From Nipton goes Skyline Solar, Photo Credit: Oltmans Construction Co.

I first became aware of a new Skyline Solar, Inc. project located in Nipton, California USA (http://www.nipton.com/) via the California Solar Statistics website which provides program and application information on the California Solar Initiative (CSI). I contacted Skyline Solar in April 2010; they didn’t comment preferring to announce finished projects.

Well it took a while, but I reviewed the Site Plan Permit for the project at the San Bernardino County Land Use Services Department North Desert Office in Victorville after the Victor Valley College Solar Power Plant Celebration.

From Nipton goes Skyline Solar

The Site Plan (shown above) describes a 100.8 kWp DC system consisting of 56 High Gain Solar Arrays or 876 HGS Panels. By my calculations, there are sixteen (16) HGS Panels per Array implying a total of 896 HGS Panels (16 times 56) so I believe the 876 number was a typo.

I phoned the permit applicant, Gerald Freeman, who was kind enough to share the project history and status. Mr. Freeman was excited and animated (a common trend!) to discuss the photovoltaic solar system which will supply 80% of Nipton’s power. While Nipton has about 30 residents, Mr. Freeman expected Gateway to Mojave National Preserve visitors to bump the population up to near 250 over the recent Memorial Day holiday weekend.

The Site Plan Permit application was submitted in December 2009 and approved in early January 2010. The system installation began in February and was completed by the end of April 2010. Three (3) interconnections with Edison International (NYSE:EIX) subsidiary Southern California Edison (SCE) have been approved and the final three (3) interconnections should be completed in the next few weeks. Substation modifications were required by SCE to complete the interconnections.

Mr. Freeman has a Power Purchase Agreement (PPA) with a specially created finance entity, Sustainable Investments LLC, and has an option to buy the systems after five (5) years. Skyline Solar’s role is as the system manufacturer, designer, and installer.

The Nipton system is divided into two sites to the north and south of Nipton Road respectively. The southern site has three (3) Columns with twelve (12) HGS Arrays each, twice as long as the Columns at the VTA Demonstration Project. The HGS Arrays appear to have a system capacity of 1.68 kWp, and the Columns are 20.2 kWp for a combined system capacity of 60.6 kWp. Subcontractor Oltmans Construction Co. has photos of the Skyline Solar Phase I project. The southern PV Columns will power the hotel, store, restaurant, house, and the water well.

The northern site has another Column with twelve (12) HGS Arrays; the short Column with eight (8) HGS Arrays on the Site Plan was postponed because of the economic crisis. The northern PV Column will power the school and perhaps two houses.

Per the CSI data, the installation uses twelve (12) SMA Solar Technology AG (ETR:S92) Sunny Boy 7000US Grid-Tied Inverters or three (3) per Column.

Since In Search of Skyline Solar – Part 3, it appears the power per HGS Panel 100 has been boosted almost 48% from ~71 Watt (W) to 105 W. I assume the modules have been improved or rerated from over a year of actual VTA performance data or both. Although the Du Pont Apollo DA105-A2 105W Thin Film a-Si Module is mentioned in the CSI reservations, this module was chosen as an equivalent placeholder pending the in process certification of the Skyline Solar monocrystalline solar module by the CEC (California Energy Commission).

As indicated in the CSI Program Handbook section 6.1, Equipment Certifications and Rating Criteria:

As described in Section 2.2.1, an exception may be made for new equipment that has not yet received certification but for which the certification process has been initiated.

Equipment must be certified before any incentive payments will be made.

Once certified, I expect the Skyline Solar module will be among the CSI List of Other Eligible Solar Electric Generating Technologies.

CSI Reservation Number Confusion
Again reviewing the CSI Reservation data, there are a total of 752 modules implying 47 HGS Arrays. From a forwarded email, I learned there are an even 48 HGS Arrays. I therefore analyzed and adjusted the CSI data for the mysterious and undocumented 48th Array to calculate the ~80.6 kiloWatt-peak (kWp) DC Nameplate Rating and a ~70.4 kW CEC PTC Rating.

For the cumulative ~102 kW AC CSI Rating (“Alternating current output of photovoltaic module calculated by multiplying the CEC PTC Rating with the Design Factor.”) of the installation, I adjusted for the 48th Array and an inconsistent design factor. I believe the high ~1.45 Design Factor reflects the combined performance benefits of Skyline Solar’s 10x concentration and 1-axis tracking in generating kilowatt-hours (kWh) of electricity at the location.

Molycorp Minerals, LLC
Mr. Freeman is hopeful Nipton will complete the remaining portion of the solar project in the near future. According to “Molycorp Files for $350M IPO to Crank Out Minerals for Greentech” by Josie Garthwaite at earth2Tech and “Challenging China in Rare Earth Mining” by Keith Bradsher for The New York Times, Molycorp is planning “to modernize and expand” the Mountain Pass Rare Earth Operations (mine) with the initial public offering proceeds. If the Mountain Pass mine reopens, Mr. Freeman expects 1100-1200 employees will be hired by Molycorp by yearend 2011, growing Nipton’s permanent resident population.

View Larger Map

I understand a ribbon cutting ceremony for the Nipton Skyline Solar installation is scheduled for Friday, June 11, 2010.

Skyline Solar did not accept my offer to fact check the details of my post.

©2010 GUNTHER Portfolio. All Rights Reserved.

[San Jose, California USA]

It’s all in the tracking.

After many rainy days, the sun broke out last Saturday before Noon, and I was solar powered for a Silicon Valley tour. After taking pictures of the First Solar skunk works, I decided to visit the Skyline Solar, Inc. High Gain Solar (HGS) Project at the Cerone Division of the Santa Clara Valley Transportation Authority (VTA).

Strolling down the public Highway 237 Bikeway, I admired the grazing thick fleeced sheep (at least I think they were sheep) before reaching the HGS Demonstration Project. Without an agenda, I looked things over and began the return walk. Then, when I looked back, I noticed an anomaly. The HGS array column next to the building was not tracking in sync with the other three as shown in the photo. I could only recall having seen the columns track in relative unison.

From Skyline Solar VTA Update

I wasn’t certain anything was amiss. Despite the clouds, the sunlight appeared to be reaching all the columns. Even if the sunlight was uneven, I thought Skyline Solar’s single axis horizontal trackers would follow the expected location of the sun although I don’t know what algorithm is used.

I asked Skyline Solar the same questions, and I was relieved when Skyline Solar acknowledged a column was offline and would be back in service on Monday. Their acknowledgement saved me a bunch of technical due diligence.

Driving by the VTA along Route 237 after lunch on Wednesday, I observed all the columns were again tracking in concert. Skyline Solar tells me the column was offline because of human error. One of their technicians left the column parked after installing an update in the rain and in haste thought the column had been returned to track mode.

I don’t know if I am lucky or a harbinger of bad luck!

At Dow Jones Alternative Energy Innovations Fall 2009, I heard Skyline Solar CEO Bob MacDonald mentioned the company was due to break ground on another project by the end of 2009 without providing any details. I wonder if he discussed the project at the Fifth Annual Piper Jaffray Clean Technology & Renewables Conference?

“Don’t Look Back”

©2010 GUNTHER Portfolio. All Rights Reserved.

From Skyline Solar Arizona Test Site, Photo Credit: Barker Morrissey Contracting

When I heard Skyline Solar, Inc. mentioned an Arizona test site during their presentation at Dow Jones Alternative Energy Innovations Fall 2009, I was all over it. Later, I found BARKER MORRISSEY Contracting had installed a Skyline Solar High Gain Solar (HGS) Array at the Tucson Electric Power (TEP) Solar Test Field on East Irvington Road in Tucson, Arizona USA.

View Larger Map

As noted in Skyline Solar Test Site:

The project included the detailed installation of Skyline’s single axis tracker. This tracker consists of highly reflective metal sheets on top of reflective racks that direct light to Skyline’s High Gain Solar Panels.

I understand the HGS Array was installed in mid to late July and turned over to TEP around August 2009. It was supposed to have taken two days to excavate and pour the tracker footings and less than a day to install the HGS trackers.

In “The Power of Partnerships” by Lew Serviss for The University of Arizona’s Arizona Engineering Online, the Arizona Research Institute for Solar Energy (AzRISE) partnered with Tucson Electric Power, a subsidiary of UniSource Energy Corporation (NYSE:UNS), “on a program to monitor the efficiency of solar panels at TEP’s test yard.”

Per the above photo and my calculations from In Search of Skyline Solar – Part 3, I estimate the system capacity is 2.2 kW assuming the same module rating of 71 Wp (Watt-peak). While I heard from TEP Public Relations the Skyline Solar HGS installation had a system capacity of 22 kW, the information was contradicted by the BARKER MORRISSEY photo and AzRISE sources.

In the spirit of partnership, TEP decided to evaluate the efficiency and effectiveness of the Skyline Solar HGS solution, and Skyline Solar was interested in independent third party testing conducted by AzRISE. AzRISE will monitor the HGS Array and analyze and compare the output to single sun silicon solar modules.

At a second test yard, TEP will evaluate other single and dual axis tracking photovoltaic systems. Larger project plans include “TEP Unveils Plans for Giant Photovoltaic Array and New Solar Power Plant” for a 25 MW (MegaWatt) photovoltaic (PV) array as well as a 5 MW concentrating solar power (CSP) plant slated for completion by January 2012 and “TEP Seeks Federal Stimulus Funding for “Bright Tucson” Solar Project” for “energy storage systems and a “demand response” program to optimize the output of a new 1.6-megawatt (MW) photovoltaic (PV) array.”

Skyline Solar chose not to acknowledge or respond to my questions about the test site. While curious, I was not surprised. Despite (4) four dedicated posts about Skyline Solar, the Blog does not even get a Skyline Solar In The News reference implying GUNTHER Portfolio must be =the= place for analytic Skyline Solar coverage.

Please don’t forget to vote in the new sidebar PV POLL: Will Skyline Solar’s High Gain Solar (HGS) approach succeed?

©2010 GUNTHER Portfolio. All Rights Reserved.

It’s been like forever (1 year, 8 months, 10 days) since my last Solar Light Flashes. I’ve always planned to resurrect the haphazard post. Twitter delayed the return but sometimes 140 characters are insufficient.

From 24th EU PVSEC

centrotherm photovoltaics AG (ETR:CTN)

Only the Photovoltaic (PV) Industry plasters roadmaps or manufacturing costs on exhibition stand signage. The last official centrotherm CIGS (copper indium gallium diselenide) news was “Success in the thin film division: centrotherm photovoltaics achieves 13 percent efficiency for mass production”. Tom Cheyney chatted with centrotherm in “EU PVSEC short takes: Talking CIGS turnkey, eyeballing a Nanosolar panel, and more” at PV-tech.org.

I wonder what the latest is on Sunshine PV Corp.’s installation and ramp of a 30 MW (MegaWatt) centrotherm CIGS production line?

From 24th EU PVSEC

German Renewable Energy Sources Act (EEG) 2009: Direct Use

Cornelia Viertl, Senior Advisor for Solar Energy and Geothermal Energy at the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, presented the “Political Framework for the PV market in Germany” at EU PVSEC. The slide on Direct Use shown above attracted my attention.

The EEG Direct Use provision has been painted by a few US Feed-in Tariff (FiT) naysayers as a German step towards California style Performance Based Incentives or even net metering. In reality, the Special tariff option =pays= the consumer €0.2501 per kWh (kiloWatt-hour) for each kWh of electricity consumed over a 20 year period! The Direct Use tariff is in effect a Feed-in Tariff minus a flat residential electricity rate. In practice, a German residential PV installation selecting the Direct Use option can achieve a zero Euro electric bill with less than half the PV system capacity required under California net metering rules.

As I tweeted back then, the silliest thing I heard at Intersolar NA 2009 was said by Prometheus Institute President Travis Bradford during his “State of the Solar Industry” presentation. Mr. Bradford said:

A lot of people that are promoting Feed-in Tariffs in the United States um just know at the same time Germany is trying to move to a California based model. So how are you going to reconcile that?

With German PV Feed-in Tariffs under pressure because of the steep fall in solar module prices and the new conservative CDU FDP coalition government, I expect FiT detractors will disinform during Solar Power International 2009 at every opportunity.

From 24th EU PVSEC

Fraunhofer ISE (Institute for Solar Energy Systems)

At the Fraunhofer ISE stand, a FLATCON® Module with Reflective Secondary Optics was on display hinting at the possible future direction of Concentrix Solar GmbH. Still under development, the modules with reflective secondary optics were said to have achieved efficiencies as high as 29.1% outdoors without citing further details.

From 24th EU PVSEC

Global Solar Energy, Inc.

Is something wrong at Global Solar? When I had an unpleasant question for them, I discovered Global Solar had dropped the PR firm listed on their website, and I never got a response from the company. Global Solar has been mum (perhaps by contract?) throughout The Dow Chemical Company (NYSE:DOW) CIGS solar shingle hoopla, “DOW™ POWERHOUSE™ Solar Shingle Unveiled”, or please see “Dow Unveils Solar Shingles” by Todd Woody for the New York Times Green Inc. Blog. So what happens if a nail is hammered through a CIGS cell by accident?

From 24th EU PVSEC

KCC Polysilicon

After achieving 150 MT (Metric Ton) polysilicon pilot production in 2008, KCC Corporation (SEO:002380) claims to be on schedule to complete the construction of two (2) polysilicon factories with 3000 MT annual capacity each by the end of 2009. One is fully owned by KCC while the second is a joint venture (JV) between KCC and Hyundai Heavy Industries Co., Ltd. (SEO:009540) called Korean Advanced Material (KAM). Phase I mass production is slated to ramp at both factories in the first to second quarter of 2010. KCC will produce the TCS (Trichlorosilane) used for polysilicon production.

From 24th EU PVSEC

Q-Cells SE (ETR:QCE)

Q-Cells CEO Anton Milner made quite the EU PVSEC entrance when he arrived in the solar taxi. OK, I did not witness nor believe that happened, but the concept was made possible by a Q-Cells’ community initiative.

From 24th EU PVSEC

RTS Corporation

RTS Corporation President Osamu IKKI presented “PV market of Japan: Rising again with the new support framework”. As the above slide shows, RTS projects the Japanese PV market will grow to 400-500 MW in 2009 and 1.0-1.2 GW by 2012. In the near term, residential and municipal (schools) PV applications dominate. Japanese utilities have announced Distributed Generation PV projects from 1.5 MW to 18 MW in size slated for completion over the next few years.

From 24th EU PVSEC

Schmid Group

When I saw the sign, I just had to take a few photos at the Schmid stand without any particular agenda.

From 24th EU PVSEC

Schmid Silicon Technology GmbH (SST)

Since Schmid Pilot Production Topping Out, “Installation of first equipment has started” (Deutsch) was the news somewhere around September 14, 2009. Per SST, potential customers are waiting for the successful completion of pilot production to prove the Schmid Process.

From 24th EU PVSEC

Skyline Solar, Inc.

Skyline Solar had a stand at EU PVSEC (and will have one at Solar Power International 2009 also known as SPI 09). Why? Exactly. Don’t they need to get their modules certified before their solution has any hope of being bankable?

Judging by the participation of Skyline Solar VP of Marketing Tim Keating in the SPI 09 panel, “Shifting from Installed Costs to Performance Costs: Why $/W is No Longer Relevant to the End Market”, on Tuesday, Oct 27, 2009, from 11:00AM to 12:30PM, accelerating PV’s path to grid parity with High Gain Solar (HGS) lies through price and cost obfuscation.

From 24th EU PVSEC

SolarEdge Technologies Inc.

At EU PVSEC, I learned SolarEdge has some 25 MW (MegaWatts) of backlog with production at about 200 kW (kiloWatts) per week. Since Close to the SolarEdge, SolarEdge has racked up awards (Global Cleantech 100, Frost & Sullivan), partners (HaWi, Isofotón), and investors. I expect further big news around SPI 09 though SolarEdge is forgoing their trademark exhibition edge location for central stand 2438.

From 24th EU PVSEC

Sony Chemicals Europe B.V.

When I saw the SONY stand, I thought it might be for solar modules or a PV powered PSP (PlayStation Portable). Sony Chemical & Information Device Corporation was promoting photovoltaic module materials through its European subsidiary, Sony Chemicals Europe B.V.

Products included a Solar Cell Conductive Film SP102F1 used as a connecting material between metal ribbons and solar cells in crystalline silicon and thin film PV modules and a tentative datasheet for an Encapsulant with backsheet.

From 24th EU PVSEC

Tigo Energy

I met with Tigo just before their announcement on gaining UL compliance, “Tigo Energy Achieves Compliance/Certification Landmark”. Tigo also announced the Module Maximizer-ES (MM-ES), perfect for string retrofit installations, had a $56 MSRP (Manufacturer’s Suggested Retail Price). Tigo mentioned the Module Maximizer solution is seeing traction in retrofit applications in Spain and even in Germany with an unnamed commercial sized PV system. Tigo was also awarded the Global Cleantech 100 honor like a competitor mentioned above. Perhaps the tie I declared in Intersolar 2009: My Photovoltaic Top 10 List was prescient?

Is Tigo’s $56 MSRP kryptonite to SolarMagic priced at $199 each and requiring the one $79 blocking diode per string?

From 24th EU PVSEC

Tyco Electronics Ltd. (NYSE:TEL)

Tyco earns my creative promotion award by joining twitter (http://twitter.com/TycoElectronics) and offering a “Twitter Goodie” to those visiting the Tyco stand and uttering the phrase. Now I didn’t know about the chance to win a SOLARLOK Service Kit by dropping off a business card.

From 24th EU PVSEC

And that completes a rather wordy Solar Light Flashes. The End.

©2010 GUNTHER Portfolio. All Rights Reserved.

High Gain Solar (HGS) power plant dedication including HGS module ratings.

After In Search of Skyline Solar – Part 2, I managed to attend the dedication of the Skyline Solar High Gain Solar (HGS) power plant at the Santa Clara Valley Transportation Authority (VTA) Cerone Bus Maintenance and Operations Division a while back on Friday, May 15, 2009. Funny thing was that the VTA Public Information Officer, not Skyline Solar, extended the invitation although the dedication was open to the public.

“Skyline Solar Plans Launch of First Product” by Ucilia Wang at Greentech Media captured the limited news originating from the event.

Skyline Solar, Inc. CEO Bob MacDonald thanked San Jose Major Chuck Reed for arranging the match between the VTA and Skyline Solar. The original Skyline Solar deployment site was planned for the Morgan Hill area but this was delayed by land permitting and easement issues.

CEO MacDonald said:

So this is Skyline’s approach to more effectively using materials so that we can get costs down and get the scale up. This is a relatively modest step in that direction, but we intend to be moving very quickly going forward and doing larger projects later this year and substantially larger projects on the MegaWatt scale in 2010.

The 24-30 kWp (kiloWatt-peak) Demonstration Project system capacity was declared to be 27 kWp. I am not sure why this was uncertain. Checking out the HDS Arrays amongst the crowd, I snapped a photo of what I believe is the module rating label. Skyline Solar refers to a module as an HGS Panel.

Since this almost matches the theoretical module power rating after dividing 27 kWp by the number of Columns (4), HGS Arrays per Column (6), sections per HGS Array (4), and modules or HGS Panels per section (4), I believe this is measured under concentration conditions.

Each module consists of two independent strings of thirteen (13) monocrystalline solar cells, sized around one quarter of a 156 mm (millimeter) square cell, accessed by a junction box at each end. I guess each quarter cell from unknown suppliers can produce about 1 Watt. Two (2) strings times thirteen (13) cells times 1 Watt equals 26 Watts under one sun. It appears Skyline Solar believes they can extract almost three (3) times the one sun power from the monocrystalline silicon solar cells under 10x concentration.

I asked Skyline Solar representatives two questions.

Q: Why are some modules painted white while most are just aluminum?
A: Specification variation was sited; no one knew why.

I thought either these white modules had different vendor solar cells or the white was supposed to reflect and maybe recapture the light in the trough. As can be seen in the Picasa slideshow solar cell close-up, all the cells were front contact monocrystalline silicon solar cells.

Second, I asked to look at the inverters towards the back of the columns and roped off from the public. I got a quick No on this one even though I offered not to take photos. Of course, I wanted to sneak a peek at the instantaneous power production.

During his remarks, Jeff Byron, Commissioner, California Energy Commission, said:

Utilities like to own and operate their own generation. They really don’t like it when other people have it. It’s nothing disparaging of utilities; that’s their business.

But we want renewables to have an opportunity to have an equal footing, and the way to do that is through a Feed-in Tariff. So if you hear this term, Feed-in Tariff or FiT, we need to make it very easy for projects like this as they scale up into the MegaWatt scale to have an opportunity to easily get on the grid and sell their power in at a reasonable price.

This statement generated loud applause from the audience. Enough said.

©2010 GUNTHER Portfolio. All Rights Reserved.

Pilot High Gain Solar (HGS) Project at the Cerone Division of the Santa Clara Valley Transportation Authority (VTA).
Project and electricity free to VTA!
HGS concentrating issue at the open end of the trough?

From Skyline Solar’s HGS Pilot Project at VTA Cerone Division

My In Search of Skyline Solar post provided a preview of last Monday’s “Skyline Solar Emerges from Stealth after Achieving Key Customer, Development and Financing Milestones” press release. This was the first I heard of the 24-30 kW (kilowatt) Demonstration Project at the VTA.

Even my machinations about remote prototype locations didn’t anticipate this system being hidden in plain sight. I noticed the installation driving west on Route 237 twice the week before Skyline’s supposed emergence from stealth mode. While I planned to check it out, I thought it was a small CSP (Concentrating Solar Power) plant and didn’t make the connection to Skyline Solar. In my defense, I hadn’t seen more than a few dual trough concentrating solar photovoltaic modules strung together before, and I do need to remain attentive to my driving and not gawk at solar installations.

View Skyline Solar’s HGS Pilot Project at VTA Cerone Division in a larger map

Regarding the Skyline Solar pilot project, the Agenda for the Committee for Transit Accessibility meeting on Wednesday, April 8, 2009 said:

Solar Installation

The installation of solar panels is currently underway at the Cerone Operating Division. This pilot project is a result of a partnership with Skyline Solar of Mountain View. The contractor has experienced delays due to rain and installation is now approximately 50% complete. Barring further rain delays we anticipate the installation will be completed the first week of April.

This project has the potential to bring to market a new type of solar collector that collects more energy per square foot and is less expensive to procure than traditional solar flat panels. Skyline Solar is building this at no cost to VTA. In turn VTA will receive $15,000 to $20,000 in free electricity.

From VTA Media Relations, I learned the prototype Solar Installation is planned to last 12 to 18 months and was already generating a small amount of power. Also, a project press event is scheduled for later this week. I heard elsewhere San Jose Major Chuck Reed will be on hand for the Pilot Solar Project inauguration. Since this is California, you never know who else might show up.

Chatting with a VTA employee, I understand the project did not require usage or building permits since VTA is exempt from those regulations. Fire and I assume electrical inspections were required though.

The four (4) Skyline Solar HGS array columns are oriented in a north to south direction with the open end of the troughs facing south. Each column consists of six (6) HDS arrays in this installation. From the Skyline Solar provided 24 to 30 kW system capacity, each column is rated at 6 to 7.5 kW, and each HDS array at 1 to 1.25 kW.

As can be seen above and in the following Picasa slideshows, I noticed “dark” silicon solar cells towards the open end of the troughs. Is this an optical illusion? This effect was less pronounced looking down the trough from the open end. I never observed dark solar cells at the closed end of the troughs.

On the Demonstration Project webpage, Skyline Solar said:

“Bright line running along HGS panels shows where light is being converted to electricity.”

During two visits, I observed the effect was most pronounced at noon and 50% (percent) improved by afternoon at 3PM. Skyline Solar’s “Four columns of Skyline HGS arrays” photo only displays a trace of this trough edge effect later in the day at almost maximum single-axis tracking to the west. Did Skyline Solar make a conscious decision to maximize late day power generation?

Skyline Solar was mum to a loaded question I sent them on this; my question was not even acknowledged.

Has Skyline Solar added a parallel bypass diode per silicon solar cell at the trough edge to handle this issue? Is a latitude tilt or installation adjustment needed?

If that wasn’t enough, it also seems as though the concentration resulted in nonuniform solar cell illumination and was most intense at and just above the horizontal center of the solar cells raising concerns about the efficient use of the material and the concentration alignment.

In the second Picasa slideshow, four (4) KACO Solar inverters are used per column. The smallest KACO Solar blueplanet 1501xi inverter sold in the United States is rated for 1.8 kW maximum DC, and four could be sufficient to handle a 6 kW column but not the 7.5 kW upper end. While I don’t know the exact inverter ratings, why were fewer larger units not used instead? Has this been done to capture better granular performance data on the HDS arrays within each column?

In last month’s Agenda for the VTA BOARD OF DIRECTORS MEETING, a review of VTA’s SUSTAINABILITY PROGRAM ACCOMPLISHMENTS included a photovoltaic study for a 1.5 MegaWatt system:

In September 2008, completed a solar assessment of the Guadalupe Division and North Yard. Identified that these sites could accommodate a 1.5 MW system at a cost of $12.5 million with a 13 year payback period. VTA is currently evaluating funding options.

Now, at about $8.33 per Watt ($12.5 million / 1.5 MW), this seems quite expensive for a small utility scale photovoltaic power plant. Perhaps this includes additional land preparation and mitigation costs? Sounds like a great candidate project for economic stimulus funds.

VTA’s Sustainability Fact Sheet details the Santa Clara Valley Transportation Authority’s commitment to green activities including solar powered bus stops. I was an occasional rider of the Rapid 522 and Local Line 22 VTA services last summer and fall during my recovery. I learned to wait for the 522 since it would always overtake an earlier 22 bus.

The prototype solar project has not been the leading attraction for San Jose citizens at the VTA Cerone Division. The sheep and goats grazing project has generated more public interest thus far.

©2010 GUNTHER Portfolio. All Rights Reserved.

Finding the concentrating photovoltaic (PV) solar collector.
Skyline Solar CEO Bob MacDonald presenting at Dow Jones Alternative Energy Innovations Spring 2009 next week.

Since posting Skyline Solar Dawn, I’ve been keen on learning more about Skyline Solar’s High Gain Silicon PV solution. Some PV insiders may have followed my cryptic closing comment, The Truth is Out There. As I understand it, the slide below showing the Skyline Solar solution was presented by Doug Rose with SunPower Corporation (NASDAQ:SPWRA, NASDAQ:SPWRB) at the Solar Power International 2008 State-of-the-Art CPV session in violation of an NDA (Non-Disclosure Agreement). [There was no NDA in place, see GP Correction note below.] This slide pegs the Skyline Solar trough concentration at 13x (thirteen times).

From State-of-the-Art CPV by SunPower at Solar Power International 2008

A quick search revealed the headquarters of Skyline Solar, Inc. is not far from downtown Mountain View. The first time I drove past the office building, I didn’t notice anything special. Months later, I decided to pedal by during a bike ride. This was when I first noticed a metal structure in the back lot behind the building. Could it be this easy? I had imagined their prototypes would be on sun at a remote site near Skyline Blvd., on the campus of Skyline College, or perhaps following in the footsteps of SolFocus at PARC (Palo Alto Research Center).

Unobtrusive from the road, the dual trough concentrating solar photovoltaic modules are nestled behind a fence covered with an opaque film and circled with medium sized trees. On my first field trip, I photographed the backside of the PV modules. It was a sunny day, and the units were tracking the sun away from my view point. Later in March, I captured part of the inside trough and the silicon solar cell receivers when the sky was overcast with my Blackberry mobile.

At almost the same instant, four (4) Skyline Solar patent applications were published at both the United States Patent and Trademark Office (USPTO) and WIPO:

USPTO Patent Application 20090056787 March 5, 2009
Concentrating solar collector

USPTO Patent Application 20090056786 March 5, 2009
Photovoltaic receiver

USPTO Patent Application 20090056785 March 5, 2009
DUAL TROUGH CONCENTRATING SOLAR PHOTOVOLTAIC MODULE

USPTO Patent Application 20090056698 March 5, 2009
Solar collector framework

I have not had a chance to review these patents in depth, but here are a few quick observations. Keying on the DUAL TROUGH CONCENTRATING SOLAR PHOTOVOLTAIC MODULE patent, I believe the dual trough arrangement concentrates light from a reflector panel (two per trough) to the opposite photovoltaic receiver. There are four (4) PV receivers per dual trough module. Each dual trough module is mounted on a single-axis tracker.

ALANOD Aluminium-Veredlung GmbH & Co. KG is mentioned as one source for the aluminum strip on the reflector panels using MIRO-SUN® PV for Photovoltaic Applications reflection material. An interesting option provides multiple, redundant layers on the reflector panels which can be removed as they are worn over the presumable twenty (20) plus year product life.

[0044]In one embodiment, each reflector panel 106 may be made of Miro-Sun.RTM. KKSP, made by Alanod of Ennepatal, Germany. The Miro-Sun.RTM. KKSP is a 0.5 mm thick aluminum strip that may have a specialty surface providing over 90% specular reflection over the band in which silicon photovoltaic cells operate. A protective lacquer coating may be applied to the top of the reflector panels 106 to increase abrasion and weather resistance. In another embodiment, the reflector panels 106 may be made of any high reflection material, produced by Alanod or a plurality of other vendors. In still another embodiment, the reflector panel 106 may have a silver coated polymer-based laminate over the aluminum strip. Once the reflective properties of the silver coated laminate are degraded from weather and/or the sunlight, the silver coated laminate may be removed to thereby expose a new reflective layer. This allows the collector 100 to be used for longer periods of time without having to be replaced, easily maintained, and less costly. A reflector panel may have between about 1-5 layers of silver coated laminate.

The design appears to favor about 78mm (3.07 inch) square monocrystalline silicon solar cells while almost every alternative crystalline silicon solar cell technology, process, and shape is claimed possible.

[0070]Each of the plurality of PV or solar cells 406 may be connected electrically in series to form a solar cell string 410. The solar cell string 410 may be formed by any known means such as soldering each solar cell together via interconnect wires 414. Each solar cell 406 may have a cell size of about 78.times.78 mm and may be a square wafer manufactured from a monocrystalline silicon boule. Alternatively, the solar cell may be any type of known solar cell such as multi-crystalline, single-crystalline, rear contact, emitter wrap-through, LGBC (laser grooved buried contact), PERL (passivated emitter with rear laterally diffused cell), multi-junction, silicon ribbon, thin film PV cells, and the like. Although each solar cell 406 is illustrated as a square, the shape of the solar cell 406 is not intended to be limiting as any shape may be used such as a rectangle, square with one or more rounded or truncated comers, hexagon, and the like.

With series cell resistance a concern in the concentration application, Day4 Energy Inc. solar cells with the Day4 Electrode inter-connection are one potential source. For back contact monocrystalline cells, SunPower would rank as a favored supplier if the smaller cell size is manufacturable, and they elect to service a cell customer.

[0071]The plurality of solar cells may be modified such that they have a lower series resistance when electrically connected. In one embodiment, the back surface field strength of the solar cell may be increased and the top-surface conductive grid may be thickened or increased in number to reduce the series resistance in traditional non rear-contact solar cells. In another embodiment, for rear contact PV cells, the back metallization of the solar cells may be thickened.

Each photovoltaic receiver has twenty-four (24) series connected silicon solar cells.

[0072]Each solar cell 406 may be positioned with a small gap between each other to allow room for electrical connections, differential thermal expansion, and mechanical tolerances. A single solar receiver 400 may have any number of solar cells 406 to form a cell string. In one embodiment, one solar receiver 400 may have about twenty four solar cells 406 and may be electrically connected in series, parallel, or any combination. Each solar cell 406 when illuminated may generate approximately 1/2 volt. Thus, if all cells are connected in series the single solar receiver 400 may generate a total of 12 volts.

In addition to the above, the intricate heatsink design and simplified tracking arrangement appear novel.

The City of San Jose mentioned Skyline Solar as a possible contender for solar demonstration projects in “San Jose explores solar energy farms” by Lisa Sibley for the Silicon Valley / San Jose Business Journal.

Skyline Solar is among the Presenting Companies at the Dow Jones Alternative Energy Innovations Spring 2009 event from April 21-22, 2009, in Redwood City, California USA. It would appear Skyline Solar CEO Bob MacDonald is prepared to tell =all= regarding development schedules, business plans, and funding requirements to prospective investors next week.

Curious that Skyline Solar opted out of commenting on this post.

I don’t think today’s press release by GreenVolts, “GreenVolts Appoints Executive Chairman” elevating Bob Cart to Executive Chairman invalidates my post, “GreenVolts Jolts Concentrating PhotoVoltaic (CPV) Business Plans”. How actual events unfold over the next few months will tell the tale. Please see “GreenVolts Replaces CEO Bob Cart” at Greentech Media for their take.

GP Correction: Neither SunPower Corporation nor Doug Rose was under NDA with Skyline Solar at the time of the presentation. The Skyline Solar slide had been presented in public before, and the dual trough concentrator module photo was later removed upon Skyline Solar’s request.

©2010 GUNTHER Portfolio. All Rights Reserved.

[San Francisco, California USA]

Skyline Solar CEO Bob MacDonald presents at PHOTON’s 1st PV Start-up Conference.

Stealth mode Skyline Solar, Inc. presented Tuesday, December 2, 2008, on the first day of PHOTON‘s Searching for the »Second Solar« Conference Series USA. Mr. MacDonald provided a big picture view of Skyline Solar’s plans to accelerate the time to residential and wholesale grid parity by leveraging aluminum to replace silicon though concentration and tracking. Using the above photo, Skyline Solar teased attendees with tantalizing glimpses of their patented though confidential High Gain Silicon PV (Photovoltaic) solution.

High Gain Silicon PV targets commercial and utility scale solar applications ranging from 100 kW (kiloWatts) to 100 MW (MegaWatts) overlapping the high end of crystalline silicon PV and the low end of CSP (Concentrating Solar Power). In addition, it would appear to address a wider range of climates and solar insolations than competing HCPV (High Concentration PhotoVoltaic) solutions.

Skyline Solar seeks to leverage PV industry investments in crystalline silicon solar cell development and combine them with reflective optics and aluminum to create a cost reduced class of tracked system concentration technologies.

As an example, Mr. MacDonald cited the application of reflective materials used for high efficiency lighting and solar thermal to PV. These materials are already in high volume roll to roll production with 10 GW (GigaWatt) annual capacity.

About the system architecture, CEO MacDonald said:

What we are developing is a linear concentrator at the core. It’s a quite straight forward design that takes a reflective optical sheet and forms it into a parabolic section that focuses the light onto a straight line. Along that line you put your linear module. So, it’s essentially a silicon module that’s enclosed by an aluminum reflector.

Among the benefits are complete low end to end cost including simple manufacturability, low cost shipping, efficient installation, capital efficiency, and 20+ year reliability while maximizing generated kilowatt-hours of electricity per silicon solar cell. Challenges of this approach include losing some percentage of the diffuse component of sunlight balanced against the optical structures and thermal management for specific applications and climates.

Regarding the concentration ratio of the High Gain PV solution, Bob MacDonald said:

So we can design that anywhere from 5 to 50x concentration. Of course, we can have very long conversations is that geometric, optic, or peak concentration, but at this stage, we are not yet going into those details.

See the above Picasa slideshow for a photo and Skyline Solar slides.

Skyline Solar was selected by the U.S. Department of Energy (DOE) for the Solar Energy Technologies Program Photovoltaic Technology Incubator Selections as part of the Solar America Initiative – Technology Development. On September 29, 2008, DOE to Provide Up to $17.6 Million for Solar Photovoltaic Technology Development included:

Skyline Solar (Mountain View, Calif.) has developed an integrated lightweight, single-axis tracked system that has been demonstrated to reflect and concentrate sunlight over 10X onto silicon cells. The use of mirrors to concentrate light will reduce the use of the greatest cost driver for traditional silicon modules, the solar cells, by over 90%.  Additionally, the design leverages the mainstream PV industrial base and amplifies its capacity through significant concentration to enable rapid scaling. It seeks to dramatically lower the cost to manufacture modules and install complete systems to achieve a levelized cost of energy below grid parity. By the end of this project, Skyline plans to deliver modules that exceed 12m2 area and 15 percent aperture-area efficiency.  (Up to $3 million)

Per the “VC Rumor Mill: Skyline Solar Funding and More” by Eric Wesoff at the Greentech Media Green Light Blog, Skyline Solar has reportedly closed a $25 million round from New Enterprise Associates.

Later during the panel discussion, Bob MacDonald said:

The First Solar of concentration hasn’t yet happened, and I think we are just right on the precipice of that.

SolFocus, Inc. might differ with that observation after “SolFocus and EMPE Solar Sign $103 Million Deal for 10+MW UtilityScale Project” (Ed. Note: this should be projects), yet it is still early in the development of the CPV market.

For further PHOTON’s 1st PV Start-up Conference coverage, please see “First Solar president at PHOTON’s Start-up Conference: »Second solar is upon us«” by Garrett Hering.

The Truth is Out There.

©2010 GUNTHER Portfolio. All Rights Reserved.