Guides for depot energy managers

Time-of-use rates for AV fleet charging: how to read your tariff

Q: Do weekends count as off-peak?

Sometimes. PG&E's BEV hours are the same every day, while SCE's summer on-peak applies on weekdays only and weekends drop to mid-peak. FPL's GSDT-1 on-peak hours are weekdays.

On some rates the same kWh costs nearly five times as much at 6 p.m. as at 6 a.m. Read the hours, the prices and the fine print before you set a depot's charging window.

By Greg Bessoni, Founder and CEO, XoomPark · November 4, 2026

A time-of-use rate prices the same kWh differently by hour, day and season. Read three things: the hours of each period, the price per kWh in each, and every charge billed per kW, which the hourly price never shows. Then put your charging window in the cheapest period your cars can actually be parked for.

Commercial EV and fleet charging rates in robotaxi markets, energy price per kWh, from each utility's published tariff. FPL prices are base rates before the fuel charge.
Utility and rate	Most expensive hours	Cheapest hours	Price spread
PG&E BEV-1, San Francisco Bay Area¹	4 to 9 p.m. daily: $0.357	9 a.m. to 2 p.m. daily: $0.138	2.6 to 1
SCE TOU-EV-8, Los Angeles³	Summer weekdays 4 to 9 p.m.: $0.922	Winter 8 a.m. to 4 p.m.: $0.136	6.8 to 1 across seasons
FPL GSDT-1, Miami⁴	On-peak (by season): 6.019 cents base	Off-peak: 1.524 cents base	About 4 to 1 before fuel
NV Energy LGS-2, Las Vegas⁷	Summer 3:01 to 9 p.m.: $0.125	Summer off-peak: $0.053	2.3 to 1
Austin Energy fleet charging rate⁸	No time periods	No time periods	Flat; the demand charge does the work

What hours count as peak on an EV charging rate?

Late afternoon and evening, almost everywhere: 4 to 9 p.m. on PG&E and SCE, 3 to 8 p.m. on weekdays on APS in Phoenix.⁹ But the cheapest hours differ by utility. On PG&E's BEV rate the cheapest period is 9 a.m. to 2 p.m., not the middle of the night.

PG&E's Schedule BEV, built for business EV charging, has three periods: peak 4 to 9 p.m., off-peak 9 p.m. to 9 a.m. plus 2 to 4 p.m., and super off-peak 9 a.m. to 2 p.m. The tariff says the hours apply every day of the year, weekends and holidays included, and that the schedule has no seasonal variation.¹ That is unusually simple, and it is why PG&E is the easiest tariff in this group to plan around.

SCE's TOU-EV-8 has seasons. Summer, June 1 to October 1, puts weekdays from 4 to 9 p.m. on-peak and leaves the other hours off-peak. Winter splits the day three ways: mid-peak 4 to 9 p.m., off-peak 9 p.m. to 8 a.m. and super off-peak 8 a.m. to 4 p.m.³ Weekends and holidays in summer drop to mid-peak, so a schedule tuned on a Tuesday can cost differently on a Saturday.

FPL's optional time-of-use rate for mid-size businesses, GSDT-1, moves its peak with the season. From November through March, weekday on-peak runs 6 to 10 a.m. and 6 to 10 p.m. Eastern; from April through October it runs noon to 9 p.m.⁴ The winter morning peak is the trap: an overnight schedule that is still finishing cars at 7 a.m. on a January weekday is charging on-peak.

How much does the same night of charging cost in each window?

For a 40-car robotaxi yard drawing 3,200 kWh a night, the energy alone runs from about $443 in PG&E's super off-peak hours to $1,143 at PG&E's peak, and to $2,950 in SCE's summer on-peak hours. The window you pick can cost more than the chargers.

Energy cost of one 3,200 kWh night by period, energy charges only. Demand, subscription and fixed charges are extra. SCE prices are delivery plus generation, below 2 kV.
Rate and period	$ per kWh	One night	30 nights
PG&E BEV-1, super off-peak¹	0.13844	$443	$13,290
PG&E BEV-1, off-peak¹	0.16510	$528	$15,850
PG&E BEV-1, peak¹	0.35711	$1,143	$34,283
SCE TOU-EV-8, winter super off-peak³	0.13609	$435	$13,065
SCE TOU-EV-8, summer off-peak³	0.19049	$610	$18,287
SCE TOU-EV-8, summer on-peak³	0.92192	$2,950	$88,504
NV Energy LGS-2, summer off-peak⁷	0.05335	$171	$5,122
NV Energy LGS-2, summer on-peak⁷	0.12513	$400	$12,012

The 3,200 kWh comes from our overnight charging schedule: 40 robotaxis, 150 miles each, at EPA's 48 kWh per 100 miles. On SCE in summer, letting the yard start charging when the cars come back at 6 p.m. instead of after 9 p.m. multiplies the energy bill for those hours by 4.8.

What does the price per kWh leave out?

Everything billed per kW. Most commercial rates add a monthly charge on your highest draw, and EV rates replace it with something else: a subscription on PG&E, a temporary $0 on SCE, a shrinking discount on NV Energy. These can outweigh the energy.

PG&E BEV replaces the customer charge and the usual demand charge with a subscription: $12.41 per 10 kW block on BEV-1, and $95.56 per 50 kW block on BEV-2-S for loads over 100 kW. Going over your subscription costs an overage fee per kW, measured on 15-minute intervals: $2.48 on BEV-1 and $3.82 on BEV-2-S.¹
SCE TOU-EV-8 shows its facilities demand charge at $0.00 per kW. SCE says demand charges are not applicable until the California Public Utilities Commission decides otherwise. That is a pause, not a promise.²
NV Energy's EVCCR-TOU rider cuts the demand charge for separately metered DC fast charging, but the cut is shrinking: it fell from 100% in 2019 to 30% from April 1, 2026, and the transition ends April 1, 2029.⁶
Austin Energy's fleet and public charging rate has no time periods at all. It bills $13.76 per kW of demand plus a $5.03 per kW regulatory charge, measured on the 15 minutes of greatest use.⁸

NREL found that only about 55% of the U.S. rates it studied for DC fast charging included demand charges, and that those charges usually run under $15 per kW but can top $25.¹¹ Our guide to demand charges works through what they cost a depot.

Which EV-only rates will a robotaxi depot actually qualify for?

Fewer than the names suggest. Several EV rates are built for public chargers, capped at a handful of customers or limited to one charger type. Read the eligibility section before you budget on the price.

Eligibility rules that can keep a private robotaxi depot off an EV rate, from each tariff.
Rate	The rule	What it means for a depot
FPL GSD-1EV⁴	Charging installations must be accessible to the public	A private depot likely does not qualify
Austin Energy fleet and public charging⁸	At least 90% EV load, average billed demand over 100 kW, limited to ten customers	Large depots can qualify, if a slot is open
NV Energy EVCCR-TOU⁶	Separately metered DC fast charging of at least 50 kW, capped at 500 meters	Level 2 charging does not qualify
PG&E BEV-1 and BEV-2¹	BEV-1 for up to 100 kW, BEV-2 for more	A 40-car yard is a BEV-2 customer

The Department of Energy's Alternative Fuels Data Center keeps a list of utilities that offer a time-of-use rate only for EV charging, with 31 non-residential entries when we checked. PG&E is on it; SCE, FPL, NV Energy, Austin Energy and APS are not, and their EV options are riders or general rates instead.¹⁰ Use the list as a starting point, then read your own utility's tariff book.

We priced one robotaxi night on three utilities' tariffs

The cheapest window for a 3,200 kWh night ranged from about $171 on NV Energy's summer off-peak price to $443 on PG&E's super off-peak. The most expensive was SCE's summer on-peak at $2,950. The spread inside one utility was bigger than the spread between utilities.

Method: we took the energy prices from each utility's current tariff sheet, effective dates as listed in the sources, and multiplied by 3,200 kWh. We left out demand, subscription and fixed charges so the windows compare cleanly, and we left FPL out of the dollar figures because its time-of-use fuel charge wasn't in the sheets we read; on FPL's standard GSD-1 rate, fuel added 3.201 cents per kWh in October 2026.⁵ These are list prices, before taxes and local fees.

What surprised us: two of the four utilities make the middle of the day the cheapest time to charge. PG&E's super off-peak is 9 a.m. to 2 p.m. all year,¹ and SCE's winter super off-peak is 8 a.m. to 4 p.m.³ A robotaxi fleet that is busiest at the morning and evening commutes could charge in the midday lull for less than it pays overnight.

When a time-of-use rate is the wrong choice

Your cars can't be parked in the cheap hours. If the fleet runs through the night and the cheap window is overnight, a time-of-use rate can cost more than a flat rate.
Your load is small. PG&E's BEV-1 tops out at 100 kW,¹ and many EV rates have minimum sizes; a small pilot yard may be better on a general rate.
The rate you want is for public chargers. FPL's GSD-1EV requires public access,⁴ so a private depot shouldn't plan on it.
You're pricing on a discount that ends. NV Energy's EV demand reduction ends in April 2029,⁶ and SCE's $0 demand charge can change when the Commission rules.²

Questions depot energy managers ask

What is a time-of-use rate?

An electricity rate that charges different prices per kWh in different hours, days and seasons. For fleet charging the usual pattern is an expensive late-afternoon and evening peak and cheaper overnight or midday hours.

When is electricity cheapest for AV fleet charging?

It depends on the utility. On PG&E's BEV rate it is 9 a.m. to 2 p.m. every day.¹ On SCE in winter it is 8 a.m. to 4 p.m.³ NV Energy's EV recharge period runs from 12:01 a.m. to noon.⁶

Do weekends count as off-peak?

Sometimes. PG&E's BEV hours are the same every day,¹ while SCE's summer on-peak applies on weekdays only and weekends drop to mid-peak.³ FPL's GSDT-1 on-peak hours are weekdays.⁴

Is a time-of-use rate always cheaper for a robotaxi fleet?

Only if the cars charge in the cheap hours. A yard that starts charging as cars return at 6 p.m. pays peak prices on most of these tariffs. Check the demand or subscription charges too; they can outweigh the energy savings.

Where do I find my utility's EV rate?

Start with the Alternative Fuels Data Center's list of utility EV rates,¹⁰ then read the schedule in your utility's tariff book. The eligibility section matters as much as the prices.

Sources

Sources are public. XoomPark isn't affiliated with the companies referenced in this post.

Authorship

Written by Greg Bessoni in collaboration with Claude Opus 5.5

Role breakdown: Strategy, structure and final verification by Greg Bessoni; research synthesis and draft prose by Claude Opus 5.5.

About the author

Greg Bessoni is the founder and ceo, xoompark. He writes about fleet operations, curb logistics and AV infrastructure.