SMA String VS Solar Edge with Power Optimizers

[silversaver]

Any reason why the "good" company can't do SolarEdge?

Because the company hasn't yet established a reliable track record.

[drmtesta]

Any reason why the "good" company can't do SolarEdge?

That will be my conversation tomorrow . . . great minds!!

[HX_Guy]

We had a bad experience with the company providing the Solar Edge system. They pulled hard sell technique, sign by tomorrow thing we didn't like. They apologized and we are dealing with a different rep. The company my wife likes was overall much more professional and detailed in their approach. We asked them to come close in price and they did. Bottom line is all of these installers are young companies. Even if they are attached to an older, larger company. They are divisions that can be shut down and my sense is the larger company would not be liable. Feels like the risk is essentially the same with whoever you choose (meaning risk of going under). IDK.

Don't be afraid to supervise the work and make sure it gets done right. Ask questions on here during the process. As long as the install is done correctly (and really that means proper roof attachment and proper wiring) then there really isn't much else at risk if the company does go under. You'll have manufacturer warranties if the super small chance that something does malfunction in the future.

[drmtesta]

Don't be afraid to supervise the work and make sure it gets done right. Ask questions on here during the process. As long as the install is done correctly (and really that means proper roof attachment and proper wiring) then there really isn't much else at risk if the company does go under. You'll have manufacturer warranties if the super small chance that something does malfunction in the future.

Good to know. . .thanks!!!!

[Ian S]

So one of the competing companies came back with a matched offer using an SMA 10,000 inverter rather than 2 - 5,000 inverters. Does this change anything or is Solor Edge still the way to go? Any disadvantages to a single larger inverter. Both systems would have 20 year warranties.

I don't think you can get the Secure Power outlet on the larger inverter. That outlet provides power in the event of a grid outage; it's a feature unique to SMA but you have to make sure it's included. But again it only seems to be available on the smaller SMA inverters. You should also check and see what the SMA monitoring software is like and the info it provides. Obviously you won't get the individual panel info that you get with the Solar Edge system. TBH, nearly three years in, I find my frequency of checking production numbers has dropped off dramatically. YMMV.

Without the Secure Power outlet, the single SMA inverter really offers no advantage (other than SMA's lengthy business history) so I'd be inclined to go with the Solar Edge system.

[solar pete]

I don't think you can get the Secure Power outlet on the larger inverter. That outlet provides power in the event of a grid outage; it's a feature unique to SMA but you have to make sure it's included. But again it only seems to be available on the smaller SMA inverters. You should also check and see what the SMA monitoring software is like and the info it provides. Obviously you won't get the individual panel info that you get with the Solar Edge system. TBH, nearly three years in, I find my frequency of checking production numbers has dropped off dramatically. YMMV.

Without the Secure Power outlet, the single SMA inverter really offers no advantage (other than SMA's lengthy business history) so I'd be inclined to go with the Solar Edge system.

Hi All,

I for one would be going with 2 x SB5000 you get two power outlets in the event of a black out, and I believe SMA lengthy business history is precisely why they should be considered. Solar Edge might be ok but no one can tell you of an example of one that has been working for 15 + years, I can with SMA.

[drmtesta]

So now we have a third option, which is LG 305 panels with micro inverters. The thing is, we could include thermal pool heating and a variable speed pump for the same price as the other systems.

Option 1: 32 SP 327 Panels with Solar Edge
Option 2: 32 SP 327 Panels with 1- 10,000 SMA Inverter
Option 3: 34 LG 305 Panels with Enphase Micro Inverters, Pool thermal and variable speed pump included for same price as above.

What to do???

[Ian S]

So now we have a third option, which is LG 305 panels with micro inverters. The thing is, we could include thermal pool heating and a variable speed pump for the same price as the other systems.

Option 1: 32 SP 327 Panels with Solar Edge
Option 2: 32 SP 327 Panels with 1- 10,000 SMA Inverter
Option 3: 34 LG 305 Panels with Enphase Micro Inverters, Pool thermal and variable speed pump included for same price as above.

What to do???

Kinda goes along with SunPower being high priced. As for micros, my only concern would be installing them in a hot climate. Cooler climate fine but also be aware that you have more potential failure points and labor to replace them on a roof may not be included in the warranty. Maybe see about the LGs with Solar Edge which puts less electronics on the roof compared to Enphase.

[drmtesta]

Kinda goes along with SunPower being high priced. As for micros, my only concern would be installing them in a hot climate. Cooler climate fine but also be aware that you have more potential failure points and labor to replace them on a roof may not be included in the warranty. Maybe see about the LGs with Solar Edge which puts less electronics on the roof compared to Enphase.

Good point. My concern is the degradation of the LG panels vs SP. Seems like SP is getting good real world numbers. Do the optimizers that come with Soloar Edge have the same issue as the micro inverters in the heat? it's hot here in the summer. . .very LOL

[Ian S]

Good point. My concern is the degradation of the LG panels vs SP. Seems like SP is getting good real world numbers. Do the optimizers that come with Soloar Edge have the same issue as the micro inverters in the heat? it's hot here in the summer. . .very LOL

The advantage of the Solar edge system over Enphase is that there are less electronics on the roof - you still have the main inverter that's at ground level and in a cooler place. I'm in Phoenix, and have no significant shading issues so would not have gone with micros. My string inverter is a rebadged SMA and it's indoors out of the worst heat. So far my Sunpower panels seem to be dealing with the heat. I only went with Sunpower as they had a very cheap prepaid lease here for a very brief time and beat all the others handily on price. As for SP vs LG, I think the general consensus around here is that any advantage in lower degradation rate is probably offset by the higher initial cost.

[J.P.M.]

Good point. My concern is the degradation of the LG panels vs SP. Seems like SP is getting good real world numbers. Do the optimizers that come with Soloar Edge have the same issue as the micro inverters in the heat? it's hot here in the summer. . .very LOL

Depending on how you do the financial analysis and how many years you stretch it out, the lower S.P. annual degradation vs. LG ( 0.4 % vs. 0.7% ) is likely not worth the S.P. upfront premium.

[drmtesta]

Depending on how you do the financial analysis and how many years you stretch it out, the lower S.P. annual degradation vs. LG ( 0.4 % vs. 0.7% ) is likely not worth the S.P. upfront premium.

To be honest, we have not found the 15-25% increase in cost for the SP system that has been reported by others. It's expensive, but only about 10% more expensive than comparable LG or Kyocera systems. If it was 20% higher we wouldn't do it.

[drmtesta]

So this is a direct email quote from the competing company who proposed the single SMA 10,000 inverter. Do you agree with the statements below or is there ambiguity like everything many of these guys say?
Thanks in advance

1) This upstart company was founded in 2006 and entered the R&D stage

2) The company began manufacturing in 2009 and shipped its first products in 2010. Their products have been in operation for just over 4 years.

3) Solar Edge is a private firm, as such, it's financials are not public. However, having been in business (selling) for only four years after four years of R&D it is not likely this firm has yet to turn a profit. In fact, they went back to their original investors for another round of funding recently to finance additional growth indicating they have no cash.

4) Solar Edge uses DC-DC optimizers connected to the back of each solar module, similar to a microiverter, but the DC to DC optimizer does not convert the DC power to AC power so less components are required than a microinverter at the module location. The power electronics are located at the single point inverter located elsewhere (ground level).

5) The optimizers that we have installed in the past fail, like microinverters. Like we did with microinverters, we installed optimizer systems to beta-test them. They were among our most problematic systems. We have since stopped working with these power optimizers.

6) German Utility giant, EON, did a study on optimizers and found no noticeable advantage in systems with no shade impact.

7) They subcontract their manufacturing to a company called Flextronics. SolarEdge inverters are not made in the US, like SMA.

The promise of DC-DC optimizers lies in the belief that modules connected in strings have wildly varying voltages and currents due to manufacturing inconsistencies. This is a fallacy. Sunpower modules are manufactured in batches using the same silicon ingot batches and therefore the cells and corresponding modules have virtually identical voltages and currents coming off the factory line. Since we try to engineer our system to be as reliable and productive as possible, using Sunpower modules with a single SMA inverter offers the most reliable and efficient proven product for the long term along with warranties that we feel will be around in 20-25 years to cover you if necessary. Anytime you introduce more components into a solar system, you introduce possible points of failure and points which have some sort of efficiency rating meaning you are losing power even if it's only 3-4%. Solar Edge is a less expensive product to install with which is why some companies chose to work with it but we've decided a while ago that until it's more refined and improved to our standards, we are going to stick with what has worked.

[sensij]

Some of those points are factual, others, less so. Sullivan lost all credibility with me when they started marketing BS about net metering ending this summer, so I'm not inclined to believe them on the points that can not be verified in the public record.

Edit: I'm not sure I would use failures in what is described as a beta test as a knock against any particular system. That is what beta testing is for, after all.

Double edit: The transformerless inverters made by SMA have also been on the market only a few years. NEC didn't really allow them before that. Claiming that SMA the company is better just because they have been around longer is strikes me as the same kind of fallacy they are trying to accuse others of. There is no way to know who will be around in the future, any company can disappear at any time. SolarEdge is likely to go public this year, so the point about private ownership doesn't carry much weight any more either.

[Ian S]

The arguments made in the email make some sense. I would take issue with #3, though. It is not unusual for a new and growing private company to seek additional funding for growth. If they get that funding, I'd say it's a positive not a negative. In fact, there's a good chance that Solar Edge will go public in an IPO this year. That article also states that the company was profitable for the last six month of 2014. I find it interesting that Solar Edge seems to be catching up quickly to Enphase in number of units shipped. Item #5 is careful not to state which optimizers they found problematic - it's unclear whether they tested what Solar Edge is currently selling.

That installer appears to be fairly conservative - going with the tried and true - and there's nothing wrong with that. SMA has an enviable and lengthy track record which is a real plus in this business.