Where's the rest of the cost?

[motorcyclemikie]

well you already mentioned a 4 year ROI.

The equipment you mention is NOT going to continue to work in any way though with the grid outage.

My utility cost is $0.12kWh and I have a 12 year ROI but mine is bimodal so we get benefits right away with power during outages. It is the added cost due to battery and bimodal inverter that pushed my ROI to 12 years though...

I was origionally looking at a wind generator as we have a windy conditions here also.

[ButchDeal]

I hear you John, I think I could flip off the service entrance switch and back feed with my $65 Harbor Freight generator to energize the system

ok You have a lot of "I Think" going on which is not going to work.
This is yes another. SolarEdge will NOT sync to the Harbor FRIGHT genset, and if you manage to hack it to somehow sync, well that will be the end of your genset...

i'm 70yo, am I looking for a 20 yr payoff?

Sounds like you have a plan to not make it to 71

You might want to take a look at the SolarEdge document on gensets: https://www.solaredge.com/sites/defa...generators.pdf

[ButchDeal]

[QUOTE=motorcyclemikie;n390756]

You'll also notice I am stuck on the P800 until I prove to myself otherwise, Solaredge says it IS compatable with the 3 phase inverters, they didn't say NOT with single phase inverters.

/QUOTE]

SolarEdge doesn't list every configuration that is NOT compatible. They ONLY list compatible configurations...

[ButchDeal]

No, it probably isn't cost effective we are $.13 KWH, at $100mo current power bill this $4-5K (materials cost) will take over 4yrs. to pay off, I find that attractive though and I want to be able to survive when (not if) the grid goes down.

I might also add another variable most people never factor into their calculations, i'm 70yo, am I looking for a 20 yr payoff?

well you already mentioned a 4 year ROI.

The equipment you mention is NOT going to continue to work in any way though with the grid outage.

My utility cost is $0.12kWh and I have a 12 year ROI but mine is bimodal so we get benefits right away with power during outages. It is the added cost due to battery and bimodal inverter that pushed my ROI to 12 years though...

[motorcyclemikie]

You're inverter (SolarEdge SE7600) has an auto shut down feature, required by code on many (most?) grid tied installations. If the grid goes down your inverter shuts down as well.

I hear you John, I think I could flip off the service entrance switch and back feed with my $65 Harbor Freight generator to energize the system

I have a 4KW honda gen also

[John_Dumke]

I find that attractive though and I want to be able to survive when (not if) the grid goes down.

You're inverter (SolarEdge SE7600) has an auto shut down feature, required by code on many (most?) grid tied installations. If the grid goes down your inverter shuts down as well.

[motorcyclemikie]

No - it does not give you 12.5A at 60VDC.

What you're describing is probably about 80VDC and ~8A.

Yes sir Foo, I wasn't being exact on the numbers.

I assumed the per 250w panel 30vdc out as mfg. stated -- 250w / 30v = 8.33A (P/E=I)

2 panels in parallel is 500w / 30v = 16.66A

with the added 3rd panel in series with the previous 2 panels is 750w / 60v = 12.50A

You'll notice that the 2 panels exceed the current limits of the P800 optimizer until you add the third panel, I think that might cause confusion here.

You'll also notice I am stuck on the P800 until I prove to myself otherwise, Solaredge says it IS compatable with the 3 phase inverters, they didn't say NOT with single phase inverters.


With the PV panels being cheaper than optimizers, I can see eliminating excessive unneeded cost at this point,

[motorcyclemikie]

What is your cost for electricity? My best guess is that I pay about .23 per kWh. If you are paying much less, then maybe solar isn't worth it?

No, it probably isn't cost effective we are $.13 KWH, at $100mo current power bill this $4-5K (materials cost) will take over 4yrs. to pay off, I find that attractive though and I want to be able to survive when (not if) the grid goes down.

I might also add another variable most people never factor into their calculations, i'm 70yo, am I looking for a 20 yr payoff?

[John_Dumke]

Thanks John, good write up, I can see you have been there! I want to put in a system without the big bucks and the fluff. Heck, you can still buy a small house on a acre here for less than most people spend on a PV system.

What is your cost for electricity? My best guess is that I pay about .23 per kWh. If you are paying much less, then maybe solar isn't worth it?

[foo1bar]

You know John, I have not explained my idea correctly, I want to attach three 250w panels to one optimizer, if you can use 8 optimizers instead of 24 it might save you a considerable amount of money. This be done with 2 panels in parallel, in series with the third it gives 12.5Amax 60vdc at 750w (3X250w)

No - it does not give you 12.5A at 60VDC.

What you're describing is probably about 80VDC and ~8A. At least I believe you are describing is something like




...../--A---\
----<........>---C----
.....\--B---/


Where the letters are modules and the left side and right side connect to the optijmizer. And ignoring the '.' I had to put in to get it to show up right.
It'll really depend on the IV curves for the panels and what the optimizer would choose for an operating point.
But with an Isc of 8.54A, we can know that would be your max current for the above configuration (higher current could be possible, but then C would have 0 or less than zero volts across it.

[motorcyclemikie]

I don't really thing that there will be a way to test the inverter SE7600 with one optimizer. As other have suggested, there needs to be a minimum of 8 (I believe) optimizers in a string for the string to work. In addition the inverter needs to be connected to power to work, which I believe would be 240v.

You know John, I have not explained my idea correctly, I want to attach three 250w panels to one optimizer, if you can use 8 optimizers instead of 24 it might save you a considerable amount of money. This be done with 2 panels in parallel, in series with the third it gives 12.5Amax 60vdc at 750w (3X250w) I chose a optimizer (P800) above those electrical requirements. I have several power supplies that will simulate PV panels.

If everything else fails I could always buy 24 optimizers instead of 8. I'm also thinking that less would increase the relialiabilty overall of the system

[motorcyclemikie]

Thanks John, good write up, I can see you have been there! I want to put in a system without the big bucks and the fluff. Heck, you can still buy a small house on a acre here for less than most people spend on a PV system.

[John_Dumke]

Motorcycle Mikie,

I just finished installing a 9.24kW system on my home myself. In the link below I wrote up an article for marketing purposes, I am a Real Estate Broker. I do however have a BSME and a general contractors license. When it came to solar I knew nothing, so lots of research. Even though the article is long, there is still so much that I left out. As an example, I ordered my system through Renvu.com they sent me optimizers that were not compatible with my panels. This was only uncovered after I built out the system on the SolarEdge online design tool.

I don't really think that there will be a way to test the inverter SE7600 with one optimizer. As other have suggested, there needs to be a minimum of 8 (I believe) optimizers in a string for the string to work. In addition the inverter needs to be connected to power to work, which I believe would be 240v.

The error in my case was that I ordered P400-5 optimizers which technically should have worked with my Hanwha 385 watt panels. But based upon SolarEdge design tool, the Hanwha 385 watt panels needed to be paired with P505 optimizers. Renvu didn't catch this, but were very gracious in taking back product and shipping new product for free. The sales rep could not confirm exactly why the website didn't allow the P400-5 / Hanwha 385w match. Only that if they system didn't match up the product it was because SolarEdge engineering didn't want that match up. Renvu confirmed this as well.

Point of the story is that I still don't really have a complete explanation of why the P400-5, which can handle up to 400 watts wasn't allowed. Might it work but fail early, might it work by not correctly, would it not even register with inverter? I do not know. All I know is that I followed the manufactures specs and design tools and hopefully will avoid crawling up on the roof again and removing 24 panels and having to spend $2,000 replacing optimizers. Or worse yet, have a buggy system that causes me troubleshooting headaches that can never be solved.

And yes I wrench on motorcycles as well.

http://www.LBRE.com/solar

[motorcyclemikie]

thank you Foo yes I am on step number five and ready to continue on I appreciate your help my friend

[foo1bar]

Butch that is exactly what I am talking about I know all that I have done that and I would be speaking from experience not just what I heard from somebody's brother that's cousin did it.after listening to the people at SunEdge I think their credibility is very low they don't know answers that they should that are basic

I'm going to assume by "SunEdge" you mean Solaredge.
The people you get on the phone at Solaredge are going to be first-line support and/or sales.
Like any company you don't have the highly skilled people working the phones. The people working the phones are going to be able to escalate some things - usually something like "I'm an installer and the system I installed is having problems because X, Y, and Z". But most of the things they're going to deal with are probably the easier to answer issues, and you're asking about something that's pretty much off-label.

basically can anybody point me to a link on here that is a system around five or six KW that I could just copy that's all I want

Search for "DIY system in CA site:solarpaneltalk.com" on google - that'll be thread where I documented my build. It's 8.96kW, so slightly bigger than what you're thinking, but similar.

I'll second the suggestion made by someone else of using a supplier's website to come up with a "kit". I used Renvu's web tool as a starting point for what I bought. I made changes as I had a complex roof layout. But it gave me a good starting point - made me realize some details like needing to connect electrically across a rail joint. I think it also helped me with identifying what methodology I'd use for bonding/grounding the rails and module frames. (I went with iron ridge and their "grounding mid clamp" to connect modules to rails for the most part. Then a lug that connected the ground wire to the rail.)

I think the questions you need to have solid answers to before you are buying things:
1> how much kwh do I need?
2> how much kw of modules will get me there?
3> what's my POCO's policy/rules for net metering?
4> What is my AHJ requirements for a permit?
5> What is my AHJ requirements w.r.t. roof attachment (ex. my city has a "streamlined" process that if you have attachments every 4 feet they're willing to accept it without any further engineering review / framing analysis.
6> What is requirement for firemen access setbacks? (If your system won't fit, can you get a waiver from fire dept?)
7> Is there a requirement for rapid shut down in my location? (AHJ can answer - possibly indirectly by answering next question.)
8> Which version of NEC code am I going to need to build to?