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XeroCoat’s antireflective material might add zeros to the bottom line, megawatts to the power line

28 July 2008 | By Tom Cheyney | Chip Shots

Anyone who's been driving yield enhancement in a chip fab, conversion efficiencies in solar cells and modules or productivity improvements in either sector knows that a few percent here, a few percent there can add up to millions of dollars in savings or improved bottom-line margins.

A few years ago Michael Harvey, Paul Meredith and a team of researchers at the University of Queensland in Australia discovered a relatively inexpensive, single-layer, liquid antireflective coating (ARC) that could be deposited on the glass superstrate of a photovoltaic panel and permit about 99% of the sun's rays to reach the cell. Those few percentage points of reduced reflectivity and increased light transmission could mean added power output from the solar unit--and significant savings to the module manufacturer and increased revenues and energy returns to the system operator.

XeroCoat's Hood believes less reflectivity
could lead to more profitability.

The fruits of these Aussie labors have been commercialized in start-up form in XeroCoat, now headquartered in Redwood City, CA. Cofounder Harvey has become CTO of the new venture, and solar materials/optical coating industry veteran Tom Hood has come on board as president and CEO. A Series B funding round that closed earlier this month pulled in $6.75 million, and the company has a PhD-rich staff of 25 at its 25,000 square-foot applications facility as well as a small R&D group led by other cofounder and now-VP of materials development Meredith back in Brisbane (Australia, not the town up the peninsula from company HQ).

During our meeting at Intersolar North America, Hood said that an estimated 400 MW of light was lost due to reflection off of modules last year. This represents an ARC market opportunity in the $1 billion range by 2013, especially since less than 5% of the market now uses such coatings. The XeroCoat folks believe that their high-performance ARC has applications across all solar platforms, "anywhere that reflection causes loss," according to Hood.

Given the wide range of coatings already available in different low- and high-end markets, why hasn't something like this been done before? Apparently, nothing with the kind of durability, low cost, and high transmission properties has come along, especially something like the full-spectrum X coat that can be applied at room-temperature in atmospheric (nonvacuum) conditions, with a noncomplicated curing process. Harvey explained that the new porous silicon-oxide material (~100 nm thick, +/- 5% uniformity) also integrates well with existing processes.

The stats presented by Hood and Harvey are compelling. On a bright sunny day at noon, about 4% of the solar energy is lost to reflection. Slap on that single layer of XeroCoat's ARC and all but 1% of that lost PV potential input is recaptured. For the other (AM and PM) times of the day, the angle of incidence changes, the amount of reflection increases as does the amount of lost energy, something that the new coating can be tuned for, leading to even higher percentage gains (about 6%) in energy capture--or as much as 4% in previously untapped kilowatt-hours.

Transmittance is not futile, according to XeroCoat's data.

If you take that noontime net gain of 3% and run the numbers, it translates into serious improvements on the module and system side, according to the XeroCoat crew. A 230-watt-peak module treated with a layer of the X coat will see a 3% rise in output, becoming in effect a 237-Wp unit. For every 100 MW of modules, that means somewhere between a $4.5 million and $8.5 million pop in profit, Hood explained.

On the system side, since fewer modules are needed for project, the BOS costs are less and the amount of revenue rises--a classic more-bang-for-the-buck (or less bucks, or Euro, or RMB) scenario. The company exec said that in the case of a 10-MW solar PV farm in Spain, using the X coating would result in 3000 fewer modules being needed for the installation.

XeroCoat's biz dev strategy involves a flexible, customer-centric approach. After fitting out its development line in California with what Hood called "components and tools that look like production equipment" that can handle 1 x 1-1/2 meter glass panels for customer testing and qualification (the first evaluations are under way), the company expects to know what a real manufacturing line will look like. It will then order tools for its first line or lines in Q109, which will be built near customers in Europe and/or China.

The other option will be to integrate XeroCoat deposition tools inside the module factories themselves under private-label licensing agreements, adding the ARC to the panels before they go out the door. Whether supplying to the module makers or being incorporated into their process flows, Hood said the key is to be close geographically to the customers.

As for those hoped-for customers, Hood pointed out that the X coating is "technology agnostic" and could be applied to crystalline silicon, thin film, and concentrating PV optical surfaces as well as most of those shiny parabolas on thermal systems as well.

Nothing like your product having a shot at penetrating just about the entire market range of solar energy solutions to give a start-up's employees and investors real optimism for a profitable outcome.