New Solar Install

[woferry]

Hi. Been following this forum for a few months now, decided it's time to make my first post. Tesla just finished my roof work on Tuesday, city final inspection is scheduled for next week, and then there's the wait for PTO from PG&E. So there's still at least a few weeks before it will be producing anything, and I'll be anxiously waiting until then, but it's good to have the construction part of this project over with.

So, let's see if you can spot the panels. (and if I can get image attachments to work here)



I've taken lots of pictures over the course of the project, as well as time-lapse video that I need to go through to produce a reasonable-length video, so more will follow as I get the chance. Plus it was rainy yesterday when I took the above pictures and the gutters go up today, so when there's finally some sun I'll work to get more shots and use a friend's drone I borrowed to try some different angles. I'll note that the back shot is a bit of a panorama to get it to fit, so lines do get a bit distorted on that one.

 

[Maximapolak]

Awesome !!!

How much? What kW?

 

[Vines]

Looks pretty nice! Good to see those solar tiles in action. I am also curious as to the details like system size and price.

 

[woferry]

Awesome !!!

How much? What kW?

So the cost part does get a bit tricky, due to everything involved. I'll start out with "a lot", and "much more than the website estimated when I put down my deposit". They weren't late surprises, as soon as Tesla started talking to me they made it clear that the website severely underestimated. But so far (as far as I know, I keep asking if there have been any surprises and haven't gotten any response to that) it's holding to what was originally estimated/agreed upon, with the only unknown portion right now being the exact cost of the city permitting/inspection fees.

The previously published figure of $21.85/sq.ft. is clearly what they're sticking to, but that does assume a 35/65 split of solar/non-solar. The sq.ft. cost of the PV tiles is almost 4x the cost of the non-PV. When I was getting the estimate they came back with 3 sizes: 1) sized for the power I use today, 2) up-sized (~30%?) for future increase (I mentioned that I planned to add A/C and would get at least a plug-in hybrid at some point in the future), and 3) every possible tile that could be producing is (keeping in mind that there are setback rules, flashings, ridge venting, etc). The first two systems were under 10kW, and they said that they frankly weren't interested in doing a smaller system early, so they'd have gotten back to me mid-2019. The third option was 13.32kW, and is the one I went with, which is more of a 60/40 split, so the cost per sq.ft. is higher. And that number is purely the materials cost, there is also installation, one Powerwall+Gateway+install, and some extra charges/upgrades, mostly particular to my project, such as some work needed on the service line coming into the house, removal of an extra roofing layer, fascia repair (my old roof was in pretty bad shape), adding gutters, and asbestos abatement in the attic/garage. Plus a "roof preparation" cost, not sure exactly what that meant given all of the other items, I guess it might include the dumpster and other items. Strangely (to me), there's no line item for the inverters (2 Solivia 5.2 units), so I'm not sure where those costs were worked-in. And then taxes of course. So a rough break-down pre-tax (and without permit cost) was:

Materials: ~55%
Installation: ~13%
Upgrades: ~14%
Roof prep: ~9%
Powerwall: ~8%

Of the post-tax total, ~63% of that qualifies for the federal tax credit, so almost 19% of the total cost will come back in tax credit.

Anyway, from what I saw it's 561 of the SR24T3-2 PV Modules, which they seem to consider 23.75W each, so that matches their 13.32kW figure. They're arranged into 6 strings (2 on the back roof, 2 on the front roof, and one on each side of the garage, there are no producing tiles on the small plane at the front of the garage), 4 strings get paired-up to fit in the 4 available inputs of the 2 inverters.

 

[miimura]

What is the compass orientation of the house? Like which direction does the garage face?

 

[Big Dog]

did PG&E give you any flack for Option 3? (I understand that SoCal Ed won't approve too many tiles' worth of electrons going back into the grid...)

 

[SoundDaTrumpet]

Great looking roof. I calculated $3.55/kW for the solar aspect alone based upon the info provided. Nice!

 

[woferry]

What is the compass orientation of the house? Like which direction does the garage face?

I swear I get a different reading from every compass I try (digital or "analog") every time I try (made re-pointing my Dish after they took it down a real PITA), but the garage opening faces roughly ENE. The sun rises roughly over the corner where the first picture was taken, and sets over the back roof, in the peak of winter the sun peeks in one side of the patio cover and by the spring/summer/fall it comes in the other side.

did PG&E give you any flack for Option 3? (I understand that SoCal Ed won't approve too many tiles' worth of electrons going back into the grid...)

I was concerned about that too, but Tesla insisted it wouldn't be a problem. I kept asking what if we go through this whole thing and they reject it at the end, they said that would never happen, that they wouldn't start the project without confidence it will be approved. I guess we'll see when PTO comes, fingers crossed!

Great looking roof. I calculated $3.55/kW for the solar aspect alone based upon the info provided. Nice!

Thanks! My math says a little bit higher (and /W, not /kW ), but that's in the right ballpark. Definitely under $4, at least for just material, it goes over once installation is included. I never really understood, when people quote $/W is that all-up (maybe just pre-tax?), or just materials?

 

[Vines]

That price seems pretty low if its accurate. When folks talk cost per watt, its usually all in in my experience, but often doesn't include Sales tax. I wonder what they will quote these tiles for when they ramp up?

 

[Shygar]

Did they break up your contract/bill by what is covered by the ITC and what isn't?

 

[miimura]

I swear I get a different reading from every compass I try (digital or "analog") every time I try (made re-pointing my Dish after they took it down a real PITA), but the garage opening faces roughly ENE. The sun rises roughly over the corner where the first picture was taken, and sets over the back roof, in the peak of winter the sun peeks in one side of the patio cover and by the spring/summer/fall it comes in the other side.

Thanks. That makes sense. That will give you a nice broad generation envelope through the course of the day and will avoid clipping 13.5kW of solar on 10.4kW of inverters.

 

[Vines]

Did they break up your contract/bill by what is covered by the ITC and what isn't?

All of it should be right? I think that even roofing work if done with solar is eligible, PW are definitely eligible. I am not a money guy though, so I am not the best informed on these matters. Probably not the asbestos abatement.

 

[abasile]

The new roof looks great! I think it's very smart to install as many solar tiles as they'll let you. For a sustainable energy future, everything from our cars to our home heating systems is going to have to go electric. Might as well be prepared for that.

In that vein, if I were having a solar roof installed, I think I'd first want to eliminate any and all roof-vented natural gas appliances and switch to electric heat pump systems. That roof is too beautiful to have more stacks than necessary poking through it!

 

[Shygar]

All of it should be right? I think that even roofing work if done with solar is eligible, PW are definitely eligible. I am not a money guy though, so I am not the best informed on these matters. Probably not the asbestos abatement.

Well, that's kind of the question I was wondering. But in his post he said roughly 63% of the roof qualifies. My understanding is only the tiles with solar and the associated labor qualifies, so I was curious if Tesla broke that out for him. Not sure how you would figure out labor costs between solar and non-solar tiles.

 

[Maximapolak]

So the cost part does get a bit tricky, due to everything involved. I'll start out with "a lot", and "much more than the website estimated when I put down my deposit". They weren't late surprises, as soon as Tesla started talking to me they made it clear that the website severely underestimated. But so far (as far as I know, I keep asking if there have been any surprises and haven't gotten any response to that) it's holding to what was originally estimated/agreed upon, with the only unknown portion right now being the exact cost of the city permitting/inspection fees.

The previously published figure of $21.85/sq.ft. is clearly what they're sticking to, but that does assume a 35/65 split of solar/non-solar. The sq.ft. cost of the PV tiles is almost 4x the cost of the non-PV. When I was getting the estimate they came back with 3 sizes: 1) sized for the power I use today, 2) up-sized (~30%?) for future increase (I mentioned that I planned to add A/C and would get at least a plug-in hybrid at some point in the future), and 3) every possible tile that could be producing is (keeping in mind that there are setback rules, flashings, ridge venting, etc). The first two systems were under 10kW, and they said that they frankly weren't interested in doing a smaller system early, so they'd have gotten back to me mid-2019. The third option was 13.32kW, and is the one I went with, which is more of a 60/40 split, so the cost per sq.ft. is higher. And that number is purely the materials cost, there is also installation, one Powerwall+Gateway+install, and some extra charges/upgrades, mostly particular to my project, such as some work needed on the service line coming into the house, removal of an extra roofing layer, fascia repair (my old roof was in pretty bad shape), adding gutters, and asbestos abatement in the attic/garage. Plus a "roof preparation" cost, not sure exactly what that meant given all of the other items, I guess it might include the dumpster and other items. Strangely (to me), there's no line item for the inverters (2 Solivia 5.2 units), so I'm not sure where those costs were worked-in. And then taxes of course. So a rough break-down pre-tax (and without permit cost) was:

Materials: ~55%
Installation: ~13%
Upgrades: ~14%
Roof prep: ~9%
Powerwall: ~8%

Of the post-tax total, ~63% of that qualifies for the federal tax credit, so almost 19% of the total cost will come back in tax credit.

Anyway, from what I saw it's 561 of the SR24T3-2 PV Modules, which they seem to consider 23.75W each, so that matches their 13.32kW figure. They're arranged into 6 strings (2 on the back roof, 2 on the front roof, and one on each side of the garage, there are no producing tiles on the small plane at the front of the garage), 4 strings get paired-up to fit in the 4 available inputs of the 2 inverters.

That still doesn't tell me how much it cost you.

 

[msudawgfan]

That still doesn't tell me how much it cost you.

If a Powerwall is $8,000 and it is 8% of the cost... total should be approximately $100k

 

[woferry]

Did they break up your contract/bill by what is covered by the ITC and what isn't?

Yes, and according to their paperwork only the producing portion of the roof qualifies for the credit. Strictly speaking not even 100% of the "solar portion" of the Solar Roof qualifies, but the part that didn't was about 1.5% of the materials. So what they showed as eligible (of course in the legalese of "may be eligible") is most of the solar portion of the roof, the Powerwall & supporting hardware, the Powerwall installation, a portion of the roof installation (they split it up to qualifying and non-qualifying), and the portion of the taxes that covered the above items. That's what works out to 63% of the overall cost. Everything else, namely the non-solar portion of the roof, the non-qualifying installation, required electrical/structural upgrades, roof preparation, and taxes on the above, do not qualify apparently.

Thanks. That makes sense. That will give you a nice broad generation envelope through the course of the day and will avoid clipping 13.5kW of solar on 10.4kW of inverters.

Yeah, I was really questioning the size of the inverters once I saw them vs. their quoted roof capacity, but after estimating each of the 6 strings through PVWatts and reading more here about oversizing/clipping it doesn't seem so bad. The system is not evenly split across the inverters, my math says the 4 strings works out to approximately 2945W, 3325W, 5180W and 1875W, the first two on one inverter and the second two on the other. The smaller set is on the PW side of the Gateway, the larger one is on the grid side.

The new roof looks great! I think it's very smart to install as many solar tiles as they'll let you. For a sustainable energy future, everything from our cars to our home heating systems is going to have to go electric. Might as well be prepared for that.

In that vein, if I were having a solar roof installed, I think I'd first want to eliminate any and all roof-vented natural gas appliances and switch to electric heat pump systems. That roof is too beautiful to have more stacks than necessary poking through it!

Once this started happening it all happened fast enough that there was no time (nor the personal budget) to take on any additional major projects. When I eventually add A/C I do plan to switch to a heat pump (though the gas furnace air is so much nicer than any heat pump I've ever felt, I'd be tempted to keep a gas backup option), I'm dual-fuel in the kitchen and don't plan to change that, and I don't plan to change the HWH to electric, next time the tank goes I'll probably switch to gas on-demand though. Gas dryer, also, though that will probably switch to electric the next time that needs replaced.

Really, the two things that drove me to the biggest system was the scheduling and the price. I really wanted this done before this rainy season started, I failed obviously, and this turned out to be an unusually rainy season for the Bay Area, but fortunately my old roof never leaked. In fact the only time I had water in the attic was during this project (while they were still doing underlayment), where they hadn't properly covered the peak and water got in in a few places, but they were out within 30 minutes of me reporting it on a Saturday morning to take care of the leaks. On the price, while I didn't see any detailed cost breakdown until the contract was ready (so I couldn't really compare the 3 proposals to that level), their high-level summary of the other two options weren't much cheaper, and because less of it qualified for the ITC rebate the difference in the post-rebate cost was even smaller. So a system that was ~38% the size (5kW vs. 13.32kW) was still 85% the pre-ITC cost, and 94% of the post-rebate cost. So that made it a no-brainer in my mind. I'm still not totally convinced the math made sense here, when I questioned this they said that the smaller system was more complicated to wire, so it had higher costs than one might expect compared to the larger system. Having seen how the install is done I still don't quite get that, I see that it wouldn't have been much easier, but it doesn't seem like it should have been harder.

Anyway, a bit on the 'why'. I bought this house ~15 years ago, and my home inspector estimated that the roof looked like a 10-year roof that was already more than 10 years old. And the previous homeowner had the place for ~10 years and admitted they hadn't touched the roof. I'd wanted solar from the beginning, but knew it didn't make sense to put panels on a roof that needed replaced. It made sense to me that doing the roof and solar at the same time should have some benefit, so I'd looked for companies that did both but wasn't happy with anything I'd found at the time. And I'd looked at solar shingles back then as I really wasn't keen on panels, but they seemed to have enough minuses that I never pulled the trigger. But over the years shingles continued to blow off the roof so I knew things were only getting worse. Honestly I'm pretty sure the roof had leaks, but the shingles were placed on top of the original shake roof (a code violation as I understand it), and I think that roof is what kept the water out, instead the fascia boards started to really warp so I think they were getting water from behind. So when Elon made the announcement for Solar Roof I was very interested, and as soon as I heard about deposits being taken I went in. But the complete lack of any further communication (I got one Tesla marketing email over the ~14 months, and it only talked about the cars, nothing about solar) left me frustrated, and I was honestly about ready to look up how to withdraw my deposit and start talking to regular roofers when out of the blue was the email from Tesla wanting to schedule the site survey. Once I had an advisor assigned communications have been quite good, and I've had a good experience with everyone I've worked with from Tesla so far.

 

[woferry]

The gutters went up yesterday, and it was a sunny afternoon so I flew a friend's drone I'd borrowed and took some overhead shots, where you can see the solar and non-solar tiles better. I'd also taken some before pictures, though from different angles, I'll have to try to reproduce those angles as after shots before I return the drone.

 

[Shygar]

What's the cleaning process, if any? I assume you can walk on them? Do you need some kind of special shoe or is there enough grip on the tiles to not slide off the roof?

Secondly, did you go into your roof during a rainy day (like today) and check for any leaks after it was finished? I did this after they installed my panels and didn't find any leaks, but it wasn't something I wanted to find by accident 10 years from now.

 

[abasile]

The previously published figure of $21.85/sq.ft. is clearly what they're sticking to, but that does assume a 35/65 split of solar/non-solar. The sq.ft. cost of the PV tiles is almost 4x the cost of the non-PV. When I was getting the estimate they came back with 3 sizes: 1) sized for the power I use today, 2) up-sized (~30%?) for future increase (I mentioned that I planned to add A/C and would get at least a plug-in hybrid at some point in the future), and 3) every possible tile that could be producing is (keeping in mind that there are setback rules, flashings, ridge venting, etc). The first two systems were under 10kW, and they said that they frankly weren't interested in doing a smaller system early, so they'd have gotten back to me mid-2019. The third option was 13.32kW, and is the one I went with, which is more of a 60/40 split, so the cost per sq.ft. is higher. And that number is purely the materials cost, there is also installation, one Powerwall+Gateway+install, and some extra charges/upgrades, mostly particular to my project, such as some work needed on the service line coming into the house, removal of an extra roofing layer, fascia repair (my old roof was in pretty bad shape), adding gutters, and asbestos abatement in the attic/garage. Plus a "roof preparation" cost, not sure exactly what that meant given all of the other items, I guess it might include the dumpster and other items.

Tesla's online quotes of $11/ft^2 for non-solar tiles and $42/ft^2 for solar tiles, plus $10,100 for a single Powerwall, do include installation according to Tesla's website. It's understandable that they would charge extra for "non standard" work. Your project does seem to have been more involved than "normal". However, I'd be curious as to how close Tesla's final prices come to the quoted figures for more "typical" jobs. When Tesla installed our two Powerwalls, the final price was spot-on compared to the initial quote, but there weren't any significant complications.

Also, for extra stuff like removing additional roofing layers, I wonder how Tesla's prices compare with most roofers.

Once this started happening it all happened fast enough that there was no time (nor the personal budget) to take on any additional major projects.

That's totally understandable! If anticipating a potential solar roof, and one's budget allows, preemptively getting rid of natural gas stacks might be ideal. But it may not be ideal from the standpoint of cost. Within the next several years in California, I'd be surprised if there aren't new state and/or utility incentives to encourage property owners to switch to all-electric appliances and heating systems. We have a forced air natural gas furnace at our primary home, and it would cost more than $10K to replace it with heat pumps to cover all of our rooms, so we're waiting for costs to drop.

When I eventually add A/C I do plan to switch to a heat pump (though the gas furnace air is so much nicer than any heat pump I've ever felt, I'd be tempted to keep a gas backup option)

Heat pumps are designed to run more or less continuously, so the air that they output isn't as hot as from a forced air gas heater that essentially heats the home in bursts. However, an advantage of a heat pump is that it won't tend to reduce the humidity level in the house to really low levels during the winter, as it's simply recirculating the air in each room. We switched to a heat pump at another, smaller family home and it worked quite well all winter, including in February when temperatures frequently dropped into the teens (Fahrenheit). If the old gas heater still works, I agree that keeping it as a backup makes sense - why not, if it doesn't cost anything?

I'm dual-fuel in the kitchen and don't plan to change that

Dual-fuel means that you have an electric induction stovetop and a natural gas oven, right? In our case, we were doing a lot of baking and we were tired of the indoor emissions from our natural gas oven, so we just went all electric. Most home ovens aren't vented particularly well, and the exhaust gases just go into the home's living space. This includes carbon monoxide, of course. It also includes a lot of water vapor. Previously, whenever we ran the oven for long periods, we noticed condensation on the insides of our windows, but this completely stopped once we switched to electric.

I don't plan to change the HWH to electric, next time the tank goes I'll probably switch to gas on-demand though. Gas dryer, also, though that will probably switch to electric the next time that needs replaced.

We have an "on demand" tankless water heater at a rental property, due to space limitations, and I'm not a big fan. We also had one at a previous residence. Maybe they've improved in the ten years since we last installed one, but our experience with tankless water heaters is that they can be finicky about changes in the hot water flow rate. If you're in the shower and you attempt to adjust the flow of hot water, you may get nailed with an unexpected blast of cold water. In addition, we haven't noticed much in the way of natural gas savings.

It's currently possible to buy a heat pump water heater at Home Depot for less than $1200, for a 50 gallon tank. For a mild climate or a location such as a garage or basement that's not directly exposed to cold outdoor air, this might be a good option.