So how bad are string inverters vs microinverters?

[SunEagle]

This whole rapid shut down crap is a scam introduced into your regulations via sponsorship from micro and optimiser manufactures and was designed to benefit 2 equipment retailers, thats the truth of it, they tried to do the same in Australia and we fought them tooth and nail and the regulators came to see the sense in the industry s argument against it, I think its a matter of time before they get rid of these stupid regulations in the States, just my 2 cents, (rant over)

Probably another reason solar is so expensive here in the US. There is a lot of "safety" equipment required per NEC which may provide some security but mostly just increases the cost of an installation.

[Mike 134]

This whole rapid shut down crap is a scam introduced into your regulations via sponsorship from micro and optimiser manufactures and was designed to benefit 2 equipment retailers, thats the truth of it, they tried to do the same in Australia and we fought them tooth and nail and the regulators came to see the sense in the industry s argument against it, I think its a matter of time before they get rid of these stupid regulations in the States, just my 2 cents, (rant over)

Obviously you have never felt what line voltage does to your body. For those folks that do not want rapid shutdown on their solar system they should be able to sign a wavier telling the fire dept not to respond to a fire during daylight hours at their house. Makes everyone happy, you don't have the added expense of rapid shutdown and the fire dept by only responding in the darkness has no worries about a 400Volt electric shock. Win Win don't you think?

[solarix]

If you want to get the code changed to remove rapid shutdown, go to FixMLSD.com and join this grass roots organization.

[foggysail]

OK, I agree with all of you, the rapid rule is a bunch of crap, now to move onwards. So I said to Self, go the grid tie micro inverter route and be done. After complying with more fire department crap, this time the 3' pedestrian travel lane. I hoped to use Canadian Solar panels, the 450 W bifacial with a VOC of 49.1V to maximize my solar array's power density and so far..................I CANNOT FIND A grid tie micro inverter that I want to use. I don't know how much latitude experts allow for upper voltage limits, but no way will I stick an inverter into the array that has a 50VDC maximum input when the panels have 49.1 VOC.

Yes... anxious for suggestions and damn it, this could force me to a string inverter.

Thx

[Mike 134]

Foggy, do they allow the roof overhang to be part of that 3' rule in your location? Some jurisdictions out in CA (no surprise) do not. I have a gable roof so I had to provide a path on both sides of the array.

[foggysail]

Not sure Mike. I used grid paper (gees.......wish I had AutoCad experience) to see where my panels can fit.The only overhang would be about a foot or so on the gable end which I have plenty of space as it is. Maybe I have to re-examing my layout with lower voltage (wattage) panels. The CAnadian's that I was excited to use come with a weight penalty of 62.6#.

[solardreamer]

OK, I agree with all of you, the rapid rule is a bunch of crap, now to move onwards. So I said to Self, go the grid tie micro inverter route and be done. After complying with more fire department crap, this time the 3' pedestrian travel lane. I hoped to use Canadian Solar panels, the 450 W bifacial with a VOC of 49.1V to maximize my solar array's power density and so far..................I CANNOT FIND A grid tie micro inverter that I want to use. I don't know how much latitude experts allow for upper voltage limits, but no way will I stick an inverter into the array that has a 50VDC maximum input when the panels have 49.1 VOC.

Yes... anxious for suggestions and damn it, this could force me to a string inverter.

Thx

Which microinverter models have you looked at so far? I am pretty sure there are ones that support 60V and higher.

[foggysail]

Yes, I did find stuff at Amazon, they looked similar to a regular inverter, expensive and did not appear to have weather protection. Had high hopes for Enphase only to find low Vin limits. More tomorrow, have to give htis a break tonight. Not really dead on the roof yet...... there are other panels, just would need more of them. Thank you, everybody, have to say goodnight

[solardreamer]

Yes, I did find stuff at Amazon, they looked similar to a regular inverter, expensive and did not appear to have weather protection. Had high hopes for Enphase only to find low Vin limits. More tomorrow, have to give htis a break tonight. Not really dead on the roof yet...... there are other panels, just would need more of them. Thank you, everybody, have to say goodnight

Why wouldn't Enphase iQ7X work?

[solarix]

I use APSmart rapid shutdown devices with our string inverters equipped with Sunspec. Its the best way I know of to comply with the rapid shutdown B.S. I figure these devices are way more reliable than any microinverter or optimizer as they are basically a solid state switch with some simple digital controls that can communicate to the inverter. It just burns me up to have to compromise the inherent reliability of a solar array just because two companies are pushing a code rule as a market strategy for their own benefit.

[foggysail]

Why wouldn't Enphase iQ7X work?

I thought I looked at all of the Enphase's, overlooked that one. It might work! Don't understand though why it has a limited Vmp range whereas the panel's Vmp is 10 volts lower. I am going to put more effort into this. Thanks--

[foggysail]

Why wouldn't Enphase iQ7X work?

Again a thanks! I do not know how I overlooked the 7X. Also, I believe I might be better off with the IQ7 Plus because of the Vmp of the 7X is upwards to 53-64 whereas the 7Plus is a closer match to the panels at 27-45. Making progress! I have so many things going I feel the same as one does playing whack-A-mole. Goal remains to have permits around early summer.

[Warren93nature]

I would say microinverters are better because they function in a parallel circuit.

[solardreamer]

Again a thanks! I do not know how I overlooked the 7X. Also, I believe I might be better off with the IQ7 Plus because of the Vmp of the 7X is upwards to 53-64 whereas the 7Plus is a closer match to the panels at 27-45. Making progress! I have so many things going I feel the same as one does playing whack-A-mole. Goal remains to have permits around early summer.

IQ7+ is definitely more common so it would be great if it works for you. Good luck with your system.

[Mike90250]

I would say microinverters are better because they function in a parallel circuit.

But, that parallel circuit is only @ 240VAC. If there is any appreciable cable distance, you have to use larger gauge wiring to keep the line voltage loss to a minimum.

With a 500VDC string inverter, a lot of the cable loss is done away with. Engineering trade off's everywhere.