Solar Installation - 0.75 Year Later

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mervinj7
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Solar Installation - 0.75 Year Later

Post by mervinj7 » Wed Oct 02, 2019 5:56 pm

I was going to originally post a review one year after installation of my system but since the Federal Credit is diminishing this year, I'll do an early preview and update this post in 2020.

System Summary:
Location: Bay Area, CA
Panels: 22 x 330W Panasonic HIT→ 7.26kW
Inverter: SolarEdge SE10000HD (Oversized for future expansion)
Warranty
  • 25 Year on Panasonic Panels
  • 25 Year on SolarEdge Inverter (extended from 12)
  • 15 Year Workmanship warranty (no cost repair or replacement)
  • 15 Year Roof Penetration Warranty
  • 15 Year Panel Output
Install Costs
Quoted Cost: $21,300 → $2.93/Watt
2019 Fed Tax Credit: $6,390
Post tax credit Cost: $14,910 → $2.05/Watt
Estimated Energy Savings (by Installer): $3000/year
Estimated Breakeven: 5 Years

Production Data
Estimated by Installer: 12,150 kWh/year
Estimated by PVWatts: 12,186 kWh/year
Annual Production (Jan to Sept actual data, Oct to Dec Est): 12,509 kWh
Estimated Utility Savings by me: $3626-$120-XX (lost to overgeneration)?
New Breakeven: <5 years?
Last edited by mervinj7 on Thu Oct 03, 2019 11:02 am, edited 1 time in total.

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mervinj7
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Re: Solar Installation - 0.75 Year Later

Post by mervinj7 » Wed Oct 02, 2019 5:56 pm

Errata
  • Why is estimated energy savings potentially higher than expected?
    The installer used a flat $0.24/kWh for their estimate. Since then, PG&E raised their rates by 4% (so far). Another rate increase is expected shortly. I also switched from a TOU rate to a TOU EV tariff. My peak daytime rates are very high ($0.29 to $0.53/kWh) but my off-peak nighttime rate is cut to $0.14/kWh. In practice, this means that every 1 kW that is generated using solar pays for 2-4 kWs of charging my EV at night. Win-win for solar+EV customers but not so much for the utility. As of July, PG&E has closed this particular tariff (EV-A) to new customers but I am grandfathered in for 5 years from date of install. My rates in 5 years will likely be less favorable for residential solar.
  • What is my final end of year true-up bill?
    I will update this in January 2020. It's a little tricky since I may end up being a net surplus generator due to charging my EV during off-peak hours. Luckily, my CCA, Silicon Valley Clean Energy, pays out net generation at the retail rate instead of at the wholesale rate like PG&E. There is also a $10/month minimum charge for connection to the electric grid.
  • Why do we have a 10kW inverter for a 7.26kW system?
    My installed initially recommended a 7.6kW inverter for my 7.26kW system. However, we were planning on converting our house to be all-electric over the next several years. A 10kW inverter with the appropriately up-sized cabling, breakers, etc makes it a bit easier to add a third string of 2-3kW panels. Surcharge was $400 at install time. In hindsight, this was unnecessary and we should gone with the installer's recommendations.
  • Any maintenance?
    None so far in the first 9 months. We did go several months without rain which led to my panels getting visibly dirty by mid-August. A fluke rainstorm "cleaned" the panels and I noticed an immediate 8% increase in production. In the future, I will hose down the panels once a year in late July.
  • What about my roof?
    It was 7 years old at the time of solar panel install. It will likely last the lifetime of the panels (25 years). If not, the current labor costs to pull off and reinstall the panels is $2000 (less than one year's worth of production). Since my breakeven point is 5 years, it wasn't an issue.
  • How does Net Metering 2.0 work in CA?
    https://news.energysage.com/net-meterin ... d-to-know/
  • What does my current rate plan look like:
    https://www.pge.com/tariffs/assets/pdf/ ... 0(Sch).pdf
    Image
  • Why did I just look at Simple Payback? What about Net Present Value and Internal Rate of Return calculations?
    Simple payback is just that, it's simple. Here's a handy guide on how to calculate net present value and IRR. However, none of these take in account how rate plans and net metering policies can change in future years.
    https://indd.adobe.com/view/8d90633c-25 ... 27fe3f33cc
  • How did I get quotes?
    I used energysage to get about 5 quotes. However, in the end, I decided to go with a local well-reputed installer who matched the lowest quote I got from energysage for a comparable system (Premium Plus panels with SolarEdge optimizers). Lower quotes were available for non-Tier 1 panels with 12 year warranties but I wasn't interested for minor upfront savings.
  • Did I lease or finance my system?
    No, just paid all-cash upfront.
  • Did my property tax bill or home insurance bill increase?
    No. State Farm told me the solar panels are included in my dwelling coverage and that no riders were necessary. In CA, "the installation of a qualifying solar energy system will not result in either an increase or a decrease in the assessment of the existing property." Thus, the property tax base will not include the addition of solar panels until there is a subsequent change of ownership.
    http://www.boe.ca.gov/proptaxes/active- ... escription
Last edited by mervinj7 on Tue Oct 08, 2019 11:29 am, edited 6 times in total.

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baconavocado
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Re: Solar Installation - 0.75 Year Later

Post by baconavocado » Wed Oct 02, 2019 6:12 pm

So, the 330W Panasonic HIT are about 60"x40" and you've got 22, which means you have about 400 ft2 of roof that faces south?

We've been putting this off because our roof is older but I think we're going to need a new roof next year, so we'll probably look into solar. Do you know what the credits will be next summer?

Thanks for posting this, very informative.

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mervinj7
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Re: Solar Installation - 0.75 Year Later

Post by mervinj7 » Wed Oct 02, 2019 6:19 pm

baconavocado wrote:
Wed Oct 02, 2019 6:12 pm
So, the 330W Panasonic HIT are about 60"x40" and you've got 22, which means you have about 400 ft2 of roof that faces south?

We've been putting this off because our roof is older but I think we're going to need a new roof next year, so we'll probably look into solar. Do you know what the credits will be next summer?

Thanks for posting this, very informative.
That's correct. We have about 1600 sq ft of total available roof space for solar. Of that, 450 sq ft faces due south. There is some minimal shading during the late afternoon due to the sun setting behind the mountains in the west as well as my neighbor's very tall redwood trees. I don't complain since we love the views.
By credits, if you mean PG&E's new EV2-A tariff, it's far less favorable for solar+EV customers since it extends off-peak hours through most of the peak solar generations times.

https://www.pge.com/en_US/residential/r ... -plan.page

Image

chw
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Re: Solar Installation - 0.75 Year Later

Post by chw » Wed Oct 02, 2019 6:37 pm

We installed 20 of the same Panasonic panels late last year as well (Coastal New England). Our inverters are Enphase microinverters, but all warranty info the same as what you mention. Installed cost was around $3.00/watt. Our energy cost is about the same as yours, and expect break even in about 5-5.5 years. Annual energy production was estimated at 8,500 kw/year, and we are on track to slightly exceed that this year. Annual kw production will come in at about 115% of this years home need- we plan to utilize the heat pump function on our hvac system to heat our home (instead of the gas boiler) during the shoulder seasons to burn off some of the accumulated energy credit on our electric bill.

We had a 4 year old south facing roof, so conditions were ideal except for slight shading from trees in the winter months.

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Horton
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Re: Solar Installation - 0.75 Year Later

Post by Horton » Wed Oct 02, 2019 7:23 pm

Thank you for sharing the detailed information. I recently got a quote and my estimated payoff was a little over 12 years, compared to your 5 year payoff. Why the difference? Because I pay an average of $0.11 / kWh, compared to your $0.24 / kWh! :shock: :shock: :shock:

Solar is a no brainer for those in CA! That’s a great ROI :beer

Some stats on energy cost by state:

https://www.eia.gov/electricity/monthly ... epmt_5_6_a
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Horton
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Re: Solar Installation - 0.75 Year Later

Post by Horton » Wed Oct 02, 2019 7:46 pm

Just curious...how much energy do you use per year? Sounds like you use about 12,000 given your comment that you may be a net surplus generator? If so, that’s a bit surprising since I live in a significantly hotter locale, have a pretty large house (3,500 sq ft), wife/kids at home during the day, and use about 13,000 kWh.
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GMCZ71
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Re: Solar Installation - 0.75 Year Later

Post by GMCZ71 » Wed Oct 02, 2019 7:50 pm

I am afraid to check how long our payoff would be, must be 20yrs?

as if oct 1 2019
RESIDENTIAL RATE SCHEDULE
Availability
Available within the McMinnville Water and Light (MW&L) Electric Service Territory
Schedule of Monthly ChargesCustomer Charge $15.10
Consumption Charge (per kWh)
First 1000 kWh $ .05811
1001 - 1500 kWh $ .06260
Over 1500 kWh $ .06260
John

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Re: Solar Installation - 0.75 Year Later

Post by arcticpineapplecorp. » Wed Oct 02, 2019 8:21 pm

fwiw (and this may be obvious to many, but it wasn't to me and others who heard this on npr's science friday) a roofer called in and said if you're thinking about installing solar, you should do it when you need to replace your roof (or try to align it as much as possible). Otherwise, if you install solar and have to replace your roof a few years later, it increases the price of roof replacement because the solar panels have to come off and go back on, etc. I think the roofer said it could increase the cost of roof replacement by as much as 50%.
"May you live as long as you want and never want as long as you live" -- Irish Blessing | "Invest we must" -- Jack Bogle

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fortfun
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Re: Solar Installation - 0.75 Year Later

Post by fortfun » Wed Oct 02, 2019 8:55 pm

arcticpineapplecorp. wrote:
Wed Oct 02, 2019 8:21 pm
fwiw (and this may be obvious to many, but it wasn't to me and others who heard this on npr's science friday) a roofer called in and said if you're thinking about installing solar, you should do it when you need to replace your roof (or try to align it as much as possible). Otherwise, if you install solar and have to replace your roof a few years later, it increases the price of roof replacement because the solar panels have to come off and go back on, etc. I think the roofer said it could increase the cost of roof replacement by as much as 50%.
After a recent hail storm, it cost us $2,700 to have our 22 panels removed and reinstalled. Insurance covered the cost. Just to give people a sense of the cost. This was the commercial company (Sun Run). Neighbors used local contractors at a lower cost.

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Horton
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Re: Solar Installation - 0.75 Year Later

Post by Horton » Wed Oct 02, 2019 9:01 pm

My electric utility is starting a program where you can purchase up to 36 panels that they will install on a carport around town and maintain for 25 years. I’ve never been interested in having panels on my roof, but was a bit intrigued by this program since they also maintain the panels. That said, the 12 pay year payback that I mentioned upthread probably isn’t enough incentive for me to do it right now.
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mervinj7
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Re: Solar Installation - 0.75 Year Later

Post by mervinj7 » Wed Oct 02, 2019 9:19 pm

Horton wrote:
Wed Oct 02, 2019 7:46 pm
Just curious...how much energy do you use per year? Sounds like you use about 12,000 given your comment that you may be a net surplus generator? If so, that’s a bit surprising since I live in a significantly hotter locale, have a pretty large house (3,500 sq ft), wife/kids at home during the day, and use about 13,000 kWh.
The previous owners used about 14,000 kWh the year before we bought the house, so that was our basis for sizing the panels. I figure our usage is probably closer to 10-12k a year since our household is smaller. We have electric radiant floor heating that eats up 8kW per hour it's on. We also have an EV that gets driven 12,000 miles a year. Since I'm not quite sure how much we'll use the electric heat this winter, I'm uncertain how much we'll over generate. So far, we have $230 credit going into the Q4.

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Horton
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Re: Solar Installation - 0.75 Year Later

Post by Horton » Wed Oct 02, 2019 9:50 pm

mervinj7 wrote:
Wed Oct 02, 2019 9:19 pm
Horton wrote:
Wed Oct 02, 2019 7:46 pm
Just curious...how much energy do you use per year? Sounds like you use about 12,000 given your comment that you may be a net surplus generator? If so, that’s a bit surprising since I live in a significantly hotter locale, have a pretty large house (3,500 sq ft), wife/kids at home during the day, and use about 13,000 kWh.
The previous owners used about 14,000 kWh the year before we bought the house, so that was our basis for sizing the panels. I figure our usage is probably closer to 10-12k a year since our household is smaller. We have electric radiant floor heating that eats up 8kW per hour it's on. We also have an EV that gets driven 12,000 miles a year. Since I'm not quite sure how much we'll use the electric heat this winter, I'm uncertain how much we'll over generate. So far, we have $230 credit going into the Q4.
I have natural gas for heat in the winter, so that probably explains it.
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GuyInFL
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Re: Solar Installation - 0.75 Year Later

Post by GuyInFL » Wed Oct 02, 2019 10:24 pm

Horton wrote:
Wed Oct 02, 2019 9:01 pm
My electric utility is starting a program where you can purchase up to 36 panels that they will install on a carport around town and maintain for 25 years. I’ve never been interested in having panels on my roof, but was a bit intrigued by this program since they also maintain the panels. That said, the 12 pay year payback that I mentioned upthread probably isn’t enough incentive for me to do it right now.
Our utility did this but charged more to participate than our regular power rate of $0.11/kwh

financeperchance
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Re: Solar Installation - 0.75 Year Later

Post by financeperchance » Wed Oct 02, 2019 10:24 pm

Thanks for this information. You have basically the equivalent of a tax-free bond yielding about 20% a year so far, right? That's amazing!

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mervinj7
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Re: Solar Installation - 0.75 Year Later

Post by mervinj7 » Wed Oct 02, 2019 11:09 pm

financeperchance wrote:
Wed Oct 02, 2019 10:24 pm
Thanks for this information. You have basically the equivalent of a tax-free bond yielding about 20% a year so far, right? That's amazing!
Haha, I wish it were so easy to calculate ROI. Unlike a five year bond, you won't get the full investment back in five years (neglecting potential increases in house value).

https://blog.aurorasolar.com/quantifyin ... tallation/

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Re: Solar Installation - 0.75 Year Later

Post by whodidntante » Wed Oct 02, 2019 11:25 pm

Horton wrote:
Wed Oct 02, 2019 7:23 pm
Thank you for sharing the detailed information. I recently got a quote and my estimated payoff was a little over 12 years, compared to your 5 year payoff. Why the difference? Because I pay an average of $0.11 / kWh, compared to your $0.24 / kWh! :shock: :shock: :shock:

Solar is a no brainer for those in CA! That’s a great ROI :beer
I have real-time electricity pricing that is directly linked to wholesale rates. I've gotten rather skilled at curtailing usage during high-cost times. My electric bills are reasonable considering my McMansion has rooms I never use. I wonder what's in there?

Anyway, for me, I doubt solar would have a payback period. The panels would crack and the inverter would explode before I saw a dime.

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Re: Solar Installation - 0.75 Year Later

Post by Startled Cat » Wed Oct 02, 2019 11:50 pm

mervinj7 wrote:
Wed Oct 02, 2019 9:19 pm
We have electric radiant floor heating that eats up 8kW per hour it's on.
Today I felt remorse for running a 750 W space heater for several hours overnight. Reading this makes me feel slightly better about my own electricity use for heating. PG&E rates have trained me to be very frugal with electricity - so far I've been able to stay within my E-1 baseline allowance of 6.8 kWh/day (summer) to 8.2 kWh/day (winter).

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Re: Solar Installation - 0.75 Year Later

Post by MathIsMyWayr » Thu Oct 03, 2019 12:13 am

mervinj7 wrote:
Wed Oct 02, 2019 5:56 pm
Any maintenance?
None so far in the first 9 months. We did go several months without rain which led to my panels getting visibly dirty by mid-August. A fluke rainstorm "cleaned" the panels and I noticed an immediate 8% increase in production. In the future, I will hose down the panels once a year in late July.
I heard during a solar seminar that Bay area tap water is rich in minerals and will leave mineral residue/deposit on solar panels. According to them, rain water is soft and good solar panels.

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Re: Solar Installation - 0.75 Year Later

Post by harrychan » Thu Oct 03, 2019 12:15 am

How much was your electric bill before?
This is not legal or certified financial advice but you know that already.

Wannaretireearly
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Re: Solar Installation - 0.75 Year Later

Post by Wannaretireearly » Thu Oct 03, 2019 1:11 am

Tag. Great thread. Any recommendations for bay area solar companies? Any good sites which review the latest and greatest solar tech?

I have a new roof. Electric bill runs from 100 go 200 max. I guess I should look into this.
Friends have said a house battery would be great ( store your own power to use during peak times etc)
Buy Low, Sell High

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Re: Solar Installation - 0.75 Year Later

Post by Bacchus01 » Thu Oct 03, 2019 5:44 am

mervinj7 wrote:
Wed Oct 02, 2019 11:09 pm
financeperchance wrote:
Wed Oct 02, 2019 10:24 pm
Thanks for this information. You have basically the equivalent of a tax-free bond yielding about 20% a year so far, right? That's amazing!
Haha, I wish it were so easy to calculate ROI. Unlike a five year bond, you won't get the full investment back in five years (neglecting potential increases in house value).

https://blog.aurorasolar.com/quantifyin ... tallation/
It will be interesting to see if this is true. Historically, solar panels have devalued properties that I've seen, not increased them. I wonder if that will change.

chw
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Re: Solar Installation - 0.75 Year Later

Post by chw » Thu Oct 03, 2019 6:27 am

Wannaretireearly wrote:
Thu Oct 03, 2019 1:11 am
Tag. Great thread. Any recommendations for bay area solar companies? Any good sites which review the latest and greatest solar tech?

I have a new roof. Electric bill runs from 100 go 200 max. I guess I should look into this.
Friends have said a house battery would be great ( store your own power to use during peak times etc)
Check out the website EnergySage. It is one of the best resources for researching, and obtaining quotes for solar installations.

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Horton
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Re: Solar Installation - 0.75 Year Later

Post by Horton » Thu Oct 03, 2019 8:59 am

mervinj7 wrote:
Wed Oct 02, 2019 11:09 pm
financeperchance wrote:
Wed Oct 02, 2019 10:24 pm
Thanks for this information. You have basically the equivalent of a tax-free bond yielding about 20% a year so far, right? That's amazing!
Haha, I wish it were so easy to calculate ROI. Unlike a five year bond, you won't get the full investment back in five years (neglecting potential increases in house value).

https://blog.aurorasolar.com/quantifyin ... tallation/
You could use the Excel XIRR function to quickly estimate the IRR. I bet it’s close to 20% over 20+ years.
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Valuethinker
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Re: Solar Installation - 0.75 Year Later

Post by Valuethinker » Thu Oct 03, 2019 10:35 am

Just a comment on returns.

Simple payback which equals cost/ savings p.a. = years to pay back, is fine, it corresponds to an undiscounted valuation (i.e. future cash flows discounted at 0% rate). It's a good rule of thumb. However with an investment you sell it at the end which this calculation ignores.

However a proper Net Present Value or Internal Rate of Return calculation has a time value of money, and also a Terminal Value.

If you think you are in the house for the next 25 years, say, you can set terminal value = 0 (complete replacement of system).

EDIT I have ignored decommissioning cost at that time (another outflow), which you can add but should not be a large number (and in present value terms discounted by c. 80%).

Remember to do your cash flows after tax (if you are comparing to an investment alternative). And to account for replacement of inverters (every 10-15 years) and possibly the roof (in that this may force a reinstallation of your panels).

If say 10 years, you need a Terminal Value to do the calculation properly. Some possible assumptions:

- assume buyer will pay depreciated value (so say reduce value by 10/25ths ie 40% of cost) - depends on which accounting method of depreciation you use (I would argue for sum-of-the-digits over straight line, ie front loads depreciation, but I don't know what the evidence is on that.
- assume buyer will pay the future value of the cash flows - so 15 years remaining life at whatever your estimated savings are, and allowing for inflation and setting a discount rate (5%?)
- assume buyer will pay nothing (that seems harsh)
- assume it will reduce the value of the home for aesthetic reasons (that may be realistic in some 'hoods and parts of the country but generally seems harsh)

Once you have the cash flows laid out like that, with timing, you can use =XIRR() to give you the Internal Rate of Return, the discount rate at which the outlay for the system (now) equals the discounted future benefits. You then compare to your own personal discount rate so see if it meets your "hurdle" rate.

Alternately, you can do a Net Present Value calculation. To do that, you need a discount rate.

So if we are doing this in nominal terms, say 4% discount rate, midway between US Treasury bonds at 2% and stocks at 6-8%. As a base assumption.

Once again Excel provides = XNPV().
Last edited by Valuethinker on Fri Oct 04, 2019 5:16 am, edited 1 time in total.

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mervinj7
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Re: Solar Installation - 0.75 Year Later

Post by mervinj7 » Thu Oct 03, 2019 10:55 am

Valuethinker wrote:
Thu Oct 03, 2019 10:35 am
Just a comment on returns.

Simple payback which equals cost/ savings p.a. = years to pay back, is fine, it corresponds to an undiscounted valuation (i.e. future cash flows discounted at 0% rate). It's a good rule of thumb. However with an investment you sell it at the end which this calculation ignores.

However a proper Net Present Value or Internal Rate of Return calculation has a time value of money, and also a Terminal Value.
Horton wrote:
Thu Oct 03, 2019 8:59 am
You could use the Excel XIRR function to quickly estimate the IRR. I bet it’s close to 20% over 20+ years.
Before we made the decision to go forward, we did use a handy residential solar model created by a fellow Bogleheader (SmallSaver) who at the time worked for the Missoula Federal Credit Union. It will calculate ROI using the three methods alluded to by Valuethinker: Simple Payback, Net Present Value (NPV), and Internal Rate of Return (IRR). Unfortunately, I can no longer find a link to the spreadsheet but his guide is still up.

Financial Analysis of Residential Solar: https://indd.adobe.com/view/8d90633c-25 ... 27fe3f33cc

The following was a screenshot of my analysis pre-install assuming a flat $0.29/kWh rate. However, the IRR and NPV are already incorrect since TOU rates will change substantially in five years.
Image
Last edited by mervinj7 on Thu Oct 03, 2019 12:54 pm, edited 2 times in total.

kacang
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Re: Solar Installation - 0.75 Year Later

Post by kacang » Thu Oct 03, 2019 10:57 am

Wannaretireearly wrote:
Thu Oct 03, 2019 1:11 am
Tag. Great thread. Any recommendations for bay area solar companies? Any good sites which review the latest and greatest solar tech?

I have a new roof. Electric bill runs from 100 go 200 max. I guess I should look into this.
Friends have said a house battery would be great ( store your own power to use during peak times etc)
We are looking into this as well, going to get quotes from Energy Sage and Bay Area Sunshares program. Has anyone used the Sunshares program, how does it compare vs going with an Energy Sage vendor?

HoosierJim
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Re: Solar Installation - 0.75 Year Later

Post by HoosierJim » Thu Oct 03, 2019 11:07 am

mervinj7 wrote:
Wed Oct 02, 2019 5:56 pm
I also switched from a TOU rate to a TOU EV tariff. My peak daytime rates are very high ($0.29 to $0.53/kWh) but my off-peak nighttime rate is cut to $0.14/kWh.
Is that high rate after 4 pm and how much energy do you generate after 4 pm?

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mervinj7
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Re: Solar Installation - 0.75 Year Later

Post by mervinj7 » Thu Oct 03, 2019 11:15 am

HoosierJim wrote:
Thu Oct 03, 2019 11:07 am
mervinj7 wrote:
Wed Oct 02, 2019 5:56 pm
I also switched from a TOU rate to a TOU EV tariff. My peak daytime rates are very high ($0.29 to $0.53/kWh) but my off-peak nighttime rate is cut to $0.14/kWh.
Is that high rate after 4 pm and how much energy do you generate after 4 pm?
It's peak rate after 2PM for my particular tariff (EV-A) and part-peak from 7AM-2PM. From what I can estimate on my production data, about 28% of the solar production is after 2PM during summer hours. However, it will likely be changed to 4PM after my grandfathered rate runs out in 5 years at which point even less of my excess production will count towards peak hours. I will then have to reconsider changing rate plans again.

:annoyed

See my second post for the EV-A tariff. viewtopic.php?f=11&t=291738&p=4777039#p4776179

And here's my production curve for yesterday. The area under the curve after 2PM is generating solar valued at $0.53/kWh. The area to the left is part-peak and is generating solar valued at $0.29/kWh.
Image

curmudgeon
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Re: Solar Installation - 0.75 Year Later

Post by curmudgeon » Thu Oct 03, 2019 12:51 pm

mervinj7 wrote:
Thu Oct 03, 2019 11:15 am
HoosierJim wrote:
Thu Oct 03, 2019 11:07 am
mervinj7 wrote:
Wed Oct 02, 2019 5:56 pm
I also switched from a TOU rate to a TOU EV tariff. My peak daytime rates are very high ($0.29 to $0.53/kWh) but my off-peak nighttime rate is cut to $0.14/kWh.
Is that high rate after 4 pm and how much energy do you generate after 4 pm?
It's peak rate after 2PM for my particular tariff (EV-A) and part-peak from 7AM-2PM. From what I can estimate on my production data, about 28% of the solar production is after 2PM during summer hours. However, it will likely be changed to 4PM after my grandfathered rate runs out in 5 years at which point even less of my excess production will count towards peak hours. I will then have to reconsider changing rate plans again.
The various TOU tariffs, and the potential for changes, can really mess with your solar return. I don't have an EV, so my recent bay area solar installation is stuck under the TOU-B rate plan, which this year defines peak as 3pm-8pm, but starting in January will push it to 4pm-8pm, which really kills the high rate part of the day for solar production. But the difference between peak and off-peak for our rates (currently) isn't so large either.

I think there is some risk that future TOU and minimum bill tweaks will further mess with solar ROI. Net metering is rather unfair to the rest of the ratepayers, but at least in CA I don't think it will get yanked altogether for existing installations (one reason why I did my install this year after getting a new roof).

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mervinj7
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Re: Solar Installation - 0.75 Year Later

Post by mervinj7 » Fri Oct 04, 2019 11:32 am

curmudgeon wrote:
Thu Oct 03, 2019 12:51 pm
The various TOU tariffs, and the potential for changes, can really mess with your solar return. I don't have an EV, so my recent bay area solar installation is stuck under the TOU-B rate plan, which this year defines peak as 3pm-8pm, but starting in January will push it to 4pm-8pm, which really kills the high rate part of the day for solar production. But the difference between peak and off-peak for our rates (currently) isn't so large either.

I think there is some risk that future TOU and minimum bill tweaks will further mess with solar ROI. Net metering is rather unfair to the rest of the ratepayers, but at least in CA I don't think it will get yanked altogether for existing installations (one reason why I did my install this year after getting a new roof).
While, it's true that the various TOU and potential for changes makes it difficult to accurate measure solar return over 20-25 years, if one has has short simple payback period, then it's not an issue in CA with its strict grandfathering rules. For example, when NEM 3.0 is accepted as the new Net Metering Policy for CA, we will still have 20 years of grandfathered NEM 2.0 policy from the date of install. In other states (e.g. Nevada), Net Metering policies can be slashed at any time, even for existing customers.

As far as unfairness of Net Metering to non-solar ratepayers is concerned, I believe NEM 2.0 addressed many of the existing concerns by adding a minimum monthly charge, a higher interconnection fee, forced TOU rate plans, and Non-bypassable charges (NBCs) that can't be net metered away.

Here are financial calculations for my system if for some reason the Electric Rate was lowered to $0.14/kWh. Simple payback time increases to 9.2 years from 4.6. Still not too bad.

Image

mariezzz
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Re: Solar Installation - 0.75 Year Later

Post by mariezzz » Fri Oct 04, 2019 2:05 pm

fortfun wrote:
Wed Oct 02, 2019 8:55 pm
arcticpineapplecorp. wrote:
Wed Oct 02, 2019 8:21 pm
fwiw (and this may be obvious to many, but it wasn't to me and others who heard this on npr's science friday) a roofer called in and said if you're thinking about installing solar, you should do it when you need to replace your roof (or try to align it as much as possible). Otherwise, if you install solar and have to replace your roof a few years later, it increases the price of roof replacement because the solar panels have to come off and go back on, etc. I think the roofer said it could increase the cost of roof replacement by as much as 50%.
After a recent hail storm, it cost us $2,700 to have our 22 panels removed and reinstalled. Insurance covered the cost. Just to give people a sense of the cost. This was the commercial company (Sun Run). Neighbors used local contractors at a lower cost.
Anyone know if homeowners insurance increases rates if you have solar panels to cover the added costs of roof replacement? What about riders to cover the solar panels? or are they included in standard HO3 policies?

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mervinj7
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Re: Solar Installation - 0.75 Year Later

Post by mervinj7 » Fri Oct 04, 2019 4:01 pm

mariezzz wrote:
Fri Oct 04, 2019 2:05 pm
Anyone know if homeowners insurance increases rates if you have solar panels to cover the added costs of roof replacement? What about riders to cover the solar panels? or are they included in standard HO3 policies?
When I asked my State Farm agent, they said "solar panels are included in your dwelling coverage." My insurance premium did not increase and I did not add any riders.

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Nate79
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Re: Solar Installation - 0.75 Year Later

Post by Nate79 » Fri Oct 04, 2019 4:03 pm

mervinj7 wrote:
Fri Oct 04, 2019 4:01 pm
mariezzz wrote:
Fri Oct 04, 2019 2:05 pm
Anyone know if homeowners insurance increases rates if you have solar panels to cover the added costs of roof replacement? What about riders to cover the solar panels? or are they included in standard HO3 policies?
When I asked my State Farm agent, they said "solar panels are included in your dwelling coverage." My insurance premium did not increase and I did not add any riders.
Same for us. Solar panels just installed and the insurance rider did not change our insurance cost. It was surprising.

RCL
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Re: Solar Installation - 0.75 Year Later

Post by RCL » Fri Oct 04, 2019 6:23 pm

For those of you that have purchased solar, have you seen your property taxes increase due to the addition of the solar system?
It Is Best To Consult Others Before Taking Unusual Actions

chw
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Re: Solar Installation - 0.75 Year Later

Post by chw » Fri Oct 04, 2019 6:43 pm

mariezzz wrote:
Fri Oct 04, 2019 2:05 pm
fortfun wrote:
Wed Oct 02, 2019 8:55 pm
arcticpineapplecorp. wrote:
Wed Oct 02, 2019 8:21 pm
fwiw (and this may be obvious to many, but it wasn't to me and others who heard this on npr's science friday) a roofer called in and said if you're thinking about installing solar, you should do it when you need to replace your roof (or try to align it as much as possible). Otherwise, if you install solar and have to replace your roof a few years later, it increases the price of roof replacement because the solar panels have to come off and go back on, etc. I think the roofer said it could increase the cost of roof replacement by as much as 50%.
After a recent hail storm, it cost us $2,700 to have our 22 panels removed and reinstalled. Insurance covered the cost. Just to give people a sense of the cost. This was the commercial company (Sun Run). Neighbors used local contractors at a lower cost.
Anyone know if homeowners insurance increases rates if you have solar panels to cover the added costs of roof replacement? What about riders to cover the solar panels? or are they included in standard HO3 policies?
My agent bumped the dwelling coverage by the gross cost of the panels, which didn’t really impact the premium. We merely had to provide a copy of the contract, and a picture of the installed panels.

chw
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Re: Solar Installation - 0.75 Year Later

Post by chw » Fri Oct 04, 2019 6:46 pm

RCL wrote:
Fri Oct 04, 2019 6:23 pm
For those of you that have purchased solar, have you seen your property taxes increase due to the addition of the solar system?
We haven’t been reassessed yet. There may be a nominal increase in the tax assessment and taxes, but not high enough where one would decide to not install panels.

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mervinj7
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Re: Solar Installation - 0.75 Year Later

Post by mervinj7 » Fri Oct 04, 2019 6:47 pm

RCL wrote:
Fri Oct 04, 2019 6:23 pm
For those of you that have purchased solar, have you seen your property taxes increase due to the addition of the solar system?
Currently in CA, solar panels do not increase property taxes for residents. YMMV.

https://wilsontaxlaw.com/california-pro ... -extended/

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fortfun
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Re: Solar Installation - 0.75 Year Later

Post by fortfun » Fri Oct 04, 2019 9:17 pm

mariezzz wrote:
Fri Oct 04, 2019 2:05 pm
fortfun wrote:
Wed Oct 02, 2019 8:55 pm
arcticpineapplecorp. wrote:
Wed Oct 02, 2019 8:21 pm
fwiw (and this may be obvious to many, but it wasn't to me and others who heard this on npr's science friday) a roofer called in and said if you're thinking about installing solar, you should do it when you need to replace your roof (or try to align it as much as possible). Otherwise, if you install solar and have to replace your roof a few years later, it increases the price of roof replacement because the solar panels have to come off and go back on, etc. I think the roofer said it could increase the cost of roof replacement by as much as 50%.
After a recent hail storm, it cost us $2,700 to have our 22 panels removed and reinstalled. Insurance covered the cost. Just to give people a sense of the cost. This was the commercial company (Sun Run). Neighbors used local contractors at a lower cost.
Anyone know if homeowners insurance increases rates if you have solar panels to cover the added costs of roof replacement? What about riders to cover the solar panels? or are they included in standard HO3 policies?
In my experience, most quote a bit more per panel (i.e. $7/panel/yr). I would definitely make them aware of your panels so that you don't have any surprises when a big hail storm hits, etc.

Topic Author
mervinj7
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Re: Solar Installation - 0.75 Year Later

Post by mervinj7 » Mon Oct 07, 2019 11:36 am

baconavocado wrote:
Wed Oct 02, 2019 6:12 pm
We've been putting this off because our roof is older but I think we're going to need a new roof next year, so we'll probably look into solar. Do you know what the credits will be next summer?
I think I misunderstood you question but if you are talking about the Federal residential energy incentive (not the PG&E tariffs), it is stepping down over the next several years.

2019: 30%
2020: 26%
2021: 22%
2022: 0% (assuming no legislative change)

https://www.irs.gov/newsroom/energy-inc ... nd-answers

curmudgeon
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Re: Solar Installation - 0.75 Year Later

Post by curmudgeon » Mon Oct 07, 2019 12:11 pm

mervinj7 wrote:
Mon Oct 07, 2019 11:36 am
baconavocado wrote:
Wed Oct 02, 2019 6:12 pm
We've been putting this off because our roof is older but I think we're going to need a new roof next year, so we'll probably look into solar. Do you know what the credits will be next summer?
I think I misunderstood you question but if you are talking about the Federal residential energy incentive (not the PG&E tariffs), it is stepping down over the next several years.

2019: 30%
2020: 26%
2021: 22%
2022: 0% (assuming no legislative change)

https://www.irs.gov/newsroom/energy-inc ... nd-answers
The reduction in the federal tax credit is something to consider, but at least for the next two years it's not a deal breaker. The other thing I would watch out for is the potential to be locked out of net metering, or stuck into a "NEM 3.0" tariff which would value your production/use closer to market prices and mess with your economics. Some of this depends on your specific power provider as well. In PG&E territory, I don't think NEM 2.0 is guaranteed to be available to new installs beyond this year, but I don't know of specific proposals for changes either.

meebers
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Re: Solar Installation - 0.75 Year Later

Post by meebers » Mon Oct 07, 2019 8:07 pm

Has there been a calculation (cost/benefit) of a "fixed" solar array on a roof vrs a platform mounted in the yard which has the ability to "follow" the sun during the day as well as the season? Info on the web suggests 25-30% more for a single axis and an additional 10% for dual axis, but at what cost? IMHO, you could use less panels on a tracker for the same amount of energy produced??

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mervinj7
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Re: Solar Installation - 0.75 Year Later

Post by mervinj7 » Tue Oct 08, 2019 10:58 am

meebers wrote:
Mon Oct 07, 2019 8:07 pm
Has there been a calculation (cost/benefit) of a "fixed" solar array on a roof vrs a platform mounted in the yard which has the ability to "follow" the sun during the day as well as the season? Info on the web suggests 25-30% more for a single axis and an additional 10% for dual axis, but at what cost? IMHO, you could use less panels on a tracker for the same amount of energy produced??
I did no calculation on the matter but for residential applications, solar panels are only about 1/3 of the total costs of the install. I'm assuming adding in the installation complexity, labor costs, and maintenance related to a tracking system would negate any benefits from reducing the number of panels by 25%. Perhaps the financials work out differently for an utility scale application where labor is a smaller percentage of costs.

HoosierJim
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Re: Solar Installation - 0.75 Year Later

Post by HoosierJim » Wed Oct 09, 2019 9:35 am

As PG&E cuts power to an area of California, is there anything in the short term (sans installing batteries) that a user can do to allow the inverter to run without grid connection?

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samsoes
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Re: Solar Installation - 0.75 Year Later

Post by samsoes » Wed Oct 09, 2019 9:46 am

HoosierJim wrote:
Wed Oct 09, 2019 9:35 am
As PG&E cuts power to an area of California, is there anything in the short term (sans installing batteries) that a user can do to allow the inverter to run without grid connection?
Not likely. The requirement that your panel system shuts down when commercial power is out protects line workers from getting electrocuted by your generated power when they are working on lines assumed to not to be live.
"Happiness Is Not My Companion" - Gen. Gouverneur K. Warren. | (Avatar is the statue of Gen. Warren atop Little Round Top @ Gettysburg National Military Park.)

curmudgeon
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Re: Solar Installation - 0.75 Year Later

Post by curmudgeon » Wed Oct 09, 2019 10:37 am

samsoes wrote:
Wed Oct 09, 2019 9:46 am
HoosierJim wrote:
Wed Oct 09, 2019 9:35 am
As PG&E cuts power to an area of California, is there anything in the short term (sans installing batteries) that a user can do to allow the inverter to run without grid connection?
Not likely. The requirement that your panel system shuts down when commercial power is out protects line workers from getting electrocuted by your generated power when they are working on lines assumed to not to be live.
There is one string inverter (the older "Sunny Boy") that I'm aware of which has an option for an outlet at the inverter box which can remain powered during utility outages. If you ran an extension cord around the house, 10 hours or so of power during the day would probably be enough to at least avoid losing the contents of your fridge. I thought it was a little gimmicky, and didn't go down that route :( I suspect trying to retrofit some properly engineered/permitted solution like that to my micro-inverter system would be pretty costly.

emoore
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Re: Solar Installation - 0.75 Year Later

Post by emoore » Wed Oct 09, 2019 11:28 am

samsoes wrote:
Wed Oct 09, 2019 9:46 am
HoosierJim wrote:
Wed Oct 09, 2019 9:35 am
As PG&E cuts power to an area of California, is there anything in the short term (sans installing batteries) that a user can do to allow the inverter to run without grid connection?
Not likely. The requirement that your panel system shuts down when commercial power is out protects line workers from getting electrocuted by your generated power when they are working on lines assumed to not to be live.
Can't you use a battery backup system like a powerwall to charge and use when the grid goes down? Might not be helpful for this power outage but it would be something I would consider adding to my solar if I had frequent and extended power outages.

HoosierJim
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Re: Solar Installation - 0.75 Year Later

Post by HoosierJim » Wed Oct 09, 2019 11:29 am

samsoes wrote:
Wed Oct 09, 2019 9:46 am

Not likely. The requirement that your panel system shuts down when commercial power is out protects line workers from getting electrocuted by your generated power when they are working on lines assumed to not to be live.
Shame to have thousands of unusable KW on a sunny but windy day.

They do sell a breaker interlock to avoid backfeed. https://youtu.be/n7DkaorEQPQ
Last edited by HoosierJim on Wed Oct 09, 2019 11:32 am, edited 1 time in total.

wilked
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Re: Solar Installation - 0.75 Year Later

Post by wilked » Wed Oct 09, 2019 11:31 am

emoore wrote:
Wed Oct 09, 2019 11:28 am
samsoes wrote:
Wed Oct 09, 2019 9:46 am
HoosierJim wrote:
Wed Oct 09, 2019 9:35 am
As PG&E cuts power to an area of California, is there anything in the short term (sans installing batteries) that a user can do to allow the inverter to run without grid connection?
Not likely. The requirement that your panel system shuts down when commercial power is out protects line workers from getting electrocuted by your generated power when they are working on lines assumed to not to be live.
Can't you use a battery backup system like a powerwall to charge and use when the grid goes down? Might not be helpful for this power outage but it would be something I would consider adding to my solar if I had frequent and extended power outages.
Just be certain you have the extra $20K in your pocket beforehand
https://teslamotorsclub.com/tmc/threads ... st.148797/

emoore
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Re: Solar Installation - 0.75 Year Later

Post by emoore » Wed Oct 09, 2019 11:36 am

wilked wrote:
Wed Oct 09, 2019 11:31 am
emoore wrote:
Wed Oct 09, 2019 11:28 am
samsoes wrote:
Wed Oct 09, 2019 9:46 am
HoosierJim wrote:
Wed Oct 09, 2019 9:35 am
As PG&E cuts power to an area of California, is there anything in the short term (sans installing batteries) that a user can do to allow the inverter to run without grid connection?
Not likely. The requirement that your panel system shuts down when commercial power is out protects line workers from getting electrocuted by your generated power when they are working on lines assumed to not to be live.
Can't you use a battery backup system like a powerwall to charge and use when the grid goes down? Might not be helpful for this power outage but it would be something I would consider adding to my solar if I had frequent and extended power outages.
Just be certain you have the extra $20K in your pocket beforehand
https://teslamotorsclub.com/tmc/threads ... st.148797/
Yeah 15-20K for 2 of them (27 Kwh storage). Plus this year it would be 30% less from the federal rebate. That makes it competitive with whole house natural gas backup generators.

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