Thoughts on TekK solar panels?

[inetdog]

I'm curious why you would be so skeptical of their claim that they can yield 30% more power by reflecting more light onto the modules. That hardly seems like snake-oil on the face of it, and I usually have a reasonably well-tuned BS detector. I'm not saying you're wrong, I really want to understand--they're making what seems to me to be a fairly reasonable (maybe even kind of boring) claim, they published data from NREL and others which backs up the claim, I even talked to the guy who runs one of the sites where they got the data from. What am I missing?

I think that what both Russ and I are seeing is that any reflector based system will require constant aiming to get the reflection to uniformly cover the panel of the module.
Unless the modules use amorphous silicon, it will not do you much if any good to increase the light on just one part of the panel.
And it cannot help but take up more space. General experience so far is that if you have the space, you are better off using it for larger panels.

Now there is a known diffuse reflection effect that can benefit panels in cold climates with very clean snow on the ground. But those reflectors are very large and free, and can just stay in one place.

A similar technology is being touted by Ford in the form of a Fresnel lens which forms the roof of a carport above an EV with solar panels on the roof.
They plan to do some tracking by having the car automatically move back and forth under the lens. But with a horizontal panel and a horizontal lens, there is a pretty strict limit on how much that kind of single axis tracking can do for you. It also requires the driveway to be pointed in exactly the right direction for the the location.

[silversaver]

I'm disappointed with this response. I was hoping for someone with some real insight and/or experience around this product to offer some actual thoughts in response to the question.

I also find the attitude rather surprising--that I should fire my installer because he offered me an unconventional option which I found interesting enough to research further. For what it's worth, the other three options he provided are all very conventional.

So, back to the original question: Does anyone here have any experience with TenK modules? Is this a product which may be worth a modest premium?

If nobody is familiar with this, that's fine.

I did a search for you in California CSI database and only found 1 installation done with TenK module in Monterey, California. It is completed in 09/2013. It is a 190W X 28 modules @ 5.32kW DC system at price of $46,871 by installer company Western Sun System Inc. Referrence # PGE-CSI-64508


Base on CSI database that Western Sun System Inc happen to be a SunPower dealer with the only installation job done with TenK modules.

California is a big state with only 1 installation done. The chance that you get a feedback on TenK module is nearly 0.000001% estimate.

Why don't you pick up your phone and call the only one installer that had done a TenK modules installation job and ask them for a feedback?

That is about $8.81 per Watt DC cost. If you are rich and like to test new product, go for it. Please come back and share your experience with us in next few years.


PS.

Take a second look it was using a grid/hybrid inverter, perhaps install on a battery backup system.

[russ]

I'm curious why you would be so skeptical of their claim that they can yield 30% more power by reflecting more light onto the modules.

30% more light on the panel will raise the temp - more losses due to operating over the optimal cell temperature. The 30% will be true if the unit tracks or is this taking the loss of a fixed position - for the 30% fixed position a lot of heat is going into the panels at solar noon.

Many companies have tried the concept - there are a couple of PV/water heater combinations using parabolic concentrators where the cells are kept cool - very expensive and little track record because of that.

Your situation (state) is unique - kind of like Ontario - a special break for local products - this means a very small market for a highly overpriced panel. No one in another state will even be vaguely interested.

With the 85% price break maybe they do make sense - maybe.

[pleppik]

Why don't you pick up your phone and call the only one installer that had done a TenK modules installation job and ask them for a feedback?

That is about $8.81 per Watt DC cost. If you are rich and like to test new product, go for it. Please come back and share your experience with us in next few years.

There's several installation here in the Twin Cities area, and I have been speaking to people with direct experience. I was quoted $4.65/watt for the complete system (before any incentives), which is about a 10% premium to the best (cheapest) quote I got for any system here, but cheaper than the most expensive system I was quoted.

Still, I figure if there was a chance I might find another stone to turn, it can't hurt to ask.

Given then incentives available, there's a strong chance this is the system I'll go with. I don't mind taking some risk with a new company and product, as long as it's a calculated risk. And of course whether I install this system or some other, I will let everyone know my experiences.

[silversaver]

I'm very interest at the panel after watching the video. It looks like a very promising product if you have shading issue. The reflector will collect more sun...etc, but durability might be an issue. I believe the largest capacity were 410W panel, wondering how big the panel is?

http://www.youtube.com/watch?v=dWECG-XjndM&feature=player_embedded

I believe this is design for flat roof to be benefit from the systems reflectors.... and they are huge...

[silversaver]

I'm planning a new solar installation this spring, and my installer has suggested a system built around modules from TenK Solar.

I've been reading some of the company's marketing literature, and the TenK modules seem to be a very different architecture than is usual in the solar world today. They do the MPP tracking in the module itself, and the company claims they get something close to optimal output even when part of a module is shaded.

They also output DC from multiple modules to a low voltage (60V) DC bus, with multiple inverters attached to the DC bus. But since there's not a 1:1 relationship between inverters and modules as you would have for microinverters, they claim they can do some magic to bring inverters on- and off-line to reduce the duty cycle for each inverter and reduce their chance of failure.

For our home, our installer is quoting us a system with TenK modules for about a 10% per watt premium over a more traditional microinverter-based installation.

The claim that TenK makes is that their modules will give us a higher yield per watt than a traditional architecture (we have some partial shading issues)--our contractor says he can't quantify this but it sounds plausible. TenK also claims that their architecture will be more fault-tolerant if an inverter fails, since other inverters will be able to take over, and also that the reduced duty cycle on the inverters will prolong their lives.

Has anyone had any experience with the TenK system? Is this a product worth a (modest) premium?

There's several installation here in the Twin Cities area, and I have been speaking to people with direct experience. I was quoted $4.65/watt for the complete system (before any incentives), which is about a 10% premium to the best (cheapest) quote I got for any system here, but cheaper than the most expensive system I was quoted.

Still, I figure if there was a chance I might find another stone to turn, it can't hurt to ask.

Given then incentives available, there's a strong chance this is the system I'll go with. I don't mind taking some risk with a new company and product, as long as it's a calculated risk. And of course whether I install this system or some other, I will let everyone know my experiences.

Hmm, Are you for real? You are paying the "premium" on a brand new product that has no history. How can you calculate the "risk" on a 6 years old company? If you are getting a bargain deal testing brand new product, I agree. Your logic doesn't sounds reasonable in any mean.....

[SunEagle]

No question you are taking a chance on a new arrival as well as paying a premium on top of the unknown longevity of the hardware.

Although after checking out their website the commercial installations look pretty clean. I couldn't tell how easy it was to access the DC/AC converters for each panel or even where they were mounted. It does look like a bunch of hardware is under the "reflecting" panel at the end of the row but that may be all AC voltage hardware. I just can't tell if each panel converts its 57 VDC close to the panel and then runs it as AC or they run the DC to a combiner location. They do mention and show an "Inverter Bus" under a reflector but is this central to a row of panels or for just a couple of panels. I would just like to see more of the interconnection and what it takes to perform maintenance on a single panel.

The website also has 4 links to "live" solar data at operating installations. Nice advertising.

Since the system is more for a flat roof installation maybe doing a car port for a residential is more practical. It even makes access to the underside of the panels easy. Just a thought.

[pleppik]

Hmm, Are you for real? You are paying the "premium" on a brand new product that has no history. How can you calculate the "risk" on a 6 years old company? If you are getting a bargain deal testing brand new product, I agree. Your logic doesn't sounds reasonable in any mean.....

If you read through the whole thread (which is getting pretty long, so you can be excused if you didn't), the 10% premium is more than paid for by the fact that there are incentives available for me for this product which are not available for me for other products.

So in the end, I'm getting it at a very steep discount relative to other products. For people who don't qualify for the same incentives I'm getting (i.e. people who don't live in Minnesota), it's a 10% premium for a product which purports to produce 30% more kWh per watt, which is effectively a 15% or so discount per kWh if you believe the reflector panels do what they're supposed to do.

[bcroe]

the TenK system can get the state credits it would wind up being considerably less expensive (between the federal and state credits alone, we will get back about 85% of the cost of the system).

they have published data from a dozen test sites around the country (including NREL) over two years showing that they get about 30% more production per installed watt than a conventional design. The claim is that part of the improvement is in the reflectors, and part of it is their module design which allows them to get more power out of a module which isn't uniformly illuminated.

In our installation, we don't have the option of using the reflectors as it's on a sloped roof, but we're hoping that this design might give us a little more yield because--in theory--it should deal with partial shading more efficiently than a standard module.

There is no arguing an 85% credit. But since you can't use their reflectors, don't expect a big improvement
(30%) over a microinverter design. You might want to consider the issue of clearing snow all
winter; its a pretty big issue here a couple hundred miles south, and that on a ground mount.
Bruce Roe

[silversaver]

If you read through the whole thread (which is getting pretty long, so you can be excused if you didn't), the 10% premium is more than paid for by the fact that there are incentives available for me for this product which are not available for me for other products.

So in the end, I'm getting it at a very steep discount relative to other products. For people who don't qualify for the same incentives I'm getting (i.e. people who don't live in Minnesota), it's a 10% premium for a product which purports to produce 30% more kWh per watt, which is effectively a 15% or so discount per kWh if you believe the reflector panels do what they're supposed to do.

I did read about your sloped SW and SE roofs which cannot utilize the reflectors desgin, but you keep mention about the 30% extra production....etc

My question is if you don't have the reflectors, how do you come up with extra 30% production? I do understand the reflector will help to collect more sun light. I do know you have 85% cover by state and fed, but not sure about other solar manufacture. SunPower cannot use with microinverters.

[pleppik]

I did read about your sloped SW and SE roofs which cannot utilize the reflectors desgin, but you keep mention about the 30% extra production....etc

My question is if you don't have the reflectors, how do you come up with extra 30% production? I do understand the reflector will help to collect more sun light. I do know you have 85% cover by state and fed, but not sure about other solar manufacture. SunPower cannot use with microinverters.

Maybe I'm not communicating well. I'm not expecting 30% more power from my system, period, full stop. At best, I'm hoping I might get a small bit more power (vs. microinverters) because it might deal more gracefully with partial shading.

But I am trying to learn as much as I can about what this company is trying to do, and in flat-roof installations this is one of their big selling points, and also one that several people expressed skepticism about.

So my reasons for going this route have to do with the unusual combination of incentives available to me, and my willingness to be a guinea pig to capture those incentives. But I also want to understand how it may work for other people, including people who don't have the same incentives available or site restrictions. I also want to understand how some of the more experienced people here approach considerations like that. That has more to do with my own curiosity.

[silversaver]

If the incentives can outweight other factors, then do it. How big of solar are you getting? At 190W per panel, you will need a larger roof space to accomendating these panels. I don't think these poly panels wouldn't fail too easy, I've more concern about these inverter buses. I think they are just like microinverters. As I recall, the Enphase M190 has pretty high failure rate. There isn't any info you can get about Tenksolar even on their website...

[pleppik]

If the incentives can outweight other factors, then do it. How big of solar are you getting? At 190W per panel, you will need a larger roof space to accomendating these panels. I don't think these poly panels wouldn't fail too easy, I've more concern about these inverter buses. I think they are just like microinverters. As I recall, the Enphase M190 has pretty high failure rate. There isn't any info you can get about Tenksolar even on their website...

We're planning a 6.5kw system built around 410W panels.

[Ezrio315]

Thoughts on TekK solar panels.

I'm planning a new solar installation this spring, and my installer has suggested a system built around modules from TenK Solar.

I've been reading some of the company's marketing literature, and the TenK modules seem to be a very different architecture than is usual in the solar world today. They do the MPP tracking in the module itself, and the company claims they get something close to optimal output even when part of a module is shaded.

They also output DC from multiple modules to a low voltage (60V) DC bus, with multiple inverters attached to the DC bus. But since there's not a 1:1 relationship between inverters and modules as you would have for microinverters, they claim they can do some magic to bring inverters on- and off-line to reduce the duty cycle for each inverter and reduce their chance of failure.

For our home, our installer is quoting us a system with TenK modules for about a 10% per watt premium over a more traditional microinverter-based installation.

The claim that TenK makes is that their modules will give us a higher yield per watt than a traditional architecture (we have some partial shading issues)--our contractor says he can't quantify this but it sounds plausible. TenK also claims that their architecture will be more fault-tolerant if an inverter fails, since other inverters will be able to take over, and also that the reduced duty cycle on the inverters will prolong their lives.

Has anyone had any experience with the TenK system? Is this a product worth a (modest) premium?

Hi Pleppik.

TenK solar includes an integrated photovoltaic system with designs and manufactures that leverage integrated electricity and a low voltage with parallel structures. If we compared it with conventional solar systems, this structure provides 55% better density of energy, higher reliability, and here is only PV system is this.

[russ]

We're planning a 6.5kw system built around 410W panels.

What is the physical size - that is what Silver is talking about.