A Few Questions About Price Shopping...

I have not installed solar yet on my roof, but (solar reviews . com / solar-companies) is the website I am looking at if I decide to do it.

The price difference will be noticeable but probably not a deal breaker.
A bigger concern is system complexity and so system reliability. .
One commandment for good engineering design is the KISS principle.
Micro inverter systems have 1 inverter per panel (or sometimes for 2 panels) with all the associated added wiring and complexities. Result: More to go wrong.
Most string systems have 1 inverter per system. Things are simpler with fewer components to fail.
Also, string inverters are usually/often in a garage where things are out of the elements and cooler. Even if outside, they're accessible and usually in a cooler spot.
Micro inverters are attached to about the hottest thing on a roof - a PV panel.
Electronic components don't care for elevated temps. much.
It's also probably not part of a good engineering design to put failure prone components in places that are hard to get to. A system with 20 micros has a lot more probability of failure than a 20 panel system with one is string inverter.
How will a micro in the middle of a 20 panel system be changed out ? Answer: Start by removing some panels to be able to get at the one that needs service and hope all is put back together as it should.

The big selling point of micros is that they have advantages for shady applications. Well, if you have a mostly unshaded location, what do you need micros for ?
To check for bad panels (a pretty futile exercise as panels are highly reliable - at least a lot more than micros seem to be), get a dual input staring inverter and compare string outputs. You'll most likely find a problem as fast.

Like the novelty of looking at each panel's output ? My experience is that most users with an IQ higher than that of a turnip get bored with that after a week or two.

If you have a mostly shade free site, get a string inverter. Get a better design for less money, have greater system reliability and better accessibility.
Want more proof ? Check old threads here and note how many problems show up relating to micro and optimizer systems vs. problems that show up with string inverter systems.

BTW, also check micro warranties. They might be 25 years but they also quite likely won't cover all the labor necessary to get at a failed micro.

Thank you. I will ask about a string system.

Don't do so until you get more information/PV knowledge. Have you read the book yet ?

Yes. I did find the book and read it. Definitely helps to know some of the vocabulary on the technical side.

I asked the company about a string system. They said they do not offer that as an option "for good reason". They basically make the opposite argument that it creates a single point of failure for the entire system. Where the microinverters allow for the rest of the system to continue working if one panel goes out.

I also talked to an electrician and he was really confused by their wanting to add a sub-panel. He said my 200 amp panel has plenty of space for the system they are proposing. So, I have to try and sort that out with them.

In the meantime, I also got a quote from Tesla that is the best price. Are there any strong opinions about Tesla around here?

After dealing with SolarCity and their evil spawn Tesla for about 20 or so installs in my HOA as I described previously, I wouldn't let them on my property. Very unprofessional. You want junk that's poorly installed by morons and nitwits, feel free. You'll get a lot less than you pay for.
Stay with local, established vendors that are also licensed electrical contractors and have been around since before PV came on the scene. You'll have a higher probability of getting a professional job done by professionals and a higher probability of getting what you pay for.

On the opposite argument of string vs. micro, most folks never look at their output. In all likelihood, you won't either. So, tell me, If one or several inverter's fail, how long will it take you to notice it the relatively small loss of output ?
If a string inverter fails, your billing will be screaming at you with the next billing cycle, and the fix will be far easier and probably less costly, at least for the first 10 years of system operation.
Actually, micro inverters create 1 additional failure point for each micro. The claimed benefit of micros is that system output does not drop to zero, but there are other considerations like how often do you want to make a rip to the roof ?
If you don't have a lot of shade, why pay more for an increase in the probability of system problems ?
To reiterate from a prior thread, look at postings here and note how many of them refer or deal with problems with micros and optimizers vs. threads that deal with problems caused by string inverters.
IMO only, folks who are knowledgeable about PV seem to usually have string inverter systems. I believe there's a reason for that - mostly that they are knowledgeable enough to see through vendor B.S. .
Another "good" reason vendors (according to a vendors anyway) think micros are superior might be that micro equipped systems are easier to install and less labor intensive.
Just know that from an engineering standpoint, micro inverter systems have less reliability built into them by virtue of having more stuff to go wrong.

Thank you. It seems like Tesla uses local labor just like anyone else. So, is it possible that the crew you dealt with in your area was bad and they could be better in other areas?

No company is guaranteed to stay around. But, Tesla being connected to the EV business seems to improve the chances they will be here in 10 years if/when the panels stop working. I do worry that the smaller local companies will be long gone before the panels have issues. Especially now with NEM 3.0. I think that is going to push a lot of them out. Some of them even suggested as much to me.

I agree about the string vs micro question. It seems like the argument for micro only makes sense if you assume a case where some of the panels go down for a long period of time. But, that contradicts the guarantee everyone offers where the panels get fixed or replaced when they go down.

I noticed in one of your posts that this will be a roof mounted system. That said you'll be forced to have some type of electronics attached to each panel on the roof to meet the rapid shutdown requirements.

Just panels and a string inverter would be preferred but can only do that with a ground mounted system per the latest NEC

Disagree.

1) String inverter systems carry very high DC voltages across your roof and the cabling itself presents a very high risk from nicks/cuts that may deterioate with time and cause arcing across to metal and can potentially cause fires. This is especially high risk across arrays with long strings of panels. Having microinverters convert the DC into AC straight dramatically reduces the fire risk along the cables spanning the roof down to the load. There is no risk of arcing from the panel to the inverter itself because its under 50v DC.

2) While large numbers of inverters present multiple points of failure, they also provide large reduncies. If you are a household that consumes high kWh a month and any downtime will already cause you to be paying full price for imports for that period especially if you dont know about it while running string inverters. If a micro goes down, only that portion is unavailable and your monthly bill will correspondingly show less reduction in imports. On top of that, the cost of replacing a single high power string inverter will vastly outweight the cost of replacing a single microinverter even with the cost of going up to the roof to repair. Plus, if you are tight on budget, you can leave it until you can afford to replace it with a small loss of production vs having an entire array of zero production until the string inverter is replaced.

The upfront cost of microinverters will always be higher but the downstream costs and risks will ultimately be lower. String inverters have lifespans of 10 yrs while microinverters have been rated or warrantied as high as 25 years. Usually any failures will be within the first 6 months of installation normally covered under the initial warranties.

Ultimately it rests of your appetite for risk. Personally, I would rather pay more up front now to lower the risk of arcing induced fires on my roof and have the contingency of continued energy production. Even if multiple inverters failed at the same time, I can opt to replace them all at once or one at a time without sacrificing my entire array's production.

Opinions vary.

1.) Proper design and professional installation using current codes and standards have worked well so far with respect to preventing fires caused by high(er) voltage used by string inverter systems.

2.) To a point, system redundancies are useful and desirable provided there is a reliable method of checking system output on a regular basis. Monitoring system output can perform that function but it's been my experience that monitoring often fails at the human interface. Besides not knowing what they're looking at, homeowners generally/often don't know such systems even exist and if they do, they seem to not care about them once the novelty wears off (which usually takes a couple of weeks/a month of looking before that slips off the routine). Result: If output drops, the combination of the variable nature of the input energy source and lack of attention to system functioning/output by (IMO) most residential users, any system output decreases have a rather high likelihood of going unnoticed.
System monitors are great only if they are used. If not, they are useless. That's the rub.
On the other hand, if a string inverter dies, my guess is that a system output drop to zero will have a higher probability of being noticed at the next bill (provided the owner bothers to look at the electric bill) than a relatively small output drop of a few % caused by a micro failure.
Bottom line: Micro failures have a higher probability of staying under the radar meaning the advantage of monitoring is reduced as f(user noninvolvement) along with system output.

3.) Given what I've seen of the ratio of microinverter failures in my HOA and as related on this forum vs. the number of string inverter problems seen and reported, as well as the idea that there is a probability of more than one failure of a micro in a microinverter equipped system over time, seems to me the cost factor of replacing one string inverter, while more than the cost of replacing one micro - and that's before any particulars, depending on manufacturer exclusion or policies about labor charges or limits on the number of times a micro can be replaced, may need to be compared to the cost of replacing more than one micro. How many more ?. Don't know, but that may depend on several things such as the professionalism of the initial install, the system design, weather, climate and something associated with the MTBF of the micros.
And, all that's before the mostly unknown and probably not calculable cost/hassle of disturbing parts of the system that need to be dis/reassembled to get at a micro not on the edge of an array and then hoping everything got reassembled correctly. Seems to me that such additional system disturbance will take a toll on future system reliability each time a micro on a panel needs service. At the risk of stating the obvious, such disturbances are unnecessary if string inverters are used.

4.) Redundancy is nice, but I'd rather eliminate the need for the redundancy than incorporate it by default.

5.) Mostly because I look at life as a set of probabilities, I partly agree that ultimately the choice of micros vs. string inverters rests to a pretty large degree on one's tolerance for risk.
But knowing (or at least thinking I might know) something of engineering design and maybe a bit about solar energy system design, and, IMO, only based on education, training and experience as well as interaction with neighbors through my HOA work, the probability of having fewer problems and less down time for residential PV systems is greater for string inverter equipped systems than for microinverter equipped systems.

Basically, I'm also of the opinion that if more potential residential and actual PV owners knew what I think I know, there would be a lot fewer microinverter systems around, but that's just more opinion.

And, like I wrote above, opinions vary.
I've seen, read and heard about a lot more problems and failures caused by micros (and SolarEdge optimizer systems for that matter) than I have of fires that can be traced to design flaws with string inverter systems.
Part of the problem with microinverter systems, besides gross violation of the KISS principle, may stem from putting electronics that are temperature and environmentally sensitive on roofs that are subject to about the most extreme temperatures on a property as well as being about the hardest locations to get to.

Micro inverters may be needed in certain circumstances.
I would agree with reducing the risk of fire, which I do by
ground mounting my panels. But micro inverters put out
250VAC (here), the peak voltage is close to my DC strings.

For reliability I note there are 2 DC and 2 AC conductor
connections for every micro inverter. A string has only
one per panel, plus 1 more. The prime failure mode here
has been in the wiring, after a decade the (100 plus) panels
and inverters are all original. Nicks and cuts, sounds like
better cable management is needed. The only ones here
were couple critters nibbling on them (with fatal results).

That approach sounds like keeping most of the micros going
most of the time, completely unacceptable to me. I keep
everything going all the time. When there was a wiring failure,
it caused enough variation to be noticed immediately, with
repair of that string within a day. Going out in our 0 deg
weather today for micro replacement would not be likely,
failures would accumulate over the winter.

But my string inverter is mounted in my cool, dry, illuminated
shed, not too difficult to deal with if needed. As opposed to
keeping a basket of micros around for regular replacements,
I have just 1 string inverter mounted as a spare down the wall.
If failure does happen, just switching the DC input pair and
closing the breaker will put it in service, no waiting for good
weather.

Almiost all work involving PV array wiring here is done in the
dark, no lost production.

Cost, strings are the cheapest, esp when you consider the
greatly reduced cost of wiring the entire system up. You may
compare the demonstrated life of string inverters to that
projected for micros, they are in a tough invironment with a
limited cost, they have yet to demonstrate the numbers.
We shall see. Bruce Roe

Agreed. There will always be two camps to this and there will be situations where each will prevail over the other. Technology will always get better and more reliable with time. We all have our own appetites and expectations and everyone is always right in their own eyes with their own rationalisation for their decisions.

DC voltage is added together in series. Anything above 120v DC is enough to kill. I believe max is 1500v DC per string. DC voltage and AC voltage of the same value isnt the same.

Anyway, everyone has their opinions and their priorities. My opinion is micros are just safer and more future proof. Biggest drawback from micros is the ac-coupled battery inefficiency.

A friend of mine is lookling at a house in the Sierra foothills of Northern Caifornia. Has solar out the ying-yang already, but he might want to go off-grid and I don't blame him. Reading about all the new regs (NEM1 for example), I'm glad the huse already has solar but he's flush and wants to be off- grid. He understands about batteries.

Generally speaking, at about 40 north, with 26 panels on the roof, can he go off-grid? Thanks in advance.

Unless he has a hybrid inverter that can charge batteries without a grid he will have to get a charge controller that is matched up to the panel input and battery system. Sounds like a lot of work and money to me.