Are SCE Peak Time Rebate (PTR)/Save Power Days Credits "Real Money" under NEM?

[Ward L]

I don't know what happened to my posts! I had composed a nice detailed response and when I posted it only the first sentence was displayed. The moderator suggested I not use apostrophes as that might be the culprit. I am setting up my spreadsheet to calculate the cost/return of solar for my situation depending on the size of the system installed. Yes, I am on the standard SoCal Edison (and yes, when I say Edison I mean SoCal Edison or SCE) tiered residential rate. When I finish my calculations I'll start a new thread. I am happy to learn something new, but I am pretty familiar with the various tariff rate options. SCE does use the tiered rate in reverse when you overproduce, meaning your cumulative energy charge is calculated with a higher negative kWh cost in tier 2. I don't think they give you anymore cash back because of this. For sure, I do not completely understand how SCE calculates the amount they pay for the excess kWh at the end of the year. .

[Mike90250]

apostrophes 's used with standard plane jane fonts and character sets work. Using fancy stuff, cell phone fonts, apple/mac fonts, generally fail. Sorry

[ButchDeal]

apostrophes 's used with standard plane jane fonts and character sets work. Using fancy stuff, cell phone fonts, apple/mac fonts, generally fail. Sorry

It isn't the font but the character. Microsoft will convert to an open / close apostrophe instead of the backtick or apostrophe, also a long dash instead of minus symbol, and ellipsis character instead of three dots. There may be others. These characters are part of the character set and not some strange font set.

Macs with chrome will also convert to some of these characters in the browser, as will iphones

Also some people just type a different character for the apostrophe. here are some other options....

https://www.cs.sfu.ca/~ggbaker/reference/characters/#single

[SunEagle]

It isn't the font but the character. Microsoft will convert to an open / close apostrophe instead of the backtick or apostrophe, also a long dash instead of minus symbol, and ellipsis character instead of three dots. There may be others. These characters are part of the character set and not some strange font set.

Macs with chrome will also convert to some of these characters in the browser, as will iphones

Also some people just type a different character for the apostrophe. here are some other options....

https://www.cs.sfu.ca/~ggbaker/refer...acters/#single

I believe the Forum's IT staff is working on the apostrophe issue.

[J.P.M.]

I don't know what happened to my posts! I had composed a nice detailed response and when I posted it only the first sentence was displayed. The moderator suggested I not use apostrophes as that might be the culprit. I am setting up my spreadsheet to calculate the cost/return of solar for my situation depending on the size of the system installed. Yes, I am on the standard SoCal Edison (and yes, when I say Edison I mean SoCal Edison or SCE) tiered residential rate. When I finish my calculations I'll start a new thread. I am happy to learn something new, but I am pretty familiar with the various tariff rate options. SCE does use the tiered rate in reverse when you overproduce, meaning your cumulative energy charge is calculated with a higher negative kWh cost in tier 2. I don't think they give you anymore cash back because of this. For sure, I do not completely understand how SCE calculates the amount they pay for the excess kWh at the end of the year. .

On how excess generation payments are calculated :On systems that provide a significant or entire portion of an annual load, over the course of 12 billing periods, some billing periods will show an excess generation, others will show a deficit. At he end of 12 billing periods, if there is a net excess generation (the sum of the prior 12 months +'s and -'s), that excess is paid at a rate per kWh which is equal to the blended wholesale rate that SCE paid to suppliers for power over the recent past several months that they bought to supply to their customers.

So, to explain the excess generation credit (and note, not how to calculate a monthly bill) and using very simple numbers, say a user is on tiered rates, SCE schedule "D" (and note that there are several tiered rate schedules, with several baseline allocations each, hence my prickiness about which schedule you are actually on and your climate zone), and the annual use is, say, 10,000 kWh/yr. over some single year, some months more some less than (10,000/12) kWh/month average, and the user has a PV system that generates, say 12,000 kWh over that same 12 month period, also some months more and some less but not in the same pattern as the monthly consumption, meaning for some billing periods generation will be more than consumption and other billing periods usage will exceed generation. At the end of the relevant year of 12 billing periods the PV system will have generated 12,000 - 10,000 kWh net, or 2,000 kWh excess kWh. That 2,000 kWh excess will cause a payment to be made to the account holder at the rate of something like $0.03/kWh or (2,000 kWh)*($0.03/kWh) = $60.

Now, let's see if we can get a feel, using some average annual system output numbers as an example (ONLY) to get a feel for what the financial impacts of oversizing might be.
To generate 10,000 kWh/yr., and assuming a well designed PV system will generate ~ 1,750 kWh/yr per installed STC kW (like mine has done for the last 5+ years) will require a system size of (10,000 kWh/yr)/(1,750kWh/yr./STC kW) = 5.71 kW. BUT, since it's actually generating 12,000 kWh/yr., to a first approx., the system is probably something like (12,000/1,750) = 6.86 STC kW in size. So, in this simple example, the system is 6.86 - 5.71 = 1.15 kW oversized.

So be it. However, and using what are perhaps somewhat conservative prices for So. CA turnkey systems of, say, $3.00/installed STC W, that 1.15 STC kW has cost the owner (1,150 STC W) * ($3.00/STC W)* (.7) = $2,415 after tax credit. Now, that $2,415 is paying back ~ $60/yr. in excess generation credits or a simple 2.5 % ROI. I believe I can do better and keep the flexibility of the $2,415 intact by not oversizing and using the funds not spent on PV oversizing for better and more flexible endeavors (like, as one example only a bond fund that pays > 2.5% that I can get out of in a day or less.

Now, as for turning the excess capacity to recharge the batteries on an (added) EV, the economics get a little more involved, but perhaps more favorable.

Say a user drives 12,000 miles /yr., and a user's current ICE gets 30 mpg and gasoline is $ 3.00/gal. Oil changes cost $ 40/ea. and oil is changed every 5,000 miles. So, annual fuel and simple differential maint. costs on the ice are (12,000 miles/yr/30 mpg)*$3.00/gal + (12,000 miles/yr/5,000miles/oil change)*($40/oil change) ~ $1,200/yr. + $96/yr = $1,296/yr., say $1,300/yr.

The user is considering getting an EV to replace both the fuel and oil change cost only, and not considering the cost of replacing an otherwise fit for purpose vehicle or the cost(s) of financing of a new EV.

Say the proposed EV gets 3.5 miles/kWh, and all the energy is added from a 240 V home charger that's 90% efficient. POCO billing is on tiered rate, SCE plan D.

Two scenarios: 1.) Using the current 6.86 STC kW system. 2.) Sizing a system to include 10,000 kWh/yr + (12,000 miles/yr)/((3.5 miles/kWh)*(.9)) = 13,810 kWh/yr.

1.) From above, the 6.86 kW system which will generate 12,000 kWh/yr. will require a purchase of an additional 1,810 kWh/yr. from SCE. (10,000 +3,810 -12,000) kWh/yr. Since I'd assume (a bit of a risky assumption but if not likely, at least possible), most billing months will be at a net tier one rate because every billing period's monthly net billing use will likely be < the baseline allowance. The rate charged for that 1,810 kWh will therefore be at $0.1793/kWh, or $325 extra charges/yr. for the 1,810 kWh/yr. extra usage from a new EV that the 6.86 kW system doesn't provide.

However, the 2,000 kWh/yr. of current excess production that the 6.86 STC kW system will meet of the 3,810 kWh added EV load will displace ((2,000 kWh*3.5 miles /kWh)*(.9))/*($3.00/gal./30 mpg) = $630 + (~ $100 in oil changes) = $730 in avoided fuel purchases and oil changes. The net savings will therefore be ~ $730 - the $325 in extra electrical charges = $395/yr. to the good., but you would lose the $60/yr. excess generation credit and pay a few $$ in NBC. Still, ~ $325/ yr. to the good +/- a few bucks.

2.) A new system to handle the entire 13,810 kWh/yr. load will be 13,810 kWh/yr. /1,750 kWh/yr. per STC kW = 7.89 STC kW. At the same $3.00/STC w turnkey price = $16,569 system price after tax credit. That will save all vehicle fuel and oil change costs plus all but a max savings reduction of about $120/ yr. of the domestic electrical usage of 10,000 kWh/yr. for min. billing and also less whatever the NBC charges are for the user.

The very approx. savings on tiered billing for such a system total tiered bill: For tier one will, on average be for 440 kWh/mo. @ $0.1793/kWh = $946 For tier two, 711 kWh/mo. @$0.23041/kWh = $1966, so VERY approx. $2,912/yr. less any NBC, less any min. daily min. billing charges for days when the PV system offsets the entire 24 hr. load. Add to those savings of ~ $1,300 for avoided fuel and differential maint.

But, to be fair, the differential cost of a new EV vs. a new ICE vehicleas well as the loss of any remaining service life of the ICE vehicle that's traded out before the end of its service life ought to be addressed.

So, $16,569/($2,912/yr.) = ~ 5.7 yrs. That number is pretty useless as a financial measure of cost effectiveness except maybe as a rough comparison with alternative places to put the money, but it's probably lower than it was a few years ago and that is at least not bad.

All of the above is VERY approximate, is an example only of back of the envelope type analysis, and takes no account of such things as the time value of money, discount rates for funds, or any comparison of alternatives type of analysis, or any serious financial analysis. But it may be useful as an example of a way to begin to analyze or think about a situation.

[Ampster]

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But, to be fair, the differential cost of a new EV vs. a new ICE vehicle as well as the loss of any remaining service life of the ICE vehicle that's traded out before the end of its service life ought to be addressed.
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All of the above is VERY approximate, is an example only of back of the envelope type analysis, and takes no account of such things as the time value of money, discount rates for funds, or any comparison of alternatives type of analysis, or any serious financial analysis. But it may be useful as an example of a way to begin to analyze or think about a situation.

Great analysis. The only thing that I would add in terms of vehicle costs is concerned is the incentives for purchase or lease of an EV. For leasing or purchasing some manufactures have offered very favorable terms especially for compliance cars because every sale of a compliance car gets them a credit in states like California. Without that credit the manufacture would have to purchase credits or pay a fee. Furthermore the purchaser gets a California cash rebate for approximately $2,500 (actual amount can be greater or less depending on purchaser's income). There is also another approximate $500 cash rebate administered through the various public utilities. Then there is the Federal tax credit of $7,500 which does not apply to cars from Tesla or General Motors. That credit is going away in the next few years for all cars.
The above may be part of what @J.P.M intended when he mentioned "serious financial analysis".

[J.P.M.]

Great analysis. The only thing that I would add in terms of vehicle costs is concerned is the incentives for purchase or lease of an EV. For leasing or purchasing some manufactures have offered very favorable terms especially for compliance cars because every sale of a compliance car gets them a credit in states like California. Without that credit the manufacture would have to purchase credits or pay a fee. Furthermore the purchaser gets a California cash rebate for approximately $2,500 (actual amount can be greater or less depending on purchaser's income). There is also another approximate $500 cash rebate administered through the various public utilities. Then there is the Federal tax credit of $7,500 which does not apply to cars from Tesla or General Motors. That credit is going away in the next few years for all cars.
The above may be part of what @J.P.M intended when he mentioned "serious financial analysis".

Well, it may seem great to you. It's really not much more than what might be best described as a concatenation of brain farts about stuff that's not much more than a set of precursor thoughts on the way to serious considerations of financial matters with respect to residential PV viability.

What you wrote above is not part of what I had in mind with respect to serious financial analysis. For clarity, I'd suggest rereading the last paragraph of that post.

The above with respect to tax credits for EV purchases is no more than information that is openly available. As such, and just like the cost of other equipment and services, it may be necessary information as input to any analysis, but separate from the methods of any analysis used.

The entire post I wrote was meant as little more than a B.S. session about some things that may be useful to consider, and some ways to think about the situation on the way to further deliberations when trying to figure out if a PV system makes financial sense at all before the more involved and IMO only, required analysis that involves time value of money or other methods of analysis is done. Hopefully, any examples I used can have other numbers plugged in as the OP may find use for, and so (perhaps) gain some insight(s), or at least formulate some stuff to think about.

See texts on financial analysis and/or the financial decision making process for more info. What I wrote, if useful for anything at all, is all very preliminary to any decision making process worthy of the name.

Anyway, and more IMO stuff only, as far as vehicles go, in general they are not cost effective - at least not new ones - more like a necessary and somewhat self inflicted evil. Part of my goal when writing "serious financial analysis" was to be specific to some degree about limiting my written spoor to some things to think about with respect to the cost effectiveness of PV systems and not muddy the waters with other issues.

FWIW, and a bit off topic, rebates and other mechanisms to manipulate users such as tax credits with phony deal/save stories that do nothing to improve product quality, while effectively raising prices in ways end users are clueless about do little more than enrich sellers and make for an environment that allows and enables otherwise unqualified people to survive in a softer environment than would exist without rebates/tax credits while allowing lower product quality to persist. I believe such shoring up generally works against any progress of making alternate energy more efficient and more cost effective. But that's a separate subject that's off topic.

[SunEagle]

For some reason this thread has attracted way too many spammers so I am closing it.

A note to other Moderators. Keep an eye out for posts that start in Hii followed by a weblink.