Cheapest 2019 rapid shutdown solution for new system

[josepr]

Greetings,

I’m in the process of designing a grid tied system. Plan vanilla installation. No shading. Only need 4k but will install 5K (to ensure enough production for 20-25 years). Initially was planning to use a SMA or SolarEdge string inverter (no optimizers). But found we are a NEC 2017 jurisdiction (with the new 2019 rapid shutdown requirements). My question is: What is the most cost-effective solution for a small/medium grid tied array of 5K that needs to comply with the 2019 rapid shutdown rules? Thanks.

[bob-n]

I found that a low cost yet high performance system is APsystems QS1 microinverters. They are rapid shutdown compliant. One QS1 handles 4 panels. That means fewer boxes than a traditional microinverter install, so lower cost and easier installation. With only 5K of panels, you don't even need separate circuits. You can simply combine every QS1 output to one single breaker in your main panel through a disconnect switch. It doesn't get any simpler.

However, please confirm that they meet your exact needs before commiting. You can find their spec on the web with a google search. There are many dealers for APsystems. You can find the dealer list on the APsystems website.

Note: Don't expect any factory support. Buy from a reputable dealer that will support you.

[solarix]

I don't use microinverters because of our super hot Arizona roofs, but have gone to the SMA (Tigo TS4-R-F) rapid shutdown modules now that NEC2017 has come to town here.

[Ampster]

You could add Optimizers to your SolarEdge inverter or as @Solarix suggested Tigo Optimizers to your SMA system. You could price both and see which is the least expensive to get you the compliance you need. I did not find anything less expensive, except for a small system of less than 10 panels where microinverters had a sweet spot. I think microinverters would be more expensive for a system of 5kW, but some of that may depend on how many panels (based on panel size) you need to get to that system size.

[josepr]

Do you know of a simple solution? One that just requires the string inverter and a module behind the panel. No gateways, control wires, etc. Have checked the SMA solution. But in addition to the module behind the panel it requires a gateway or something like that.

[solarix]

The SMA solution just requires the TIGO units on each PV panel. Have to use the latest -41 version of the inverter though as you need its Sunspec interface to communicate with the Tigos. Cheapest solution I've found. And I've searched everywhere in an effort to protect my customers from this rapid shutdown nonsense.

[Ampster]

Do you know of a simple solution? One that just requires the string inverter and a module behind the panel. No gateways, control wires, etc. Have checked the SMA solution. But in addition to the module behind the panel it requires a gateway or something like that.

SolarEdge is simple, it is just the cost of optimizers, since the DC disconnect is on the inverter and I believe that satisfies NEC. I think @Solarix has some more knowledge about the SMA/Tigo solutions. I think that is why I have heard opinions that Enphase and SolarEdge own the rapid shutdown space because the currently have the most cost effective solutions. Others may have a more informed opinion. I hope there are more solutions.

[JSchnee21]

SolarEdge (Optimizers are required with a Solar Edge Inverter) or a classic string inverter (Fronius, SMA, etc.) with TIGO or similar. These are the only two options (since you ruled out Enphase).

Of these, I'd personally go with SolarEdge. Perhaps not the least expensive, but definitely the most value. Which ever inverter you go with try to mount it out of direct sun if possible (North face, East face, garage, basement)

There are a number of newer tiny companies offering rapid shutdown retrofits for classic string inverters. But other than Tigo, most are very small/new -- thus no track record and likely to go out of business.. Even Tigo is a lightweight compare to SolarEdge or Enphase, for example.

[hardwired]

The SMA solution just requires the TIGO units on each PV panel. Have to use the latest -41 version of the inverter though as you need its Sunspec interface to communicate with the Tigos. Cheapest solution I've found. And I've searched everywhere in an effort to protect my customers from this rapid shutdown nonsense.

Are the Tigo's DC-DC converters like the Solaredge Optimizers and sllow a string with some shaded panels still to provide output to the inverter?

Is this the correct model Tigo TS4-R-F and whats a good hybrid inverter and battery system that plays well together?

[jflorey2]

Are the Tigo's DC-DC converters like the Solaredge Optimizers and sllow a string with some shaded panels still to provide output to the inverter?

No, the TS4-R-F is shutdown only.

[Kennedy Muberekwa]

Hello colleagues, I have got a small home system with (3x250 watt panels) that support two 100AH Narada gel batteries. Of late the batteries are producing an unpleasant odour and a beep sound or at times a boiling sound inside. Could it be that the batteries are now dead? I have been using the system for two years without problems.

[SunEagle]

Hello colleagues, I have got a small home system with (3x250 watt panels) that support two 100AH Narada gel batteries. Of late the batteries are producing an unpleasant odour and a beep sound or at times a boiling sound inside. Could it be that the batteries are now dead? I have been using the system for two years without problems.

I am actually surprised those GEL batteries lasted 2 years. Usually they don't like to be heavily cycled and more than likely they have boiled off any fluid that was in them.

If you can, I would look into 6V FLA type which can provide you with more than 200Ah 12v system. But depending on what your CC is 750watts of panels may be generating a charge rate higher than C/8 which can hurt most battery chemistries.

[azdave]

What is the most cost-effective solution for a small/medium grid tied array of 5K that needs to comply with the 2019 rapid shutdown rules? Thanks.

Where's bcroe today? He's late to the thread to recommend a ground mount system (which are usually not subject to rapid shutdown requirements).

[Ampster]

Where's bcroe today? He's late to the thread to recommend a ground mount system (which are usually not subject to rapid shutdown requirements).

Yes, Rapid Shut Down, may have changed the economics of ground mount vs roof mount installation costs as they affect overall system costs.

[bcroe]

Where's bcroe today? He's late to the thread to recommend a ground mount
system (which are usually not subject to rapid shutdown requirements).

Huh, I was picking up a sand blasting job... Ground mounting solves the problem, but likely
is not the most cost effective solution. Bruce Roe