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Tangled up in Bloo (Solar): Start-up believes 3-D PV has a commercial not-too-distant future
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In case you’ve been asleep and not checking on the progress made in the research community, here’s a news flash: nanotechnology will be one of the key enablers of the next (AKA third, fourth) generation(s) of photovoltaic cells and modules. Whether done in a solution/print processing in atmospheric conditions, a more standard vacuum process, or some sort of sci-fi scenario to be deciphered later, the scaling down of materials could quite possibly lead to the scaling up of efficiencies, at costs competitive with or better than what the first- and second-gen PV crowd can muster. At least that’s how the argument goes for many of what I like to call the “nano-whatsits” crowd.
One such nano-enabled start-up with a funny name has recently re-emerged from quasi-stealth mode with medium-term time-to-market ambitions—Bloo Solar.
The West Sacramento, CA-based company has been around for about five years, started up initially by a trio of UC Davis professors under the name Q1 NanoSystems. The technology did not spin out of any university work per se, but was developed by Ruxandra Vidu and brothers John and Brian Argo, the latter two pushing the nascent nanotech in a photovoltaic direction, according to Larry Bawden, who came on board as CEO about two years ago.
The company calls its secret sauce technology by the name “Solar Brush.” These “nanocables” are three-dimensional needle-like structures, coated with ultrathin films, grown on substrates in numbers that Bawden characterized as in the “zillions.” (See accompanying images) The Bloo crew uses electroplating as the key enabling process technology, an electrochemical/electrolytic method akin to the copper deposition process used in the interconnect sequence in semiconductor manufacturing.
These billions of bristles are oriented in aspect ratios between 6:1 and 9:1 because that works best “for a whole host of performance and producibility reasons,” the CEO explained during our phone chat. The resulting microarray has significantly more light-trapping surface area per meter of surface and potentially vastly more energy conversion than conventional planar PV, according to Bloo. Because the high-purity films are supposedly defect-free, the likelihood of deleterious recombination effects is minimized.
Bawden wouldn’t divulge the precise dimensions or composition of the films or the specifics of just how much conversion efficiency can be squeezed out of the cells (although a presentation he shared put the theoretical single-junction cell number at 44%). He did point out that the power distribution from a PV system with Bloo-style modules would chart out in an “umbrella-shaped curve” over the course of the day, much like the performance of a concentrator PV or monocrystalline-silicon-based tracking system. 
“What we like to say is, it’s like a two-axis tracker, without any moving parts,” because of the enhanced light trapping of those photon-loving nanocables, he quipped. As a result, the company’s projected levelized cost of energy numbers are well under a dime per kilowatt-hour.
As with many self-respecting nanotech firms, several patents flow in the pipeline, both in the U.S. and internationally, but Bawden stayed pretty tight-lipped about any details there for obvious reasons.
After a flurry of hiccups in its path to commercialization caused by the macroeconomically induced funding crunch and ironing out some process development issues, the company is all about accelerating its time-to-market gameplan, with a roadmap for starting up a prototyping pilot line by 2012.
With more than $3 million in Series A funds still keeping things hopping through the first half of 2010, Bawden told me he is busy talking with investors and potential partners in hopes of getting a Series B closed later this year.
The latest step-change comes in Bloo’s relationship with SVTC, the development foundry that specializes in taking proof-of-concept technologies, turning them into working devices, and readying them for production and entrée into the commercial sphere. Although better known in the semiconductor, MEMS, and biotech arenas, SVTC has done quite a lot with PV companies and even started up a separate solar unit.
The boys at Bloo started talking with SVTC about a year ago, according to Bawden. The conversations became more serious during the summer and then got real serious during the fourth quarter of the year.
He called SVTC, “a good group to work with, very professional, they’ve met pretty much all of our expectations and have pushed the schedule ahead in several areas.” Much of the past quarter has been focused on small device testing. “We’ve been getting great results versus the benchmarks we had going in.” 
For now, Bloo’s work is taking place at SVTC’s Fab 1, not at its dedicated solar facility. Bawden (pictured at left) said that moving to the PV line has been under discussion but the startup wouldn’t “pull the trigger” on that until the Series B funds roll in.
The nanobrush PV devices will be processed using 200mm silicon wafers as carrier substrates, although silicon will not be the ultimate material—glass, nickel, aluminum, or some blend have been investigated--for the rigid (no flex at first) 156mm square PV cells envisioned for commercial use.
“Originally we’re building centimeter by centimeter square cells, so this SVTC platform will allow us to get to 8-in. within three months,” he explained. “We’re still testing on smaller sizes, doing a bunch of design of experiments because we can get through characterization quickly. The platform works, and the manufacturing processes are being defined and demonstrated, and we’re ordering a production tool.”
Other partners include First Nano (which has a workspace at SVTC) and EAG, “which does a lot of SEMs and TEMs for us, and makes cross-sections so we can correlate deposition processes with results we’re looking for. We’ve got a couple of custom tool guys doing some work for us on process development, with more announcements on partnerships coming later this quarter,” Bawden shared.
If all goes well with the SVTC arrangement and the Series B funding round succeeds, the timeline for commercialization goes from that 2012 pilot line to the first production-scale facility starting build-out later that year.
As for the size of the proposed manufacturing line, the Bloo man said that “the number we want to optimize around is 50MW, modulized, and be able to replicate that, once we get the yields up and everything done. Most of our decisions lean on the low-risk approach, then we can incrementally grow.”
Since it will soon outgrow its current location and will be hiring a lot of new personnel over the next few quarters, the site selection process is already in progress. Commenting that he had plans for two large sites in front of him as we were talking on the phone, Bawden said that the company expects to find a larger facility in the greater Sacramento area by June.
Although the company originally saw itself as a solar module manufacturer, Bloo’s wazoo revealed somewhat cryptically that “we are having a couple of discussions that are turning out very interesting, that might take us off that a little way. That’s all I can say.”
But what he will say is, at the end of the day, any decision to license/outsource/joint venture/et al. must meet what he called Bloo Solar’s “criteria of choice—time to market.”
This is one third-generation solar company that doesn’t want to wait a generation to get its innovative nano-PV product into the commercial space.
PHOTOS COURTESY OF BLOO SOLAR
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