://www.rmi.org/Press%20Releases press release at http://www.rmi.org/Content/Files/EVgo_p ... e_2017.pdf.

Report at http://blog.rmi.org/Content/Files/eLab_ ... s_2017.pdf.

Excerpt of press release
RMI Publishes Report with EVgo on Utility Rate Structures to Support
Growth of EV Fast Charging
Los Angeles and Boulder, Colo., April 11, 2017 – EVgo, the nation’s largest public electric vehicle (EV)
fast-charging network, and Rocky Mountain Institute (RMI) have released a report regarding the future
of EV fast-charging utility rates. The report, titled EVgo Fleet and Tariff Analysis, found that public fast-charging
infrastructure is critical to EV deployment; however, California’s state legislators and regulators
must make future adjustments to allow for more cost-effective fast-charging services. More cost-effective
utility rates ultimately will help support the state’s efforts to move toward an electrified
consumer vehicle fleet and simultaneously cut emissions.
...
RMI’s study found that, under certain electricity tariffs, current demand charges can make up as much
as 90 percent of the monthly bill of operational public DC fast chargers, driving the cost of delivered
electricity as high as $1.96 per kilowatt-hour (kWh) during summer months in some locations. These
charges are nearly seven times as high as the current gasoline equivalent cost of $0.29/kWh, meaning it
is difficult for DC Fast charging providers like EVgo to remain competitive with the costs of operating
petroleum-fueled vehicles.

'13 blue Leaf SV w/premium package (owned)
'13 blue Leaf SV w/QC + LED & premium packages (lease over, car returned)
'06 Prius

SageBrush
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Re: Rocky Mountain Institute and Evgo fleet and tariff analysis (relates to DC FCing)

Wed Apr 12, 2017 12:19 am

Enter stage left: Tesla batteries
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Bought off-lease Jan 2017 from N. California with 63.9 Ahr after 22k miles
Car is now enjoying an easy life in Colorado

alozzy
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Re: Rocky Mountain Institute and Evgo fleet and tariff analysis (relates to DC FCing)

Wed Apr 12, 2017 12:21 pm

I've often wondered if a high rpm (100k +) carbon fiber flywheel, combined with an EVSE, could be a way to supplement the peak output. I don't think there's enough kinetic energy in a flywheel to last for a full half hour charge, but it could still help.

The EVSE enclosure would include an electric motor that slowly accelerates the flywheel whenever the EVSE is idle, so it's ready to add energy for the next charge cycle.
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
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GRA
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Re: Rocky Mountain Institute and Evgo fleet and tariff analysis (relates to DC FCing)

Wed Apr 12, 2017 5:27 pm

Cheap storage is likely to be critical to profitable DCQCs, unless the utilities themselves are allowed to operate them.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

GRA
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Re: Rocky Mountain Institute and Evgo fleet and tariff analysis (relates to DC FCing)

Wed Apr 12, 2017 6:48 pm

From page 19 of the report, under Recommendations:
It is clear from our analysis that demand charges, more than other rate components, are the primary reason why it is
economically challenging to operate public DCFC profitably in California
. As our analysis of chargers on the SDG&E ALToU
Commercial rate clearly demonstrates, demand charges make up the vast majority of the bill, regardless of the
charger’s utilization
. The fact that the proposed new EV-specific tariffs eliminate demand charges for a period of time, or
for “Option R” charger installations, which also feature on-site renewable energy generators, indicates that the utilities
understand this issue.

Switching to the proposed SDG&E and SCE tariffs that rely on dynamic adder charges rather than more conventional
demand charges seems to solve many of the problems inherent in the existing tariffs. These new tariffs better align the
utility costs with charges paid by EVgo, and could produce a fairer outcome in which it is possible for DCFC operators like
EVgo to obtain a flatter, more predictable cost structure.

The question that remains is whether or not the new tariffs that the California IOUs have proposed can enable a profitable
business for public DCFC charging companies
, and whether there may be alternative approaches to rate design that would be more attractive. . . .
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

alozzy
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Re: Rocky Mountain Institute and Evgo fleet and tariff analysis (relates to DC FCing)

Wed Apr 12, 2017 11:42 pm

Looks like a commercial product is already in the works that incorporates flywheels with EVSEs to reduce demand load on the grid and the accompanying fees:

https://media.wix.com/ugd/56cf92_27c5e7 ... ab166f.pdf
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
1-1/4" Curt #11396 hitch
After market, DIY LED DRLs
LeafSpy Pro + Konnwei KW902 ELM327 BT OBDII dongle
Loving my first BEV :D

VitaminJ
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Re: Rocky Mountain Institute and Evgo fleet and tariff analysis (relates to DC FCing)

Thu Apr 13, 2017 11:32 am

SageBrush wrote:Enter stage left: Tesla batteries

Yep just put a battery buffer in the DCQC. The local electric go-kart track does this, they have charging stations for their karts which have a big battery in them. The storage battery charges up slowly while the kart is not being charged or out on the track, then when the kart needs to be charged up quickly for the next race, the charging station dumps it's stored charge into the kart all at once, and then goes back to filling itself up slower from the grid.
2013 Ocean Blue SV w/ QC and LED
- +0.2 mi/kwh Aeromods
- Leaf Box
- 2lb 5Ah LiFe 12v battery

alozzy
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Re: Rocky Mountain Institute and Evgo fleet and tariff analysis (relates to DC FCing)

Thu Apr 13, 2017 11:43 am

Image

Supplementing EVSEs with flywheels seems like a more long term, environmentally friendly solution to me
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
1-1/4" Curt #11396 hitch
After market, DIY LED DRLs
LeafSpy Pro + Konnwei KW902 ELM327 BT OBDII dongle
Loving my first BEV :D

VitaminJ
Posts: 358
Joined: Tue Jan 03, 2017 11:46 am
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Re: Rocky Mountain Institute and Evgo fleet and tariff analysis (relates to DC FCing)

Thu Apr 13, 2017 11:51 am

Interesting table. I wonder how they plan on building a flywheel that can store energy for hours and still be "totally green." No high strength alloys? No carbon fiber or resins? No precision machining required? Where did you get that from?

And check out these "flow batteries" with a liquid electrolyte that has 0 degradation with age. It can also be used from 100% to 0%, full depth of discharge.

https://www.youtube.com/watch?v=4OHstY_kKUY
2013 Ocean Blue SV w/ QC and LED
- +0.2 mi/kwh Aeromods
- Leaf Box
- 2lb 5Ah LiFe 12v battery

alozzy
Posts: 601
Joined: Fri Jan 20, 2017 4:25 pm
Delivery Date: 18 Jan 2017
Location: Vancouver, BC
Contact: Website

Re: Rocky Mountain Institute and Evgo fleet and tariff analysis (relates to DC FCing)

Thu Apr 13, 2017 1:08 pm

I referenced the source in a PDF URL above.

This is just one commercial example I found, another is Stornetic.

This NASA video gives a good overview of the concepts, although it doesn't get into details about RPM, diameter of the flywheel, weight, power generation, etc:

https://www.youtube.com/watch?v=mz_7UF4KQpk

This one is decent too:

https://www.youtube.com/watch?v=eCtlfj4kMJs

Flywheels are an ancient technology, but adding a vacuum sealed chamber, a strong carbon fiber rotor, and magnetic levitation for near zero friction makes them a very interesting energy storage solution.

Specifically for DCQC providers, marrying an EVSE to a modern flywheel design might allow them to avoid a lot of demand charges as EV charging seems like an ideal fit for that - short peaks of demand followed by periods when the flywheel can be "energized" for the next charge cycle
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
1-1/4" Curt #11396 hitch
After market, DIY LED DRLs
LeafSpy Pro + Konnwei KW902 ELM327 BT OBDII dongle
Loving my first BEV :D

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