Silicon accounts for about 20 percent to 25 percent of the cost of a PV module. If vendors can put a dent in that cost by reducing the amount of silicon used with Twin Creeks equipment-built thin silicon cells, solar manufacturing could once again become a profitable business.

These days, solar panels sell for less than a dollar per watt, and the cost is rapidly approaching $ 0.80 per watt. This is great news for consumers and installers.

But the problem is that the manufacturing cost is also in the neighborhood of $ 0.80 per watt. And that means no manufacturer of solar panels is making money. Just look at the recent earnings reports from Suntech or SunPower.

Without some change in the manufacturing cost structure, the crystalline silicon module business will remain a graveyard.

So perhaps Twin Creeks just might have that disruptive piece that can bring module makers like Suntech, SunPower, Trina, Yingli, or JA Solar back into the black.

Why Thin Silicon?

Current silicon wafer thickness is in the 150-micron range. Traditionally, wafers are freed from blocks of silicon using wire saws in a process that is messy, complex and reaching its limits. The wire saws use silicon carbide as an abrasive in the slurry and it’s difficult to reclaim the lost materials from the resulting sawdust-SiC mix. There is a cost to the lost materials as well as the spent wires themselves. As manufacturers push the limit of wafer thickness, they are resorting to even more expensive methods like diamond wire saws.

It’s an obvious weak link and cost target in the solar value chain. Manufacturers spend a great deal of time and energy to fabricate blocks of polysilicon, only to see up to half of that hard-earned material turned into sawdust in the wafer production step.

In fact, according to Twin Creek’s CEO Siva Sivaram, you only need wafers that are 20 to 30 microns thick to get the charge carrier out while still getting good conversion efficiencies.

Twin Creeks allows vendors to dispense with saws, furnaces, and cell finishing equipment from the likes of Applied Materials HCT and Meyer Burger as well as slurry and thick wafers. Twin Creeks replaces that production chain with a beast of an ion implant machine (see picture below).

Ion Implantation

Twin Creek’s process is known as PIE, for Proton-Induced Exfoliation. A hydrogen ion or proton is accelerated to 1.2 million electron-volts and shot into a crystal material — in this case, silicon — where it settles at a finite depth. The hydrogen ions line up at that finite depth, where they are then heated, resulting in a wafer that cleaves right off the substrate along the crystalline plane.

The proton energy determines how deep the protons go and therefore sets the thickness of the wafer.

An ion implanter is a big piece of equipment emitting protons and must be shielded for safety. Other firms performing this process have told GTM that surface roughness is better than sawn wafers, and some use an etch-and-anneal step to preserve lifetime once the wafers are cleaved.

The ion implant process produces a wafer which uses a tenth of the material, and 20-micron wafers don’t crack, according to the Twin Creeks CEO who said, “At 20 microns, silicon is completely flexible.”

The firm can provide a reference process for handling the unusually thin wafers. Each machine can produce 1.5 million wafers per year. That means a firm with hundred of megawatts of c-Si capacity would have to buy scores of these multi-million-dollar machines if electing to make this disruptive shift.

Twin Creek’s CEO Siva Sivaram told GTM, “We are a capital equipment company and will remain a capital equipment company. San Jose is where we integrate, Boston is where the equipment is designed and built, and Mississippi is where we demo the process on a 25-megawatt cell line. There has been no marketing and there is one sales guy. We are talking now because we have a product ready to ship along with 20 issued patents and a pile on the way.”

Other firms in the thin silicon business:

Ampulse claims that the firm’s “c-Si thin-film technology takes advantage of HW-CVD techniques to directly deposit a very thin layer of c-Si onto a uniquely textured and flexible metal substrate.”

As reported by Ed Gunther, AstroWatt has developed a semiconductor-on-metal technology for creating thin silicon wafers. Gunther reports, “After partial processing, a monocrystalline silicon wafer is attached to an inexpensive, flexible 50-um metal foil also acting as the solar cell’s rear contact. Next, the foil, along with about 25 um of silicon, is exfoliated using a cleaving process.” By reusing a 600-um wafer for multiple exfoliations, AstroWatt claims “up to 4X reduction in substrate cost” is possible, and the metal substrate is crucial for wafer handling in existing equipment.” AstroWatt also stated the theoretical peak silicon solar cell efficiency can be achieved with a 25-um silicon wafer thickness.

Bandgap Engineering has developed tunable methods for nano-structuring silicon. The firm claims that the absorption of nano-silicon is enhanced by up to several orders of magnitude over bare silicon over a wide range of wavelengths. This enables nano-silicon to absorb the light in the first four microns versus the top 50 to 100 microns that bulk silicon needs to absorb most of the light.  This could impact cell efficiency and direct manufacturing cost — and make for much thinner wafers.

Crystal Solar uses a vapor deposition process for making thin crystalline silicon wafers.  The firm has made wafers measuring 50 microns thick in its labs and hopes to get down to 20 microns.

1366 Technologies has a “direct wafer” technology whereby molten silicon is directly converted into wafers, which can then be processed into thin solar cells.

Silicon Genesis, known as SiGen, is also pursuing an implant-and-cleave process for wafers with thicknesses down to 20 microns.

A Disruptive Process

Backing an equipment vendor is an unorthodox approach to solar startup technology and solar venture capital in the current solar era. But certainly the billions of VC sunk into building module companies hasn’t worked out very well (see Solyndra, Nanosolar, etc.) — so equipment could be a better avenue to success.

Twin Creeks is bringing a large piece of new disruptive equipment to the current established c-Si solar manufacturing flow. If the firm can show a cost and performance benefit, there is a chance for adoption. However, capital equipment like this has a very long sales cycle and a limited number of customers.

Twin Creeks offers a disruptive change in the way solar module manufacturers make wafers and cells and threatens the way things have been typically been done. But that’s what entrepreneurs do, and that’s what venture capital is supposed to do. And this is an audacious and potentially disruptive bet by some brave entrepreneurs and investors. The solar industry could use the disruption.

Twin Creeks has raised more than $ 80 million from Crosslink Capital, Benchmark Capital, Artis, and DAG Ventures.

Go Green

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A record-setting third quarter is in the books, with the U.S. installing 449 megawatts of PV, more than the U.S. installed in all of 2009. The total solar installed this year in the U.S. is already over one gigawatt, according to a recent report by SEIA® and GTM Research. The 2010 U.S. total was 887 megawatts.

And installations in the fourth quarter are predicted to be an even larger figure.

The U.S. solar energy industry continues to be one of the fastest-growing sectors of the American economy in 2011. In total, cumulative grid-connected solar electric installations have reached more than 3 gigawatts — enough to power nearly 600,000 U.S. homes.

The growth in the third quarter of 2011 is due to “utility-scale project completions, a strong residential market, effective policies and the plummeting price of solar panels” according to the report.

 
So, why the long face?

Well, in addition to the good news from the SEIA and GTM Research, the report cautions that “the U.S. solar market faces substantial market uncertainty with financing and political risks, including the looming expiration of Section 1603 Treasury Program.”

The Department of Treasury’s 1603 program, the tax grant program, is due to expire on Dec. 31 unless Congress extends it. In the absence of an extension of the program, the report predicts that “there will be a tax equity bottleneck for projects in 2012, leading to a possible slowdown in installations in late 2012 and into 2013.”

According to Rhone Resch, President and CEO of SEIA, “The 1603 program has done more to expand the use of renewable energy than any other policy in U.S. history.”

The report finds that “[w]ith the 1603 Treasury Program scheduled to expire at the end of this year, solar project developers will be scrambling to either complete, or safe harbor, projects in the fourth quarter of 2011 in order to qualify for the program’s grant. This will undoubtedly produce robust installation numbers through the end of 2011. However, the uncertainty surrounding the program’s extension threatens the market’s growth in 2012 and beyond.”

The other looming threat to the progress of solar installation in the U.S. is the trade petition against Chinese solar imports, which will have an uncertain impact on the market if duties are ultimately levied.

Go Green

We get quite a few magazines at our house. My husband subscribes to a couple of gaming magazines, and somehow every time we buy concert tickets we end up receiving issues of Rolling Stone in the mail. Couple that with other glossy mailings, like junk mail and catalogs, and we’ve got quite the collection of magazine paper.

Rather than tossing all of those trees immediately into the recycle bin, you can give them a brand new life.

1. Turn an old magazine into a recycled plant stand.

2. Make some recycled magazine boxes to store your knick knacks.

3. Turn them into recycled gift bows for birthday or holiday presents.

4. Fold the pages into origami.

5. Wrap small gifts in the pages.

6. Make recycled paper beads (video).

7. Whip up a bouquet of recycled magazine page flowers.

Image Credit: Creative Commons photo by theseanster93

Maintaining a healthy gut isn’t as easy as popping a magic pill. “If you’re going to use probiotics, then drink, smoke and eat badly, that’s not going to cut it,” says Georgianna Donadio, PhD, nutritionist and founder of the National Institute of Whole Health. “The entire system must be in sync; the flora is just the tip of the iceberg.”

To take a big-picture approach to your gut, consider these steps:

• Eat several small meals during the day instead of pigging out at dinner. “Cramming in all your food at the end of the day stresses the gut by giving it too much food at once,” says Leslie Bonci, a registered dietitian and director of the Sports Nutrition Center at the University of Pittsburgh. And don’t forget to drink plenty of water to keep the
food moving.

• Prioritize whole foods. That means stocking up on vegetables, fruits, nuts and legumes. If the food on your plate looks like food in the wild (e.g., grapes, not grape roll-ups), you’re off to a good start.

• Eat probiotic foods. Shoot for at least one daily serving of a food with probiotic or “live” cultures. Try yogurt, kefir (a fermented dairy drink), miso or tempeh. Look for the phrase “contains live cultures” or “active cultures” on the label.

• Bulk up on fiber. The more fiber you have in your diet, the more diversity you’ll have in your ecosystem. Aim for 25 to 38 grams of fiber a day, says Bonci. “Most people are still shy of their fiber intake.”

• Cut back on sugar. Refined sugars acidify the system and prompt the body to make more bile — and some types of bad bacteria feast on sugar and bile acids. Therefore, too much sugar may tip the bacterial balance toward the dark side. “With all the sugar we throw down these days, it’s no wonder our bacteria colonies are out of whack,” says Bonci.

Seven Ways to Tame Your Sweet Tooth

• Relax. In a 1999 study published in the international journal Gut, people in gastrointestinal clinics cited severe life stress as a precursor to their gastrointestinal problems. Although the connection isn’t clear, scientists do know that stress breeds inflammation and also upsets the parasympathetic nervous system, which controls the contractions of the intestine, thereby changing the speed at which food moves through you. Stress affects our biochemistry at many levels.

• Get seven to eight hours of sleep every night. Sleep not only regulates hormones in the gut that contribute to feelings of hunger and satiety, it also shores up the immune system. When the body is deprived of sleep, even for one night, the immune system suffers, says Bonci.

Like tending a vegetable patch, maintaining a balanced microflora environment requires daily attention. Need more good reasons to give your bacteria the respect they deserve? Consider this: “If a freeze, flood or nuclear explosion destroyed all the humans on Earth, bacteria would survive,” says Gregor Reid, PhD. “They are definitely going to have the last laugh.”

Related:

• 10 Benefits and Uses for Miso
• Eating Animalcules

A new study done by an engineering professor at Stanford University has found that the energy efficiency of computers doubles roughly every 18 months, and has done so since the very first general purpose computer, the Electronic Numerical Integrator and Computer (ENIAC) that was built in 1956.

With help from Intel and Microsoft, Professor Jonathan Koomey was able to gather information about computing devices from 1956 until now and with this new finding, Koomey is revising and improving Moore’s law — the observation that computer processing power doubles every 18 months.  Fortunately, the things that contribute to that power improvement (reducing component size, capacitance and communication time between them) also increase energy efficiency.

This finding has great implications for the future of computers and battery-powered devices.  As we constantly increase the performance power of computers and gadgets, we’ll be improving their energy efficiency as well — a much needed trend as we become more reliant on our portable devices.

Also, theoretically, we’re far from the limit of how much electricity we can save.  In 1985, physicists projected that we could improve computer energy efficiency by a factor of 100 billion and since then we’ve only hit a factor of about 40,000.

via MIT Tech Review

Austin Hay is still in high school, but he’s building his own house. It’s only 130 square feet, but it makes him a homeowner without a mortgage at just 16 years old.

Right now, it’s in his parents’ backyard, but he’s built it on wheels so he plans to take it to college and then wherever he goes after he graduates.

Moving out at 16

He’s been sleeping in his tiny home for a few months now and he’s already decided not to return to big (his parents’ home is 1800 square feet). “Living small means less bills, living big means more bills. I don’t want to pay big bills,” he explained from the tiny stoop of his new home.

Hay’s 130-square-foot home may make him the youngest member of the growing Small House Movement. Perhaps not coincidentally, Hay has spent his childhood at one of the movement’s epicenters (See Land of Tiny Home People).

From the land of the Tiny Home People

In his county (Sonoma), there are at least three tiny homebuilding companies (not to mention the independents), as well as the founder of the Tiny House Blog and the country’s biggest Tiny Home star Jay Shafer. Shafer, owns Tumbleweed Tiny House Company, has been something of a role model. Take a tour of Jay’s 96 square foot house here.

Before breaking ground, Hay attended one of Shafer’s monthly tiny open house tours and Shafer gave plans to build his home (it’s a Fencl design like the one Shafer lived in for years).

A $ 12,000 home

Hay expects to spend about $ 12,000 building his home (the used trailer cost him $ 2000) and he’s paying for it working two summer jobs (at a camp and at a park snack bar). He’s cut his costs in half (the home’s estimated DIY price is $ 23,000) Though this is a considerable discount from the home’s estimated price of $ 23,000 because Hay has scavenged everything from doors, windows and flooring to the kitchen sink (the hardwood floors were $ 25 at a salvage yard and so was the stainless steel sink).

Tiny construction waste

Like most in the Small House Movement, cost isn’t Hay’s only concern. He’s also aware the tiny homes consume less heat/AC/building materials and so leave a lighter environmental footprint. To make the point, he’s been collecting all of his building waste and after nearly a year of building, he only has two half-filled garbage cans filled with items he couldn’t recycle.

With a little help from Santa

In this video, Hay shows us his tiny home, his handiwork, the salvaged bits and where he hopes to put all his furniture and appliances (including the camping oven that was a gift from “Santa”).

More from ecomii:

• Scroll Through Some of the World’s Coolest Microhomes
• Can Diet Sodas Make You Fat?
• Meatless Monday: So Hot Right Now
• Food Fast Not Fast Food
• Best Grill Tips This Summer

The investment is going to BrightSource Energy, a company that develops and operates large-scale solar power plants, specifically to fund its Ivanpah project.

Ivanpah is a solar electric generating system that uses solar thermal technology and “an environmentally responsible design,” to deliver reliable, clean and low-cost power to Californians, according to the project’s website.

The plant will generate energy with a technology called power towers. Mirrors, called heliostats, are arranged in an array and aim the sun’s rays at a receiver atop a tower. The receiver generates steam; the steam causes a turbine to rotate; the rotation causes a generator to generate electricity. Because such large quantities of solar energy are being directed to such a small area, the power towers are very efficient.

The power tower at Ivanpah will be around 450 feet tall. The plant will use 173,000 heliostats, and each heliostat will have two mirrors, making Ivanpah the largest project of its kind.

Construction at Ivanpah should be completed in 2013. Here’s a video from the plant’s groundbreaking ceremony:

Google’s been on something of a clean energy investment kick over the past year or so. The company was granted the ability to buy and sell energy as a public utility last February, ostensibly to find better ways to power its own massive data centers.

A short time later, Google began making significant investments in green energy technologies. The company sealed a $38 million wind farm investment in May, bought 20 years’ worth of wind farm energy in July and provided a substantial investment for a huge offshore wind farm in October.

Rick Needham is Google’s Director of Green Business Operations. On the company blog, he writes, “We hope that investing in Ivanpah spurs continued development and deployment of this promising technology while encouraging other companies to make similar investments in renewable energy.”