SMA String VS Solar Edge with Power Optimizers

[SunEagle]

i said 1970s for a reason

I loved my 1965 Corvair monza and it did get 32MPG our 1955 Cadillac only could get 7MPG though (2.5 ton car)

I owned that 1961 in the 70's. I could not afford it new so got it when it was 10 years old with 42k miles on it for $500.

[ButchDeal]

Just to add to the fun -

How will the rapid shutdown requirement affect the SMA setup, down the road ?
My understanding is that the SE setup lends itself to implementing rapid shutdown while it will be very expensive to retrofit a SMA setup.

SolarEdge has rapid shutdown built in and automatic rapid shutdown built into the new HDWave versions as well (next level).

https://www.youtube.com/watch?v=fBGLlPFpTSU

SMA has a rapid shutdown solution which is costly and cumbersome to implement now but does not meet new automatic rapid shutdown requirements.

SMA did purchase Tigo which makes optimizers.
I suspect that they intend to use the Tigo IP to convert the SMA inverters to more of a SolarEdge type system. This will allow more integrated rapid shutdown (but not by just adding existing Tigo optimizers to an SMA inverter).

Will existing SMA setup's be grandfathered in and exempt from rapid shutdown ?

generally something does not need to brought up to current code unless there is a change made to it. So yes.

[lanb]

Just to add to the fun -

How will the rapid shutdown requirement affect the SMA setup, down the road ?
My understanding is that the SE setup lends itself to implementing rapid shutdown while it will be very expensive to retrofit a SMA setup.

Will existing SMA setup's be grandfathered in and exempt from rapid shutdown ?

[bcroe]

I loved my 1961 T-Bird, 390 4 barrel but it did only get about 11 mpg.

I liked my 62 Olds, but finally dumped it for being obsolete. That heavier, plain Jane 77 Olds in front of my array
does 0-60 1.4 seconds faster than that T Bird, faster 1/4 mile, also gets 19 mpg, all on crap 87 unleaded. Yes I
compare cars to the 70s. Bruce Roe

[ButchDeal]

I loved my 1961 T-Bird, 390 4 barrel but it did only get about 11 mpg.

i said 1970s for a reason

I loved my 1965 Corvair monza and it did get 32MPG our 1955 Cadillac only could get 7MPG though (2.5 ton car)

[SunEagle]

The newer optimizers have been out for some time now. We have have very few failures. The failures we have had can easily be traced to a few installers with poor practices, easily corrected with training.
The equipment is improved and proven, Do you base your auto purchase decisions on the reliability of cars made in the 1970s?

I loved my 1961 T-Bird, 390 4 barrel but it did only get about 11 mpg.

[ButchDeal]

low power (as in 10's of watts) vs 100w+ And the complex parts are usually in the passenger cabin

neither is typically true of any hybrid system.

[ButchDeal]

The original SolarEdge optimizers had no electrolytic caps in them. I checked before getting involved with them and was the reason I thought they would be better than the Enphase design. Still had a bunch of them fail within two years.

The newer optimizers have been out for some time now. We have have very few failures. The failures we have had can easily be traced to a few installers with poor practices, easily corrected with training.
The equipment is improved and proven, Do you base your auto purchase decisions on the reliability of cars made in the 1970s?

[jflorey2]

I've never liked the argument that it's hot on the roof, and the parts will die. These electronic boxes are designed to withstand the heat.

Failure rates double per 10C increase in temperatures.

Heat on a roof is not an unknown factor. Car manufactures have all sorts of electronics under the hood that are punished by heat for decades and they keep on working.

Nowadays high temperature/high power power components under the hood (i.e. inverter FETs, rectifiers, inductors) are actively cooled either with fans or liquid coolant systems. On-roof systems usually do not have those sorts of mitigations.

Note that there are systems (down-hole monitoring for example) that do indeed work at extreme temperatures. They often have lifetimes of weeks to months.

[Mike90250]

car electronics and high under hood temps

A short warranty (5 years) and low power (as in 10's of watts) vs 100w+ And the complex parts are usually in the passenger cabin

[solarix]

The original SolarEdge optimizers had no electrolytic caps in them. I checked before getting involved with them and was the reason I thought they would be better than the Enphase design. Still had a bunch of them fail within two years. Oh ya, car electronics and high under hood temps. That's a good one - how long do auto makers warranty their stuff?

[bcroe]

Have you looked at the Tigo optimizers? They can be used on a single string and the output still connected to a string inverter.

That will something to consider, thanks. First I'll finish moving/adding panels, and removing shade. Then see
just what benefit might be possible. It seemed like a fun project, the strings are 3KW, a little bigger than any
switcher built here before. The idea of uneven size strings is interesting, now all strings have 720 cells. Bruce Roe

[steveholtam]

I've never liked the argument that it's hot on the roof, and the parts will die. These electronic boxes are designed to withstand the heat. Heat on a roof is not an unknown factor. Car manufactures have all sorts of electronics under the hood that are punished by heat for decades and they keep on working. Only time will tell, but so far there does not appear to be heat issues with the newer models.

[jflorey2]

The situation here might be a string some 30' long, and the panels get shaded one by one. A
"string optimizer" might keep the remaining unshaded panels working a while longer at their
full efficiency; the shaded ones going to bypass. Not every string here needs this. Bruce Roe

Have you looked at the Tigo optimizers? They can be used on a single string and the output still connected to a string inverter.

[bcroe]

The situation here might be a string some 30' long, and the panels get shaded one by one. A
"string optimizer" might keep the remaining unshaded panels working a while longer at their
full efficiency; the shaded ones going to bypass. Not every string here needs this. Bruce Roe