Time of Use Electric Tariffs

A pass through some TOU tariffs in the USA

This note is a companion to Time-Shifting Your Energy Consumption and Time, Location and Electricity Costs. My original intention was to write a single post but the section on TOU Tariffs kept growing, so I extracted it into its own post and then I did the same with the section providing background on Electricity Costs. I have used the pass through electrical rates to learn more about electricity in the USA, not just the TOU portion, so bear with me for some diversions.

Electricity Rates

A Time Of Use (TOU) tariff attempts to leverage the time-variability of electricity cost by offering different rates at different times with the intention of modifying the ratepayer’s behavior and shifting their energy usage.

This post capture the key properties of several residential TOU tariffs in the USA. I grouped the tariffs roughly by US Census Area though maybe Grid Area would have been better.

The two main properties are:

• Time Periods. Usually Peak, Partial Peak, and Off Peak hours and days

• Per kWh rates for each period.

Highlights

Key highlights of the rates covered in this post:

• Hawaii has the highest rates. California is second highest.

• The structure of periods (Peak/Partial Peak/Off Peak) varies. Modern tariffs acknowledge leverage the electricity from renewables through a Super Off Peak period but that is not uniform.

• The spread between Peak and Off Peak rates varies. Many stay within 2x but they are 3x in Hawaii and 14x in ConEdison!

• Some utilities provide multiple TOU tariffs. In some cases this is done to accommodate people’s daily schedules. In other cases, the utilities provide a tradeoff of simpler tariffs with limited savings vs more complex tariffs that could deliver more savings.

• In general, the more plans there are, the more careful the customer has to be to make the best choice.

• Some of the utilities I cover are from Retailer Choice States.

There are several additional points that I want to explore in later posts.

• The offerings in Retailer Choice States are varied. The Generation portion of the bill may pass along details like Demand Charges. I hope to revisit these states, probably starting with Texas.

• A few plans have Demand Charges, Community Solar, Rooftop Solar Grid Connection Fees.

• Some utilities provide district energy.

California

PG&E

I am most familiar with these rates as our household is in the PG&E territory (see Comparing PG&E to CCAs and POUs and PG&E Residential Electrical Tariffs).

PG&E has several general TOU rates, including E-ELECT, E-TOU-C, E-TOU-D. They vary on whether they provide baseline allowances or not, the hours, whether weekends are off-peak, etc. Some rates have extra requirements; our household has EV chargers and we use the EV2-A rate.

Periods

Peak: 4pm-9pm | Partial Peak: 3pm-4pm, 9pm-midnight | Off Peak: rest

Rates change over the year, June 2024 was very expensive, right now it is just expensive

[Jun 2024] Peak: 0.64317 | Partial Peak: 0.53268 | Off Peak: 0.33067 $/kWh
[Jan 2025] Peak: 0.49936 | Partial Peak: 0.48266 | Off Peak: 0.31396 $/kWh

The Delivery cost (controlled by PG&E) is lowest for Off Peak periods, which means that a reduction in Generation cost (controlled by PCE, our CCA) delivers the largest gain to us in that period. I’ll try to write a note on that point.

PG&E’s rates are the same for all of its territory, even though the climate, wildfire risk, solar irradiance and others vary significantly in its very large territory.

Other California IOUs: SCE & SDGE

The other 2 big IOUs in California also have TOU rates. These tariffs are structured fairly similar to those of PG&E so I will just provide a link to them and some commentary. In general, both SCE and SDGE seem to have more modern tariffs than PG&E, possibly because PG&E has trouble implementing new rates (see their Billing System saga).

Southern California Edison

Southern California Edison is the second largest IOU in California. They have several TOU tariffs including TOU-D-4-9, TOU-D-5-8, TOU-D-Prime. I see two main differences with the PG&E tariff:

• Off Peak starts after 9pm or 8pm, while PG&E starts at midnight

• There is a Super Off Peak rate in the Winter, 8am to 4pm or 5pm.

The climate in the SCE territory is different than that of PG&E, plus they have more solar irradiance, still, I wonder why PG&E does not offer a similar TOU rate.

San Diego Gas and Electric

San Diego Gas and Electric provides service in the area around San Diego. They also have several TOU tariffs. Their general structure is similar to SCE. The Off Peak rate starts at 8pm or 9pm, and they are more nuanced with Super Off Peak than PG&E. Here is from one of their rates

SMUD

The Sacramento Municipal Utility District is a Publicly Owned Utility that serves the city of Sacramento. SMUD started implementing TOU tariffs back in 1993. Their TOU tariff is as follows:

Periods

[Summer (Jun - Sep)] Peak: 5pm-8pm | Mid Peak: Noon-5pm, 8pm-Midnight | Off Peak: Midnight-noon
[Winter] Peak: 5pm-8pm | Off Peak: Midnight-5pm, 8pm-Midnight

Rates

[Summer] Off Peak: 0.1505 $/kWh | Mid Peak: 0.2077 $/kWh | Peak: 0.3655 $/kWh
[Winter] Off Peak: 0.1215 $/kWh | Peak: 0.1678 $/kWh

The SMUD rates are a lot lower than PG&E. SMUD’s territory is much smaller than PG&E. Our house, in the Mid SF Peninsula, is in a territory not dissimilar than that of SMUDs, except for extra fire hazards around the Santa Cruz mountains. To me, it seems clear that there is significant cost-shifting within the different PG&E territories. That is reasonable but I’ve never seen it quantified.

Hawaii

Hawaii gets its own section because it is an island and has the highest electric rates in the USA (California is second). Hawaii is currently running a Pilot program with the intention of deploying TOU tariffs to everybody later this year. The pilot is testing different tariffs all with the same basic structure

Periods

Peak: 5pm-9pm | Mid Peak: 9pm-9am | Off Peak: 9am-5pm

Rates

Rates vary by island. Below are those Schedule R, of Hawai’i

Off Peak: 0.215048 $/kWh | Mid Peak: 0.430096 $/kWh | Peak: 0.645144 $/kWh

Hawaii has a large penetration of Solar, including rooftop solar. They have Community Solar (Shared Solar), and a modern looking Smart Renewable Energy Export program. These are topics I’d like to write about.

MidWest

The US Census places Texas in the MidWest, but, it is a fully deregulated market, plus it is Texas, so it goes in its own section. I don’t have other TOU entries from the MidWest.

Texas! and Deregulated Markets

Texas is different… because it is Texas and because it is one of the states with a free energy market. I am planning a post on those, so I’ll just leave here a link… plus a link Spanish Retailer Electric Market.

The full list of States with Retail Electricity Choice is:

Connecticut, Delaware, Illinois, New Hampshire, Maine, Maryland, Massachusetts, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Texas, and Washington DC.

West

Fort Collins

The Electrical Services Department of the City of Fort Collins, Colorado provides TOU rates that vary with the type of customers. They also have Community Solar and interesting Export Rates.

Periods

[Summer (May - Sep)] Peak: 2pm-7pm weekdays | Off Peak: other hours
[Winter (Oct - Apr)] Peak Winter: 5pm-9pm weekdays | Off Peak: other hours

Rates

The rates vary with type of customer: Standard, Electric Heat Customers, and Solar.

Standard

[Summer] Peak: 0.3047 $/kWh | Off Peak: 0.0846 $/kWh
[Winter] Peak: 0.2809 $/kWh | Off Peak: 0.0846 $/kWh
Extra for any kWh over 700: 0.0298 $/kWh

Electric Heat (resistive, central HP, mini-splits)

[Summer] Peak: 0.3130 $/kWh | Off Peak: 0.0929 $/kWh
[Winter] Peak: 0.2892 $/kWh | Off Peak: 0.0929 $/kWh
Extra for any kWh over 700: N/A

Credits

The credit that Solar Customers get for exporting electricity depends on the type of customer, and the time of day

Standard

[Summer] Peak: -0.2510 $/kWh | Off Peak: -0.0636 $/kWh
[Winter] Peak: -0.2179 $/kWh | Off Peak: -0.0636 $/kWh

Electric Heat

[Summer] Peak: -0.2510 $/kWh | Off Peak: -0.0698 $/kWh
[Winter] Peak: -0.2241 $/kWh | Off Peak: -0.0698 $/kWh

The export rates for Community Solar are similar but a bit less generous than those from rooftop solar.

Note that the export rates are less generous than California’s NEM 2.0 but much more generous than NBT (aka NEM 3.0).

APS (Arizona)

Arizona Public Service is Arizona’s largest utility company. Despite its name it is an Investor Owned Utility (IOU). APS has several TOU rates: RTOUE47, R3-47 and Overnight EV Charging. The R3-47 rate has demand charges (called energy charged by APS). All tariffs have a Super Off Peak period when renewable energy is prevalent in the grid.

R-3

This rate has three parts: a basic service charge, a demand charge for the highest amount of demand (kW) averaged in a one hour On-Peak period for the month, and an energy charge for the total energy (kWh) used for the entire month

Periods

Peak: 4pm-7pm Mon to Fri
Super Off Peak: 10am-3pm Mon to Fri only on Winter
Off Peak: otherwise, plus holidays.

Energy Rates

[Summer] Peak Demand Charge: 19.585 $/kW
[Summer] Peak: 0.14227 $/kWh | Off Peak: 0.0.05943 $/kWh

[Winter] Peak Demand Charge: 13.747 $/kW
[Winter] Peak: 0.09932 $/kWh | Off Peak: 0.05938 $/kWh | Super Off Peak: 0.03495 $/kWh

Noteworthy is that the demand charge is very high! A very good reason to not consume during on peak hours. Add a battery if you need to!

R-3 has an extra charge for Grid Access of 0.215 $/kW-DC.

TOU-E

Periods

Peak: 4pm-7pm Mon-Fri | Winter Super Off Peak: 10am-3pm Mon-Fri | Off Peak: other

Rates

[Summer] Peak: 0.34396 $/kWh | Off Peak: 0.12345 $/kWh
[Winter] Peak: 0.32543 $/kWh | Off Peak: 0.12351 $/kWh | Super Off Peak: 0.03495 $/kWh

Delivery at APS is much smaller than Generation. For example, Summer Peak Delivery is 0.03469 $/kWh while Summer Generation is 0.29469 $/kWh. This is very different than in PG&E where Delivery is 60% of total charges.

Like with R-3, TOU-E has an extra charge for “Grid Access”. 0.242 $/kW-DC.

SRP - Arizona

The Salt River Project is a community-based, not-for-profit organization providing reliable, affordable and sustainable water and energy to more than 2 million people in central Arizona. SRP has several Time of Day Electricity Tariffs. EZ-3 limits Peak hours to 3 hours a day, TOU has more restrictions but provides more savings, and a Residential Demand Pilot plan. SRP also has several Residential Solar Plans including a Time of Use Export Plan.

SRP EZ-3

There are two versions: EZ-3 3-6pm and EZ-3 4-6pm. Rates vary slightly. Below I’m using 3-6pm

Periods

Peak: 3pm-6pm Mon-Fri | Off Peak: Other

Energy Rates

[Winter (Nov - Apr)] Peak: 0.1327 $/kWh | Off Peak: 0.1002 $/kWh
[Summer (May, Jun, Sep, Oct)] Peak: 0.3096 $/kWh | Off Peak: 0.1006 $/kWh.
[Summer Peak (Jul, Aug)] Peak: 0.3645 $/kWh | Off Peak: 0.1054 $/kWh.

SRP TOU

SRP TOU Residential plan is

Periods

[Summer (May - Oct)] Peak: 2pm-8pm Mon to Fri | Off Peak: Other hours
[Winter (Nov - Apr)] Peak: 5am-9am & 5pm-9pm Mon to Fri | Off Peak: Other hours

Energy Rates

[Winter (Nov - Apr)] Peak: 0.1215 $/kWh | Off Peak: 0.0955 $/kWh
[Summer (May, Jun, Sep, Oct) ] Peak: 0.2295 $/kWh | Off Peak: 0.0928 $/kWh.
[Summer Peak (Jul, Aug) ] Peak: 0.2610 $/kWh | Off Peak: 0.0931 $/kWh.

SRP Demand Residential Pilot

SRP also has a Pilot on Demand Residential (PDF). There seems to be a proposal to make it permanent.

NorthEast - Wisconsin

We Energies - Wisconsin

We Energies is one of the main providers in Wisconsin. They have TOU rates with the usual Peak and Off Peak rate structure, but an interesting twist is that the customer can choose between 4 different options for On Peak. The Spread Peak/Off Peak is close to 3x.

Periods

Peak - Choose between 7am-7pm, 8am-8pm, 9am-9pm and 10am-10pm

Rates

Peak: 0.27006 $/kWh | Off Peak: 0.10387 $/kWh

We Energies have Demand Charges (for business accounts like RG2, I believe) and that they also provide Steam as a service as district heating.

NorthEast - Right To Choose States

Connecticut, New Hampshire, New York, New Jersey, and Massachusetts give the customer the right to choose retailer. See Power To Choose in NY, Power Switch (and intro) in NJ, and Energy Switch in MA, Energy CT in CT, Switch Info in NH.

National Grid

National Grid is a utility that serves New York and Massachusetts (website). As a state with retailer choice, a customer can choose the retailer. Full breakdown of rates is HERE. Rates in the National Grid include a “Delivery Rate” and a “Commodity Rate” (aka Generation). The SC-1 VTOU rate has:

Periods

Peak: 7am-11pm. Both Delivery and Commodity
Off Peak: 11pm-7am. Both Delivery and Commodity
Super-Peak: 2pm-6pm (June to August). Only for the Commodity component

Rates

Delivery. Peak: 0.09605 $/kWh | Off Peak: 0.01609 $/kWh
Commodity - Varies. For Dec 2024, Central Region, 0.0710 $/kWh; full details HERE.
Total - Peak: 0.16705 $/kWh | Off Peak: 0.08709 $/kWh

Consolidated Edison

Con Edison serves customers in New York and New Jersey. ConEd has a TOU tariff with very low Off Peak rates

Periods

Peak: Weekdays: 8am-10pm
Off Peak: Other hours on Weekdays and all day in Weekends

Rates

[Summer (June - Sept)] - Peak: 0.3523 $/kWh | Off Peak: 0.0249 $/kWh
[Winter] Peak: 0.1305 $/kWh | Off Peak: 0.0249 $/kWh.

Recap

A Time Of Use (TOU) tariff attempts to leverage the time-variability of electricity cost by offering different rates at different times with the intention of modifying the ratepayer’s behavior and shifting their energy usage. Electricity Retailers in the USA are currently providing multiple TOU tariffs with different time periods and different rates. Periods change, from the simple Peak | OffPeak to additional Super Peak and Super OffPeak. The spread can vary very significantly, from close to 1-to-1 to 1-to-16, and so does the absolute prices, ranging all the way to the high rates in California and Hawaii.

The post on Time, Location and Electricity Costs provides background on why TOUs exist, and Time-Shifting Your Energy Consumption explores how to leverage TOUs to alleviate the cost of our electricity consumption.