Solar roof panels

[Tracy Duquette]

Has anyone heard of the companies in Toronto called Sunbee and EScience? HOw are they rated and what is their reputation. I am looking to have them install a solar roof on our barn

What should it cost to ahve a unit of 46 panels ... 250 watts and 46 215 watt microinverters installed on a roof top? Anyone know a good price installed? nI just want to know what to expect.

[Anil Patel GTA]

Has anyone heard of the companies in Toronto called Sunbee and EScience? HOw are they rated and what is their reputation. I am looking to have them install a solar roof on our barn

What should it cost to ahve a unit of 46 panels ... 250 watts and 46 215 watt microinverters installed on a roof top? Anyone know a good price installed? nI just want to know what to expect.

is there any reason you want to use micro inverters. i just find microinverters are better options for systems under 3 kw or if you have shading problems.

you just need to find a company who will actually take the time to size strings.

[Tracy Duquette]

I heard that micro inverters are much easier and the way to go for a 10 kw system

[Anil Patel GTA]

I heard that micro inverters are much easier and the way to go for a 10 kw system

its easier for the sales man because he can sell you as many panels as he wants without having to do any simple design work.

I didn't enjoy replacing micro inverters under solar panels with so little space to access them when i got a call from a friend to help with the task.

others may beg to differ.

out of the manufactures I have worked with, emphase has to be the worst in my opinion.

I have left it as my inverter choice of last resort for systems I believe are unsuitable for string inverters.


fronius
Power one
sma
kaco
satcon
emphase

if you do a search on the largest inverter manufactures you will notice that i have worked with almost every large manufacture.


i would like to hear someone else's opinion who has worked with string and micro inverters to keep me honest.

[Rob Beckers]

Hi Tracy,

To start with prices: For an 11,500 Wat solar array we would charge $63,250 plus HST (you can get the HST back by registering for a business number). That would include everything; the $1,500 meter fee, engineering, permits etc. That is for an install with regular string inverters (2x Power-One 5kW in this case), and decent brand-name PV modules (we've been using Heliene).

For Enphase inverters we charge an extra $0.60 per Watt due to the additional cost of the inverters. So, that makes for an installed cost of $70,150 plus HST for your solar array.

I realize that my business is not the cheapest one around for solar PV installations (not the most expensive one either though). Our focus is more on quality, we only do a small number of installations each year. Part of the price is in the materials, we use top-quality materials for racking, panels, inverters etc. That is one area where the cheaper installers save on their costs.

I would be curious what they quoted you (and what's included/excluded so it's possible to compare prices).

I always try hard to talk people out of using micro-inverters or optimizers, unless they really need them (which is rarely the case; even with shading there are ways to accommodate it with string inverters, without loosing out on energy production). The beauty of traditional solar PV is that it's almost indestructible, very simple, there's no maintenance, and once installed it generally works for 20+ years. It makes no sense to me to stick lots of failure-prone electronics under the panels. I can guarantee you that at least one of those micro-inverters will fail over a 20-year time span. It's not a question of "if", but "when". Murphy's law dictates that it will always be the one that is hardest to replace, so you'll be paying someone to pull panels off just to reach the broken micro-inverter (and it doesn't help that you'll get a free replacement inverter, you'll be paying for labour).

What sells Enphase inverters is their Web monitoring, and it truly is beautiful! Once people have seen that they want Enphase. Just beware of the trade-offs you're making for it, and the reality is that most people will watch their solar energy production far less often after the novelty has worn off a few months down the road.

-RoB-

[Anil Patel GTA]

http://www.sustainableenergy.com/index.php?id=5 i'll delete the link if i'm not allowed to post it.

http://www.sustainableenergy.com/typo3temp/pics/f85d4a93bc.jpg

Have you used any of these inverters. I haven't had the pleasure yet. You can mimic micro inverters shade tolerance using only 3 panels to a string(60 cell modules). also there is no high voltage. Would be good competition for micro inverters combined with monitoring combiner box. seems a lot more reliable than tigo maximisers.

I have had a job using thin film DuPont last year and there was lots of wiring. and that was about 100 panels 4 to a string.

[Rob Beckers]

http://www.sustainableenergy.com/index.php?id=5 i'll delete the link if i'm not allowed to post it.

http://www.sustainableenergy.com/typo3temp/pics/f85d4a93bc.jpg

Have you used any of these inverters. I haven't had the pleasure yet. You can mimic micro inverters shade tolerance using only 3 panels to a string(60 cell modules). also there is no high voltage. Would be good competition for micro inverters combined with monitoring combiner box. seems a lot more reliable than tigo maximisers.

I have had a job using thin film DuPont last year and there was lots of wiring. and that was about 100 panels 4 to a string.

I've seen those optimizers for parallel connection of panels. Maybe I misunderstand; it seems a solution in search of a problem (by the way, Tigo also makes optimizers for parallel connected panels). There is advantage to traditional series strings, the high voltage keeps the wire size and losses down. Shading, and the effect on solar PV strings, is very much misunderstood (and that includes most installers). I've written about this before. (http://www.greenpowertalk.org/showthread.php?t=12380#23) Regular series strings deal very well with shade, as long as you don't put multiple strings in parallel. Optimizers would not be able to get significantly more energy out of the vast, vast majority of cases, if those strings were installed right (using regular string inverters).

Sometimes the simplest solutions really are best...

-RoB-

[Michel de Breyne]

Let me preface this by saying that I'm not an installer and my experience is limited.

The reliability of the string inverters is one of the reasons mentioned to choose that over micro-inverters but from what I've read, I'd have to disagree. If nothing else, most string inverters come with a 10 yr warranty (many offer 15 or 20 yrs at an additional cost). Enphase M215 comes with a 25 yr warranty (M190 and M210 are 15 yrs). If a micro-invertor fails, you'll be down 1 panel. If a string inverter fails, depending on your configuration, half or all your panels would go down. How long would it be done before you noticed it? How long would it take to get a replacement once you do notice it? As mentioned, depending on where it fails, replacing a micro-inverter might involve a fair amount of labour but replacing a string inverter isn't exactly trivial either - I'd be curious to know how much that would cost.

As mentioned, I don't have much experience with solar arrays but I know from motor homes and boats that inverters fail quite freqently often within 5-10 years.

[Anil Patel GTA]

I've seen those optimizers for parallel connection of panels. Maybe I misunderstand; it seems a solution in search of a problem (by the way, Tigo also makes optimizers for parallel connected panels). There is advantage to traditional series strings, the high voltage keeps the wire size and losses down. Shading, and the effect on solar PV strings, is very much misunderstood (and that includes most installers). I've written about this before. (http://www.greenpowertalk.org/showthread.php?t=12380#23) Regular series strings deal very well with shade, as long as you don't put multiple strings in parallel. Optimizers would not be able to get significantly more energy out of the vast, vast majority of cases, if those strings were installed right (using regular string inverters).

Sometimes the simplest solutions really are best...

-RoB-

this does not use any optimizers or is a optimizers.

[Anil Patel GTA]

Let me preface this by saying that I'm not an installer and my experience is limited.

The reliability of the string inverters is one of the reasons mentioned to choose that over micro-inverters but from what I've read, I'd have to disagree. If nothing else, most string inverters come with a 10 yr warranty (many offer 15 or 20 yrs at an additional cost). Enphase M215 comes with a 25 yr warranty (M190 and M210 are 15 yrs). If a micro-invertor fails, you'll be down 1 panel. If a string inverter fails, depending on your configuration, half or all your panels would go down. How long would it be done before you noticed it? How long would it take to get a replacement once you do notice it? As mentioned, depending on where it fails, replacing a micro-inverter might involve a fair amount of labour but replacing a string inverter isn't exactly trivial either - I'd be curious to know how much that would cost.

As mentioned, I don't have much experience with solar arrays but I know from motor homes and boats that inverters fail quite freqently often within 5-10 years.

Fronius: Replacing Power modules / Leistungsteiltausch - YouTube

this is how easy it is to replace an inverter. i would be able to replace a whole string inverter faster that a micro inverter. when you consider you need to go on a steep roof and try and disconnect an inverter.

remember you need to re ground everything after as well. its really tight under there trying to reach those screws holding the inverter to the rail and the clamp holding the ground wire to the micro inverter.

[Rob Beckers]

Michael, do not mistake warranty period for reliability. Micro-inverters give very long warranties because they recognize that failure (and the excessive amount of work to replace one on a roof) is their weak point. They give long warranties because those things cost them next to nothing to manufacture, and their profit margins are such that they can afford to give you a new one. You'll be paying for the labour to pull panels off, replace the inverter, and put them back up again. If you're unlucky you'll be doing this more than once over a 20-year period...

Since neither micro- nor string-inverters have been around long enough (not the current crop with this generation of semiconductors) to have any real statistics, my own unscientific take is that most good string inverters will work for 20 or more years, some will fail prematurely (if I had to put numbers on it I'd give it an 80% chance of 20-year service). While micro-inverters have a somewhat lower part count, and run at lower power levels, they won't have significantly better survival rates. But, instead of 2 string inverters for a 10kW solar array, you now put up 42 of them! Your chance of having at least one fail over a 20-year time period just went up dramatically!

Recognizing that a string inverter failed is pretty easy, especially since all the major brands now have monitor tools (I have a little wireless touch-screen device sitting next to the computer that shows what the inverters and panels on my roof are doing). Having 5kW drop out on you is easy to recognize. Replacing one is a matter of an hour of labour, maybe two, depending on brand/type. Power-One will send out a new one upon reporting a problem, and you ship back the broken one (at their expense) in the box that the new one came in. If it's outside warranty you'll have to pay; they have fixed rates to replace an inverter. That's Power-One, I don't know how others do it. If you go through the right channels you can easily have it replaced within a week.

-RoB-

[Anil Patel GTA]

this does not use any optimizers or is a optimizers.

quote form text from link. " not require the increased cost of module level electronics"

[Anil Patel GTA]

this does not use any optimizers or is a optimizers.

quote form text from link. " This proprietary technology represents the industry’s first power optimization technology that does not require the increased cost of module level electronics"

[Tracy Duquette]

Let me preface this by saying that I'm not an installer and my experience is limited.

The reliability of the string inverters is one of the reasons mentioned to choose that over micro-inverters but from what I've read, I'd have to disagree. If nothing else, most string inverters come with a 10 yr warranty (many offer 15 or 20 yrs at an additional cost). Enphase M215 comes with a 25 yr warranty (M190 and M210 are 15 yrs). If a micro-invertor fails, you'll be down 1 panel. If a string inverter fails, depending on your configuration, half or all your panels would go down. How long would it be done before you noticed it? How long would it take to get a replacement once you do notice it? As mentioned, depending on where it fails, replacing a micro-inverter might involve a fair amount of labour but replacing a string inverter isn't exactly trivial either - I'd be curious to know how much that would cost.

As mentioned, I don't have much experience with solar arrays but I know from motor homes and boats that inverters fail quite freqently often within 5-10 years.

I have a 25 yr warranty on the micro inverters with a 10 yr labor warranty also. That seems pretty fair.

[Anil Patel GTA]

I have a 25 yr warranty on the micro inverters with a 10 yr labor warranty also. That seems pretty fair.

I say take it. but if the company goes out of business your SOL for the labor.

I wouldn't want to deal with the headache of doing paperwork every few years for burnt out inverters and having to replace them for free. especially for 50 of em. The quote probably has those costs built in. If not its pretty easy for a large company to go out of business like this.

Enjoy the beautiful module level monitoring I feel is only rivaled by the tigo system.

[Tracy Duquette]

I say take it. but if the company goes out of business your SOL for the labor.

I wouldn't want to deal with the headache of doing paperwork every few years for burnt out inverters and having to replace them for free. especially for 50 of em. The quote probably has those costs built in. If not its pretty easy for a large company to go out of business like this.

Enjoy the beautiful module level monitoring I feel is only rivaled by the tigo system.

I know I thought of that " IF the company goes out of business. I guess that is the chance I will have to take, no matter who I get to install

[Tracy Duquette]

I say take it. but if the company goes out of business your SOL for the labor.

I wouldn't want to deal with the headache of doing paperwork every few years for burnt out inverters and having to replace them for free. especially for 50 of em. The quote probably has those costs built in. If not its pretty easy for a large company to go out of business like this.

Enjoy the beautiful module level monitoring I feel is only rivaled by the tigo system.

Our electrician is from this area so hopefully he can install them if I need help in the future with the inverters.

[Anil Patel GTA]

Our electrician is from this area so hopefully he can install them if I need help in the future with the inverters.

perfect. its always better to go with a local guy. why don't you get the electrician to do the whole job.

[Tracy Duquette]

perfect. its always better to go with a local guy. why don't you get the electrician to do the whole job.

The company will install the inverters and the panels so I get my warranty, then the electrician is going to do the rest, run the wire, hook up to grid.

[Tracy Duquette]

The company will install the inverters and the panels so I get my warranty, then the electrician is going to do the rest, run the wire, hook up to grid.
IF I would have got a local guy to install the panels and microinverters...It would have cost me way to much. His quote was approx 5,000 more than Toronto. Too expensive

[Anil Patel GTA]

here is an article i found about micro inverters


http://www.enecsys.com/downloads/UnderstandingMTBF.pdf