Demand Charges, storage costs and Public DCQC

[WetEV]

Not nerfing.

I don't see how that reduces demand charges per hour charging unless you are advocating congestion as a solution.

Congestion happens, is part of a reasonable cost solution, and needs to be accounted for. If there isn't congestion on the busiest hour of the busiest day of the year, you have chargers that are sitting unused all the time.

The 50kW cars don't need to pay for 150kW demand charges, only for 50kW demand charges. Also, a 50kW charger is cheaper to buy and install than a 150kW. Consider two different installations:

1) 3 50kW chargers, and 3 150kW chargers

vs

2) 4 150kW chargers.

Total demand charges are the same for the site, if 100% use is hit just once during the month. And yes, hitting 100% probably means congestion will happen. If there is a significant number of 50kW cars then they can use the slower and cheaper 50kW units. If more than 3 150kW cars are there at once, they have a fallback of a slower charge rate, which I would usually think would be better than nothing.

If I needed to add 50kWh or more to a car while I was eating dinner, a slower charge rate would be better.


I wonder if EA made a mistake by not installing 2 or 3 50kW chargers at each location. Perhaps not as well, as perhaps the slow rate in the future will be 150kW and the fast rate will be 350kW.

 

[SageBrush]

I don't see how that reduces demand charges per hour charging unless you are advocating congestion as a solution.

Consider two different installations: ...

I agree that advantages exist in your suggestion, but if I am thinking about this right a reduction in demand charges is not one of them unless you leverage congestion. And there is a definite downside to your suggestion, since it lets people cherry pick their charge rate and increase the likelihood and time that the higher rate charger will be unprofitable or high priced. If the intent is to accelerate the EV transition and encourage vendors to place high kW chargers, that is not the way to go about it.

 

[WetEV]

If the intent is to accelerate the EV transition and encourage vendors to place high kW chargers, that is not the way to go about it.

Why would a range of charging speed options slow the EV transition? I guess I don't see that.

Charge time of overnight meaning something like L2, 240V 40A or 9.6kW would be a nice option at hotels. Maybe a bit more as battery sizes increase. Figure on 10 hours (sleep, breakfast, etc) typical and wanting to get at least 80% of the battery charged: 200kWh batteries would want close to 19.2kW, the J1772 maximum.

Charge time of an hour or so meaning 50kW or again a bit more in the future would be a nice option for longer stops like dinner.

Charge time as fast as realistic meaning near 350kW sustained for most of the SOC would be nice for quick stops. Not even the Porsche Taycan does that, yet.

Source https://www.taycanforum.com/forum/threads/first-350kw-ea-charge-experience-connection-success-but-slower-than-expected.2854/

350kW is the CCS limit as of now. Perhaps somewhat faster will be possible in the future.

 

[SageBrush]

Why would a range of charging speed options slow the EV transition? I guess I don't see that.

I was only thinking about the case of mixing 150+ kW and 50 kW DCFC in the same location with different per minute usage rates.

 

[WetEV]

So what are the economics of storage added to a DCQC?

Batteries cost money. As does the power conversions to convert AC to DC to charge the battery, and DC to likely DC to discharge the battery and charge the car.

An interesting upcoming project is the Guemes Island Ferry. I've yet to make it to Guemes Island, but it sounds like an interesting vacation spot, and a fair number of people live on the island.

https://www.guemesislandferry.com/

This is an old diesel ferry that needs replacement.

https://www.goskagit.com/news/local_news/county-receives-1-million-for-electric-ferry-charging-equipment/article_11e54408-0c0d-5ec8-9efc-7eebfed5a3fb.html

So here is the design problem. What is the minimum cost design for charging equipment?

Demand charges on Schedule 26.

https://www.pse.com/-/media/Project/PSE/Portal/Rate-documents/Electric2/elec_sch_026.pdf?sc_lang=en

The designs presented have battery storage at the terminal, so the power draw can be managed.

 

[jlv]

I've met people who have used their DC FC inlet on their Leaf 0 times or a minimal # of times spread out over years. Turbo3 (Leaf Spy author) on his '11 Leaf when I spoke to him a few years ago I think said he'd used it like 5 times.

Early on I used the CHAdeMO in my LEAF to try to extend my range to the greater Boston area (e.g., for 100 mile round trips). It was mostly a disaster, since the often-broken CHAdeMOs that existed around this area in 2015 were unreliable. Later on, I only used the CHAdeMO for some free range from the Nissan dealer when I was shopping at the Home Depot across the road.

Thus, people not using the DC FC on a LEAF or a Bolt don't surprise me at all. Those aren't cars people buy to take trips in. Be careful of selection bias.

These days, I use the DC FC on my cars all the time. Frequent 200 mile (one way) trips to ME. This week we're heading out to Buffalo (450 miles one way) for the first time since the pandemic struck.

Or I can look at my brother-in-law, who lives in Portland, OR. He had a LEAF since 2011 and replaced it with a Bolt in 2016. Neither car went far out of town (mostly because I don't think my sister liked traveling in either car). Last year he replaced the Bolt with a Model Y. Since then they've been on several multiday road trips of 200+ miles and are planning a trip to the Idaho border for next month.

 

[WetEV]

Thus, people not using the DC FC on a LEAF or a Bolt don't surprise me at all. Those aren't cars people buy to take trips in. Be careful of selection bias.

I didn't buy a LEAF to make trips in.

I ended up taking a lot of trips in the LEAF. Comfort, quiet, and the local DCQC was sufficient with planning. And destination charging to fill gaps.

 

[jlv]

I didn't buy a LEAF to make trips in.

Nor did I. Just like I said, "Those aren't cars people buy to take trips in."

 

[cwerdna]

I've met people who have used their DC FC inlet on their Leaf 0 times or a minimal # of times spread out over years. Turbo3 (Leaf Spy author) on his '11 Leaf when I spoke to him a few years ago I think said he'd used it like 5 times.

Early on I used the CHAdeMO in my LEAF to try to extend my range to the greater Boston area (e.g., for 100 mile round trips). It was mostly a disaster, since the often-broken CHAdeMOs that existed around this area in 2015 were unreliable. Later on, I only used the CHAdeMO for some free range from the Nissan dealer when I was shopping at the Home Depot across the road.

Thus, people not using the DC FC on a LEAF or a Bolt don't surprise me at all. Those aren't cars people buy to take trips in. Be careful of selection bias.

These days, I use the DC FC on my cars all the time. Frequent 200 mile (one way) trips to ME. This week we're heading out to Buffalo (450 miles one way) for the first time since the pandemic struck.

Or I can look at my brother-in-law, who lives in Portland, OR. He had a LEAF since 2011 and replaced it with a Bolt in 2016. Neither car went far out of town (mostly because I don't think my sister liked traveling in either car). Last year he replaced the Bolt with a Model Y. Since then they've been on several multiday road trips of 200+ miles and are planning a trip to the Idaho border for next month.

As for selection bias, I had an ICEV (now former 06 Prius) alongside my previous Leaf (with CHAdeMO), current Leaf (no CHAdeMO) until end of Jan 2019, when I got my Bolt. It's not like I went on a lot of road trips. As I said, my last one was in mid-2017. It's not like it was something that had been planned in a big way. A college classmate unexpectedly died and I was attending her funeral in So Cal + doing a bit of sightseeing in LA. I only found out about her passing maybe a day after it happened. I had no warning/idea she was having health problems (specifically cancer that killed her). I had that (now former) Prius from Jan 2016 until end of Jan 2019.

Where would I go on such road trips? My current work keeps me quite busy and the WFH COVID situation, some people on paternity leave and weekly time critical commitments for work, I find it impossible to take more than 5 or 6 days off at time except during December (when those commitments are on pause due to the company itself basically going on pause).

Driving to LA is over 330 miles one way and is pretty tiring to drive solo. It is just a 1 hour flight away. Driving to Vegas is over 500 miles, one way and is very tiring to drive solo. It is only a 1.5 hour flight.

FWIW, I had considered wanting to go to LA in Dec 2020 but due to COVID and the situation being VERY bad in LA at that time, there was no point in going. Nobody was vaxxed yet, infection rate and hospitalizations were very bad and everything would be closed anyway.

 

[SageBrush]

JLV and Cwerdna, what do your personal testimonials have to do with the thread topic ?

 

[cwerdna]

Mod and Cwerdna, what do your personal testimonials have to do with the thread topic ?

Was in reply to the below:

A big part of the reason to spend more money on an EV is to gain faster charging.

For some people. For others, it doesn't enter into the equation at all, or is a minor consideration.

Seemed to be of little to no importance for Leftie. I outlined my cases + that of many other people at https://mynissanleaf.com/viewtopic.php?p=604770#p604770.

$12K+ is enough to pay for lots of 1 to 1.5 hour flights, rentals cars and gas. And, that much costlier car is missing things I do use on my Leaf and Bolt (and n/a even as an option) + has numerous things I DO NOT want (e.g. glass roof).

 

[SageBrush]

Mod and Cwerdna, what do your personal testimonials have to do with the thread topic ?

Was in reply to the below:

A big part of the reason to spend more money on an EV is to gain faster charging.

For some people. For others, it doesn't enter into the equation at all, or is a minor consideration.

Seemed to be of little to no importance for Leftie. I outlined my cases + that of many other people at

I refer you to the thread topic. NEVs and CEVs (aka local EVs and city-wide EVs) are irrelevant to the topic. Lefty was saying that people spend big bucks for NEVs. I don't doubt at least 6 such people exist. For everybody else who wants an EV to take trips in, either they know before-hand or learn fast enough that DC charging under 75 kW is a drag. This is relevant to the topic because it touches on demand charges. I bought a Tesla, and I suspect part of the reason that WetEV paid a lot for his E-tron, is to have a general purpose EV that is good for long trips. If either car had 50 kW or 75 kW charging the car value would have been markedly diminished.

This is all fodder for my contention that installing 50 kW chargers alongside 150+ kW chargers is not a good idea, in the sense that it will result in more expensive 150+ kW charging due to related demand charges. WetEV is not wrong in thinking that a rapid expansion of 150+ kW EVs will at least partially solve the current widespread problem of high demand charges for few users.

 

[DougWantsALeaf]

I know this is a little off the core topic, but I would certainly rather have more 50KW chargers than fewer 150KW or very few 350KW chargers until the high end chargers fall to more commodity prices. Thus is both for congestion and fail over concerns when going cross country. I give Tesla credit as they have spent the money to kind of do both.

I personally believe that once every highway stop has 3-4 DC choices like they have gas stations today, even if only 50KW in speed, it would ease most fears for most converting ice drivers.

It feels like the commodity point today with DC chargers is in the 200amp space. When you factor in the cost to wire up.the power, permits, etc. It feels like the difference in a 125 amp or 200 amp capable DC stop is fairly small now.... but I don't know that with any certainty.

 

[LeftieBiker]

NEVs and CEVs (aka local EVs and city-wide EVs) are irrelevant to the topic. Lefty was saying that people spend big bucks for NEVs. I don't doubt at least 6 such people exist.

Go ahead and be dismissive of other peoples' arguments, without supporting facts. It diminishes the respect you get, and it certainly doesn't make you popular, but it makes you feel superior and that seems to be what counts for you. The user filter is designed in part for this kind of scenario. I'm going to, once again, avail myself of that feature.

Sagebrush has incorrectly labeled EVs not used for longer trips as "Neighborhood Electric Vehicles." They are that only when their top speed is limited to no more than 25MPH.

 

[SageBrush]

I know this is a little off the core topic, but I would certainly rather have more 50KW chargers than fewer 150KW or very few 350KW chargers until the high end chargers fall to more commodity prices. Thus is both for congestion and fail over concerns when going cross country. I give Tesla credit as they have spent the money to kind of do both.

I've read that EA paid through the nose for its DCFC location installations but that may not reflect much more than gouging EA. Back in the day of the 150 kW Supercharger, Tesla said it costs them ~ $200k per 8 charger location. I have not read any updates on the 250 kW variety they are installing nowadays. However, if you go back in this thread to my PNM rate schedule link, you will see that the demand rate for a BIG feed (IIRC 8 MW) is not more expensive that under 1 MW. The only difference is the minimum charge.

If the Tesla cost reports are indicative then demand charges dwarf installation costs.

 

[GerryAZ]

Demand charges depend upon the rate structure. As an example, I have two different rate structures from the same utility (residential for my house and commercial for my workshop/garage). The demand charge at the house is based upon 1 hour peak during the month (on peak hours only). The demand charge (if I go above the 20 kW threshold) at the garage is based upon 15 minute peak anytime during the month. With a 15-minute peak for commercial and most charging sessions lasting longer than that, the demand charge will likely be equal to the maximum that a charger can supply so there needs to be a lot of use during the month to amortize that charge over enough cars to make it cost effective. If a location has several chargers of various size, it will probably be supplied from a single meter so the demand charge would be the highest 15 minute period during the month (likely equal to all units on at the same time). Therefore, fewer units with higher utilization rate will result in the least monthly cost and least cost per charging session. Tesla has an advantage with many of their stations having solar panels so they can offset some of the charging cost by selling power to the utility when cars are not charging and reducing demand charges when cars charge during daylight hours.

I am another EV driver who has no intention of taking long trips using DCQC. I have a total of 12 QC sessions on my 2019 SL Plus after 21 months and over 30k miles of driving. Some of those could have been avoided by charging at home in preparation for trips across the metro Phoenix area, but I was experimenting to see peak charge rates and charge tapering related to temperature and charging station. Some of the charging stations I used dropped the charge rate to below 20 kW after about 15 minutes (I suspect to minimize demand charges) even though the per minute rate I was charged did not drop. I now avoid those stations, if possible, when I do choose to use DCQC. It goes without saying that charging at home during off peak time is much less cost than DCQC and that is part of the reason I chose the Plus with its larger battery and longer range (minimize the need to use DCQC).

 

[GetOffYourGas]

Lower power services avoid demand charges with the trade of higher per-kWh rates. Many new residential meters are going in with 300A service, which is nominally 72kW, and they don't have demand charges attached. So clearly a 50kW charger could be installed on such a service. I think this is the advantage of 50kW chargers. If you expect low utilization, this might be the right solution. And if it really is low utilization, then there aren't as many users to be annoyed at the slow rate.

 

[WetEV]

Lower power services avoid demand charges with the trade of higher per-kWh rates. Many new residential meters are going in with 300A service, which is nominally 72kW, and they don't have demand charges attached. So clearly a 50kW charger could be installed on such a service. I think this is the advantage of 50kW chargers. If you expect low utilization, this might be the right solution. And if it really is low utilization, then there aren't as many users to be annoyed at the slow rate.

50kW or less has no demand charge. If in remote place, a 50kW unit would look fairly nice.

Or battery storage. With the same feed, higher power and/or more stations could be supplied for a fraction of the time.

 

[SageBrush]

50kW or less has no demand charge.

I think that varies by utility, whether it is a business, and monthly volumetric and load data.
And at best it serves ONE slow DCFC

 

[salyavin]

I agree on storage particularly for rural. Charge it at 50kw and maybe solar as well and discharge at some faster rate say 150kw. In a heavily used area the storage would get depleted but not in the middle of Wyoming I would think. In a depleted situation I guess you would just drop to 50kw.
Another thing I like about storage is you may not have to run lines out there at all depending in climate and just charge the battery off solar like those new portable solar l2 stations from Jeep / EA (we have one over in Moab for whatever reason) with a large enough battery and inverter and low enough usage you could probably output >50kw but you could only handle a small number of vehicles. Useless if covered in snow.