California Supercharging cost goes up by 20%

[STS-134]

I work with government regulators as part of my job in various standards bodies, I assure you that is NOT how it works. They intentionally leave things a little vague, so they can come back and bite your head off. Doesn't matter how many or how few tiers you have. You can't say you are targeting a specific kWh rate, because that gives the impression that you are selling electricity.

In my experience, in the private sector it's about the letter of the law, not the spirit of the law. But in the public sector, it's the opposite.

Besides, you really want a table with 250 line items to display in the infotainment in the Tesla when you tap a supercharger?

I'll give you that the 250 tier system is against the spirit of the law. But then again, I don't think preventing EV charging companies from billing people by the amount of electricity they actually use (that they are actually buying from the utilities) was actually the spirit of this law at the time it was written. It was written to prevent someone other than a utility from setting up a generator and transmission lines and starting their own mini electrical grid to serve neighborhoods, or to prevent say an HOA from declaring itself the sole electrical distributor in its neighborhood and then reselling energy to all houses within that neighborhood at a profit. In general, it was designed to give the utility company a monopoly on generation, transmission, distribution, and metering of electrical service in a specific geographic area, and was written at a time in the 1970s (at least that's what it appears, from the wording of 49-34A-42 referencing a specific date of March 21, 1975) when nobody envisioned that cars would be "fueled" with electricity instead of gasoline. So you could argue that the spirit of the law was actually to protect the utilities' role as the sole transmitter and distributor of electricity in the area -- a role that is not threatened by EV charging companies that are buying their electricity from said utilities in the first place and simply putting it into cars.

But yes, it's entirely possible the regulators could come back and decide that even under the 4 tier system, it looks like a duck and quacks like a duck, and determine that Tesla shall be regulated like a utility. I wouldn't want to tempt fate and poke that sleeping bear by having 250 tiers

Actually, I would want to do exactly that.

 

[stopcrazypp]

That is not legal, at least in South Dakota. In South Dakota, it is not legal to charge for electricity provided/consumed if you are not a regulated utility. kWh is the unit of measure for electricity consumption, so by definition, you would be charging for electricity consumed, which is explicitly illegal. By only having 4 tiers, there is no direct correlation to how much you actually consumed, whereas in your proposal you are essentially metering it with your frequent polling, especially since you are targeting a specific unit of measure.

Summary from South Dakota Public Utility

Yep, beat me to it.

 

[stopcrazypp]

Not exactly. They publish a table of say 25 or 250 different tiered rates, and have a note that says how they came up with the pricing for each tier.

Where is the statute that specifically says it's illegal to "suggest" kWh pricing? I don't think I've ever seen one. And they can post all 250 levels either in the app, on the screen in the car, or on the display at the charger (if it's EA or Chargepoint).

It's illegal to charge by kWh pricing because that is only allowed for utilities in certain states. Using a formula to very poorly hide that you did isn't likely to go well with regulators (what's to stop other companies that actually wanted to be a unregulated utility to do so?). I doubt any charge provider will want try to test this.

All they have to do is post something like this (it's very easy to generate in Excel or any other spreadsheet):

*These prices were generated by targeting a rate of approximately 43¢/kWh. In accordance with the law, your bill will not list kWh, but will list minutes spent charging at each tier. You are not being billed by kWh but the price you get should be fairly close to 43¢/kWh.

Average Power (kW)	Price per minute (evaluted every minute)
1	0.007166666667
2	0.01433333333
3	0.0215
4	0.02866666667
5	0.03583333333
6	0.043
7	0.05016666667
8	0.05733333333
9	0.0645
10	0.07166666667
11	0.07883333333
12	0.086
13	0.09316666667
14	0.1003333333
15	0.1075
16	0.1146666667
17	0.1218333333
18	0.129
19	0.1361666667
20	0.1433333333
21	0.1505
22	0.1576666667
23	0.1648333333
24	0.172
25	0.1791666667
26	0.1863333333
27	0.1935
28	0.2006666667
29	0.2078333333
30	0.215
31	0.2221666667
32	0.2293333333
33	0.2365
34	0.2436666667
35	0.2508333333
36	0.258
37	0.2651666667
38	0.2723333333
39	0.2795
40	0.2866666667
41	0.2938333333
42	0.301
43	0.3081666667
44	0.3153333333
45	0.3225
46	0.3296666667
47	0.3368333333
48	0.344
49	0.3511666667
50	0.3583333333
51	0.3655
52	0.3726666667
53	0.3798333333
54	0.387
55	0.3941666667
56	0.4013333333
57	0.4085
58	0.4156666667
59	0.4228333333
60	0.43
61	0.4371666667
62	0.4443333333
63	0.4515
64	0.4586666667
65	0.4658333333
66	0.473
67	0.4801666667
68	0.4873333333
69	0.4945
70	0.5016666667
71	0.5088333333
72	0.516
73	0.5231666667
74	0.5303333333
75	0.5375
76	0.5446666667
77	0.5518333333
78	0.559
79	0.5661666667
80	0.5733333333
81	0.5805
82	0.5876666667
83	0.5948333333
84	0.602
85	0.6091666667
86	0.6163333333
87	0.6235
88	0.6306666667
89	0.6378333333
90	0.645
91	0.6521666667
92	0.6593333333
93	0.6665
94	0.6736666667
95	0.6808333333
96	0.688
97	0.6951666667
98	0.7023333333
99	0.7095
100	0.7166666667
101	0.7238333333
102	0.731
103	0.7381666667
104	0.7453333333
105	0.7525
106	0.7596666667
107	0.7668333333
108	0.774
109	0.7811666667
110	0.7883333333
111	0.7955
112	0.8026666667
113	0.8098333333
114	0.817
115	0.8241666667
116	0.8313333333
117	0.8385
118	0.8456666667
119	0.8528333333
120	0.86
121	0.8671666667
122	0.8743333333
123	0.8815
124	0.8886666667
125	0.8958333333
126	0.903
127	0.9101666667
128	0.9173333333
129	0.9245
130	0.9316666667
131	0.9388333333
132	0.946
133	0.9531666667
134	0.9603333333
135	0.9675
136	0.9746666667
137	0.9818333333
138	0.989
139	0.9961666667
140	1.003333333
141	1.0105
142	1.017666667
143	1.024833333
144	1.032
145	1.039166667
146	1.046333333
147	1.0535
148	1.060666667
149	1.067833333
150	1.075
151	1.082166667
152	1.089333333
153	1.0965
154	1.103666667
155	1.110833333
156	1.118
157	1.125166667
158	1.132333333
159	1.1395
160	1.146666667
161	1.153833333
162	1.161
163	1.168166667
164	1.175333333
165	1.1825
166	1.189666667
167	1.196833333
168	1.204
169	1.211166667
170	1.218333333
171	1.2255
172	1.232666667
173	1.239833333
174	1.247
175	1.254166667
176	1.261333333
177	1.2685
178	1.275666667
179	1.282833333
180	1.29
181	1.297166667
182	1.304333333
183	1.3115
184	1.318666667
185	1.325833333
186	1.333
187	1.340166667
188	1.347333333
189	1.3545
190	1.361666667
191	1.368833333
192	1.376
193	1.383166667
194	1.390333333
195	1.3975
196	1.404666667
197	1.411833333
198	1.419
199	1.426166667
200	1.433333333
201	1.4405
202	1.447666667
203	1.454833333
204	1.462
205	1.469166667
206	1.476333333
207	1.4835
208	1.490666667
209	1.497833333
210	1.505
211	1.512166667
212	1.519333333
213	1.5265
214	1.533666667
215	1.540833333
216	1.548
217	1.555166667
218	1.562333333
219	1.5695
220	1.576666667
221	1.583833333
222	1.591
223	1.598166667
224	1.605333333
225	1.6125
226	1.619666667
227	1.626833333
228	1.634
229	1.641166667
230	1.648333333
231	1.6555
232	1.662666667
233	1.669833333
234	1.677
235	1.684166667
236	1.691333333
237	1.6985
238	1.705666667
239	1.712833333
240	1.72
241	1.727166667
242	1.734333333
243	1.7415
244	1.748666667
245	1.755833333
246	1.763
247	1.770166667
248	1.777333333
249	1.7845
250	1.791666667

Even though this table has 250 different entries in it, it is far more understandable than the gobbledygook that they're publishing currently. And you don't expect people to actually look at each entry; the point is that they know how the entries were generated.

Sorry, on its own, the table you post is far worse for a consumer to understand than just 3-4 tiers. It only makes sense if you directly post ~$0.43/kWh, but Tesla isn't allowed to do that so they would have to post the whole table. That's going to be hugely unwieldy on both the screen and app.

As another pointed out, the core difference between a 3-4 tier system is there is no direct correlation between $/kWh in the latter. The tier system is only designed to minimize the impact of very slow chargers (where there is a huge disparity in charging speeds, such that sometimes they may be considered a different class of chargers), but it's not intended to be a substitute for $/kWh as you are suggesting. Basically as a consumer your estimated cost of charging would be somewhere between lowest tier cost * minutes charged and highest tier cost * minutes charged. You can take an average of the tier costs to do a closer estimate. You are basically being charged for the usage of the station, not the energy.

 

[STS-134]

It's illegal to charge by kWh pricing because that is only allowed for utilities in certain states. Using a formula to very poorly hide that you did isn't likely to go well with regulators (what's to stop other companies that actually wanted to be a unregulated utility to do so?).

See note about the true spirit of the law in post #61. A 1970s law certainly wasn't written to make EV charging stations' cost confusing for consumers. It was written to protect utilities' regulated monopolies. An EV charging station that buys electricity from the regulated utility and then dispenses it into cars does not threaten this monopoly. This is very different from a situation where someone is selling electricity that they're generating themselves and isn't using the regulated monopoly to source it at all.

I doubt any charge provider will want try to test this.

Tesla doesn't seem shy about trying to test what regulators will let them get away with in terms of playing games and playing fart noises (or silence) instead of pedestrian warning sounds. So I don't understand their shyness about this issue, which is far less controversial as it's actually designed to help the consumer.

Sorry, on its own, the table you post is far worse for a consumer to understand than just 3-4 tiers. It only makes sense if you directly post ~$0.43/kWh, but Tesla isn't allowed to do that so they would have to post the whole table. That's going to be hugely unwieldy on both the screen and app.

That's the whole point: make it easier to understand. Just post a large table, but have a note at the top that says that the rates are "based on $x/kWh" and that the amount charged should be within y% of that value. In theory, it's possible that you get very lucky, and you average very near the top of every tier and get a lower price per kWh, or that you get unlucky and average toward the bottom of every tier and get a higher price. But we can at least put a bound on it and show what price, approximately, is being charged. Currently, when I take a look at Tesla's per minute prices, I need to get out a calculator and calculate what lower and upper bounds are for the price per kWh in each tier in order to have any idea about what the hell is going on. And if they change the rates, even just by a little bit, I have to do all of my calculations over again.

For example:
Tier 1 (0-60kW) - $0.17/minute - 17-∞ ¢/kWh
Tier 2 (60-100kW) - $0.45/minute - 27-45 ¢/kWh
Tier 3 (100-180kW) - $0.85/minute -28.3-51 ¢/kWh
Tier 4 (180-250kW) - $1.35/minute - 32.4-45 ¢/kWh

So we can see, after doing a bit of calculating, that they were targeting a price of approximately 30-45 ¢/kWh. But (1) this wasn't at all obvious from the start and (2) Tesla should publish these numbers along with the table.

As another pointed out, the core difference between a 3-4 tier system is there is no direct correlation between $/kWh in the latter. The tier system is only designed to minimize the impact of very slow chargers, but it's not intended to be a substitute for $/kWh as you are suggesting.

There is no direct correlation with a 250 tier system either. But there is a correlation for sure, even on a 4 tier system. Can't you see it from the calculations I did above? The correlation coefficient is closer to 1, but it's not equal to 1. See note about that in post #58. You can get closer and closer to the ideal case of charging by the kWh by defining more tiers but you can only approach it asymptotically. There won't be a direct correlation until you define an infinite number of tiers and evaluate continuously.

 

[avs007]

Tesla doesn't seem shy about trying to test what regulators will let them get away with in terms of playing games and playing fart noises (or silence) instead of pedestrian warning sounds. So I don't understand their shyness about this issue, which is far less controversial as it's actually designed to help the consumer.

The key difference, is that if Tesla is found to violate FMVS, they just issue a recall, and fix it so that it is compliant... However, if Tesla is found to violate the statues around selling electricity, and they are found that they are actually acting as a regulated utility when they are not, there are FAR more severe ramifications. For example, with some of the standards bodies I work in, and the regulators I work with, some of the penalties for knowingly violating government regulations/policies/etc, is JAIL. And our legal deparment was very explicit in pointing out that many of these policies have guidelines that specify that ignorance of the requirement is not a valid defense. I'm not saying this is the case with regards to electricity sales, just pointing out that there are numerous reasons why a company may be hesitant to test the waters with some regulators and not others.

 

[STS-134]

The key difference, is that if Tesla is found to violate FMVS, they just issue a recall, and fix it so that it is compliant... However, if Tesla is found to violate the statues around selling electricity, and they are found that they are actually acting as a regulated utility when they are not, there are FAR more severe ramifications. For example, with some of the standards bodies I work in, and the regulators I work with, some of the penalties for knowingly violating government regulations/policies/etc, is JAIL. And our legal deparment was very explicit in pointing out that many of these policies have guidelines that specify that ignorance of the requirement is not a valid defense. I'm not saying this is the case with regards to electricity sales, just pointing out that there are numerous reasons why a company may be hesitant to test the waters with some regulators and not others.

I'm not sure that it would just be issue a recall and be done with it if a pedestrian were to get run over and killed because a driver replaced the warning sound with silence. And the ramifications if their "FSD" system were to kill someone? Just the civil consequences would be a PR nightmare.

The South Dakota law is written in such a vague manner that you could interpret it such that even selling EV charging by time with one tier is violating the law. What the heck is "retail electricity"? What if someone publishes a rate schedule that says "as much as you can use for x minutes"? They're arguably selling electricity, regardless of whether it's by kWh or by time. But I'm pretty sure the courts would figure out that the Legislature meant to protect the regulated monopoly of the utilities and that EV charging providers are not threatening that monopoly by selling electricity to vehicle owners so long as they're sourcing it from the regulated monopoly.

 

[avs007]

There is no direct correlation with a 250 tier system either. But there is a correlation for sure, even on a 4 tier system. Can't you see it from the calculations I did above? The correlation coefficient is closer to 1, but it's not equal to 1. See note about that in post #58. You can get closer and closer to the ideal case of charging by the kWh by defining more tiers but you can only approach it asymptotically. There won't be a direct correlation until you define an infinite number of tiers and evaluate continuously.

Using that logic, the easiest way around this regulation, would be to get rid of the actual electricity meter/sensor, and replace it with a polling device that measures consumption at fixed intervals, say once every few seconds... Then have it interpolate the kWh. Then you could argue that your kWh consumption is interpolated not exact.... That wouldn't fly either. If it did, then everyone would be doing this. The point of the 4 tier system isn't to emulate kWh, it's to make per minute somewhat more fair, so that somebody with a Taycan charging at 270kw doesn't pay the same amount as someone with an e-Golf charging at 40kw.

 

[whenryb]

I just did a test on my M3P with the CCS adapter and Electrify America. Here in TN, rates are per min not per Kw which is great at peak charging rates.

I used two different chargers, 150kw and 350kw. Stats below

150kw charger - SOC from 4% to 20% - Kw delivered 13, time 7min, cost $1.84, avg Kwh delivered 111, cost per Kwh $0.142
350kw charger - SOC from 20% to 60% - Kw delivered 33, time 15min, cost $3.82, avg Kwh delivered 132, cost per Kwh $0.115

Peak on the 350kw charger was 184 Kw

Supercharger pricing here in TN @ 100-180kw is $0.76 per min compared to $0.32 per min for Electrify America.

Given the pricing above, EA is actually on par or slightly cheaper than charging at home. Electricity here in TN is really cheap.

 

[avs007]

I'm not sure that it would just be issue a recall and be done with it if a pedestrian were to get run over and killed because a driver replaced the warning sound with silence. And the ramifications if their "FSD" system were to kill someone? Just the civil consequences would be a PR nightmare.

I remember Tesla had stated that the user cannot replace the pedestrian warning sound, the sound plays in parallel to it... Regulators were worried that it would "confuse" pedestrians... As far as FSD goes, Tesla goes out of there way to warn you that it is still a level 2 system... This is no different than if I drive like an idiot with my non-tesla, and rely on the smart nanny's to keep me safe. Sure it would still be a PR issue, but Tesla NEVER advertised FSD as anything other than level 2 autonomy.

 

[STS-134]

Using that logic, the easiest way around this regulation, would be to get rid of the actual electricity meter/sensor, and replace it with a polling device that measures consumption at fixed intervals, say once every few seconds... Then have it interpolate the kWh. Then you could argue that your kWh consumption is interpolated not exact.... That wouldn't fly either. If it did, then everyone would be doing this. The point of the 4 tier system isn't to emulate kWh, it's to make per minute somewhat more fair, so that somebody with a Taycan charging at 270kw doesn't pay the same amount as someone with an e-Golf charging at 40kw.

Well no, it's to make it more fair...by more closely emulating kWh charging. Whether it's 2 tiers or 4 tiers or 20 tiers or 25000 tiers, it's still trying to more closely emulate kWh than doing it by time alone. So there's really no legal difference between 4 tiers and 250 tiers and 1000 tiers unless the law specifies a maximum number of tiers and/or error bounds the kWh pricing, etc. If you're arguing otherwise and saying that there IS a difference legally...what is the threshold at which it becomes unacceptable? 6 tiers? 8? 50? And what part of the law are you pointing at that makes you believe that?

When you're writing a law, you have to specify everything. This is the reason why we have laws dictating what sizes, colors, font sizes, and placement orientations as well as heights off the ground are acceptable for road signs. Otherwise, a municipality could put up a sign in size 3 font and turn it 90 degrees that says "speed limit 35" and then ticket people for going 40. But that's not going to fly (I once got out of a parking ticket because the signs posted were not compliant with the Manual on Uniform Traffic Control Devices...too low off the ground, not oriented properly, etc.). Otherwise we'd have questions about exactly what font sizes are acceptable and when they become too small to be read properly by motorists, etc. Is lettering that is 2" high acceptable? What about 1.9"? 1.8"? Exactly when does it become unacceptable? The law has to say.

 

[avs007]

Well no, it's to make it more fair...by more closely emulating kWh charging. Whether it's 2 tiers or 4 tiers or 20 tiers or 25000 tiers, it's still trying to more closely emulate kWh than doing it by time alone. So there's really no legal difference between 4 tiers and 250 tiers and 1000 tiers unless the law specifies a maximum number of tiers and/or error bounds the kWh pricing, etc. If you're arguing otherwise and saying that there IS a difference legally...what is the threshold at which it becomes unacceptable? 6 tiers? 8? 50? And what part of the law are you pointing at that makes you believe that?

Subjective yes, but it's completely up to the regulators with their interpretation. When you create 250 tiers, you start to look like you are giving the regulators the finger. Once you get on the wrong side of a regulator, they can start to nit-pick every little thing, and make things a nightmare for you. 4 tiers is still crude enough that it probably doesn't draw any negative attention from a regulator. Especially a local regulator. Federal is different, and tend to be more cut and dry in my experience, but we're talking about state regulators here.

 

[STS-134]

Subjective yes, but it's completely up to the regulators with their interpretation. When you create 250 tiers, you start to look like you are giving the regulators the finger. Once you get on the wrong side of a regulator, they can start to nit-pick every little thing, and make things a nightmare for you. 4 tiers is still crude enough that it probably doesn't draw any negative attention from a regulator. Especially a local regulator. Federal is different, and tend to be more cut and dry in my experience, but we're talking about state regulators here.

True. I guess I'd not be very concerned because, even though this is trying to emulate billing by the kWh, it's not actually undercutting the regulator's role or the utility's regulated monopoly. IMO, giving the regulators the finger would be doing what I'm not supposed to be doing according to the true spirit of the law while trying to comply with the letter of the law. For example, I'd see starting my own utility (generation, transmission, distribution, and metering) and pricing it with 1 tier (by time alone) as REALLY giving the regulators the finger. But IANAL (heck, I didn't even hire a lawyer for that parking ticket, but I was so angry about having been ticketed based on a sign that was underneath the meter and turned sideways that I documented everything in the area and in the course of doing my research, I found numerous violations of the law and the case ultimately got tossed).

Isn't the ultimate function of these state regulators to protect consumers? I just don't see how preventing EV charging companies from being transparent about costs protects consumers. If anything, it makes it easier for consumers to get gouged.

 

[stopcrazypp]

Subjective yes, but it's completely up to the regulators with their interpretation. When you create 250 tiers, you start to look like you are giving the regulators the finger. Once you get on the wrong side of a regulator, they can start to nit-pick every little thing, and make things a nightmare for you. 4 tiers is still crude enough that it probably doesn't draw any negative attention from a regulator. Especially a local regulator. Federal is different, and tend to be more cut and dry in my experience, but we're talking about state regulators here.

Tesla's not the only provider with a tier system too. Electrify America used to have a 3 tier system, with breakdowns at 1-75kW, 76-125 kW, and 126-350 kW. They simplified it 2 tiers with 90kW being the boundary.
Does Electrify America's New Pricing Structure Mean Lower Fees For All?

 

[STS-134]

Tesla's not the only provider with a tier system too. Electrify America used to have a 3 tier system, with breakdowns at 1-75kW, 76-125 kW, and 126-350 kW. They simplified it 2 tiers with 90kW being the boundary.
Does Electrify America's New Pricing Structure Mean Lower Fees For All?

Tesla should push a firmware update that allows us to define charging speeds and cutoff thresholds (allowing you to reduce charging speeds). For the old tier system, it would charge at 125kW until the battery can't take 125kW, then it would immediately jump down to 75kW and stay there until the battery can't take that much anymore, and shut off. For the new tier system, it would just charge at a constant 90kW until the battery can't take that much and then shut down. The name of the game is keeping yourself always at the top of one of the tiers.

 

[stopcrazypp]

See note about the true spirit of the law in post #61. A 1970s law certainly wasn't written to make EV charging stations' cost confusing for consumers. It was written to protect utilities' regulated monopolies. An EV charging station that buys electricity from the regulated utility and then dispenses it into cars does not threaten this monopoly. This is very different from a situation where someone is selling electricity that they're generating themselves and isn't using the regulated monopoly to source it at all.

Tesla doesn't seem shy about trying to test what regulators will let them get away with in terms of playing games and playing fart noises (or silence) instead of pedestrian warning sounds. So I don't understand their shyness about this issue, which is far less controversial as it's actually designed to help the consumer.

That's the whole point: make it easier to understand. Just post a large table, but have a note at the top that says that the rates are "based on $x/kWh" and that the amount charged should be within y% of that value.

The point is you can't have such a note. There can be no reference to $/kWh or any suggestion that you are billing the user for energy.

In theory, it's possible that you get very lucky, and you average very near the top of every tier and get a lower price per kWh, or that you get unlucky and average toward the bottom of every tier and get a higher price. But we can at least put a bound on it and show what price, approximately, is being charged. Currently, when I take a look at Tesla's per minute prices, I need to get out a calculator and calculate what lower and upper bounds are for the price per kWh in each tier in order to have any idea about what the hell is going on. And if they change the rates, even just by a little bit, I have to do all of my calculations over again.

For example:
Tier 1 (0-60kW) - $0.17/minute - 17-∞ ¢/kWh
Tier 2 (60-100kW) - $0.45/minute - 27-45 ¢/kWh
Tier 3 (100-180kW) - $0.85/minute -28.3-51 ¢/kWh
Tier 4 (180-250kW) - $1.35/minute - 32.4-45 ¢/kWh

So we can see, after doing a bit of calculating, that they were targeting a price of approximately 30-45 ¢/kWh. But (1) this wasn't at all obvious from the start and (2) Tesla should publish these numbers along with the table.

You are struggling because you are thinking a manner of "how much money am I paying per kWh". Instead, what the per minute billing is designed is to pay for using the charger as a service. So basically look at how many minutes your charge session is estimated to be and multiply it by the rate. Take for example a 30 minute session:

Example:
Tier 1 (0-60kW) - $0.17/minute - $5.10
Tier 2 (60-100kW) - $0.45/minute - $13.50
Tier 3 (100-180kW) - $0.85/minute - $25.50
Tier 4 (180-250kW) - $1.35/minute - $40.50

You will be paying between $5.10 to $40.50 for a 30 minute session. Most people stick closer to Tier 2 or Tier 3 (depending on what car they have, I have an M3 SR+ so Tier 2 would be where my car operates mostly), so that typically will be closer to what they are paying.

There is no direct correlation with a 250 tier system either. But there is a correlation for sure, even on a 4 tier system. Can't you see it from the calculations I did above? The correlation coefficient is closer to 1, but it's not equal to 1. See note about that in post #58. You can get closer and closer to the ideal case of charging by the kWh by defining more tiers but you can only approach it asymptotically. There won't be a direct correlation until you define an infinite number of tiers and evaluate continuously.

From your own calculation there is a pretty big spread in the $/kWh you may be paying at a station. You can't summarize it into a fair $/kWh number, as it's possible to be paying massively more (especially for the slow charging). For example, when charging at 90+%, it gets down to 20kW or lower, and the price becomes $0.51/kWh and climbing; then at boundary of 60kW you see a massive jump from $0.17/kWh to $.45/kWh.

The 250 tier system you suggest however is different in that it can be summarized directly into a $/kWh number and be fairly accurate.

 

[stopcrazypp]

True. I guess I'd not be very concerned because, even though this is trying to emulate billing by the kWh, it's not actually undercutting the regulator's role or the utility's regulated monopoly. IMO, giving the regulators the finger would be doing what I'm not supposed to be doing according to the true spirit of the law while trying to comply with the letter of the law. For example, I'd see starting my own utility (generation, transmission, distribution, and metering) and pricing it with 1 tier (by time alone) as REALLY giving the regulators the finger. But IANAL (heck, I didn't even hire a lawyer for that parking ticket, but I was so angry about having been ticketed based on a sign that was underneath the meter and turned sideways that I documented everything in the area and in the course of doing my research, I found numerous violations of the law and the case ultimately got tossed).

Isn't the ultimate function of these state regulators to protect consumers? I just don't see how preventing EV charging companies from being transparent about costs protects consumers. If anything, it makes it easier for consumers to get gouged.

From the "spirit" of the law, charger providers shouldn't be treated as utilities, even if they bill per kWh. However the states where Tesla (and other charging providers) are forced to bill by minute precisely because the utility regulators do not see it that way (in states where kWh billing is allowed, charge providers were able to convince utility regulators to make exceptions for them). Why would you think they would take kindly to efforts to circumvent that restriction? More efforts need to be made by people of those states to convince utility regulators to take a more reasonable approach to treating charging providers, but before that happens I don't see charging providers exposing themselves to the legal risks of testing the boundaries by doing any sort of faux $/kWh pricing.

 

[STS-134]

From your own calculation there is a pretty big spread in the $/kWh you may be paying at a station.

Only in the lowest tier, as the charge rate approaches zero and the cost approaches infinity (although the best deal can be found keeping the car at exactly 60kW until the battery can't take that much anymore, then shutting down. This is likely because they expect people to spend a significant amount of time at much lower charge rates if they're going above 80%). In the other tiers it's obvious that they're targeting around 35¢/kWh by defining tiers that go between 27-45¢/kWh.