Heterojunction and UV Tech

[charisjapan]

Hey All ... again,

The PV + PW system I am looking at is taking shape, and as I learn a bit more, I seem to know a lot less (bear with me, Super Newb). My project guy is coming to assess my building for install and fill me in on what can and can't be done with regulations here in the middle of Yokohama City. I've attached my latest layout with approximate "Harvest Potential" on three sides, including kWh/panel/year, and now have to fit all that into my budget. Getting two Powerwalls is pretty much settled, but the PV panels themselves are now split between two choices, both from the same company, Choshu Industries Co. (cis-solar.jp). The Premium Blue is flagship, with Half-cut Cell, Heterojunction design, and UV technology, while their Japan Black is a more standard tech with Half-cut Cells. Both are the same size, the Blue is rated 232W/20.0% while the Black is 223W/19.2%, and the Blue is about 12% more expensive.

I've read up on both technologies, but not sure how they translate into real-world benefits. Any thoughts would be appreciated. Randy

Choshu Industries Co. Solar Systems ... in Japanese, but click on the cells for nice catalogs.

PVGIS Tool used to calculate solar harvesting

 

[getakey]

what's the significance of the girl with the ping pong paddle and ball?

 

[jjrandorin]

what's the significance of the girl with the ping pong paddle and ball?

Thats almost certainly a celebrity sponsor. My guess would be someone on the national ping pong tennis team or something. I cant read Japanese though, and while I know probably a couple hundred words or so, I can only really speak what I would call travelers language.

 

[charisjapan]

what's the significance of the girl with the ping pong paddle and ball?

Haha Ishikawa Kasumi, 3-time Olympic medalist. Just retired, I guess Choshu Industries identifies with winners. I know this, because my wife was on-course to play with Team Japan … then met me! Apparently, no regrets, as she’s still with me 50 years).

 

[getakey]

Haha Ishikawa Kasumi, 3-time Olympic medalist. Just retired, I guess Choshu Industries identifies with winners. I know this, because my wife was on-course to play with Team Japan … then met me! Apparently, no regrets, as she’s still with me 50 years).

wow - your wife must have been (still is?) a great player. I was on my College ping pong team. Our #1 player was ranked in California. I was number 3 or 4 on the team but quite a ways down in skill from the #1 and #2. Before College, I went to HS in Okinawa but that was a long time ago. I regret not learning the language.

 

[holeydonut]

Lol this has to be a TMC record with a thread going off topic by the first reply. IMO, paying 12% more monies (I was originally going to say dollars) for 4% more production makes no sense. Maybe I'm missing something and the "blue non half cut" panels can work with a less costly inverters?

 

[charisjapan]

wow - your wife must have been (still is?) a great player. I was on my College ping pong team. Our #1 player was ranked in California. I was number 3 or 4 on the team but quite a ways down in skill from the #1 and #2. Before College, I went to HS in Okinawa but that was a long time ago. I regret not learning the language.

Yeah, China and Japan seem to have a lock on ping pong, lol. We were at a party about 30 years ago, and this fellow was boasting of being captain of the Princeton team ... my 5'3" wife humbled him soooo bad.

Military Brat? I came for here HS on Yokohama Navy Base (Yo-Hi), and met my wife at 17 ... and stayed for her! Changed both our courses.

Maybe we should talk a little about Tesla Energy before the thread gets canned!

How about those Powerwalls?!

 

[charisjapan]

Lol this has to be a TMC record with a thread going off topic by the first reply. IMO, paying 12% more monies (I was originally going to say dollars) for 4% more production makes no sense. Maybe I'm missing something and the "blue non half cut" panels can work with a less costly inverters?

Hahaha! A record for me, for sure.

So about those Premium Blue ...

You must've read the same article I came across, "UV Solar Panels are a Scam." Yes, UV only makes up only 4% of the radiation that hits the roof ... on a sunny day. I think they are trying to harvest that wavelength because it pierces overcast much better than the rest of the spectrum. I only read Japanese at a high school level, but with a dictionary can look up the more complicated stuff. Coupled with the Heterojunction tech, they claim better performance in "everyday" weather, not just beautiful sunny, perfect conditions. Again, I'm not much savvy to this tech, but asking for experiences and/or knowledge.

12% is the difference in retail pricing, and I hope to get a healthy discount for choosing Blue! The panels are the same size and connection as the Black, and since the panel price is only a part of the total cost, perhaps that 4+% will be worth it?

Choshu Industries has been around since 1980, working this field for most of that time, so I doubt they are going to sell a scammy product. I'm still looking into the difference between Blue and Black ... even thought the same table tennis champion is on both catalogs, lol.

Cheers, Randy

 

[jjrandorin]

Maybe we should talk a little about Tesla Energy before the thread gets canned!

How about those Powerwalls?!

Mondai Nai

I dont have any feedback on the two products. I am enjoying reading about your potential project, as well.

 

[getakey]

Military Brat?

yup, Air Force

Love my Powerwalls

 

[BGbreeder]

I would be interested if there was a Japanese solar group in Tokyo or Yokohama that has side by side data on those panels that under the rain/dust, etc. that there is any real life difference. At the price point being offered, I doubt that there is an ROI. I think that dust/grime on the panels is going to routinely dampen production more than the overcast, but you live there.

Good luck.

 

[charisjapan]

I would be interested if there was a Japanese solar group in Tokyo or Yokohama that has side by side data on those panels that under the rain/dust, etc. that there is any real life difference. At the price point being offered, I doubt that there is an ROI. I think that dust/grime on the panels is going to routinely dampen production more than the overcast, but you live there.

Good luck.

Thank you for the reply @BGbreeder ,

Yes, I wish I could get more info, too! My guy is coming today with the Choshu installer, so hoping he has some info. The Premium Blue is a new product, but the company is pretty big, and still around after 40+ years ... a good sign. Yokohama has a LOT better air quality now than 40 years ago, and my roof is about 40 feet above ground level, so hoping that helps. I will report what happens here.

The panels probably make up about 30% of the total cost of the project, as the Powerwalls alone make up 60%, so if I can get a good deal on the Blue UV panels, it might be worth it?

TTYL, Randy

 

[BGbreeder]

Given the tiny difference in performance, I doubt that it will pencil out, even if the performance holds up in the real word. UV performance is going to be especially sensitive to soot/oil particles and organic films. Being urban Japan, I'm thinking diesel exhaust (trucks/ships), tire particles, and pollen in particular.

I know Yokohama is a lot better than it was 40-50 years ago, but there is still a lot (relatively speaking) of urban dust. It just comes from lots of small sources that add up in a dense urban environment, even with the copious amounts of rain that you get. I think that you are in a really pretty part of Yokohama, lucky to have lots of green space up at the university and in parks nearby.

Bottom line: I doubt that the panels have any better performance in really life for a variety of reasons. Even if they do generate 4% more power, the cost of the panels is more than 4% more, so there is no return on investment. If they offer them to you for the same cost, I would consider them, but even then, I would not jump to do it because none of us have any idea if the blues have any sort of longevity, and there are good technical reasons not to believe that. I think that solar installs come down to MTBF for all of the components to achieve any sort of reasonable utility and ROI.

 

[charisjapan]

Given the tiny difference in performance, I doubt that it will pencil out, even if the performance holds up in the real word. UV performance is going to be especially sensitive to soot/oil particles and organic films. Being urban Japan, I'm thinking diesel exhaust (trucks/ships), tire particles, and pollen in particular.

I know Yokohama is a lot better than it was 40-50 years ago, but there is still a lot (relatively speaking) of urban dust. It just comes from lots of small sources that add up in a dense urban environment, even with the copious amounts of rain that you get. I think that you are in a really pretty part of Yokohama, lucky to have lots of green space up at the university and in parks nearby.

Bottom line: I doubt that the panels have any better performance in really life for a variety of reasons. Even if they do generate 4% more power, the cost of the panels is more than 4% more, so there is no return on investment. If they offer them to you for the same cost, I would consider them, but even then, I would not jump to do it because none of us have any idea if the blues have any sort of longevity, and there are good technical reasons not to believe that. I think that solar installs come down to MTBF for all of the components to achieve any sort of reasonable utility and ROI.

Hey @BGbreeder , just so.

As my home state is Hawaii, I gotta admit the Yokohama is comparatively filthy. We face National Route 1 to the south, so traffic dust is a real thing, even though tire dust and diesel particulates are way down, it's still there. A few times a year pollen is wicked, and some certain types are quite sappy. The worst is the oily "Yellow Sand" from China whenever they have drought conditions (pretty often). Though my carport is walled on three sides and roofed, I'm not allowed a door, so keeping the MYP waxed and clean is a must ... I'm sure the roof panels will share the same fate. To this end, I asked the installers to add several safety hooks up there so I can climb up and spray off the accumulated dust. I think the 45-degree slope of the front and back may not be too bad, but the main array is only 25-degrees. Hoping I don't have to go up there too often!

Yes, we are blessed to have a "garden" out our front windows, and the campus provides a nice 2.5 kilometer walking course for us and our dogs. Not bad, considering we have 30 million people in a 20-mile radius.

So, my project guy came yesterday, bringing price estimates for Blue and Black, and the installer with his real-world experience for both. We are going with Japan Black. The Blue has not been out long enough for a lot of data, though his installation experience showed promise. However, it is the Newest/Bestest product, and not enough volume has been sold to get a good discount. Final number for equivalent 11 kW systems was the Blue is 12% more for the solar panels, with a bit more efficiency. That number is probably more than just the UV 4%, possibly as high as 8% with the heterojunction tech, but not yet ready for prime time. As with Peroskvites, the tech is just not there as yet.

Projections for ROI on the Japan Black with a pair of Tesla Powerwalls is conservatively about 10 years with a low-interest loan. but their experience shows it could be a bit shorter ... especially if TEPCO (Tokyo Electric Power CO) continues to raise rates. (Ya think?! )

Unless there is more info available about Heterojunction and UV tech, my first questions are answered. Japan in now entering the O-Bon summer season, so nothing will happen until September ... which means I can still be enticed to change my mind. Otherwise, my financing is secured, and only need a final draft of the contract to Go Solar + Powerwall!

Cheers, Randy

 

[charisjapan]

yup, Air Force

Love my Powerwalls

Yay Wild Blue Yonder! Dad was Navy, Army Air Corps, Air Force, then flew for JAL when we came here. I guess I'm as Bratty as they come!

I am very much looking forward to Solar + Powerwalls.