Looking for feedback from homeowners of solar panels on roofs

[sumoborac]

Ok, thanks for the response. I am interested in your roof tile but I am not quite sure I understand completely. These bypass diodes are also part of my traditional panels. Nontheless, when partial shading occurs, that string will suffer quite a bit in terms of output despite the new power point tracking of my SMA inverter.

In traditional panels the baypass diodes are usually in the box on the back of the panel. So when shading occurs, it bypasses the whole vertical line in the module. So let's say you have a 24x8 cells on the module. The bypass is usually done on every 2 vertical rows, so if you have a shaded cell, the bypass will be 16 cells. Some of the modules have a bypass on every line but I haven't seen those much. If you have a shade over a horizontal row, the module won't work (or better, it will be bypassed fully).

Can you provide the number of kWs installed on that roof? Do you use a string inverter? How much in actual AC power does this system put out on a sunny day?
What kind of voltage do the connected tiles put out on a cold sunny day? I believe that a single cell has a certain nameplate rating but I am really curiouos about ACTUAL performance in the field. Do you have any data on this?

Sure. Currently I have 8 strings on the roof. The roof has two versions of styleTILE (the 9W modules, old cells and 10W modules, new cells), so 4 string of 350 modules and 4 string of 340 modules (the new cells have higher voltage output, so I had to lower the number to be safe because the Uoc can't exceed 1000V). So around 26kW. I use SamilPower SolarLake inverters 3x15kW (http://samilpower.com/product_detail.php?product_id=9) because I'll probably add another 3-4 strings on spring. I choose the SamilPower because in our country there are some non-standard request for reactive power (by some specific formula), and they created a custom firmware for us. There are only two other inverters that I know of that are allowed in our grid-tie PV arrays.
The normal output on a sunny day is around 105kWh produced. But bear in mind, that the roof isn't optimally positioned (we are facing south-south-east) so I lose about 2-3 hours of sun every day. The roof is on 15° angle. I managed to produce little over 3GWh in one month in the summer (I wish everyday would be a summer. Today the production was like 7kWh total. Fog the whole day :/ )

What do you make of this data? Good? Bad? Missed something?

I wish I could give you some certified data about all this, but every certified data costs just to much for me at the moment.

[Volusiano]

Ok, it might not be a big deal for you, but for my father it was the deciding point. And after 5 years I and new roof facing north, I found that he was right. When you make a hole in roof, there is a hole. With proper work, it can be sealed quite good. But never as good as before no-hole situation. The experience was with the chimney hole. They created a little bigger hole for the chimney and they had to seal the whole section higher from the chimney. Maybe I can't explain it good enough

You talked around the subject but never addressed my question: where do you put vent pipes when you install the styleTile if you don't cut holes in the roof to feed the vent pipes? Especially if your scenario is to replace and existing roof with styleTile -> an existing roof already has many vent pipes.

Maybe I've expressed myself wrong. The styleTILE is a great thing when you get in situation like ours was. Old roof need of replacement. Why not do it in one step with styleTILE?
It would be stupid to remove a perfectly good roof to put on styleTILE. Agreed. But looking around I see many roofs being replaced. It goes in waves, since no roof tile is forever.

Maybe for shingles roofing your styleTile can replace the shingles. But a lot of homes use concrete or clay tiles that can easily last for 50 years. The only part that needs replacement is the underlayment, which should last around 15-20 years. Your styleTile would not apply for concrete or clay tile roofs because you don't replace the tiles, only the underlayment. So your market gets narrower than originally claimed.

[SunEagle]

The integrity is quite perfect. The shape of the module is not something new. It is used for more then 150 years. Usually the tiles are from concrete - http://www.podarimo.si/slike/slika31344771806cpg.jpg
So the rain and moisture aspects are quite covered.

OK. I understand how a tile roof works but here in the US there is a layer beneath the tiles that keeps out the rain. The picture of you installing your tiles on a wooden stringers looked like there was a big opening below.

Is there another layer of roofing material below the wooden stringers that keeps out the rain? If not then how are the tiles sealed to keep out water?

[sumoborac]

Sorry to go off topic but these shingles after reviewing the site.. The contacts look a bit sketchy. No way to guarantee the friction/pressure fit will last through thermal expansion and contraction.

Why not? We solved the problem with two solutions - the expansion and contraction is solved on every tile. The male connector can move for 5mm in the row way. The friction/pressure is solved with the design of the connectors so they work like a spring.

Yes, I know, I can't know what will happen in 30 years, but thats why I'm trying on to raise money. So I can test every aspect of the styleTILE on the long run. So I can have a paper for each of the "new solutions" to back me up.

[sumoborac]

The number of connections that would be next to impossible to access scare me as much as anything.

The access is not problematic. After the new-year I'll try to make a short video about replacing the tile. All you need is 3 wood wages (like this - http://www.hastiles.com/images/plugsmain.png), a small metal saw, pliers and a replacement tile. And about 10 minutes (ok, 30 if you do it for the first time).

[sumoborac]

The OP's website painted a story of how his father objected to having to put a brand new roof in (their roof was too old and should be replaced before solar) only to have the solar people drill holes in his brand new roof. I kinda chuckled and asked myself "What's the big deal? People drill holes all over brand new roofs for vent pipes anyway. Won't you have to drill holes for vent pipes with the solar tiles, too?" LOL

Ok, it might not be a big deal for you, but for my father it was the deciding point. And after 5 years I and new roof facing north, I found that he was right. When you make a hole in roof, there is a hole. With proper work, it can be sealed quite good. But never as good as before no-hole situation. The experience was with the chimney hole. They created a little bigger hole for the chimney and they had to seal the whole section higher from the chimney. Maybe I can't explain it good enough

In the OP's first post, he said "the idea is to eliminate huge and not very beautiful solar panels of roofs of residential houses". I think this vision is flawed. I bet you not too many people think the current solar panels are ugly. People (myself included) may prefer to have the same roof style as the rest of the subdivision, and just put solar panels on top as needed. After all, the market to install new solar on top of existing roofs is vastly bigger than the market to install customized solar tiles on brand new homes.

Maybe I've expressed myself wrong. The styleTILE is a great thing when you get in situation like ours was. Old roof need of replacement. Why not do it in one step with styleTILE?
It would be stupid to remove a perfectly good roof to put on styleTILE. Agreed. But looking around I see many roofs being replaced. It goes in waves, since no roof tile is forever.
And it is a great thing when you are building a new house and you wish to have solar energy.
Yes, the market for styleTILE is smaller as installation on the roofs, but it exists. I don't want the global dominance :P

The focus of the vision should not be about the aesthetic just because the OP thinks the current solar panels are big and ugly (too subjective to be agreed by everyone). The focus should be about the economics of the savings when combining tiling and solar together into 1 piece. Show people the money (savings) and they'll follow.

Ok, I'll bite. With automated production I can get quite close to the price of normal solar panels. So the end costs of new roof+standard modules are the same as styleTILE roof. And to be honest, sometimes it feels like comparing Ford to Ferrari. Not everyone looks at the solar energy only from the economics point. Otherwise we would all drive the same cars, wouldn't we?

[sumoborac]

Baloney - I am referring to the electrical connections being problematic. Forget your "basic understanding of electricity" - loose connections, poor connections and corroded are always a concern.

This is like Dow's shingles - dead horse.

Ok, misunderstanding on my end. We designed a custom connector for this project. It deals with all 3 problems: There is only one way to connect two styleTILEs together. So no "lose connections". Not connected or connected. The poor connections are solved with the shape of the connector, so it works like a spring in a way. So there is always a good connection. Corroded - the connectors are made from bras coated with "Ni" - nickel. So far, the tests didn't showed any corrosion.

But to be fair... this is something new. So there are possibilities that not everything is done perfect the first time. But this is how evolution works.
And this is one of the goals of Indiegogo campaign. To test this things. So I can give a full answer, backed with paper.

I would love to show you the connector but currently there is no patent shield for it, so I'll shot a picture of it next week when I'm back in the office and I'll post it.

[sumoborac]

I am really interested in the questions raised here. I doubt, though, that we will hear back from the OP and get conclusive answers.
Whenever I talk to friends and acquaintances about the benefits of solar PV, they will often say: "But aren't there now these shingles available?" Everyone has heard something about these shingles (I suppose mostly they are referring to the Dow Powerhouse shingles). Nobody, however, knows anything specific. Ever. Other than a perceived aesthetic improvement, I cannot see any (and I mean: ANY) benefit over traditional panels.
I checked out the Dow Powerhouse website, and it is a letdown. Lots of happy colorful messages about savings but no hard data and no specific info on their system's setup.

I'm here. Bit late, but not my fault I didn't received any "replay to thread" email until tonight.
But I do see some benefits over the traditional panels.
1. It is a roof tile. So no need for having a roof so you can put the panels on.
2. Much better roof coverage. When you put the panels on the roof, usually there is some "extra" space around them, because there are limitations with the size of the modules. At least here in Slovenia. Like this - http://rwthomeremodeling.com/wp-cont...olar-panel.jpg
This is a standard view.
3. The looks. The "extra" space around it makes the solar panels usually sticking out. So an aesthetic improvement.
4. Repairs. In our climate we get at least 5x a year the icy hail - http://upload.wikimedia.org/wikipedi...Hailstones.jpg
Those DO break car glass. At least here. And the cost of replacing 3 or 5 250W module against 3 or 5 tiles - big difference. The cost is quite lower. I know that most PV roofs are insured, so the cost is on the insurance company, but still.

But thanks for the comment. I will update the project and page with FAQ and more detailed info about styleTILE.

It seems that it's all the rage these days to "do something with solar." Even my former HVAC contractor is now "thinking about it." I wonder what world-renowned "innovation" he will provide soon. Perhaps yet another sensational rendition of the PV roof shingle/tile?

Maybe this days it is. But the styleTILE start is about 5 years ago when most people didn't knew what solar module even is.

[russ]

I don't see it this way, but ok. Loosing one unit only effects 10W of power. The rest is OK. Each styleTILE has it's own bypass diode.

The connections are maybe a bit frightening but with basic understanding of electricity there shouldn't be any problems.

Baloney - I am referring to the electrical connections being problematic. Forget your "basic understanding of electricity" - loose connections, poor connections and corroded are always a concern.

This is like Dow's shingles - dead horse.

[sumoborac]

You missed the question about the integrity of the roof to keep out rain and moisture.

All in all the idea of integrated pv in a tile is pretty cool but the logistics on how the system works and can be maintained are the big questions.

Maybe if these panels were used on a trellis or carport that can be easily reached from the ground instead of a house roof they might have a market.

The integrity is quite perfect. The shape of the module is not something new. It is used for more then 150 years. Usually the tiles are from concrete - http://www.podarimo.si/slike/slika31344771806cpg.jpg
So the rain and moisture aspects are quite covered.

[sumoborac]

I checked out your website and I'd have to say that I'm unimpressed.

It looks like you're only at the prototype stage and are still trying raise money to get it certified as a real building material and start a production line on it. But your website is woefully lacking of information to help address many obvious concerns that people have. Don't ask people for inputs and money until you've provided enough information yet. There are so many obvious questions that you should have thought out ahead of time and answer in an FAQ on your website first.

Thank you for the feedback. Since no one is perfect I can only learn from my mistakes and try to correct them. I will update the webpage in next few days to include FAQ section. Thank you for the idea

Some obvious ones were mentioned in the posts above, I'll add a few more:

1. The tiles look really slippery. How are people going to be able to walk around on the roof surface to do service?

They are slippery as much as any solar module. Glass is glass no matter how you put it
My experience is that most of the time the styleTILE is walkable surface. In case of bigger angle, there is an easy way for walking with some foam (This is were my English fails :/ - like this: http://media-cdn.tripadvisor.com/med...e-foam-bed.jpg) bound around the sho

2. The tiles seem to be interlocked all together. How easy is it to remove a single tile for repair/replacement?

Yes, they are interlocked together with a specially designed male/female connector. The current solution requires a small hand-saw for metal to cut the connector between two tiles. The rest is just some manipulation of the tile to get it in the right position to pull out. The "replacement" tiles have a soft connector, so there is just a simple "plug'n'play" principle. The replacement of one tile is done under 10 minutes, one guy, basic tools and a replacement tile.

3. If a tile's solar cell fails, how is diagnostic done to identify the trouble tiles?

The easiest solution so far is a thermal camera. Because of the bypass diode the "broken" tile has a different temperature.
If there is no option for thermal camera, then there is only "voltmeter" solution. But with some forward thinking when putting the roof up, you can measure the U(oc) of every 2 rows and compare it when the time comes.

4. There's no information at all about the whole system, how they're connected and work as a system?

The styleTILEs are connected with special male and female connector. It's an easy plug'n'play principle, easy to build. At the end, there are two tiles with some cable and standard PV connectors on them. So it is the same as the standard solar modules.

5. What does a single tile failure do to the performance of the whole system?

Every single tile has it's own bypass diode, so the performance is down only by it's value.

6. What are the projected costs?

Currently they are high, because the styleTILE is done manually. But with automation of production, the costs go way down. In the end, there is no reason why styleTILE would be much more expensive than any solar modules. The basic structure is the same. Glass+cells+EVA+PPE. So the current price for a tile is around 30 EUR/pc. Most of it because of the manual work.

7. What is the business model?

Uf... here comes trouble :/ To be honest, I'm a bit lost on this part. There are quite some options for this thing to go forward, and so far, I haven't decided yet.

8 On and on, there are so many obvious questions that you should have anticipated and answer before asking for money.

So far, all it looks like is a proof of concept.

You can say so, but there is already one roof standing. With next spring, we will cover another one. And so far, it all works. styleTILE is not something only on paper but already in usage. For me, this is more then just proof of concept.

[sumoborac]

It gets real slippery when connections are talked about - this looks like a nightmare to me.

Lose one unit in the middle of the roof and what happens.

I don't see it this way, but ok. Loosing one unit only effects 10W of power. The rest is OK. Each styleTILE has it's own bypass diode.

The connections are maybe a bit frightening but with basic understanding of electricity there shouldn't be any problems.

[sumoborac]

One more thing ... I'm not native US/UK speaker so my English is quite rusty :/ So If I write something weird, please correct me

I personally think that traditional solar panels are not ugly at all. I like the 18 panels standard poly panels on my roof. I also like that they are NOT part of my roofing surface. This keeps the panels cooler in the summer through air circulation. Also, all the wiring and connectors are accessible for servicing.

Ok, the style part is up for discussion! But looking around in my area, most of the PV plants have unused space around the panels so it is clear from far, that there are panels on the roof. with styleTILE most people don't even recognize what they are looking at
Because the styleTILE is the part of the roof one of the "must-be" parts of roof construction is the air-tunnel. With that we get the same air-circulation as with standard panels so the temperatures are quite the same.

To be honest, I am very suspicious about anything that has the name "style" in it. I am a techie and care mostly about functionality and output. Speaking of which, I have yet to find hard data on these solar shingles. A recent internet search returned zero truly useful information about these shingles, even with little to no real-world performance available on the Dow Powerhouse shingles.

And it will be some time before we will be indexed anywhere since this is the first time I put it up on the internet. The real-world performance are only those, I've collected thru last year while the first roof is operational. But so far so good! It withstands up to 120km/h winds, up to 1m of snow (but this is more the substructure problem then the styleTILE problem). This year we had one of the hugest rain-day and there was no leak And the roof is still standing

Having said this, maybe you can enlighten us about the actual performance of this system. How does the system do in various weather scenarios, particularly involving shading and high ambient temperatures. I'd also be curious what parts of that roof of yours are accessible for servicing. Can you access the wiring from the attic? How do the shingles perform if one should fail? Will this reduce the output by affecting certain sections of the roof? What is the actual kW production with certain weather? What surface temps are reached on these roofs? Similar to the 160-170 deg. F on dark composite shingle roofs that I have measured before?

Ok, so here it goes:
The styleTILE roof was made about a year ago, so it doesn't have a long history. But still It is located in Slovenia (North of Croatia, South of Austria), so our Sun index is around 1050W/m2. Our roof is 15° angle and facing South-South-East. The wind/rain scenarios where replied few lines higher. Shading is solved with bypass diode installed in each styleTILE. You can see it in this picture. It raise the cost of the production, but with it, every 4 cells are independent. So every shaded styleTILE will reduce the output around 10W. Same goes for failure. If one of the cells fails, the rest of styleTILEs will still work without problem.
The highest temperature that was measured was 67°C so around 155°F.

I am curious about your experience as an installer but it seems to me that people who are so overly concerned with the looks of traditional PV panels usually care little about much more critical aspects of a PV array.

Yes, that is true. Most PV arrays were build from economical reasons. But the evolution goes on, and why not have a normal roof that produces electricity?

Yes, but it seems you could actually provide that feedback! All I can say is that the pattern is that of solar cells directly applied to the roof. Nice geometrical pattern but that's it. Lots of concerns about lifespan and durability, though. The looks of it alone wouldn't want me make buy it.

The styleTILE is a solar module like any other. The difference is the shape, the connectors and the usability. The rest is the same. It is made from tempered solar glass, 3.2mm thick. It has EVA foil in between and an PPE backsheet. Thats all.

Thank you for all the questions and the feedback

[sumoborac]

Hi Guys!

Thank you for you feedback! Don't know why, but I just received the first mail "Replay to thread" today, so I didn't saw any of your comments until now. So bear with me, I'll go thru each of the posts and quote/replay them today!

Gregor

[SunEagle]

Dow Powerhouse is some kind of long running joke. I was in contact with them about 4 years ago when we were early in construction of our home. If I recall foundation was just poured. They told me they would have something end of 2009. We were a little delayed during our project but when I followed up with them later that year they had no updates. Another year later after we were pretty much done with the house I get an email saying they'll have some news early 2011. Flash forward to now and there still isn't any data on their product.

That's a long time to not have something. I'm calling it vaporware... I mean potentially it could exist but all of the concerns that were brought up are valid.

Sorry to go off topic but these shingles after reviewing the site.. The contacts look a bit sketchy. No way to guarantee the friction/pressure fit will last through thermal expansion and contraction.

From what I have read the only state that recognized the Dow solar shingles was Colorado. The roof installers had to get a a certification from the state building code to be allowed to install them. Supposedly a number of roofs were installed but I never saw the results of how well the solar shingles performed.

I sent a letter to Dow indicating I would be happy to be a "test" site for Florida since I needed to replace my roof within a year or so. No one ever got back to me and I now have a new roof so the point is mute.