Cheapest inverters and*maximizers for residential 7kW system: Tigo vs. SolarEdge

[100percentRE]

I'm putting together an equipment list for a 7320W (nominal DC) residential system. I'd like to use per-panel MPPT because there are some trees on the property. I'm looking for recommendations for the cheapest inverter/maximizer combo.

Panels: 24x305W panels from Canadian solar (CS6X-305P). $.84/W delivered

System A: SolarEdge - $3561

• SolarEdge 7600W inverter (SE7600A-US-U): $1727
• 24x SolarEdge 400W maximizers (P400-2NM4ARM): $1684
• Shipping: $150
• Total inverter + maximizer cost: $3561 = $.486/W

System B: Tigo + Delta inverter:

• Delta 6600W (nomial AC) inverter. 7920W input: $1550
• 12x Tigo dual maximizers (2ES-75): $1068
• Tigo gateway (GTWY): $99
• Tigo Maximizer Management Unit (MMU): $299
• Shipping: $200
• Total inverter + maximizer cost: $3216 = $.44/W

I haven't done a full efficiency and and reliability analysis and would appreciate feedback about those factors, esp. how to compute realistic efficiency projections between the two systems based on real data.

Furthermore, there may be additional hardware I have not considered. The Delta inverter was the best price in $/W that I could find, but maybe there are other deals out there. SolarEdge has a ~$100 P700 dual panel optimizer that I would prefer to use ($.066/W savings), but I believe it only works with the 3-phase system (I sent SE an email to confirm).

What do you all think of the numbers? Can you come up with a cheaper configuration that would work well for a shade-ridden roof?

[Qtips]

I have a 3.5kW system with Trinasmart panels that have Tigo optimizers built-in on the back of the panel. It's only been four months and, knocking on wood, it has been very reliable so far, except for one panel during the initial install when that panel refused to initialize.

The major weakness with a system based on SolarEdge is that the system can only function with a SolarEdge main inverter. You can not replace a SolarEdge with another brand of main inverter. If SolarEdge ever goes out of business and your solaredge main inverter goes bad, you'd be totally screwed. With a Tigo system, if Tigo goes out of business, and if either my Tigo gateway or Tigo MMU go bad, the system can still produce power just fine. lf my Power One Aurora main inverter ever goes bad, I could simply replace it with another one or even another brand and the system would work just fine.

[ButchDeal]

I'm putting together an equipment list for a 7320W (nominal DC) residential system. I'd like to use per-panel MPPT because there are some trees on the property. I'm looking for recommendations for the cheapest inverter/maximizer combo.

Panels: 24x305W panels from Canadian solar (CS6X-305P). $.84/W delivered

System A: SolarEdge - $3561

• SolarEdge 7600W inverter (SE7600A-US-U): $1727
• 24x SolarEdge 400W maximizers (P400-2NM4ARM): $1684
• Shipping: $150
• Total inverter + maximizer cost: $3561 = $.486/W

System B: Tigo + Delta inverter:

• Delta 6600W (nomial AC) inverter. 7920W input: $1550
• 12x Tigo dual maximizers (2ES-75): $1068
• Tigo gateway (GTWY): $99
• Tigo Maximizer Management Unit (MMU): $299
• Shipping: $200
• Total inverter + maximizer cost: $3216 = $.44/W

I haven't done a full efficiency and and reliability analysis and would appreciate feedback about those factors, esp. how to compute realistic efficiency projections between the two systems based on real data.

Furthermore, there may be additional hardware I have not considered. The Delta inverter was the best price in $/W that I could find, but maybe there are other deals out there. SolarEdge has a ~$100 P700 dual panel optimizer that I would prefer to use ($.066/W savings), but I believe it only works with the 3-phase system (I sent SE an email to confirm).

What do you all think of the numbers? Can you come up with a cheaper configuration that would work well for a shade-ridden roof?

well you would be dealing with two companies for the Delta/Tigo VS Solaredge single company.
The solaredge system is also a single monitor system.
In your case you are looking at comparing a 7.6kw Solaredge system to a 6.6kw Delta system, so the SolarEdge is more expandable. (yes the Delta has a max input of 7.92kw but only an output of 6.6kw, the SolarEdge has a max input of 10.25kw)
The SolarEdge is also capable of being upgraded to battery backup or zero feed in system.

The P700 is for commercial 3 phase installs and not residential, you should be fine with the P300 though.

for a cheaper solution on a heavily shaded roof you could use the SE6000 instead of the SE7600 (not much savings but you asked).

[emartin00]

Some distributors will actually give you a discount on the SolarEdge optimizers if you buy the panels from the them too. I only paid $39 each for 20 P400s.

[foo1bar]

Have you looked at P300 or P350 from solaredge instead of P400?
Check VERY carefully that you have the correct optimizer for the module.
In your case, I think P400 isn't right - P400 is labeled as being for 96-cell, so quite possibly it won't be as optimal for your voltage range with 72-cell poly panels. Possibly could even be out of spec.

I see a price of $61 for P400 ($1464)
$56 for P300s (Don't see P350s on renvu's website, but I'm sure they'll give you a quote on it if you email or use the website chat)
Looks like $1334 for SE7600

If you're in CA, there'd be tax on that too - so ~$3100.
Shipping is something you'd have to contact them and ask - but if it's also ~$150 it'd be ~$300 cheaper with them.

I'd also look at different modules.
$.84/W for 72-cell 300W panels is high IMO.
You can probably get 300W 60-cell panels for about that price. (20% more efficient / 20% less space)
Or lower efficiency 250W 60-cell or 300W 72-cell for cheaper than what you're spending.

[ButchDeal]

It would be a P320 in the US not P350.
The P400 is for 72 and 96 cell modules.

http://solaredge.com/sites/default/files/se-P5-series-add-on-power-optimizer-datasheet-na.pdf

[emartin00]

As Butch said, There is no P350 in the US, only 300, 320, 400, 405, 600 and 700.
The P320 is for high power 60 cell modules (LG and SunPower mainly). The P400 is good for just about any 72 or 96 cell module

P400 is the correct unit for the 305W modules.

I would agree on the price though. I bought 20 Hanwha 305W modules for about $.56/W, and I've seen prices as low as $.53/W from Renvu.
As I mentioned, if you can an eye on sales, you can get the P400 for <$50 each.

[loobosh]

What is the dial on the back of the Solaredge p300 Optimizer just wondering no info on it.

[emartin00]

What is the dial on the back of the Solaredge p300 Optimizer just wondering no info on it.

What dial are you talking about?

[loobosh]

Black round it turns?

[loobosh]

What dial are you talking about?

Black round it turns? Did not want to turn it to much might be holding it together or power setting.

[Qtips]

I'd recommend choosing Tigo. I see someone is still here trying to scare people with "having to deal with two companies." When is this installer guy going to give up with his garbage?

I'm sure SolarEdge makes decent equipment, but unfortunately a system based entirely on SolarEdge means you will be at the mercy of the company surviving for the duration of your system. How likely is that? That's what I call truly a single point of failure.

Tigo is actually VERY cost effective if you can know in advance which areas of your planned array will get shading over the course of a year. You will then only need to put an optimizer on those few select panels. This fact is rarely advertised by installers or Tigo because they obviously want you to buy an optimizer for every panel in your system.

[dennis461]

This thread is growing whiskers. 05-02-2015, 08:03 PM

[Qtips]

Yeah, I understand it's an old thread and the person who posted the original questions in all likelihood already had his system installed, but oftentimes answers to these old threads can provide useful information to other people who are only now exploring solar and are still making up their minds.

[foo1bar]

I'd recommend choosing Tigo. I see someone is still here trying to scare people with "having to deal with two companies." When is this installer guy going to give up with his garbage?

As a self-installer with multiple roof angles and some shading I chose Solaredge.
I see Solaredge as a better brand name (so bigger userbase and larger likelihood of survival over 10+ years)
I see Solaredge as being a single "throat to choke" - if I were to have issues with my install. (I had one minor issue, but the distributor took care of it.)
I also like the per-module data - but I will admit it is not really a big thing from a practical perspective - it's more for fun than it is for financial benefit.

I'm sure SolarEdge makes decent equipment, but unfortunately a system based entirely on SolarEdge means you will be at the mercy of the company surviving for the duration of your system. How likely is that? That's what I call truly a single point of failure.

It is a "single point" - that is a very real drawback.
But IMO it's not that huge of a risk. If Solaredge goes bankrupt some company will buy their assets, including the necessary information / patents to create something that is compatible with their existing installed base.
And there will be a secondary market for used inventory as people switch their systems to some other solution (Tigo or whatever). So if I have one optimizer die, I'll likely be able to get one on ebay for a slightly elevated price, but not ridiculous. And if I have >25% of the system go down in a short time I'll sell the remaining working ones I own on ebay and use those proceeds to buy a new system.

[Qtips]

It is a "single point" - that is a very real drawback.
But IMO it's not that huge of a risk. If Solaredge goes bankrupt some company will buy their assets, including the necessary information / patents to create something that is compatible with their existing installed base.
And there will be a secondary market for used inventory as people switch their systems to some other solution (Tigo or whatever). So if I have one optimizer die, I'll likely be able to get one on ebay for a slightly elevated price, but not ridiculous. And if I have >25% of the system go down in a short time I'll sell the remaining working ones I own on ebay and use those proceeds to buy a new system.

Generally, betting on another company to pick up a bankrupt company's assets or absorb the troubled company is poor strategy because if the company was troubled to begin with, having a buyer doesn't make the troubled company a more viable company. Most likely a "white knight" company would buy the patents and perhaps some usable assets at fire-sale prices and use the acquired technology to create their own, often proprietary, product offerings. Often the product lines from the old company would be discontinued.

Enecsys is gone for good and so are their products. You can still find them on eBay. SolarBridge was acquired by SunPower, not sure whether the old SolarBridge microinverters are compatible with SunPower's cables and monitoring system.

Ebay would be your best bet to find replacements for discontinued product lines, but the question you'd have to ask is for HOW LONG can you reliably get old parts after the troubled company goes out of business.

There are monitoring sites that can monitor output from Enecsys micros for a fee. There is a good chance they'd be able to monitor SolarEdge output also.

[ButchDeal]

If people used this line of thinking for vehicles the only possible vehicle that you could get with full redundancy in production would be a Harley Davidson, as there are lots of aftermarket producers of parts. In fact there are lots of small bike companies that sell Harley clones without using a single Harley branded part, by basically bolting aftermarket parts together.
Try doing that with any car made in the current year.
No one worries that their expensive heat pump company might go under rendering no support for their HVAC system.

If you were to look at systems with failed string inverters from even a few years ago, they often have significant issues getting a modern inverter from the same manufacturer to work without restringing Or worse having to add modules to strings to get to proper voltages.
now if you were to thing of more likely failures like a module failed in ten years. Try finding a module to match looks, deminsions, and voltages of a 10 year old string. With solaredge not only do you easily know about the failure and have proof for the manufacturer, but you can install pretty much any module they send you to the same system.