6kW system in Agoura Hills

[gvl]

What about placing some of the panels on the NW side (area 1)? It gets plenty of sunshine in the afternoon, but obviously not in the morning. Bad idea? Do installers have estimation tools that allow them to find the optimal layout based on the TOU schedule?

[sensij]

What about placing some of the panels on the NW side (area 1)? It gets plenty of sunshine in the afternoon, but obviously not in the morning. Bad idea? Do installers have estimation tools that allow them to find the optimal layout in based on the TOU schedule?

If you have an estimate of your hourly usage for the past year, forum member InsaneOctane put together a spreadsheet that helps compare the different SCE plans. I've been making some modifications to it that will help it be more friendly for cut and pasting estimated production data from PVWatts or SAM, and hourly usage. I doubt many (any) installers have worked through the details well enough to offer a very informed opinion.

My guess is SE will outperform NW, but we could run a model and see.

[gvl]

If you have an estimate of your hourly usage for the past year, forum member InsaneOctane put together a spreadsheet that helps compare the different SCE plans. I've been making some modifications to it that will help it be more friendly for cut and pasting estimated production data from PVWatts or SAM, and hourly usage. I doubt many (any) installers have worked through the details well enough to offer a very informed opinion.

My guess is SE will outperform NW, but we could run a model and see.

One complication for this method is that my hourly usage will be significantly different after a switch to TOU, as I will need to pay attention as to what and how much I use during on-peak, mainly the pool pump and the A/C. As a half-measure a way to optimize the layout just in terms of generation that yields most credits based on the price per kWh during particular time and constraints of a particular site would be at least somewhat useful, I think.

[sensij]

One complication for this method is that my hourly usage will be significantly different after a switch to TOU, as I will need to pay attention as to what and how much I use during on-peak, mainly the pool pump and the A/C. As a half-measure a way to optimize the layout just in terms of generation that yields most credits based on the price per kWh during particular time and constraints of a particular site would be at least somewhat useful, I think.

Sure, that kind of analysis works well for the TOU-D-A plan, which has a straightforward energy value in each time of use. It doesn't work quite as well for the TOU-D-T plan which has a complicated forumla to determine when you move from level 1 to level 2 pricing based on how much net usage you have throughout the month. TOU-D-A seems to be favorable for several people here and in other forums that have posted about running the numbers, so I'll get back to you in a bit with an estimate.

What is your zip code, and what tilt / azimuth's do you want to see?

[gvl]

Sure, that kind of analysis works well for the TOU-D-A plan, which has a straightforward energy value in each time of use. It doesn't work quite as well for the TOU-D-T plan which has a complicated forumla to determine when you move from level 1 to level 2 pricing based on how much net usage you have throughout the month. TOU-D-A seems to be favorable for several people here and in other forums that have posted about running the numbers, so I'll get back to you in a bit with an estimate.

What is your zip code, and what tilt / azimuth's do you want to see?

The baseline allocation credit on TOU-D-A must complicate things as well but likely not as bad as the tiered structure on TOU-D-T. I suspect that TOU-D-T will work better in my case due to the earlier on-peak window and the SE direction of my roof, and also that it'll allow me to run my A/C from 6-8pm on the off-peak rate. I have a EV TOU meter so I get 11c for charging my EV at night anyway, so the benefit from the super-off-peak rates on TOU-D-A should be minimal. However I think I should still try to get on TOU-D-A first as my understanding is it will be phased-out and probably sooner than later, I can always switch to TOU-D-T in the future but not the other way around once the A plan is no more.

I'm in 91377, tilt is 23-degrees, azimuth is 130 for SE, 220 for SW, and 310 for NW. Thanks!

[sensij]

130 deg - Generation Value = $3215, Baseline cost = $421, net generation = $2793
220 deg - Generation Value = $3518, Baseline cost = $423, net generation = $3096
310 deg - Generation Value = $2808, Baseline cost = $417, net generation = $2391

With TOU-D-A, note that if you size your system to cover all of your non-EV loads, and then your EV consumed roughly the baseline allocation each month, the baseline cost shown above becomes a credit, and you are effectively charging your car for $0.01 / kWH. TOU-D-A and TOU-D-B are newer than TOU-D-T, and with the shifted peak hours, I would guess they are likely to outlast TOU-D-T.

TOU-D-T

130 deg - $2669 generated
220 deg - $2910 generated
310 deg - $2209 generated

I set up the model assuming very favorable generation (very low system losses), producing over 11000 kWh from a 6 kW array. Under these conditions, about 1.7% of energy is lost with clipping. Please do not use these numbers to justify the absolute price of your system, they really need to be evaluated against what your bill would be with consumption included. As a relative comparison between array orientations, I think it could be helpful.

The spreadsheet I'm using is a modification of what InsaneOctane posted in his thread, with the most significant change being the inclusion of daylight savings time adjustments.

[gvl]

Thanks, this is very good info. Great point on EV charging but my EVSE is hard-wired to the dedicated EV TOU meter, so to get that baseline credit on EV charging I'd need to rewire it to the main panel or use my portable EVSE to charge at night. Might as well just undersize the system a bit to get that baseline allocation credit on non-EV usage, right? One perk of a dedicated EV meter is that it has 11c/kWh rate until noon, so if you're generating excess energy at a higher-priced TOU-A rate at 30c/kWh from 8am to noon and charging at the same time you're generating 19c credit for each kWh that ends up in the EV battery under net-metering, at least this is how I understand it works. I get it it is just semantics but still interesting.

As for TOU-D-A/B availability, the footnote says "There are a limited number of enrollments available for this rate plan", which makes me think the T will be open for enrollment longer than A/B.

[gvl]

Got a quote today from another local installer for exactly the same equipment as in the OP, $3.40/Wt DC, which is 55c/Wt better. Looks very competitive, the installer has many positive reviews on Yelp. I typically take them with a grain of salt, especially the ones that lack substance, but in this case they seem to contain enough details to be convincing that they come from people with real experiences.

They propose a larger 10.2kW DC system that covers 95% of my total consumption, including EV usage, for the last 12 months. While it will likely cover most of my needs and provide protection from future SCE pricing games, I'm not convinced I need that much power with a TOU/net-metering to zero-out, or close to, my monthly bill. Short of sitting down and crunching all data myself, is there an agreed-upon ballpark percentage of total usage that works well for TOU with net-metering, considering most of the usage is shifted to off-peak and super off-peak?

[sushijin]

I'm in southern cal, and I paid $3.31 per watt.... 37 solar world protect panels (that have 30 years performance warranty to produce 86% at year 30)... With Enphase micro inverters, M250.... Paid 33k.... 10.2kw system. ... I think the quote you received is a bit high. Keep shopping.

I think you could get an equivalent system for a bit less with some shopping...

In December, user JD31 shared in this post some quotes.

LG280's were about 0.25 / W more than Hanwha panels, and LG280's should be probably at least 0.10 / W less than 300's. I think paying $3.50 - $3.75 / W is reasonable for the 300's if your SE roof doesn't have space for something less efficient, depending on the installer.

[sushijin]

Much better

Got a quote today from another local installer for exactly the same equipment as in the OP, $3.40/Wt DC, which is 55c/Wt better. Looks very competitive, the installer has many positive reviews on Yelp. I typically take them with a grain of salt, especially the ones that lack substance, but in this case they seem to contain enough details to be convincing that they come from people with real experiences.

They propose a larger 10.2kW DC system that covers 95% of my total consumption, including EV usage, for the last 12 months. While it will likely cover most of my needs and provide protection from future SCE pricing games, I'm not convinced I need that much power with a TOU/net-metering to zero-out, or close to, my monthly bill. Short of sitting down and crunching all data myself, is there an agreed-upon ballpark percentage of total usage that works well for TOU with net-metering, considering most of the usage is shifted to off-peak and super off-peak?

[Gmoney!]

I paid 3.37 for 5.1kw system with 17 lg300s and solaredge 6000 inverter.

I have basically the same orientation as you, slightly worse actually at 118.

Using PV watt and a spreadsheet I created, i calculated 5.1 system was enough for me. I have an EV and it along with my pool pump eat up close to 75% of my daily electrical demand between midnight and 6 am.

My spreadsheet calculations concluded that TOU-D-A was the best plan for me.

Do not listen to people who tell you to put it on the west roof just because the solar panel "friendly" sce plan gets you more peak generating credits. Do your math and see what works best for you.

But its sounds like you have a very similar situation to me, depending how much you drive your ev. I do 100 miles per day.

G

[J.P.M.]

I paid 3.37 for 5.1kw system with 17 lg300s and solaredge 6000 inverter.

I have basically the same orientation as you, slightly worse actually at 118.

Using PV watt and a spreadsheet I created, i calculated 5.1 system was enough for me. I have an EV and it along with my pool pump eat up close to 75% of my daily electrical demand between midnight and 6 am.

My spreadsheet calculations concluded that TOU-D-A was the best plan for me.

Do not listen to people who tell you to put it on the west roof just because the solar panel "friendly" sce plan gets you more peak generating credits. Do your math and see what works best for you.

But its sounds like you have a very similar situation to me, depending how much you drive your ev. I do 100 miles per day.

G

+1 on the panel orientation vs. output vs. POCO bill.

Every sit. is different.

You gotta do the math if you expect a reasonably close approximation.

Assuming a 270 deg. orientation will probably cost you money and be better for the POCO, at least in most of So. CA.

[gvl]

I paid 3.37 for 5.1kw system with 17 lg300s and solaredge 6000 inverter.

I have basically the same orientation as you, slightly worse actually at 118.

Using PV watt and a spreadsheet I created, i calculated 5.1 system was enough for me. I have an EV and it along with my pool pump eat up close to 75% of my daily electrical demand between midnight and 6 am.

My spreadsheet calculations concluded that TOU-D-A was the best plan for me.

Do not listen to people who tell you to put it on the west roof just because the solar panel "friendly" sce plan gets you more peak generating credits. Do your math and see what works best for you.

But its sounds like you have a very similar situation to me, depending how much you drive your ev. I do 100 miles per day.

G

How is your installation working out for you, and how long did you have it? Sounds like there are a lot of similarities between our situations, I drive about 60 miles a day average, need 400-500kWh/month for my EV needs. Just as another data point, do you know what is your gross consumption for 12 months?

[gvl]

I got another quote from the same installer for a similar 34xLG300=10.2kW DC system but with SolarEdge SE10000A-US/optimizers instead of M250 micros for $31,824 bringing the price down to $3.12/Wt DC, this is $2856 less than for the M250-based setup. I'm finding prices about $2k for the 10kW SE inverter, and $60 per optimizer, so for 34 panels I expected the price to drop to be about $1200-$1500. I double-checked if they forgot the optimizers as they aren't specifically called out on the quote and they confirmed they are in fact included. Is this too good to be true?

[sensij]

Is this too good to be true?

In my opinion, no. If you feel good about the installer's history and are confident they will do a good job, it looks like a very good price. I've been getting calls from San Diego installers again in the last couple weeks, working through their old contact lists. I wonder if business is a bit slow right now.