TOU for SCE in Southern California analysis

[silversaver]

Here is good example of allocation 10 cents credit/debit:



Residential Time-of-Use (TOU-D) NEM Customer FAQs
How is the Baseline Credit included in TOU-D, Option A applied to a customer’s bill?
TOU-D, Option A includes a Baseline Credit, which is applicable to up to 100 percent of a customer’s standard Baseline Allocation, as found in Preliminary Statement, Part H. (Click here for further information: https://www.sce.com/NR/sc3/tm2/pdf/ce07-12.pdf) This results in a lower energy charge for Baseline usage.
Net Consumer of Electricity
When you are a net consumer for the month (i.e., you consume more electricity from SCE than you export to the grid), a portion of your energy charges will be lowered through the baseline credit applied monthly on a $per kWh basis. For example:
• If a customer has a Baseline Allocation of 500 kWh/month and their net kWh (consumption from SCE minus exported generation) for the month is 750 kWh, the customer will receive 10 cents per kWh credit up to the 500 kWh Baseline amount, equal to a $50 credit.
• If a customer has a Baseline Allocation of 500 kWh/month and their net kWh for the month is 250 kWh, the customer will receive 10 cents per kWh credit up to the net 250 kWh, equal to a $25 credit.
Net Generator of Electricity
When you are a net generator for the month (i.e., you export more electricity than you consume from SCE that month), the Baseline Credit will appear as a monthly charge since you are multiplying a negative kWh amount by a negative billing factor. This is necessary to ensure that you receive the same rate for the exported kWh that you would have received if you had consumed that same kWh from SCE.
For example, if a customer has a Baseline Allocation of 500 kWh/month, and their net kWh for the month is -100 kWh (exported generation is greater than consumption from SCE), the customer’s bill will reflect a 10 cents per kWh charge up to the net -100 kWh of generation, which results in a $10 charge.
Note: The Baseline Allocation varies by Baseline Region. You can learn your specific region and allocation by calling us at 1-800-655-4555 and asking an SCE representative.

How does the TOU-D rate On-Peak hours impact my bill?
If you generate excess electricity (i.e., export more electricity than you consume from SCE) during the hours of 2 PM to 8 PM, your NEM credits will be calculated using the TOU-D on-peak rate for the applicable season, meaning that the kWh exported between these hours will receive the highest credit amount.
If you do not generate enough electricity to offset your on-site load during the hours of 2 PM to 8 PM, it is important to try to shift as much of your electric load (e.g., PEV charging, clothes and dish washing or pool pump operation) as you can to Off-Peak and Super Off-Peak hours to reduce your electric costs since kWh consumed in the On-Peak hours are charged at a higher rate than kWh consumed in the Off-Peak and Super Off-Peak hours
What is the Basic Charge on both Options A and B of Schedule TOU-D and why are they different?
The Basic Charge is a mechanism approved by the California Public Utilities
Commission’s (CPUC) that allows SCE to recover some of the costs associated with ensuring the grid can provide safe and reliable power to all customers. This charge ensures that all SCE residential customers, regardless of their monthly use, contribute toward the recovery of these costs.
• Customers choosing Option A are generally lower usage customers who will pay a basic charge corresponding to the customer charge in place for customers taking service on Schedule D.
• Customers choosing Option B are generally higher usage customers who will pay a higher basic charge but lower energy charges (cents/kWh).

[insaneoctane]

Probably should just let this thread die, but I had a TOU epiphany tonight. My chosen TOU plan costs me:
$0.11/kWh during "super-off peak" from 10pm to 8am
$0.30/kWh during regular "off peak" from both 8pm to 10pm and 8am to 2pm
$0.46/kWh for "peak" from 2pm to 8pm

Tonight the dishwasher was not full, there was enough room for breakfast dishes. My standard procedure would have been to conserve energy and water and not prematurely run the dishwasher until after breakfast the next day. BUT, now that I'm thinking of TOU costing, my tendency is to run the dishwasher at night when energy is cheapest. Mathematically, it's a no-brainer to run the dishwasher tonight at partial load, because I can afford to run the dishwasher FOUR times from 10pm until 8am for LESS than one time time during peak hours. It's almost 3 times vs regular off peak. Wow, it's great for me financially, but it encourages me to be more wasteful. Obviously, I'm not considering the extra cost of water, but still. Wow.

[silversaver]

Thats the beauty of TOU if the plan works for you. You might be at net 0 kWh, but you get credit on your account.

Green botton download 2014 net usage after solar from SCE, looks like TOU-D-A is a winner.

[J.P.M.]

Probably should just let this thread die, but I had a TOU epiphany tonight. My chosen TOU plan costs me:
$0.11/kWh during "super-off peak" from 10pm to 8am
$0.30/kWh during regular "off peak" from both 8pm to 10pm and 8am to 2pm
$0.46/kWh for "peak" from 2pm to 8pm

Tonight the dishwasher was not full, there was enough room for breakfast dishes. My standard procedure would have been to conserve energy and water and not prematurely run the dishwasher until after breakfast the next day. BUT, now that I'm thinking of TOU costing, my tendency is to run the dishwasher at night when energy is cheapest. Mathematically, it's a no-brainer to run the dishwasher tonight at partial load, because I can afford to run the dishwasher FOUR times from 10pm until 8am for LESS than one time time during peak hours. It's almost 3 times vs regular off peak. Wow, it's great for me financially, but it encourages me to be more wasteful. Obviously, I'm not considering the extra cost of water, but still. Wow.

Good heads' up thinking. However, if you heat your water with electricity and have a standard set up w/storage tank, depending on things like tank temp. other H2O draws, etc. the tank thermostat may call for heat (power) at times different than the appliance draw. Depending on use/draw pattern, there is a lag between when the draw takes place and when the thermostat comes on. Sometimes minutes, sometimes much longer, maybe hours.

VERY approximately, between standby tank and piping losses, a tank might lose between .3 to 1.0 deg. F./hr., say .5 deg. F. If the thermostat has, say, a 5 deg. F. "float" or "deadband", several hours may elapse between calls for heat.

For example (only), if the (say 80 gal. ?) tank temp. is say, 140 F. and the dishwasher use reduces the H2O temp. so that the thermostat "thinks" the (local- around the thermostat) temp. drops to say, 136 F., the thermostat may not call for heat. However, the tank losses to the ambient will continue through the night. At some point, maybe before or maybe after 0500 hrs. when semi peak rates come on. Or, it might be that the 2 deg. F. decrease from the dishes will cause the tank to get to the thermostat "on" point sooner (before 0500 hrs.).

Point is, when the thermostat calls for heat is usually not well understood, thought of, controlled, or very predictable. Couple that with the fact that common water heater thermostats are not very precise ( my experience after playing around with a few is that if they claim a deadband range of 5 deg. F., that's more likely something like 5 deg. F., -2/+5 deg. for a tolerance.

One solution to this is to put the water heater on a timer. That can cause some problems if the consequences are not understood, but in the case of storage of electrically heated H2O, it will control when power is used.delet will help

[bcroe]

Point is, when the thermostat calls for heat is usually not well understood, thought of, controlled, or very predictable. Couple that with the fact that common water heater thermostats are not very precise ( my experience after playing around with a few is that if they claim a deadband range of 5 deg. F., that's more likely something like 5 deg. F., -2/+5 deg. for a tolerance.

One solution to this is to put the water heater on a timer. That can cause some problems if the consequences are not understood, but in the case of storage of electrically heated H2O, it will control when power is used.delet will help

Perhaps the solution could be 2 set points for the thermostat. Set the desired temp
high for the time you want it to run, and drop it 10 degrees when you don't. That will
provide "hot water" at all times; perhaps you'll need to turn up the HOT knob some if
all the prime time heated water is used up. And give a hint you're past "optimum time".
Bruce Roe

[J.P.M.]

Perhaps the solution could be 2 set points for the thermostat. Set the desired temp
high for the time you want it to run, and drop it 10 degrees when you don't. That will
provide "hot water" at all times; perhaps you'll need to turn up the HOT knob some if
all the prime time heated water is used up. And give a hint you're past "optimum time".
Bruce Roe

I'm sure there are a number of ways to handle the situation. While what you suggest is certainly logical and possible, given the current arrangement(s) and rather primitive controls in common use for DHW applications, I doubt if the added expense and complication with the attendant likelihood of increased maint. or other problems make it likely.

Most current thermostats for DHW applications are cheap and not very precise. However, they have the advantage of low cost, simplicity and because of the simplicity, some measure of reliability.

Before declaring something a problem, an understanding of what's happening (inside the tank for one example) and why may be helpful to see if a solution or a better mousetrap is needed.

Evolution has made DHW systems quite reliable and mostly stupid proof.

Current water heating tech. in the U.S. evolved when the cost of the energy was cheap - cheaper than more insulation or use reduction. Them days are gone and probably ain't coming back.

[SunEagle]

I'm sure there are a number of ways to handle the situation. While what you suggest is certainly logical and possible, given the current arrangement(s) and rather primitive controls in common use for DHW applications, I doubt if the added expense and complication with the attendant likelihood of increased maint. or other problems make it likely.

Most current thermostats for DHW applications are cheap and not very precise. However, they have the advantage of low cost, simplicity and because of the simplicity, some measure of reliability.

Before declaring something a problem, an understanding of what's happening (inside the tank for one example) and why may be helpful to see if a solution or a better mousetrap is needed.

Evolution has made DHW systems quite reliable and mostly stupid proof.

Current water heating tech. in the U.S. evolved when the cost of the energy was cheap - cheaper than more insulation or use reduction. Them days are gone and probably ain't coming back.

Maybe instant hot water units become more economical if they are tied to TOU rates. That would still cause a life style change for anyone wanting to take a hot shower during peak rates but late night for dish-washing or early morning for showers may show a cost savings.

[bcroe]

I'm sure there are a number of ways to handle the situation. While what you suggest is certainly logical and possible, given the current arrangement(s) and rather primitive controls in common use for DHW applications, I doubt if the added expense and complication with the attendant likelihood of increased maint. or other problems make it likely.

Most current thermostats for DHW applications are cheap and not very precise. However, they have the advantage of low cost, simplicity and because of the simplicity, some measure of reliability.

Before declaring something a problem, an understanding of what's happening (inside the tank for one example) and why may be helpful to see if a solution or a better mousetrap is needed.

Evolution has made DHW systems quite reliable and mostly stupid proof.

Current water heating tech. in the U.S. evolved when the cost of the energy was cheap - cheaper than more insulation or use reduction. Them days are gone and probably ain't coming back.

I think I read TOU is a significant problem. The main issue would be properly setting a
24 hour timer to keep track of off peak time. I would just set the present thermostat to
the low temp threshold. Then attach an electronic sensor set at the high temperature,
to close a contactor in parallel with the original thermostat terminals, this only enabled
when the timer declared off peak time. Solid state is pretty reliable and the rest is
century old proven reliable. technology. I don't see any maintenance or reliability
issues. Guess this would be a custom job today, it ought to become an option on the left
coast pretty soon.

A production version might just shift the trip point of the thermostat
(mechanically or electrically) using an automatically set radio clock. Bruce Roe

[J.P.M.]

I think I read TOU is a significant problem. The main issue would be properly setting a
24 hour timer to keep track of off peak time. I would just set the present thermostat to
the low temp threshold. Then attach an electronic sensor set at the high temperature,
to close a contactor in parallel with the original thermostat terminals, this only enabled
when the timer declared off peak time. Solid state is pretty reliable and the rest is
century old proven reliable. technology. I don't see any maintenance or reliability
issues. Guess this would be a custom job today, it ought to become an option on the left
coast pretty soon.

A production version might just shift the trip point of the thermostat
(mechanically or electrically) using an automatically set radio clock. Bruce Roe

Have you seen what a plain, old water heater thermostat looks like ? One step up from a snap switch and a piece of metal that expands/contracts w/ temp. I like your idea, but I I have my doubts the market will accept anything that's new, or costs money. Dumbed down argument that's hard to refute on the surface: It ain't broke - why fix it ?

[insaneoctane]

Couple more interesting graphs for TOU analysis.
Graph 1 (line) shows % usage by type for each of 12 months
Graph 2 (2 pies) shows % usage/gen by type averaged over 12 months

I think this type of graph helps convince one that TOU would be beneficial for them.

solar tou by type.JPGsolar tou pie.JPG

[J.P.M.]

Couple more interesting graphs for TOU analysis.
Graph 1 (line) shows % usage by type for each of 12 months
Graph 2 (2 pies) shows % usage/gen by type averaged over 12 months

I think this type of graph helps convince one that TOU would be beneficial for them.

[ATTACH=CONFIG]6175[/ATTACH][ATTACH=CONFIG]6176[/ATTACH]

Slightly tongue in cheek: Keep this up and SCE will sue you for potentially reducing their bottom line. Thanx for the info and perhaps just as importantly the ideas.

[silversaver]

Wait about 4 to 5 weeks later after you switch to TOU-D-A plan, SCE will give you the "net" consumption from "Green Botton" for last 13 months usage. Each hours break down to either "+" or "-" which make the calculation easy or difficult. For me, my solar is been up and running for 15 months, so I can get a real net consumption from "Green Botton". If your solar did not run more than 12 months, it will be a mix value which make your calculation difficult becasue you are getting mix of "net" and "consumption only" values.

[gvl]

I have a somewhat less than common setup with 2 meters, one for the house one for the EV, no solar yet. SCE confirmed the 2 meters can be aggregated for the purpose of net-metering. Anyone can comment if under the TOU-D-A/net-metering the Baseline Allocation Credit is calculated for the "net" usage from 2 meters, or only the house one which is the solar will be connected to? The concern is that while I may be a net-consumer each month I can be a net-producer on the house meter and will miss out on the credit plus it will reduce the cost of the electricity that I sell. Abandoning the EV meter/rewiring the charger to the house panel would solve this issue but I'd like to avoid it.

[silversaver]

I have a somewhat less than common setup with 2 meters, one for the house one for the EV, no solar yet. SCE confirmed the 2 meters can be aggregated for the purpose of net-metering. Anyone can comment if under the TOU-D-A/net-metering the Baseline Allocation Credit is calculated for the "net" usage from 2 meters, or only the house one which is the solar will be connected to? The concern is that while I may be a net-consumer each month I can be a net-producer on the house meter and will miss out on the credit plus it will reduce the cost of the electricity that I sell. Abandoning the EV meter/rewiring the charger to the house panel would solve this issue but I'd like to avoid it.

If you choose TOU-D-A, then you really don't need TOU-EV1 2 meters plan. Any plan you choose, SCE credit you the same way they charges you.

[gvl]

[ATTACH=CONFIG]6215[/ATTACH]

If you choose TOU-D-A, then you really don't need TOU-EV1 2 meters plan. Any plan you choose, SCE credit you the same way they charges you.

Except I already have it (the TOU-EV1) and it has certain benefits like the 11c/kWh off-peak rate from 9pm to noon and lower on-peak rates than TOU-D-A, so I would like to keep it. I just want to clarify how the Baseline Allocation Credit is calculated in terms of meters. And btw, my understanding is that SCE will credit you 10c less per kWh you produce in excess of what you consume up to your monthly baseline allocation.