Obscure Technology: The Ten K Solar module

[DaveGA]

Thanks for making these inquiries, Dave. I guess there just aren't any inverters out there that will work.
I'm not quite ready to let everybody's panels go to a scrap heap yet. I have a few ideas, they're all going to take some effort for me implement but maybe I can get that back in selling what I come up with.

• Reverse-engineer the TenK control circuit, and develop my own firmware that emulates a solar panel. I made some progress reverse-engineering the programming tool a couple years ago, but without access to the source code, new firmware has to be done from scratch. There's a chance this won't work; if the output doesn't act fast enough due to hardware limitations the inverter still won't be able to optimize, but if it does work we won't need any extra hardware and you can use any inverter.
• Build an adapter circuit, something that bolts on to the TenK modules and makes their output work with microinverters. This wouldn't be particularly difficult and allows people to use their existing hardware, but it adds the cost of a third piece of hardware that would need to be added to each module.
• Design a new microinverter that works with TenK modules. Probably the hardest option; I don't doubt I could get something to work but getting the safety and reliabilty up to standards may be beyond my resources. The benefit is that this could be a drop-in replacement for failed TenK-compatible inverters which would be easy for existing array owners.
• Adapt an existing inverter. In particular, something with programmable/output limiting like a GTIL could probably be made to work, perhaps with a small added control circuit. Inverter choice would be limited but at least there would be one option, and I think this would be easy relative to the other options.

At this point I'm not sure which path to go down. Let me know if you have any thoughts.

Thank you Peter, I will review these options with my client, along with seeing if they have interest in entertaining paying you for the development work.

Regards,

Dave

 

[Peterator]

Sound good Dave, I'll DM you my contact info.

I'm guessing by the "my client" line that you have more at stake than a few panels that you want to put to use. This should be interesting.

 

[cak]

• Reverse-engineer the TenK control circuit, and develop my own firmware that emulates a solar panel. I made some progress reverse-engineering the programming tool a couple years ago, but without access to the source code, new firmware has to be done from scratch. There's a chance this won't work; if the output doesn't act fast enough due to hardware limitations the inverter still won't be able to optimize, but if it does work we won't need any extra hardware and you can use any inverter.
• Build an adapter circuit, something that bolts on to the TenK modules and makes their output work with microinverters. This wouldn't be particularly difficult and allows people to use their existing hardware, but it adds the cost of a third piece of hardware that would need to be added to each module.
• Design a new microinverter that works with TenK modules. Probably the hardest option; I don't doubt I could get something to work but getting the safety and reliabilty up to standards may be beyond my resources. The benefit is that this could be a drop-in replacement for failed TenK-compatible inverters which would be easy for existing array owners.
• Adapt an existing inverter. In particular, something with programmable/output limiting like a GTIL could probably be made to work, perhaps with a small added control circuit. Inverter choice would be limited but at least there would be one option, and I think this would be easy relative to the other options.

I wonder if an easier solution would be to gently "rip off" the boost hardware to access the solar cells output directly? You mentioned it is 15v with 8 of them in series(I don't know if that is the short circuit voltage or not) so if one put several gutted panels in series to get a raw voltage that is usable by traditional mppt inverters or charge controllers(3+ panels in series?). Some tradeoffs of this ideas is that it requires a whole system overhaul, and you need a fair number of panels to series them up.

Wherever this all ends up I work for the Clean Energy Resource Teams(CERTs) in Northeast MN and have several business sized systems that I know of that would be interested in solutions. Also CERTs is currently seeking proposals for our Seed Grants and I could see this being a project that could potentially get some funding from that ($5000 is a common grant size). PM me and we can see what connections we can make with system owners in the area.

As a side note has there been any exploration of other staff or the company that bought the IP so that we could maybe get access to it to make the options I see as preferable (adapter or re-engineering) more viable. And with the whole right to repair shift going on we could make an argument to why we should be given access to such information particularly since it has been abandoned so there is no business interest by current owners of those rights.

 

[Peterator]

I considered ripping the controls off - this presents a few challenges, not least of which is that you'd need to find a mppt inverter that can handle something like 30A on a single channel.

I do have a solution in the works - it's still in the early stages so I don't feel comfortable sharing exactly what it entails, but I hope to make it available to everyone when it's ready. Connections with system owners would be most appreciated; I'll PM you cak, and maybe look at that Seed grant.

I have no idea about where the IP ended up, I think it's been abandoned.

 

[cak]

I considered ripping the controls off - this presents a few challenges, not least of which is that you'd need to find a mppt inverter that can handle something like 30A on a single channel.

I was picturing setting the "gutted" panels being set up in series to function with string inverters rather than the micro type. I have a personal preference for the string variety because less points of potential failure.

 

[DanB]

Looking for a combiner box for this system, does anyone know if any parts are available ,it has 3 80a circuit breakers in it.

 

[Peterator]

Looking for a combiner box for this system, does anyone know if any parts are available ,it has 3 80a circuit breakers in it.

Hi Dan, sorry I didn't get back to you right away. Are you talking about the AC or DC combiner box? My recollection is the AC box is pretty much standard off-the-shelf stuff similar to other solar systems, maybe check with a local solar installer or distributer.
The DC box is unique to TenK, although it's built from off-the-shelf components. If you describe in more detail or take a picture of what you're trying to replace we might be able to help find a source of parts.

 

[DanB]

Hi Dan, sorry I didn't get back to you right away. Are you talking about the AC or DC combiner box? My recollection is the AC box is pretty much standard off-the-shelf stuff similar to other solar systems, maybe check with a local solar installer or distributer.
The DC box is unique to TenK, although it's built from off-the-shelf components. If you describe in more detail or take a picture of what you're trying to replace we might be able to help find a source of parts.

Thank you for responding, looking for the DC combiner box it has 3-80a DC circuit breaker’s, the lug that connects to the inverter melted down (looks like #1 aluminum wire)

 

[DanB]

A good combiner from a different string and bad combiner

 

[Peterator]

A good combiner from a different string and bad combiner

Oh, that looks like an old system, back when they were able to get a central inverter instead of having to use a pack of microinverters. I was wondering why you were asking about 80A breakers.
Obviously that custom cover isn't available any more, but you can find off-the-shelf breakers and build a new box. The breakers need to rated for at least 60V DC. They have to be DC rated; AC ratings are not enough.
I think you could get an electrician or a solar installer to build a new box for you or repair the old box.

Also I assume you've checked the panels and inverter connected to this panel; sometimes breaker failures are a symptom of an issue elsewhere.

 

[goodgulf]

I have a bunch of these 500W panels that have been sitting in my carport unused for a couple of years now. Any further updates? I have tried to email APSystems but thus far no response. Any suggestions to getting them to work other than charging a battery and running an inverter off the battery? I was told that they worked with the IQ7X inverter by the guy who sold them to me, but that doesn't seem to be the case since I tried. I have not tried adding the 100uF cap to see if there is anything difference. I was hoping to use some of them stand alone to charge my wife's prius using the car charger.

Thanx

 

[techsuplex]

Is there a way to boost production from these panels? I have 22 410w panels connected in series to some 48v batteries, but production at the highest is usually around 1700watts. Or is that a function of the sort of batteries I have (LG 14s 48v 60amps)

 

[cak]

Is there a way to boost production from these panels? I have 22 410w panels connected in series to some 48v batteries, but production at the highest is usually around 1700watts. Or is that a function of the sort of batteries I have (LG 14s 48v 60amps)

Based on the screenshot you are currently being limited by the batteries being full. As the voltage gets towards max (usually 54vdc for lead acid 48vdc systems, LiIon can usually go higher) then the charger will reduce the current to enter the Constant Voltage Mode and reduce the input as needed to maintain the set top voltage.