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drees
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Re: SDG&E, Solar, Net Metering, and Time of Use 2 (TOU2)

Wed Mar 30, 2016 7:49 pm

philip wrote:There are definitely some "ifs" to consider, but generally I think over-sizing is a bad idea, financially.

Yes, this is true with current rates. I sized my system originally to account for about 90% of my overall usage.

But even at 90% overall, you still get stuck with the minimum charge in the months you overproduce, which is about half the year.

If you know for sure you won't be getting any more plug-in vehicles or other large loads - then yeah, size your system accordingly.

ybitz wrote:But from elsewhere I've heard, EV-TOU2 won't be as lucrative going forward for solar owners because SDGE is going to change the peak times, right?

Yes, SDG&E is doing two things to make solar less attractive financially. Solar is in many ways becoming a victim of it's own success with net demand from 10am-4pm currently being as low as 12am-5am.

This document has proposed TOU rate periods:
https://www.sdge.com/sites/default/file ... ?nid=16476

I don't know if these TOU rate periods will be the same for EV-TOU, but I assume they will be similar.

Instead of Summer/Winter TOU periods, now they will be year round.
On peak rates will be 4pm-9pm instead of 11am-6pm 7 days a week.
Super off-peak will be 12am-6am weekdays and 12am-2pm weekends.

The estimated impact on residential rates will be an increase of over 11%.

You're going to need to produce a lot more energy off-peak to make up for energy used on-peak, or you are going to need storage. Right now at this time of year my PV system only generates 13% of it's energy on-peak.
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Re: SDG&E, Solar, Net Metering, and Time of Use 2 (TOU2)

Wed Mar 30, 2016 8:17 pm

Drees, now that we've added a second electric car (Volt 2.0), I've been planning to add more panels and was also wondering if the expansion was done after the cap whether it would be grandfathered in or not.

But my true up date is next month and, like Philip, I'm discovering that on EV-TOU2, even though I've consumed way more than I've generated, it's only going to end up costing pennies/kwh. So as much as I'd love to add panels (hate consuming more fossil fuels), I think it would take decades to pay off.

We'll see what happens if/when SDGE is able to shift peak to evening hours. (If they do, I'd love to find some vehicle-to-grid solution to feed back unused kwh's after my commute, then take 'em back when super off-peak starts.)

BTW, big shout out to Randy for encouraging me to try EV-TOU2 a couple years ago! (Last year, the boomerang kids moved back in and I way over-consumed that year too, but thanks to TOU2 and the climate bonus, I ended up with a credit at the end of the year!)
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Re: SDG&E, Solar, Net Metering, and Time of Use 2 (TOU2)

Wed Mar 30, 2016 9:02 pm

drees wrote:You're going to need to produce a lot more energy off-peak to make up for energy used on-peak, or you are going to need storage. Right now at this time of year my PV system only generates 13% of it's energy on-peak.


I've analyzed this a bit and found that my NEM credits will drop by $350 for the year with the proposed peak rate change. (I currently estimate a total of $2421 annual solar production for my system, so that would drop to $2073). This is a larger impact than what most systems would experience since my system is heavily shaded in the winter months and in the afternoons in the summer.

So to make up for the $350 difference, I would need to produce another 1500 kWh over the year in off peak, which is about another 800 watts of PV a 14% size increase for me.

However, my consumption during the current on peak summer hours, which is primarily A/C use, will shift to mostly off peak hours which may offset the additional lighting/cooking load that we would have in the new evening peak. So if we reduce our consumption and/or load shift what we can, the new TOU time period may have very little impact.

In all, I'm really not too concerned about it (I do like to analyze it though), as it won't make that big of a difference on an annual basis - a couple hundred dollars most likely. (Hey, I used to spend that much on gasoline in 2 weeks!)
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Re: SDG&E, Solar, Net Metering, and Time of Use 2 (TOU2)

Wed Mar 30, 2016 9:06 pm

drees wrote:But even at 90% overall, you still get stuck with the minimum charge in the months you overproduce, which is about half the year.


Are you sure about that? If you consumed $120 over the course of a year, any minimum charges that accrued should be wiped out at true up. I'm not 100% sure on this, as i am only going off what I have read over at solarpaneltalk. My true up is in May, waiting to see what happens there.
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Re: SDG&E, Solar, Net Metering, and Time of Use 2 (TOU2)

Thu Mar 31, 2016 1:56 am

philip wrote:
drees wrote:But even at 90% overall, you still get stuck with the minimum charge in the months you overproduce, which is about half the year.
Are you sure about that? If you consumed $120 over the course of a year, any minimum charges that accrued should be wiped out at true up. I'm not 100% sure on this, as i am only going off what I have read over at solarpaneltalk. My true up is in May, waiting to see what happens there.

100% sure, I'm looking at my SDG&E NEM Summary right now - I also true-up in May. There is a "Minimum Charge Adjustment" line which covers the months where my system generated enough energy that I had a net credit (thank to TOU rates, I generated a credit despite being a net consumer of electricity. Those periods are billed at the minimum rate of $0.17/day. My Minimum Charge Adjustment for the year will be about $31.

Now, you can have your minimum bill offset if your system generates more energy annually than you use. That energy is credited regardless at a rate of something like $0.04 / kWh. If you generate enough to offset your minimum bill, you can ask for a check.

cbiwww wrote:But my true up date is next month and, like Philip, I'm discovering that on EV-TOU2, even though I've consumed way more than I've generated, it's only going to end up costing pennies/kwh. So as much as I'd love to add panels (hate consuming more fossil fuels), I think it would take decades to pay off.

Yeah, thanks to TOU my average cost for my net consumption is only around $0.12 / kWh. But the incremental cost is still the same retail rate regardless. That means all on-peak energy is credited at $0.46 / kWh in the summer and the rest credited at $0.21-22 / kWh.

My annual true-up bill will be around $500 excluding minimum charge adjustments. Ballpark estimate that 30% of energy produced annually is on-peak at $0.46 / kWh and the rest is $0.21 / kWh. This puts the average value of each kWh generated around $0.29 / kWh and I would need to generate around 1,700 kWh to zero out my bill (at least as close as possible).

1 kW of PV generates about 1,500 kWh / year here in San Diego, so I'd only need around 1150W of PV before I hit the point of diminishing returns, financially, anyway.

But all this assumes the current rate structure and even ignoring NEM 2.0, it doesn't appear that things will continue to be this favorable.
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Re: SDG&E, Solar, Net Metering, and Time of Use 2 (TOU2)

Thu Mar 31, 2016 5:42 am

philip wrote:
ybitz wrote:My situation:

- On average, use 660 KWH/month (360 KWH house, 300 KWH for Leaf).
- $120 total for the two electric meters.
- House on regular DR rate, Leaf on EV-TOU second meter
- House in a sunny area
- I've gotten a quote for a 4KW system for about $15k after 30% federal rebate.

With all the recent changes and uncertain regarding NEM 2.0 TOU, if you were me, would you get solar?


With the #'s you gave, you are looking at more than a decade payback, I wouldn't do it. However, your quote for solar appears to be very high - $5.36/watt, unless you have unusual circumstances, you should be able to do a lot better than that.


My 5.85kW cost me $3.21 per watt installed pre ITC (Investment Tax Credit). Shop around and target a max of $3.50 per w installed. The Companies offering those prices are NOT the big companies with the massive advertising and overhead costs. My system has an IRR of around 21% over a 15 year period and a payback period of around 5.5 years.

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Re: SDG&E, Solar, Net Metering, and Time of Use 2 (TOU2)

Tue Apr 12, 2016 9:12 am

Just a heads up for those on EV-TOU2 rate schedule, my last bill for the month of March had an incorrect energy amount for the on-peak time period. It was the same as the off-peak which is wrong. I called SDG&E and the account rep agrees (very helpful, by the way) that it is wrong, but they are escalating it to see how to correct it. I suspect there is something wrong with their billing system and it is grabbing the off peak again for the on peak period.
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Re: SDG&E, Solar, Net Metering, and Time of Use 2 (TOU2)

Tue Apr 12, 2016 1:46 pm

philip wrote:Just a heads up for those on EV-TOU2 rate schedule, my last bill for the month of March had an incorrect energy amount for the on-peak time period. It was the same as the off-peak which is wrong. I called SDG&E and the account rep agrees (very helpful, by the way) that it is wrong, but they are escalating it to see how to correct it. I suspect there is something wrong with their billing system and it is grabbing the off peak again for the on peak period.
I'm convinced that part of the strategy is to make these plans so complicated that it obfuscates what is really going on, thus making it nearly impossible to determine which rate plan is the best so that people cannot see that all are actually bad plans.

It also makes finding and correcting errors much more difficult.
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Re: SDG&E, Solar, Net Metering, and Time of Use 2 (TOU2)

Thu Apr 14, 2016 12:40 am

philip wrote:Just a heads up for those on EV-TOU2 rate schedule, my last bill for the month of March had an incorrect energy amount for the on-peak time period. It was the same as the off-peak which is wrong. I called SDG&E and the account rep agrees (very helpful, by the way) that it is wrong, but they are escalating it to see how to correct it. I suspect there is something wrong with their billing system and it is grabbing the off peak again for the on peak period.

Hmm, both my March and April bills look OK to me.

RegGuheert wrote:I'm convinced that part of the strategy is to make these plans so complicated that it obfuscates what is really going on, thus making it nearly impossible to determine which rate plan is the best so that people cannot see that all are actually bad plans.

Luckily, SDG&E does provide tools that supposedly run your last year of data through rate plan simulators so you can see what you would have been charged under other rate plans (I haven't confirmed the results recently, but they do pick the plan I did estimate to be best for me). I still plan on eventually setting up and running my own energy monitoring system so I can independently verify their data and also collect data down to the circuit breaker.

FWIW, I know that many water districts and other public entities who have installed large solar systems while promising to save taxpayer money are extremely upset that SDG&E is gutting TOU rates by moving peak time to mid-late afternoon and killing the economics of their systems. They will be pushing to grandfather existing systems under original TOU periods.
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Re: SDG&E, Solar, Net Metering, and Time of Use 2 (TOU2)

Thu Apr 14, 2016 7:41 am

cbiwww wrote:Drees, now that we've added a second electric car (Volt 2.0), I've been planning to add more panels and was also wondering if the expansion was done after the cap whether it would be grandfathered in or not.

But my true up date is next month and, like Philip, I'm discovering that on EV-TOU2, even though I've consumed way more than I've generated, it's only going to end up costing pennies/kwh. So as much as I'd love to add panels (hate consuming more fossil fuels), I think it would take decades to pay off.

We'll see what happens if/when SDGE is able to shift peak to evening hours. (If they do, I'd love to find some vehicle-to-grid solution to feed back unused kwh's after my commute, then take 'em back when super off-peak starts.)

BTW, big shout out to Randy for encouraging me to try EV-TOU2 a couple years ago! (Last year, the boomerang kids moved back in and I way over-consumed that year too, but thanks to TOU2 and the climate bonus, I ended up with a credit at the end of the year!)


Hi Craig,
Thanks for the shout-out....As to your question about adding panels, there is a reference to that in the following "rules" document (Schedule NEM) on sheet 15...

http://regarchive.sdge.com/tm2/pdf/ELEC ... DS_NEM.pdf

Here is the relevant text...

"Modifications or repairs that occur after the earlier of July 1, 2017 or when SDG&E reaches its program limit that increase the system’s generation by more than the greater of 10% of the renewable electrical generating facility’s capacity at the time the customer receives the ATO letter or 1 kW, not to exceed a total generation capacity of 1 MW (2) and are sized to meet but not exceed the customer’s annual onsite load, may either choose to meter the additions separately under the successor tariff or elect for the whole renewable electrical generating facility to take service under the successor tariff. "

Back to Randy: As far as changing the TOU periods, shouldn't those actually reflect what's happening on the power system so that all customers can be billed or credited fairly? When I worked in our control center many years ago, the peak time on the power system was routinely 3 to 4pm (hence the on-peak period of noon to 6pm from all those years ago). But now the power system peak is routinely 7 or 8pm.

Yes, it's unfortunate that all of us solar power producers will get less reimbursement for noon power or 2pm power if a shift in TOU periods goes through, but noon to 6pm is not the peak time any more (we have more residential customers now than before). And if you're a business owner paying extra for power at peak times such as 1pm or 2pm, don't you want the TOU periods to accurately reflect what's going on with the power system. It goes both ways...

The current peak load at 7 or 8pm is larger now in megawatts than the old 3pm peak used to be, and since most solar is winding down at that time even in the summer, the need for utility generation is larger than ever (with an even larger ramp-up as the sun goes down to replace solar generation)...That's one reason why peak times should be pushed out (to help mitigate or manage that ramp)...

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