SCE TOU questions

[E46M3]

I did search and read countless threads and pages but still very confusing. I also asked my solar rep who I'm installing the solar with in a few weeks when everything is permitted. Can someone just explain why the 3 different TOU plans are good for? I don't get why you have to strategize when to charge if you're getting 1:1 Kwh credit. I mean if you're a net generator, it doesn't matter right? But like most, I'll probably be a net consumer, in that case, wouldn't TOU Prime be the better plan so I can charge during off peak? I asked my solar guy and here's his resonse..
"You get a retail rate for TOU based on whatever plan you're on. Solar produces most energy from 10am-2pm on the south, and 12-4 on the west roof (later in summer), so those are the retail rate hours you get credits for solar. The best return on investment is typically TOU 4-9 pm."

So why is he saying I only get retail credits for those peak producing hours? If it takes longer for solar to generate Kwh off peak, why dose that matter? I feel this can be explained in a few sentences? But so far, I haven't read anything that explains this in a clear manner but perhaps they are more confusing. Thanks!

 

[jjrandorin]

I did search and read countless threads and pages but still very confusing. I also asked my solar rep who I'm installing the solar with in a few weeks when everything is permitted. Can someone just explain why the 3 different TOU plans are good for? I don't get why you have to strategize when to charge if you're getting 1:1 Kwh credit. I mean if you're a net generator, it doesn't matter right? But like most, I'll probably be a net consumer, in that case, wouldn't TOU Prime be the better plan so I can charge during off peak? I asked my solar guy and here's his resonse..
"You get a retail rate for TOU based on whatever plan you're on. Solar produces most energy from 10am-2pm on the south, and 12-4 on the west roof (later in summer), so those are the retail rate hours you get credits for solar. The best return on investment is typically TOU 4-9 pm."

So why is he saying I only get retail credits for those peak producing hours? If it takes longer for solar to generate Kwh off peak, why dose that matter? I feel this can be explained in a few sentences? But so far, I haven't read anything that explains this in a clear manner but perhaps they are more confusing. Thanks!

These are solar questions, not model Y questions, so I moved it to the tesla energy subforum.

The summary is, you get 1:1 credit AT THE RATE THAT IS CURRENTLY IN EFFECT when you are net metering. I am not yelling at you, just attempting to call out the emphasis.

An example is, suppose you need widgets to power your home, as everything in your home runs on widgets. You have to have them. You can generate your own widgets, but only during the day, but you need widgets 24/7.

You buy your widgets from me.

I tell you:

"Ok @E46M3 I will give you 20 cents for each widget you sell to me, between midnight and 3:59pm, which is when you mostly generate your widgets. I am doing this because if you had to buy them from me at this time, they would also cost you 20 cents, so I am buying them from you at the same rate you would buy them from me."

Then, when 4pm hits and you are not generating very many widgets at all, the rate changes on widgets. I tell you:

"Ok, from 4pm to 9pm, the widgets sale price is now 50 cents. If you sell them to me, I will give you 50 cents for them. If you buy them from me at this time, the will cost you 50 cents".

You cant generate very many widgets at or after 4pm, so you have to buy them from me at the higher rate. At both times you are paying and receiving 1:1 credit, meaning the sale price to me is what you would buy them for, but you can only generate them during the cheap times, and have to buy them during the expensive times.

That doesnt get into minimum daily charges, or non bypassable charges etc. This is why for solar in CA, it is going to be basically mandatory to get a battery (or not get solar altogether), because you need to be able to both sell your widgets to the utility, AND NOT buy them at peak rates. Or, alternatively, you need to generate a LOT more widgets at off peak rates to counterbalance the punitive peak widget price.

 

[E46M3]

These are solar questions, not model Y questions, so I moved it to the tesla energy subforum.

The summary is, you get 1:1 credit AT THE RATE THAT IS CURRENTLY IN EFFECT when you are net metering. I am not yelling at you, just attempting to call out the emphasis.

An example is, suppose you need widgets to power your home, as everything in your home runs on widgets. You have to have them. You can generate your own widgets, but only during the day, but you need widgets 24/7.

You buy your widgets from me.

I tell you:

"Ok @E46M3 I will give you 20 cents for each widget you sell to me, between midnight and 3:59pm, which is when you mostly generate your widgets. I am doing this because if you had to buy them from me at this time, they would also cost you 20 cents, so I am buying them from you at the same rate you would buy them from me."

Then, when 4pm hits and you are not generating very many widgets at all, the rate changes on widgets. I tell you:

"Ok, from 4pm to 9pm, the widgets sale price is now 50 cents. If you sell them to me, I will give you 50 cents for them. If you buy them from me at this time, the will cost you 50 cents".

You cant generate very many widgets at or after 4pm, so you have to buy them from me at the higher rate. At both times you are paying and receiving 1:1 credit, meaning the sale price to me is what you would buy them for, but you can only generate them during the cheap times, and have to buy them during the expensive times.

That doesnt get into minimum daily charges, or non bypassable charges etc. This is why for solar in CA, it is going to be basically mandatory to get a battery (or not get solar altogether), because you need to be able to both sell your widgets to the utility, AND NOT buy them at peak rates. Or, alternatively, you need to generate a LOT more widgets at off peak rates to counterbalance the punitive peak widget price.

so if I generate duriing off peak and don't use most of them, I sell the excess for 20 cents/pc. But when I do need the electricity during peak and I'm a net user for that timeframe, I'd be buying the widgets at 50cents a pc? I think the confusing part is that I always hear you get 1:1 credit regardless when you sell it or buy it. So that's false right? If so, I think I get it now!

 

[jjrandorin]

so if I generate duriing off peak and don't use most of them, I sell the excess for 20 cents/pc. But when I do need the electricity during peak and I'm a net user for that timeframe, I'd be buying the widgets at 50cents a pc? I think the confusing part is that I always hear you get 1:1 credit regardless when you sell it or buy it. So that's false right? If so, I think I get it now!

You do get 1:1 credit... at the rate that is in effect at the specific point in time.

In my fictitious widget example above, you are getting 1:1 credit of 20 cents a widget, because at the time you are selling your widgets for 20 cents, you would also be buying them for 20 cents if you needed to buy any.

At the peak time of 50 cents a widget its also 1:1 credit, because you would be selling widgets for 50 cents if you had any to sell, and buying them for 50 cents if you need to buy. what changes is your ability to generate widgets (solar). The utilities keep sliding off peak time around, basically to ensure they are paying you a lot less for your solar (widgets) than when you need to buy them back at peak time when you cant generate them.

 

[E46M3]

You do get 1:1 credit... at the rate that is in effect at the specific point in time.

In my fictitious widget example above, you are getting 1:1 credit of 20 cents a widget, because at the time you are selling your widgets for 20 cents, you would also be buying them for 20 cents if you needed to buy any.

At the peak time of 50 cents a widget its also 1:1 credit, because you would be selling widgets for 50 cents if you had any to sell, and buying them for 50 cents if you need to buy. what changes is your ability to generate widgets (solar). The utilities keep sliding off peak time around, basically to ensure they are paying you a lot less for your solar (widgets) than when you need to buy them back at peak time when you cant generate them.

okay, now back to confused.. I do get 1:1 for the 20 cents timeframe and those credits do not carry over to peak? So if I need kwh during peak, those 20 cent credits are not touched? And vise versa?

Therefore, 4-9 is the better option for solar as if I need to buy during peak, it's cheaper?

 

[jjrandorin]

What do you mean those credits dont carry over to peak? If you sold me 10 widgets for 20 cents a piece, you would have 2 dollars credit. When peak rolled around, if you had to buy 10 widgets back at 50 cents a piece, that would be a cost of 5 dollars. You would have 2 dollars credit on file so you would owe me 3 dollars, even though we just bought and sold the same amount of widgets.

Im over simplifying, because I am not talking about minimum daily charges, nor "non bypassable charges" which is a charge for buying widgets from me that can not be offset by selling widgets to me, but the basic premise is the same.

 

[E46M3]

What do you mean those credits dont carry over to peak? If you sold me 10 widgets for 20 cents a piece, you would have 2 dollars credit. When peak rolled around, if you had to buy 10 widgets back at 50 cents a piece, that would be a cost of 5 dollars. You would have 2 dollars credit on file so you would owe me 3 dollars, even though we just bought and sold the same amount of widgets.

Im over simplifying, because I am not talking about minimum daily charges, nor "non bypassable charges" which is a charge for buying widgets from me that can not be offset by selling widgets to me, but the basic premise is the same.

this is the confusing part for me but I think I get it now. So really you really can't call it 1:1 credit as if I sell back during off peak, it's not 1:1 if I need to use them during peak. I think this is the part that's not clear for me.

 

[jjrandorin]

this is the confusing part for me but I think I get it now. So really you really can't call it 1:1 credit as if I sell back during off peak, it's not 1:1 if I need to use them during peak. I think this is the part that's not clear for me.

Yes, it can be called 1:1 because the buy and the sell price at all times is the same. You are thinking of the widget like a "forever stamp" or something. You dont get a widget back for every widget you sell. You sell them and buy them at the same rate, at the exact time you are selling and buying them.

It appears to me that you are thinking 1:1 means "I sold a widget, I get a widget" and in this case thats not what it means. It means "when I sell my widgets, at the time I sell them to you, its the same price as me buying one from you".

 

[E46M3]

Yes, it can be called 1:1 because the buy and the sell price at all times is the same. You are thinking of the widget like a "forever stamp" or something. You dont get a widget back for every widget you sell. You sell them and buy them at the same rate, at the exact time you are selling and buying them.

It appears to me that you are thinking 1:1 means "I sold a widget, I get a widget" and in this case thats not what it means. It means "when I sell my widgets, at the time I sell them to you, its the same price as me buying one from you".

got it! So now that this is clear to me I think I can go a bit deeper into this... if you dont mind sharing your knowledge. I don't have solar yet but will in a few weeks, right now, I think Prime definitely makes sense to me as it's cheaper to charge during off peak. But once solar, what's the minimum charges for the two TOU rates? I think you might have mentioned, NBC's and daily charges. I work 3 days in office and 2 days home(8-5). So I can charge during the day on those WFH days. The other days I'm in the office, obviously I can charge at night but this would be using the daily credits I saved up. My weekly average would be roughly 300 miles. So I really only need to charge maybe 2-3 times a week. Is 4-9 the better option after going solar? I realize I'm asking you to basically pick the plan for me but really I'm just trying to understand it. Thanks!

 

[jjrandorin]

I cant advise on that, sorry as I have dived into that. My own situation is different, since I am on NEM 1 which does not force a time of use plan. Perhaps one of our other regulars in this subforum is able to help you dive into that.

 

[E46M3]

I cant advise on that, sorry as I have dived into that. My own situation is different, since I am on NEM 1 which does not force a time of use plan. Perhaps one of our other regulars in this subforum is able to help you dive into that.

appreciate your help! you've done more than I've could have researched it myself, thanks!

 

[idealsol]

I’ve been on SCE Prime since we added solar a couple years ago
I think for us, with fairly high usage, and 2 ev’s it was a pretty easy choice and it’s worked out well
We just got our true up bill, have a 12.4 kWh system, and our bill was$34 for year
Prevoius year with just one EV we were negative -450 ish
I think each user needs to look at their situation
My biggest concern for the OP would being sure his system was done in time to get NEM 2.0 You don’t want to get stuck with 3.0

 

[E46M3]

I’ve been on SCE Prime since we added solar a couple years ago
I think for us, with fairly high usage, and 2 ev’s it was a pretty easy choice and it’s worked out well
We just got our true up bill, have a 12.4 kWh system, and our bill was$34 for year
Prevoius year with just one EV we were negative -450 ish
I think each user needs to look at their situation
My biggest concern for the OP would being sure his system was done in time to get NEM 2.0 You don’t want to get stuck with 3.0

I'm targeting NEM 2.0 obviously and system is designed and doc will be submitted within a week or two. I have one MY thus far and our system is a 10kwh system. Have you looked into 4-9 TOU and found out it's not economical to switch? just wondering how you came about choosing prime?

 

[RichardCullip]

Perhaps a real life example will help you understand TOU periods. Note that I am in SDG&E territory and on their TOU-DR1 rate plan so your numbers will be different but the TOU concepts will be the same. Here's my latest month's numbers

For my On-Peak period I used 101kWh and solar generated 10kWh which nets out to 91kWh for which I was charged $0.51883/kWh, a sub-total of $47.21

For my Off-Peak period I used 258kWh and solar generated 409kWh which nets out to -151kWh for which I was credited with $0.43447/kWh, a sub-total of -$65.60

For my Super Off-Peak period I used 151kWh and solar generated 86kWh which nets out to 65kWh for which I was charged $0.41000/kWh, a sub-total of $26.65

I also was charged $0.02706/kWh for the 322kWh of NBCs I accumulated for a sub-total of $8.71

Add them all together and I owed SDG&E $16.87 for the month. Since I have a 12 month true-up that ends in May, I don't have to pay this now but will pay the 12 month total come my true-up bill

Your values for usage and solar production will vary with your TOU periods and your billing rate but the concepts will be the same as my example

 

[E46M3]

Perhaps a real life example will help you understand TOU periods. Note that I am in SDG&E territory and on their TOU-DR1 rate plan so your numbers will be different but the TOU concepts will be the same. Here's my latest month's numbers

For my On-Peak period I used 101kWh and solar generated 10kWh which nets out to 91kWh for which I was charged $0.51883/kWh, a sub-total of $47.21

For my Off-Peak period I used 258kWh and solar generated 409kWh which nets out to -151kWh for which I was credited with $0.43447/kWh, a sub-total of -$65.60

For my Super Off-Peak period I used 151kWh and solar generated 86kWh which nets out to 65kWh for which I was charged $0.41000/kWh, a sub-total of $26.65

I also was charged $0.02706/kWh for the 322kWh of NBCs I accumulated for a sub-total of $8.71

Add them all together and I owed SDG&E $16.87 for the month. Since I have a 12 month true-up that ends in May, I don't have to pay this now but will pay the 12 month total come my true-up bill

Your values for usage and solar production will vary with your TOU periods and your billing rate but the concepts will be the same as my example

I think we might have very similar consumption if you only had one EV but since you have two, we might be proportionally similar? In any event, do you strategize your charging timing? is it usually during off peak when the sun is producing and you only charge from solar and not grid?

 

[RichardCullip]

As a net producer for the year I try to minimize NBCs when charging my RAV4 Prime. If the sun is shinning brightly I charge it early afternoon so solar production supplies most of the charge. If it's a rainy/cloudy day, I charge at night during my Super Off-Peak period (after midnight).

My total bill for the year works out to be the minimum daily charges plus any NBCs I use.

 

[idealsol]

I'm targeting NEM 2.0 obviously and system is designed and doc will be submitted within a week or two. I have one MY thus far and our system is a 10kwh system. Have you looked into 4-9 TOU and found out it's not economical to switch? just wondering how you came about choosing prime?

I can’t recall exactly how I arrived at that decision, but I believe that the higher daily cost of Prime was more that offset by the lower non-peak charging rates. I’m sure our fairly high usage played into that decision. We produced 22.6 and 23.2 MWh over last 2 years to pretty much break even. I haven’t checked in some time but does the SCE rate comparison tool work for you? Rate Plan Comparison Tool

 

[yblaser]

The benefit of TOU-D-4-9PM is that the differential between peak and off peak rates are lower so that your energy production during the day can more easily offset your peak usage. It also has a smaller daily charge. The benefit of TOU-D-PRIME is a low off peak rate that is offset by a higher peak rate and a higher daily charge (~$170/year).

Which is better really depends on your specific usage and solar production although I would guess TOU-D-4-9PM would probably be better than -PRIME. Do you have an estimate on how much power you consume yearly and how much you solar system should produce? IF you really use significantly more than you produce then at some point TOU-D-PRIME makes sense as the money you are saving with the lower off peak rates makes up for the daily charge and the higher peak rates. To put it in perspective you would have to consume an additional 170 kWh/month off peak just to break even with the daily charge. If you add in the higher peak rate you probably need to consume ~350 kWh/month above your production to break even with TOU-D-4-9PM.

 

[E46M3]

I can’t recall exactly how I arrived at that decision, but I believe that the higher daily cost of Prime was more that offset by the lower non-peak charging rates. I’m sure our fairly high usage played into that decision. We produced 22.6 and 23.2 MWh over last 2 years to pretty much break even. I haven’t checked in some time but does the SCE rate comparison tool work for you? Rate Plan Comparison Tool

I did run that comparison tool and as of right now(no solar and not charging EV yet), Prime is the better plan according to that comparison. I'd save $240.

 

[E46M3]

The benefit of TOU-D-4-9PM is that the differential between peak and off peak rates are lower so that your energy production during the day can more easily offset your peak usage. It also has a smaller daily charge. The benefit of TOU-D-PRIME is a low off peak rate that is offset by a higher peak rate and a higher daily charge (~$170/year).

Which is better really depends on your specific usage and solar production although I would guess TOU-D-4-9PM would probably be better than -PRIME. Do you have an estimate on how much power you consume yearly and how much you solar system should produce? IF you really use significantly more than you produce then at some point TOU-D-PRIME makes sense as the money you are saving with the lower off peak rates makes up for the daily charge and the higher peak rates. To put it in perspective you would have to consume an additional 170 kWh/month off peak just to break even with the daily charge. If you add in the higher peak rate you probably need to consume ~350 kWh/month above your production to break even with TOU-D-4-9PM.

my annual projected usage is just under 11K Kwh and my system est production is 15.6K. So 4.6K is for the EV and I slightly upsized it.