SRS Energy, who have developed a so-called "residential solution" for United Solar (see page 28 of the Investor day presentation), is in full-force marketing offensive. Last week they used a hapless "journalist" to plant a CNET story [cached] containing several false and misleading statements.
The article starts with the picture above and the credit reads "Solé Power Tile system developed for US Tile by SRS Energy integrates seamlessly with its terra-cotta counterparts." Presumably, the dark-blueish tiles are "solar tiles that offer style" (at least that’s what the title of the article implies). That picture is fake, of course. A total fabrication. No tile on that roof generates any electricity! All the blue tiles are actually red clay tilesin real life (the picture is simply digitally altered in someimage-editing software). The picture on the left shows how the actualroof looks like (from a brochure of US Tile). If that is not convincing enough,
a partially altered picture can be found on SRS Energy’s web site and in another article [cached] -the vegetation in all these pictures looks exactly the same, whichexcludes the possibility that the building was reroofed with the bluetiles at some point. It is all one and the same picture, only the roofhas been digitally "painted." If you have the patience, you can spotthe differences and similarities here.
But these are not all the fake pictures SRS Energy can offer. Look at the image on the company’s home page , which can also be found in their "sell sheet," and in this story [cached]. A fake,of course. The actual roof is done entirely with red ceramic tiles.Here are the actual and "remastered" pictures side by side:
You can find the actual picture on US Tile’s web site, by clicking on "Why US Tile," and then on "see Faux Mission."
Thedeception and misinformation do not end with fake pictures. Here aresome of the statements made in the story by SRS Energy’s MarketingDirector, who claims to "work for the greater good."
- "Cell efficiency for the tiles is between 8 percent and 10 percent."That, of course, is an outright lie (except maybe for a few hours oflight exposure – Unisolar laminate degrade rapidly in the first hoursand weeks under the sun until they settle to their rated efficiency).The stabilized cell efficiency of the PV laminate material is lower. Asthis spreadsheetshows, Unisolar’s best "stated" cell efficiency is 8.5%, but the tilesystem from SRS Energy won’t use those cells. According to theirdocumentation, the 3-cell tile is 17 Watts,and as each Unisolar cell is 0.239 meter x 0.356 meter, it means theeffective cell efficiency is 6.7%, which corresponds to 7.5% "stated"cell efficiency (the same cell used in Unisolar’s latest laminate, PVL-128). However, to make things worse, the documentationstates that 30 interlocking tiles cover 100 sq ft, and since each panelis 17 W, that means 510 Watts per 100 sq ft. (actually, this and thisstories claim the tiles are only rated 500 watts per sq ft). Using the510 number and dividing by the area in square meters, the calculated"panel"-level efficiency is just 5.5% (30 * 17 W / 9.29030 sq m /1000). Even the PVL-128 laminate (made with 22 cells) has a slightlyhigher, 5.9%, panel-level efficiency.
- "That [cell efficiency] puts it slightly below what others in thin-film photovoltaics have been getting." Not true. First Solar’s panel-level efficiency is at least 10.4%, thus the solar tile efficiency is not just slightly below, but 47% below that of First Solar’s thin-film modules. This is one of the reasons why First Solar sales are increasing, while Unisolar sales are declining.
- "SRSEnergy system’s overall efficiency makes up for the difference insunlight to electricity conversion figures. ‘If a homeowner bought 4kWof crystalline silicon panels and then 4KW of the Solé US Tiles, theywill get 10 to 15 percent more output in terms of a KWh (kilowatt hour)on their electricity’" The "make-up" statement is a red herring,of course – a 4KW solar tile system will occupy 3.5x the area of a 4KWcrystalline SunPower system. The "10-15% more kWh/kW" statement isfalse as well, including the concocted explanations of panels waking upearlier, or better absorbing the light spectrum, etc. Severaldocumented real-world performance records in various climates in the USand Europe demonstrate that the alleged kWh/kW advantage is a myth (I, II, III, IV, V, VI).The advantage, if any, is 5% and below. Thus, "effective" panel-levelefficiency could potentially rise to only 5.8% (5.5% *1.05). Of course,that 5% advantage will be there only in the first 5-10 years, as thefaster degradation of the Unisolar laminates relative to otherthin-film and crystalline modules will eliminate it over time (averageannual degradation for Unisolar triple-junction laminates has beenshown, see page 9,to be 1.22%, while crystalline’s is typically 0.5-0.7%). But that’s notall. What makes things worse is that the tiles are curved, thus evenfor a roof that is south-oriented and tilted at optimal angle, thelight hits the PV cells at various suboptimal angles. Even a casualsimulation analysis with the PVWattscalculator indicates that, in fact, the curvature could result in lessenergy than a flat panel tilted at zero degrees slope. For example,a flat panel, tilted flat (zero degrees), in San Diego is estimated togenerate 1314 kWh/kW AC electricity a year. A south-oriented30-degrees-tilted flat panel generates 1500 KWh/KW, but east-oriented30-degree-tilted panel generates just 1160 KWH/KW, while awest-oriented 30-degree-tilted one does 1268 KWH/KW (note how the east-and west-oriented tilted panels generate less electricity than azero-tilt panel). Thus, almost certainly the tiles will underperformcrystalline and CdTe panels (which, of course, both have flat surfaces)on the same roof on kWh/kW basis.
- "SRSEnergy’s statistics say the average homeowner with Solé Power Tiles canget 860 kilowatt hours per square foot annually living in an area with’5.8 peak sun hours’ per day." SRS Energy has no suchstatistics, as they would contradict the real world experience ofinstallations with Unisolar laminates. Actually, the laws of physics make it impossiblefor a PV solar system to generate 860 kilowatt hours per square footannually in an area with "5.8 peak sun hours" per day. SRS Energy’s literaturemakes a more believable claim of 860 kilowatt hours per square (asquare is 100 sq ft). But even that claim is deceptive. For the "860kWh per square" claim to be true, the tiles must be generating 1686kWh/KW AC electricty on an annual basis (as a square has 0.510 kW worthof solar tiles). Luckily, there are few Unisolar installation in SanDiego, an area with "5.8 peak sun hours," according to PVWatts(solar radiation hitting south-oriented 30-degree tilted panels), sothe claim can be verified. SIT has installed Unisolar-based roofs at 28schools in the area (installations and performance have been summarizedin a spreadsheet).The median/average performance was below 1470 kWh/kW, or 13% less thanwhat SRS Energy claims. A Unisolar system installed by Sullivan Solar,an installer in the area (see the same spreadsheet) has done a bitbetter, 1550 kWH/kW (accidentally, just 1% better than the average andmedian of three crystalline installations nearby). True, these Unisolarinstallations are on flat roofs, but as explained above, zero-degreetilt "panels" would likely outperform the curved solar tiles.
TheCNET story ends with a picture of the SRS Energy’ CEO’s ice-creamparlor (sporting mostly red tiles and a row of the blueish solartiles), which according to the story is "the first commercial buildings to implement the Solé Power Tile system." But his store’s home page shows grey shingles and so does Google maps’ satellite image.So, SRS Energy’s CEO had to waste money and labor to tear down andreplace a perfectly nice roof, so that he could install 1KW or so worthof solar? Is that SRS’ idea of "eco-nomics?". Is that "the sustainable upgrade [made] a simple one for the homeowner, which means it is also more accessible?" (see here [cached]).
The CEO stated [cached] that “choosingto upgrade to a sustainable roof from SRS Energy puts energy savings inhomeowners’ pockets immediately and delivers compelling long-termreturns.” That wasn’t the case with his "sustainable" roof, buthe is clearly hoping that the showcase will transfer the homeowners’savings into his pockets, and, hopefully, deliver some return on the millions [cached] put in his venture by "angel" investors.
Beforeanalyzing the prospects of a success for this product, let’s exploresome more "marketing messages" scattered across product documentationand planted articles:
- "SRS Energy materials are UL recognized as trusted and safe solar roofing components." (source: here). Possibly, but why is the “UL Recognized" logo missing from the "sell" sheet? The solar tile is obviously not UL certified,and using UL recognized materials means little for an electricaldevice. Here is an example: copper wire is UL certified, but solderingit to short the solar tile electric connector will lead to overheatingand even fire under the sun. Will these tiles ever pass any UL or IECcertification? Note that Unisolar laminates’ IEC 61730 certification may still be "pending," and the original Unisolar "residential product", the SHR-17solar shingles (now taken off the market), no longer carry the ULcertification and were shown to degrade in likely violation of theirwarranty (and then Unisolar simply stopped disclosing degradation data).
- "Solé Power Tile … bringing the first building-integrated photovoltaic (BIPV) roofing product to curved roofing systems." (sources: here [cached] and here [cached]) . This is patently false, of course, as SRS Energy’s patent application, as well as the CAD drawing indicate that the tiles have to be nailed to straight, not curved, underlayment given their interlocking design.
- Chart titled "They wake up earlier and stay up later" and footnoted "Amorphoussilicon thin-film technology incorporated within the Solé Power Tileallows the system to produce an estimated 8-20% more energy thanincumbent crystalline silicon panels" (source: here).
Lookat the Y-axis label on the left. It is in kWh. What this chart claims,then, is that by 1 pm, "conventional" glass modules have generated 400Wh while the tiles have generated only 350 Wh worth of electricalenergy. In the afternoon, all this generated electrical energy isconsumed, bringing net PV generation for the day to zero (for both theconventional panels and the tiles). Of course, the label is wrong. Itshould be "kW" not "kWh." One is a measure for power, the other, forenergy. But these are probably minor details for SRS Energy and their clay tile partner.Unfortunately, even if the axis were labeled "kW," that pricture wouldcontradict SRS Energy’s message that the Unisolar’s panels somehow donot "degrade in performance as they get hotter" [cached].Around 1pm, a time not known for the lowest temperature during the day,conventional panels, according to this chart, outperform the solartiles!
- The rest of the Performance and Savings sheet is all wrong, as well. A 4KW tile system in a "5.5 hour day" area (San Franciscoor Santa Cruz) will not generate 6,022 KWh on an annual basis. Even anoptimally (30 degrees) tilted and well-ventilated Unisolar laminategenerates only 1500-1650 kWh/kW in Santa Cruz. A zero-degree-tilted flat laminate makes 1275 kWh/kW, on average. As discussed already, even optimally tilted curvedtiles will likely generate much less than optimally tilted flat panels.Thus, the most SRS Energy can hope for is 1500 kWh/kW for their tiles.That comes to 6,000 kWh for a 4KW system, which is well below the 6,800kWh in their "illustration." The crystalline number of 6,022 kWh in the"example" is more plausible, by the way. Finally, the term "Efficiency"(see the third term in the calculation illustration) conventionallyapplies to conversion efficiency, not performance ratio.
- "TheSolé Power Tile™ energy advantage allows the system to deliver moresavings in the form of a reduced or eliminated electricity bill andcreates value with increased homeowner equity" (source: the Performance and Savings sheet). To illustrate that bold statement, SRS Energy attaches an electrical bill that indicates 376 kWh electrical energy usage. In fact, the bill shows that electricty consumption increased from 176 kWh in the period 2/14/2009-2/28/2009 to 200 kWhin the periof 3/1/2009-3/17/2009. This surely does not look like ahouse with a solar system installed. It is even more weird that SRSEnergy has decided to "magnify" that 376 kWh energy usage and label it 379 kWh.A Freudian slip, no doubt. The energy bill did not get reduced. Itincreased! The hapless homeowner will actually experience a destructionof value – more on that below.
So, setting aside the marketing propaganda, does this new product make any sense? The answer appears to be no:
- Just two SunPower SP-315panels (61 inch x 41 inch each, covering a combined area of 17.6 sq ft)deliver 24% more power under STC than 30 solar tiles (covering 100 sqft). Two SunPower panels can be installed in minutes, laying 30 tilesand carefully connecting them to the underlayment circuitry may takehours. No wonder SunPower has 20%+ share in the California rooftop PVmarket (the first intended market [cached] for the tiles), while Unisolar’s share there is 0.1%, according to the CSI.
- Cost will be prohibitive, even after ITC. The tiles need to sell for $6 or more per Watt for SRS Energy to break even (initial plans were for $8 per Watt [cached]). Unfortunately, thin-film solar panels can be found for less than $2 per Watton the market these days, and all the tiles will save in terms ofequipment or materials is a rack (which is only anywhere between 60c to10c per Watt, depending on the installation size).
- The solar tiles will not be viewed as a roofing material. Clay tiles can be purchased for $200 per square [cached].At $6 per Watt, the solar tiles will cost $3,000+ per square ($6 x510W), or 15x as much. Their color is attrocious, and they are made ofplastic (polypropylene).There are reasons why people generally don’t put plastic tiles on theirroofs that are supposed to last at least 20 years (cost, discoloration,delamination, degradation from UV radiation over time, and fire hazards [cached]come to mind). The weird rare color makes things worse – a thoughtfulhomeowner would wonder who will provide the dark blueish tiles in 5-6years if breakage or loss occurs, if the sole manufacture ofthe Solé tiles has (god forbid) discontinued the product (the owners ofthe Unisolar’s SHR-17 shingles are currently in that pickle).
- GoingPV with solar tiles rather than regular solar panels will be viewed asa risky proposition by the customer, given that 99.9% of the PV marketin California is flat glass panels, even ignoring the lack of certifications or ineligibility for state incentives. Jumping on the tile bandwagon won’t be an "incremental rather than monumental" decision SRS Energy wants us to believe [cached]. Quite the opposite. Of course, SRS Energy could easily "absorb the headaches and paperwork surrounding solar incentive programs" – there simply won’t be any state incentives in California for this product.
- Plastic is not a truly "sustainable" material (as it is made from hydrocarbons) and it is not a clean way for homeowners to go "green", despite SRS Energy’s claims [cached] to the contrary. The solar tiles may not be a truly LEED product either, despite SRS Energy’s claims – unlike ceramic tiles which absorb moisture at night, and thus cool the roof during the day, plastic does not absorb water.
CertainTeed, arguably the country’s third-largest roofing company, acquired [cached] an equity stake in SRS Energy in 2008. What were they thinking?
