From time to time the National Renewal Energy Lab (NREL) reminds us that the US used to be a leader in innovation. This time it’s in the area of solar thin film technology. The goal with solar thin film technology is to surpass the efficiency level of silicon solar cells. Efficiency refers to the rate at which sunlight falling on a solar cell is converted to electricity. Silicon has been the most efficient material, but it is is expensive and limited, so the world is seeking alternatives. (Picture above from the Dept. of Energy shows thin film manufactured by Iowa Thin Film Technologies.)

NREL has set a new world record using CIGS (copper indium gallium diselenide) thin film, which in tests has reached 19.9 percent efficiency, coming very close to the 20.3 percent level of multicrystalline solar cells.
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If solar panels cost $1/watt, you can sell them (installation included) for $2/watt. Coal (installation included) costs $2.10/watt. To date, solar is still reaching to compete with coal, but the margins are closing. To (over)simplify how this works, you need to ignore issues like subsidies, qualitative costs, or kinks in the supply chain, and boil it down to money. Two hurtles that must be jumped before photo voltaic solar cells become cheaper than coal: efficiency and production cost. Fortunately the solar industry has already made important gains in both. Today, we’re going to talk about two types of solar panels: silicon and thin-film, and solar’s quest for $1/watt. (more…)

What if you could produce clean solar energy night and day, rain or shine, and never hit the bank for a single P.V. solar panel? Photo voltaic panels can be pricey, so the solar industry is always trying to lower costs and boost efficiency in the quest to compete with coal. One fast-growing, cost-effective solar technology uses heat to generate energy 24 hours a day, and it can store energy without batteries. In this post I’m going to investigate solar-thermal technologies.

It’s called “Concentrated Solar Power” or C.S.P. The idea is simple; no complex chemistry or fancy silicon wafers required. Glorified mirrors shaped like satellite dishes (or parabolic troughs) direct the sun’s rays towards a reservoir. The concentrated solar heat boils water into steam, and steam powers a turbine. When the water cools off it’s collected and cycled back through the system. The mirrors can even track the sun across the sky to maximize efficiency. Water is not the only fluid that can be used, but its unique properties have made it popular. More on that below. (more…)

Interview: Dr. W.S. Sampath at CSU has developed new “thin film” solar technology

Thin film has been the holy grail of solar technology: everyone is seeking it, but so far its market penetration is well under 5%, and its use in large-area applications, such as for solar photovoltaic (PV) modules large enough to power buildings, has barely developed. (Thin film light absorbers are about 1 micron thick and are less costly to produce, as compared to the silicon found in traditional solar PV modules, which at around 200 microns thick is still thinner than a human hair.)

So I was very interested to hear that Dr. W. S. Sampath, professor of mechanical engineering at Colorado State University (CSU), has developed a new, more streamlined production process that promises to reduce the cost of thin film even more. The company bringing his product to market is AVA Solar, who received a $3 million solar incubator grant from the U.S. Department of Energy’s Solar America Initiative. I spoke to Dr. Sampath by telephone on Friday, and asked him how his technology is different from that of First Solar, currently the market leader.

“The difference is in the manufacturing process. It is much more streamlined and integrated, with fewer production steps, which brings down the manufacturing cost.” Dr. Sampath was careful to note that AVA Solar worked in collaboration with First Solar in developing the production process. “There is a huge demand, so it makes sense to work together.” In other words, when the world is beating a path to your door for a better solar mousetrap, it pays to be open and collaborate to achieve faster, better and cheaper solutions, so as to grow the market much faster. (more…)

When we think about “clean” energy, we envision big, dark solar panels out in a field or on a roof. Or maybe wind turbines with those big whooshing propellers. What we don’t often think about are the other components that make solar panels and other technologies possible and practical for everyday use.

One very important component of these systems is the inverter. Inverters make it possible to hook your solar panels (or other energy dynamo) into batteries, your electrical system, and/or feed electricity back into the grid. An inverter’s most important task is to convert D.C. (direct current) electricity into A.C. (alternating current). In case you’ve forgotten your high school chemistry, A.C. is all the rage with the power company. Depending on the type of inverter you buy, they can pump all the excess electricity you produce into batteries or back into the power grid. And yes, the power company will pay you for the energy you send them. (more…)

John Sedgwick is the Co-founder and Vice President of Solaicx, a company that manufactures silicon ingots and wafers for solar electric (PV) panels. They are then supplied to solar panel manufacturers across the globe.

Solaicx began production at their new manufacturing plant in Portland, Oregon at the end of 2007. While current capacity of the plant is 40 MW, production will increase to 180 MW in the future.

CleanTechnica: What kinds of general trends have you seen in the solar industry as a whole?

John Sedgwick: The general objective of the entire industry is to reduce costs. What we see in markets across the world is, as you lower the levelized costs of solar electricity down to the levelized cost of traditional electricity, the markets just go vertical. When you look over time, the industry is doing dramatically well at reducing costs.That’s even when you take into account some significant challenges, things like polysilicon shortages and other shortages that have popped up as a direct result of a market that has been growing at 35%, 40%, and 50% a year have caused shortages that have increased some costs in the chain. Yet, because of manufacturing efficiencies, conversion efficiencies, and economies of scale, the industry has been able to hold the line on any cost increases and has done pretty well at reducing costs. (more…)

Thin film solar technology has attracted interest from venture capitalists because of its higher efficiency, lower use of limited silicon, and more easily automated production processes. Now, established Japanese players in the solar arena are getting in the thin film game, followed by companies in China and India, as reported in Renewable Energy World.

• Mitsubishi Chemical already produces materials for the solar industry but sees opportunity to produce the cells themselves
• Sanyo is an established producer of crystalline solar cells, but has opened an Advanced PV Development Center in Gifu, Japan to concentrate on developing thin film technology.

This is good news for solar energy advocates, as these companies have the capital and the knowledge base to ramp up production more rapidly than startups, while increasing efficiency and cost savings. According to Sanyo’s Makoto Tanaka:

“‘Our target date for volume production was 2012, but in order to move that up, we’ve decided to invest an additional US $14 million,’ said Tanaka, bringing total investment … to some US $70M through 2010. He noted that the production ramp should be eased because part of the new process is very similar to that already used in Sanyo’s mainstay heterojunction with intrinsic thin-layer (HIT) cells, which sandwich a single-crystal silicon substrate between layers of amorphous silicon thin films.”

Sadly, the United States is not one of the countries competing on this scale with Sanyo and Mitsubishi, who see their main competition coming from China and India. Though the U.S. company Nanosolar has been a leading innovator in thin film, and Open Energy is making big inroads in the production of Building Integrated Photovoltaic (BIPV) modules using thin film tech, they are still comparatively small players in the space, along with FirstSolar. Let’s hope that the U.S. steps up to provide the kind of legislative support that U.S. companies need to move forward at a faster pace in developing new solar technologies.

Image Credit: Ovonic.com

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Solar Thin-film Ready to Ramp Up Production?