Tesla Solar....well.....solar, but not Tesla.

[EchoStache]

2nd local Solar company came in at $41,500 for 12 kW system. Almost $14,000 higher.  There's just no way I can justify that.  Kinda like option A) $41,500, or we'll give you a $14,000 discount for a little crappier service and some delays.  Ok, I'll take the discount. 

Tesla:
After the site inspection on 1/7,  the new design was uploaded 1/25/2023 and I was notified by text message.  On 1/26/2023(today), I received another text about the redesign and was asked what would be a good time for a phone call.  I told them 3:30 p.m.  They called at *exactly* 3:30.  The new design is now on the correct house with 12kW, but with 11 panels on the front of the house and only 19 on the back.  I told the rep that I wanted all 29/30 panels on the back of the house if anyway possible.  He said he would submit and let me know when the redesign was done.  Received a text a couple hours later that the redesign was done.  They increased system size to 14kW and added panels to the front of the house.  That isn't what I asked for, at all.  I mean, I was surprised how quickly they updated, but it's not what I asked for.

So, I tried chat on the website under my account.  I got a reply quickly.  Told them what I wanted and they checked.  Within a couple minutes, they said they were not able to place any more panels on the back.  So I requested 12 panels on the front(for symmetry), making the system 12.4kW and now just waiting for that redesign.  I think the price will be right around $29k, or $20,300 after tax incentive.

The 14kW system currently shown is generating an estimated 14,800 kWh/year, so the 12.4 system should be around 13,100/year.  I'm probably getting less than optimal generation due to the orientation of my house and size/configuration of my roof.

At $2.30/watt, I think I have no other choice than giving Tesla a try.

[grantmeaname]

I've been enjoying following along on this!

Where in the world are you? I'm surprised you don't have more options than that - I have 7.

[EchoStache]

I've been enjoying following along on this!

Where in the world are you? I'm surprised you don't have more options than that - I have 7.

I have a few more companies I need to get ahold of for quotes. 

[PathtoFIRE]

That yearly kWh seems low for a 14kW system.

One point you might want to check on is whether there is a tiered permitting system where you're at. We weren't made aware of that, and went with a larger than needed system (in anticipationg of electrifying most of our gas appliances in the future), and then found out instead of 2-3 weeks for city permitting, we got bumped up into a permitting tier that may end up taking almost 4 months for the city permit (we're 7 weeks in, and installer is saying fingers crossed we get the permit in early March).

[EchoStache]

Here's an area of significant concern.  An advantage of solar is the SREC's that one gets over the years.  These could potentially generate a significant cash value every year as I understand it, and are subject to change.  Although this could decrease, it doesn't seem unreasonable to assume they might increase as the push for clean energy is embraced.

It appears that Tesla is providing me with a 1 time credit of $1,116 off the purchase price of the system for SREC's, but that all future SREC's go to Tesla, forever.

The other detailed quote I have received from a local installer on the other hand, shows current SREC's of $569 for the first year.  Their amortized estimate shows the SREC credit dropping sharply over time, which they explained by saying that they cannot guarantee that SRECs will remain at their current rate, so they show a worst case scenario of much lower SREC credits over time.  Only the first three years are shown as similar to today's rate.  So three year SRECs are totaling $1643.

This is a concern with Tesla because if rates stay at around $569, that's obviously $5690/10 years, $11,380 over 20 years.

Local installer $41,500
Tesla $27,404(after 1 time SREC credit)
Diff: -$14,106.

Losing a $569 SREC every year for ever is 4% of the price difference.  So my opportunity cost on the $14,106 savings based on SRECs I'd be losing is 4%.  The additional $14,106 I don't spend on solar is money I can invest and do better than 4%.

However, this makes me think it may be worthwhile to do more due diligence in getting more quotes.  If, for example, I find a good local installer to do that job for $35,000 and let me keep the SRECs, it might be better long term than the cheaper Tesla pricing for which I have to give up SRECs.

Open to any discussion on this topic.  I was ready to pull the trigger with Tesla based on $2.30/watt but this gives me pause.

Another way of looking at things would be the after tax credit cost:
Local: $29,057
Tesla: $19182.8
Diff: -$9874

[EchoStache]

Another topic swirling in my head.  I'm *estimating* the 12.4kW system will be ~adequate for my needs.  I don't see this generating a huge annual surplus, nor do I see us paying much in electricity yearly.

I could easily have a 14kW system installed vs 12.4kW.  This would increase net cost after rebate by $2,576.  The additional 1.6kW of size would generate ~ 1,742 kW.  If I need this additional electricity, it saves me about $296/year for an 8.7 year payback on the upfront cost, not including SREC's(if I end up with them).  Worth consideration.

If I *don't* use the additional 1742 kW, I would get slightly less return as a credit at about $0.14/kWh or $244/year(I don't get the distribution charge portion credited for overproduction, only the generation charge).

-In upcoming years, our electricity costs will decrease as our young adult children move out.

-We have two electric cars.

-We are likely to be away from home A LOT for the next decade for work.(less electricity, less car charging at home).

-Net metering will refund over production if electric usage drops significantly for those years.

-If we switch to electric heat via heat pump(likely, if financially viable), electric use will increase.

Having the system a bit too big won't be a disaster due to net metering, but not quite as beneficial as using the electricity generated.

Not having the system big enough to cover 100% of our needs has no easy solution.  Not sure Tesla solar(if we go that route) is easily upgradeable.

[bryan995]

Our 12kw solar produces 21,000 kwh per year (20,950kwh last year).
Very sunny SoCal location.  36 panels: 21 west, 9 south, 6 east
https://imgur.com/a/3LAiZMw

Also two EV,
Model Y 50kwh battery -  3.3mi/kwh
F150 Lighting 98kwh battery - 2mi/kwh
(Driving the truck uses a ton of juice!)

electric hot-tub, 2 x 3ton AC, chest freezer.
Natural gas furnace. Natural gas dryer. Natural gas on demand water heater.

Will likely move to a dual fuel (heat pump) furnace at some point. We use electric space heaters to offset gas usage currently (it is official stupid expensive now, $5.68/therm!)

We just about break even at the end of each year. Last year we had a $900 credit. This is with very favorable AC usage.  Think 69’F no matter what :) Could obviously use less if we needed but it is suboptimal to be a net producer.

It’s hard to upgrade later. So get what you need for the next 20 years, now :)

-

Re the SRECs - first I have ever really heard or read of them. Is it a state specific thing? I went with Tesla so there was no mention of this.  Paid their far lower total cost and then received the 26% federal tax credit.

[EchoStache]

I think California works weird in terms of SREC's meaning you have to produce at least 100kWh to even apply so it's maybe limited to commercial customers.  In many states, individual owners can get a yearly credit or rebate for every 1,000 kWh of production.  In PA it is around $46 but in some states like NJ it is quite a bit higher.  Buyers can typically choose to own their own SRECs but companies can also try to keep them for themselves.

[Abe]

I think California works weird in terms of SREC's meaning you have to produce at least 100kWh to even apply so it's maybe limited to commercial customers.  In many states, individual owners can get a yearly credit or rebate for every 1,000 kWh of production.  In PA it is around $46 but in some states like NJ it is quite a bit higher.  Buyers can typically choose to own their own SRECs but companies can also try to keep them for themselves.

I agree it varies quite a bit from state to state. In Texas we don't get any of that.

FWIW in Houston our system is 10kW and we produced 13.2MWh in 2022, and produced 5.7MWh over 5.5 months in 2021 (would've come to 12.4MWh over that year). We have quite a bit more cloud cover during the year than SoCal. 

[GilesMM]

I think California works weird in terms of SREC's meaning you have to produce at least 100kWh to even apply so it's maybe limited to commercial customers.  In many states, individual owners can get a yearly credit or rebate for every 1,000 kWh of production.  In PA it is around $46 but in some states like NJ it is quite a bit higher.  Buyers can typically choose to own their own SRECs but companies can also try to keep them for themselves.

I think only 7 states offer residential-scale SRECS: NJ, PA, DC, MD, PA and OH.  DC has the best.

[GilesMM]

...
It’s hard to upgrade later. So get what you need for the next 20 years, now :)

..

Not sure how hard it is to add panels but depends on your situation.  We installed a two-array ground system that will generate a bit less than we use in a year. Our state does not offer SRECs or pay us for excess production so not good to be oversized.  I had the installer run the wiring for a third array in case we switch over to heat pumps and EV vehicles one day.  The "upgrade" would be just whacking an identical third array in front of the other two and hooking it up to an inverter.  I assume solar credits would apply to that future expense.  And the cost of the extra wiring was buried in the eligible cost of the two-array system...

[EchoStache]

Received a 3rd quote from a local installer via email for a 12kW system.  $33-$36k, and I keep SRECs.  So *minimum of $6k higher, and would take ten years of SREC's to match the additional cost.  However, my best guess is that SREC value will decrease as time goes on, since the more solar is installed, the lower the value of SREC's.  The IRA will most assuredly cause an increase in solar installation.  The $6k+ in upfront savings also has an opportunity cost that offsets much of the potential gain that SRECs provide.

Also, I am still faced with the decision of local company vs Tesla.  Which one is most likely to be in business in 10, 20+ years.

I haven't officially pulled the trigger yet, but I think I have to go with Tesla.  Now I just have to decide for sure 12.4kW vs 14kW. 

14kW: $30,960/21,672
or
12.4kW: $27,404/19,183

A net difference of $2489.  From what I understand, I have to get electricity from my utility in order to be on net metering.  I am buying electricity from an alternate supplier at a lower rate currently.  But assuming I install a 12.4kW system, I will then be paying my utilities higher rate for any electricity I don't generate.  Therefore, I need to use the higher rate to calculate the benefit of the bigger system, which is currently $.020/kWh.  Yes, pretty high.  An extra 1700 kW of generation saves me up to $340, or $252 if it is all excess.  A 100% guaranteed, risk free 10.12-13.66% return.  I think I've just talked myself into the bigger system.  So now I have to request a 3rd redesign to go from 12.4kW back to the 14kW which was the 2nd design they presented to me.  This was fast and easy the first two times.  Will discuss my thoughts with the wifey tomorrow, so stay tuned for a potential Sunday evening update.

Financing will be another question.  I'm tempted just to go with Tesla's financing which is 10% down, then 120 months at 7.25%.  Eek.  I see 5.75 for home equity with my mortgage lender but not sure if I have enough equity to stay under 80% if that's the requirement.  I definitely don't have the cash to pay outright. 

I think Tesla allows cc payment for the down payment. 

[GilesMM]

Why not ask the local companies to match the Tesla price?  You have nothing to lose by asking.

[mistymoney]

Why not ask the local companies to match the Tesla price?  You have nothing to lose by asking.

so - if they match the price then what?

[Villanelle]

Why not ask the local companies to match the Tesla price?  You have nothing to lose by asking.

Yes, this.  Or at least tell them that you'd prefer to go with someone local but that Tesla's prices are much better, and see if they can come down some, even if they can't match all the way down tot Tesla's quote.  The ask costs you nothing.  (This assumes the price is your primary motivator, and/or that you'd prefer to go local if prices were the same or close to it.  That may not be the case.)

[mistymoney]

Why not ask the local companies to match the Tesla price?  You have nothing to lose by asking.

Yes, this.  Or at least tell them that you'd prefer to go with someone local but that Tesla's prices are much better, and see if they can come down some, even if they can't match all the way down tot Tesla's quote.  The ask costs you nothing.  (This assumes the price is your primary motivator, and/or that you'd prefer to go local if prices were the same or close to it.  That may not be the case.)

I'm confused about these comments. Is your assumption that tesla isn't working through local builders? I thought that they were. Or are you thinking that the solar panels are being built locally/more locally for installers doing nontesla?

Seems like a lot of posters are suggesting to avoid the tesla option - even if the quote is the best. I am planning on getting a tesla roof as well, so I'd appreciate some insight into what the assumptions here are. That if price is the same - go with nottesla, and if you ask the others to match and they come down some but still a bit more - go with nontesla. I'm not sure I'm understanding what is driving this focus.

Is it the product? customer service? etc.?

[EchoStache]

I sent a text message to Tesla solar last night(Saturday 2/4/2023) that I wanted a redesign on the system from 12.4kW to 14kW. 

Sunday 2/5/2023, 1:30 pm:
System redesign has been uploaded to my account.  Here is a screenshot of the details.

[EchoStache]

I think the consensus regarding Tesla vs a local installer is that the Tesla experience is less hands on, poor communication, long wait times, frustration with contacting Tesla with issues, long delays after installation is complete for getting PTO, etc.    For this reason, there are some who are willing to pay more for the potential higher quality service and response time of a local installer.

In my case, I am very strongly leaning towards the stance that it almost doesn't matter if a local company gets close on price.  It seems like Tesla stands the best chance of being around long term to handle warranty issues regardless of how big of a headache it might turn out to be.  If they are in business, the warranty experience will be better than a local company that doesn't exist anymore.

I'm aware of these issues and, since I'm not expecting fast, exceptionally hands on service, I don't think I will be frustrated and disappointed.  The agreement clearly states that *estimated* time to begin installation is 7-90 days after placing the order.  Estimated completion is 7-90 days after installation begins.  So I'm going to assume at least 6 months from the date I place the order, and just kick back and relax and let the process happen.

So far, Tesla's response and communication has been quite good, even excellent. 

I sent a message today regarding when the down payment is due, and waiting for that reply.
Edit:
"Tesla Financing: Down payment is due after your system passes inspection, which typically occurs within a week after your system has been installed. Your first payment is typically due 35 days from the time your utility provider provides Permission to Operate (PTO) or a date that we schedule for off-grid systems. Monthly payments are then due on that same date each month going forward."
 

Wow, that's pretty great.  Not a penny due until the system is fully installed and has passed inspection(I assume by my utility).  Only thing I will have paid at that point is the $250 deposit.  And no payment due on the loan until I am generating sweet sexy solar electricity. 

[mistymoney]

I think the consensus regarding Tesla vs a local installer is that the Tesla experience is less hands on, poor communication, long wait times, frustration with contacting Tesla with issues, long delays after installation is complete for getting PTO, etc.    For this reason, there are some who are willing to pay more for the potential higher quality service and response time of a local installer.

In my case, I am very strongly leaning towards the stance that it almost doesn't matter if a local company gets close on price.  It seems like Tesla stands the best chance of being around long term to handle warranty issues regardless of how big of a headache it might turn out to be.  If they are in business, the warranty experience will be better than a local company that doesn't exist anymore.

I'm aware of these issues and, since I'm not expecting fast, exceptionally hands on service, I don't think I will be frustrated and disappointed.  The agreement clearly states that *estimated* time to begin installation is 7-90 days after placing the order.  Estimated completion is 7-90 days after installation begins.  So I'm going to assume at least 6 months from the date I place the order, and just kick back and relax and let the process happen.

So far, Tesla's response and communication has been quite good, even excellent. 

I sent a message today regarding when the down payment is due, and waiting for that reply.
Edit:
"Tesla Financing: Down payment is due after your system passes inspection, which typically occurs within a week after your system has been installed. Your first payment is typically due 35 days from the time your utility provider provides Permission to Operate (PTO) or a date that we schedule for off-grid systems. Monthly payments are then due on that same date each month going forward."
 

Wow, that's pretty great.  Not a penny due until the system is fully installed and has passed inspection(I assume by my utility).  Only thing I will have paid at that point is the $250 deposit.  And no payment due on the loan until I am generating sweet sexy solar electricity.

Thank you for that synopsis! Very helpful.

[GilesMM]

...
In my case, I am very strongly leaning towards the stance that it almost doesn't matter if a local company gets close on price.  It seems like Tesla stands the best chance of being around long term to handle warranty issues regardless of how big of a headache it might turn out to be.  If they are in business, the warranty experience will be better than a local company that doesn't exist anymore.

...

Assuming installation is correct, which can mostly be confirmed at commissioning, you are looking at the warranty for the individual panels and the inverters.  Most local installers are not also manufacturing this equipment, they buy it from manufacturers who provide the warranty.  Usually 25 years on panels and 10 or 15 on inverters.  Worst case a panel goes out and manufacturer is gone, you buy a new one for maybe $500.  Inverters would be maybe $3000.    My panel maker has been around 13 years and the invert company 17 years, about the same as Tesla solar.  They are less likely to go bankrupt than to merge with another company that would likely honor the warranty.  I had a panel that burned out the first week and the installer (a local family-owned electrical company) was out almost immediately to replace it.  They have been fantastic about communication and site-visits to discuss all the engineering in person.  I'm sort of anti-Tesla for personal reasons; I didn't get a bid from them but what I paid was comparable to the Tesla quote here.

[EchoStache]

...
In my case, I am very strongly leaning towards the stance that it almost doesn't matter if a local company gets close on price.  It seems like Tesla stands the best chance of being around long term to handle warranty issues regardless of how big of a headache it might turn out to be.  If they are in business, the warranty experience will be better than a local company that doesn't exist anymore.

...

Assuming installation is correct, which can mostly be confirmed at commissioning, you are looking at the warranty for the individual panels and the inverters.  Most local installers are not also manufacturing this equipment, they buy it from manufacturers who provide the warranty.  Usually 25 years on panels and 10 or 15 on inverters.  Worst case a panel goes out and manufacturer is gone, you buy a new one for maybe $500.  Inverters would be maybe $3000.    My panel maker has been around 13 years and the invert company 17 years, about the same as Tesla solar.  They are less likely to go bankrupt than to merge with another company that would likely honor the warranty.  I had a panel that burned out the first week and the installer (a local family-owned electrical company) was out almost immediately to replace it.  They have been fantastic about communication and site-visits to discuss all the engineering in person.  I'm sort of anti-Tesla for personal reasons; I didn't get a bid from them but what I paid was comparable to the Tesla quote here.

Thanks for this insight!  Sounds like you made out quite well with your solar, both from a pricing perspective and good service.  Are you happy with the production and the decision to go solar now that you are operating?

[EchoStache]

2/5/2023

Placed order for the 14kW system.  Accidentally selected cash for payment type, and meant to select finance.  Sent a text to let them know.

Let's see how this goes!

[GilesMM]

...

Thanks for this insight!  Sounds like you made out quite well with your solar, both from a pricing perspective and good service.  Are you happy with the production and the decision to go solar now that you are operating?

Our electricity prices are average, so payout will be long.  However, our utility announced a 15% increase for 2023 so not as long as previously forecast.  Production is in line with expectations given the cloudy winters we have here. I can see production  Am keen to see how much excess we can bank starting in March and continuing until AC and irrigation needs overwhelm the panels (around July).  Our state uses a net metering scheme so excess is credited to future bills; thus Mar-Jun might be negative utility usage which would then pay for July-Oct or Nov.  Our biggest variable is how much we irrigate and draw water out of the ground using the well pump.


The inverters show a lot of info on a web or phone-based app. A public example from a nearby array.

[Paper Chaser]

I'm sorry if it's already been covered and I missed it but what's the type and age of your roof?

[EchoStache]

House and roof are new, about 1 year old or so.  Shingles.

2/6/2023, 11:30 am

Tesla re-sent the info to select "finance" as type of payment.   I filled it out. Was super short and easy as in, 1 screen worth of info on my phone, from work.

A few minutes later, got credit approval and now have detailed design documents.  They are too small to see on my phone so I'll have to go over them tonight.  I have to submit documents to my HOA now for approval.

[shortduck]

does anyone know about the breakeven chart for this?

[bryan995]

I sent a text message to Tesla solar last night(Saturday 1/4/2023) that I wanted a redesign on the system from 12.4kW to 14kW. 

Sunday 1/5/2023, 1:30 pm:
System redesign has been uploaded to my account.  Here is a screenshot of the details.

7.25% is wild! We got 0.99% w/ 10% down only a short short time ago.  Should have gone even bigger with interest rates so low.  At least it made the finance vs cash purchase option very very easy.

I think you are going to be happy the larger system.  Usage and cost will only increase as the world pivots to using electricity for everything and anything. 

[EchoStache]

I'm reviewing the system design, and the inverters they are using strikes me as odd.  I'm not a solar engineer/designer, but it  is my understanding that the solar DC/AC ratio is generally somewhere in the neighborhood of 1.25 and can go quite a bit higher and still perform optimally.

So for example, for the 19 panels on the back of my house, 19x400=7600 watts; DC.  This means that a ~5,000 watt inverter would be used along with those 7600 watts of panels to have an approximate DC/AC ratio of 1.25.   The reason for a bit of undersizing i.e. not 1:1, is that a smaller inverter will produce more power early in the day and late in the afternoon compared to a larger inverter.  So even if power generation clips just a little on the brightest, sunniest days for a short while during the suns peak, the extra power generated at other times more than makes up for it, and will generate more total power throughout the year.  This is my understanding from my limited research/knowledge.

So, here is why I'm concerned.  For the back with 19 panels i.e. 7600 watts, they are using a 10kW inverter, which, afaik is way oversized. DC/AC = 0.76

For the 16 panels up front i.e. 6400 watts, they are using a 6kW inverter.  This also seems almost too big, although it is 1.07 DC/AC.

I'm going to send a message asking about this.

[GilesMM]

Do the front and rear panels face different azimuth and elevation?

[EchoStache]

Well, they are facing opposite directions of course, 180 degrees from each other.  I don't have 100% optimal facing roof on either side.  This leads me to believe that the panels will not produce their maximum rated power very often, which makes me think that undersizing the inverters would be even more beneficial to better take advantage of non peak sun situations i.e. kick on earlier and stay on later.  I've never heard of using an inverter larger than the peak panel power.  Even a 1:1 ratio should never clip, so why go even bigger? 

I mean, the fact that a 14kW system is only being guaranteed 14.8kW/year tells me that they won't be making peak power very often.  OR?

For illustrative purposes:

[GilesMM]

Correct. My inverters are 83% of panel rating. Have yet to see inverters maxed out so far.

[EchoStache]

I went onto PVwatts and estimated this:

Rear array:
220 azimuth, 0.79 ratio 9755kW/year production. <----current design
1.2 ratio, 9820/year for +65kW. 

Front array:
40 azimuth, 1.1 ratio 5345kW/year <----current design
1.4 ratio 5369 for +24kW

Yearly generation with smaller inverters would be +89kW or $13.17-$17.8/year.  Max $178/ten years with the tradeoff of cooler running and potentially longer lasting inverters?  I've read excess heat on small inverters can be an issue with longevity.

It's worth noting that this puts my estimated yearly production at 15,100, and my guarantee from Tesla is 14,800.  That's pretty close!

I'm rather surprised Tesla is using such large inverters since smaller ones are cheaper and also possibly boost production a bit.  Maybe these inverters perform better than some in terms of off peak production???

Edit: well, edited the heck out of the post to simplify and condense.

[monarda]

I only get inverter clipping for a month or two each year, and only on the sunniest days. Doesn't amount to much, in total.

Compare sunny days in April to August of 2020 here:
ETA: These are Enphase microinverters

[EchoStache]

Update:

Tesla solar reached back out after my inquiry about inverter sizing.  They passed along a reply from engineering.  Although the response didn't have the detail I was looking for, they basically ensured that they designed the system in the most optimal way possible, and used inverters(brand) that are required by my utility.  My utility does not allow Tesla inverters.

Also, I poked around a bit and found that the startup voltage is the important factor in regards to how early or late in the day an inverter will generate power in low sunlight conditions.  Typically, smaller inverters have lower startup voltage.  However, it seems that the Delta inverters all have very low startup voltage of 35 volts regardless of size.  So this actually makes me feel really good about the system, and that it will not be sacrificing off peak output.

I have to send the plans to my HOA for approval.  It's not a holdup at this point as Tesla is in the process of applying for permits and such.

[bryan995]

I have the Tesla branded inverters. They are sized as 95% of the panel size (8kW)   
They offer two inverter sizes / 3.8 kW and 7.6 kW. My system has the single 7.6kW.

Never had any issues with start up or peak clipping. I’ve seen anywhere from 0.1kWh to ~7kWh being pulled from the sun.

Plus with yours being a bit oversized, now you have the ability to later add more panels without having to make other larger changes to the system.  :)

Some relevant threads - seems that some folks are asking for optimizers to be installed as well.
https://teslamotorsclub.com/tmc/threads/delta-m8-vs-tesla-inverter.288168/
https://teslamotorsclub.com/tmc/threads/solar-inverter-changed-prior-to-install.223883/page-2#post-6637117

[EchoStache]

Oof.  I thought I had made my final decision, but I have some more decision making to do.

Tesla: 14kW, Delta inverters, 14,800kWh/year production guarantee. $30,940, Tesla keeps all SREC's forever.
Local: 11.7kW, Enphase micro-inverters, 12,900kWh/year production guarantee. $32,765, SREC's are mine currently ~$575/year.

Net cost:
Tesla $21,658
Local: $22,935
Difference: $1277

Local comes out ~even after two years of SREC's.  Tesla generates 1900kWh/year more.  This is $380/year if I use the electricity, $281 if I sell it back with net metering.

Assuming SREC's remain in place as is, Local comes out ahead by $2-$300/year so 4-6 years to balance out the slightly higher upfront cost.

To me, the cost, production, SREC's, etc are relatively even between the two systems.  So the question comes down to; do I want Tesla or a local installer?  Do I want Delta inverters or micro inverters as the local system offers. 

Another big difference is warranty:
Local: Solaria panels have 25 year labor, power, parts warranty.  Inverters have 25 year manufacturer warranty.
Tesla is 10 years labor, 25 year panel(parts and production only, no labor), 10 year inverter. 

I've seen a few complaints about the Delta inverters giving horrible production due to even very slight wispy cloud coverage.  Not sure if this is a legitimate, widespread issue or not, but I definitely want to make sure I'm doing my due diligence.  The use of Delta inverters is a very isolated issue since my electricity provider does not allow Tesla inverters.  So it's entirely possible that my Tesla system will perform differently than most other Tesla systems.  It's also possible that folks were/are having system design issues other than the Delta inverters themselves. 


I'm going to meet and talk in more detail with the local installer this coming week.


Seems like there's a good chance the improved warranty coverage would save money long term with local.

Just have to hope the local company will remain in business for warranty coverage. Mainly labor as I suppose the parts are manufacturer warranty. 

[GilesMM]

I would definitely go local (as I did).  Those are good parts warranties.  Labor is not a big deal once the system is installed.  The vendor (or most anyone) can swap out a bad solar panel or dead inverter in no time so hard to rack up significant labor costs. No big crews involved.

[EchoStache]

Yeah, I'm imagining a worst case scenario:

Year 11 inverter failure:

-Tesla, no warranty on parts or labor.  Several thousand to replace
-Local, who is out of business.  Inverter is covered under warranty, pay labor to any installer to replace, exactly the same as if the local company were still in business.

The money is coming out similar enough that inverter vs micro inverter, warranty, SRECs, and service become a bigger factor.

Lets see how things go with a more detailed meeting this week.

[monarda]

Here's my scenario with microinverters- I'm in year 12 now. One of the 8 microinverters installed in 2011 is on the fritz, meaning it works most of the time, but for about 20 days last year, it had lower production. Went to zero and then back up, in almost a static-ey sort of way. Is it even a problem with production, or reporting? So I looked into the warranty (local company). Parts covered, labor not. It was suggested to wait until the end of the warranty period (15 years) and then see how much production is lost compared to the cost to replace. And see if any other microinverters have gone out.  This is a big advantage of microinverters, IMO. Most of your system remains functional, but if there's a problem with the 'big' inverter, then it's more of a problem that needs addressing.

[EchoStache]

I returned to my house from a late afternoon/early evening walk yesterday.  The sun was quite low in the sky by this point, but I noticed that half of the back of the house/roof was shaded due to a large tree.  This won't be a problem until quite late in the day so it won't affect production most of the time.  However, with micro-inverters, this is likely to allow more production later in the day compared to a single inverter which will completely shut down production from the rear array(7600 kW) as soon as the first panel is shaded.  Another point in favor of micro inverters.

[GilesMM]

Here's my scenario with microinverters- I'm in year 12 now. One of the 8 microinverters installed in 2011 is on the fritz, meaning it works most of the time, but for about 20 days last year, it had lower production. Went to zero and then back up, in almost a static-ey sort of way. Is it even a problem with production, or reporting? So I looked into the warranty (local company). Parts covered, labor not. It was suggested to wait until the end of the warranty period (15 years) and then see how much production is lost compared to the cost to replace. And see if any other microinverters have gone out.  This is a big advantage of microinverters, IMO. Most of your system remains functional, but if there's a problem with the 'big' inverter, then it's more of a problem that needs addressing.

Why wait?  You can only make one warranty claim?  The labor for a microinverter should be minimal - aren't they just plug-n-play?  It might even be a DIY item (with some Youtube help).

[LennStar]

It seems that Tesla is having huge problems in delivery?

Also the tech isn't improved so by now there should be cheaper and/or better options out there.

Can't say for teh US though.

[monarda]

Here's my scenario with microinverters- I'm in year 12 now. One of the 8 microinverters installed in 2011 is on the fritz, meaning it works most of the time, but for about 20 days last year, it had lower production. Went to zero and then back up, in almost a static-ey sort of way. Is it even a problem with production, or reporting? So I looked into the warranty (local company). Parts covered, labor not. It was suggested to wait until the end of the warranty period (15 years) and then see how much production is lost compared to the cost to replace. And see if any other microinverters have gone out.  This is a big advantage of microinverters, IMO. Most of your system remains functional, but if there's a problem with the 'big' inverter, then it's more of a problem that needs addressing.

Why wait?  You can only make one warranty claim?  The labor for a microinverter should be minimal - aren't they just plug-n-play?  It might even be a DIY item (with some Youtube help).

Not DIY. I don't want to climb on the roof.
The losses we're experiencing are minimal. Like I said, there were only 20 or so bad days last year.
If it were totally dead I might go ahead. And the labor isn't minimal, either. (trip charge, etc)

[EchoStache]

I sent an email to the local installer to redesign the system with all 11.7kW on the back of the roof.  If they can do this, production increases to ~15kWh/year as estimated on PVWatts.  This will fill the entire roof with no setback so not 100% sure if possible, but two other local installers said they can fill the entire roof for my location in terms of code.  Tesla would not consider this option. 

If this installer will do this, I think it makes it a no brainer.  Almost equivalent cost, higher production, micro inverters, better warranty, and SRECs.

[EchoStache]

I cancelled my Tesla Solar order today.  The current plan is to move forward with a local company with 10.53kW all on the back side of my roof for $30,762 before incentives.

Reached out to my lender today about financing as I don't have the cash on hand, so we'll see how that goes.

I might start a new thread since I will no longer be moving forward with Tesla.

Reasons:

1) Tesla won't consider installing more than 7.6kW on the back of the house, which is the side that offers the best production.  Other company is going to try to fit 10.53kW with a 12,777kW production guarantee.

2) Tesla cannot add panels down the road if I ever want to add capacity.  New company can easily expand with micro inverters.

3) Tesla will not be able to incorporate V2H EV battery backup capability.  Enphase is actively working on a bidirectional EV charger.  Imagine two EV's with 150-200kW of battery backup capability without spending many tens of thousands for solar battery backup, only to have a measly 20 or 30kW which would take three Tesla Powerwalls.

4) Enphase micro inverters have 25 year warranty.  Tesla inverter is 10 years.

5) Panels have 25 year parts, labor, and production warranty.  Tesla is 25 years parts and production but no labor after year 10.

6) String inverters(Tesla) will reduce production of the entire rear roof array late afternoon when my roof gets partial shade.  Micro inverters will give full production for all non shaded panels.

7) SRECs will yield a significant financial benefit over time.  Tesla wanted to give me a $1200 discount in exchange for them keeping all SREC's forever.  That's two years worth of SRECs at current rates.  I'll be keeping SREC's with local peeps.

8) Eliminates the possibility of poor service with Tesla, since cost is now similar and there are many other benefits.

[grantmeaname]

That all sounds excellent. IMO I'd love to keep track of your process from here in this thread...

[NorCal]

You really did your homework, and those are the same considerations I’d be considering for my house.  I think you’re making the right call, and I look forward to updates as you progress.

[monarda]

I might start a new thread since I will no longer be moving forward with Tesla.

You can just change the name of this thread.

I think you made a good call!

[Paper Chaser]

Tesla will not be able to incorporate V2H EV battery backup capability.  Enphase is actively working on a bidirectional EV charger.  Imagine two EV's with 150-200kW of battery backup capability without spending many tens of thousands for solar battery backup, only to have a measly 20 or 30kW which would take three Tesla Powerwalls.

This is interesting. Definitely something that you'd think a car company would have incentive to integrate. For a project with such a long lifespan, having the potential for V2G seems like an obvious advantage.

[PathtoFIRE]

Yeah, thanks for working all of that out loud here on this thread, I had already rejected Tesla for much more vague reasons, but it is good to see there were some good reasons for my choice, even if I didn't consider them at the time.