New Photovoltaics Made with Titanium Foil

Memorize writes "A company called Daystartech has released a new type of photovoltaic cell which, unlike almost all the cells currently in use, does not silicon. This is based on a thin titanium film. Given the current shortage of solar-grade silicon, and all-time high oil prices, maybe titanium solar panels are here at the right time. The questions are, will they release it as a consumer solar product, and what will be the price per kilowatt hour?"

Comments

Slicon Shortage

[klausner]

Like, you think that titanium, and the equipment required to work titanium comes cheap? Cheaper than sand?

Re:Slicon Shortage

[darkmeridian]

It's not meant to replace largescale silicon photovoltaic cells. Instead, it's meant for use on UAVs and balloons and stuff. Price doesn't matter here, right?

Re:Slicon Shortage

[dbIII]

Like, you think that titanium, and the equipment required to work titanium comes cheap? Cheaper than sand?

Titanium is also available in sand, most commonly in the form of rutile and ilmanite. Most readers here have probaly eaten titanium dioxide taken from sand, it is frequently used as a white food colouring and paint pigment.

It costs a lot to do anything with titanium because the oxide forms quickly on any exposed surface and takes a lot of energy to break down.

Re:Slicon Shortage

[Rei]

Slicon?

The interesting thing here is that the fastest growing solar cell market is not silicon: it's organic solar cells. They're incredibly cheap, but currently inefficient. However, their efficiency has been growing dramatically. One company, nanosolar, claims to have achieved almost the efficiency of amorphous silicon cells. Their patent is rather interesting, and well worth a read.

Re:Slicon Shortage

[Rei]

Monocrystalline silicon is incredibly expensive. Polycrystalline silicon (which has largely taken over in the solar cell market) is simply "very expensive". Silicon is common, but pure silicon crystals require clean-room conditions to grow.

Titanium isn't that rare. The ore isn't the primary cost component (like, say, gold). Instead, like aluminum, the main costs are in refining. Unlike aluminum, however, there is currently no continuous production process - only an expensive batch production process. Even the inventor of the process, William Kroll expected to have it be replaced within decades of its implementation in 1940; no suitable replacement was found, however.

Fortunately, it looks like there are some on the horizon. Most interestingly, it appears that electrolysis can be conducted directly on titanium oxide (this has huge potential applications for other hard-to-refine metals as well, and may allow for the creation of new alloys). There's also a aluminum-style molten-salt electrolysis process (FFC-Cambridge) in testing.

Titanium isn't inherently hard to work with, persay; you just need to be properly equipped to work with it and experienced with it. You have to use *very* pure argon in welding, and you have to keep the argon going for longer after you take the heat off. You also have to avoid working it with aluminum tools, which can alloy with the metal and weaken it. Etc.

There are some benefits, though. Impurities in titanium are very easy to spot, as they tend to discolor. Also, titanium is *very* fatigue resistant, and aircraft with titanium structural components have sometimes even been found to be stronger after being flown a few times than when they were built.

Re:Slicon Shortage

[Rei]

I should also add that titanium is really just the backing. It's a great backing, given it's strength and condition-tolerances compared to its mass, but it's not what generates the power The cell itself is actually a copper-indium-gallium-diselenide cell - not that it's cheap, either ;)

Re:Slicon Shortage

[Qzukk]

Yes, actually. This isn't just some sand scooped off a beach. Solar panel grade silicon comes from the leftovers after semiconductor grade silicon users have picked through their crystal wafers, which is why there is a shortage in the first place, since there is a narrow range of quality ("almost" good enough for semiconductors). As for titanium, my 30 year old encyclopeda says its one of the 10 most common metals on the planet. Titanium Oxide is cheaply produced and used liberally in paint.

Titanium is malleable when hot (meaning you can flatten it into foil). So producing titanium foil is probably not a difficult task, depending on how hot "hot" is. (Though the article mentions that the titanium foil used is thinner than household aluminum foil. The process looks like it would be easy anyway, but time consuming.)

As for your post on waste products, the most common smelting procedure in use works without catalyst or flux to produce pig-iron and Titanium Oxide, though this process is common because of its use in paint. This process was recently developed for producing metallic titanium, its outputs are salt (NaCl), titanium, and whatever impurities get washed into the liquid sodium stream and removed later.

Re:Slicon Shortage

[ikeleib]

Also, titanium is *very* fatigue resistant, and aircraft with titanium structural components have sometimes even been found to be stronger after being flown a few times than when they were built.

The above refers to one aircraft in particular. The SR-71/A-12 was found to have a stronger airframe after flight. This is not really due to titanium itself, but rather the gentle heating and cooling that the aircraft underwent with each flight. It annealed the metal, thereby making it stronger and helping to eliminate the fatigue that is normally problematic in airplane structures.

Re:Slicon Shortage

[Anonymous Coward]

I've achieved self-replicating organic solar cells in my back yard. Some of them are even tasty.

Re:Slicon Shortage

[Arthur Dent]

Actually a new titanium refining process was discovered a short while ago

Here we report an electrochemical method for the direct reduction of solid TiO2, in which the oxygen is ionized, dissolved in a molten salt and discharged at the anode, leaving pure titanium at the cathode. The simplicity and rapidity of this process compared to conventional routes should result in reduced production costs and the approach should be applicable to a wide range of metal oxides.

Re:Slicon Shortage

[digitalchinky]

The USA has miles upon miles of old military aircraft from what I've seen on television. There should be quite a large amount of titanium left in wing attachments, turbines, and other hard points on decaying fighter jets. I have a small rod of it (from an Airforce friend) that was scrap from an F-111 wing repair. Not very big, but big enough to see how damn strong the stuff is. (few centimeters long)

Took some serious hitting with a sledge hammer and a vice to put any kind of a bend in the metal. Impressive stuff.

Re:Slicon Shortage

[dhovis]

IIRC, the problem with titanium is not so much that the raw material is expensive. The problem is not even so much that it oxidizes readily (aluminum does too). The problem is that it has a high melting point, and is very difficult to forge and to machine.

Pure Ti-metal has a hexagonal close packed microstructure (HCP). Most other metals have a cubic structure (either face centered cubic:FCC or body centered cubic:BCC). FCC and HCP have the same packing effficincy, but it is much easier to form and move dislocations in a lot of different directions in either FCC or BCC than for HCP. Dislocations are necessary for forging, and forging creates such a tangle of dislocations that it actually strengthens the material.

That is why Apple moved away from Ti for Powerbooks, IMHO. It impossible to economically bend the titanium to form the laptop shell without making the metal so thin that it is way to flexible. So the old Ti-Powerbooks had a Ti top and bottom, with Ti-painted plastic in between. This paint invariably started to flake, which led to lots of complaints. Apple wisely switched to an aircraft grade of aluminum, which can be sufficiently bent and machined to form the entire shell of the laptop, not just the top and bottom.

Anyway, that is the basics. IAAMSBTDNCMA (I am a materials scientist, but this does not constitute materials advice)

Re:Slicon Shortage

[theshowmecanuck]

They don't use sand to produce silicon, they use quartz rock. They reduce (redox reaction) the SiO2 using coal and charcoal to produce the initial Silicon metal(oid). Or to put it in layman's terms, it is smelted in a reaction similar to reducing iron in a blast furnace (except with silicon, it is done in a three phase AC powered arc furnace). The reactions happen in the gas phase at over 1400 degrees C. Chunks of quartz are more suitable since the gases can move between them. Sand just clogs things up... kind of like smothering a fire.

Si02 + 2C = 2CO + Si

Once this silicon is produced, it is refined into super-pure semiconductor grade silicon, or more usually, into silicone rubber pre-cursors. I used to work in silicon smelting R&D and so I have some idea about what I'm talking about. (We built and ran the worlds largest direct current arc furnace during a series of pilot runs in the early 90's to research making lower cost silicon. That was before Russia opened up. After they did, they flooded the market with cheaper silicon, and there was no point trying to create lower cost silicon.) The biggest use of silicon is in making silicone rubber (but not so many boobs any more). The raw material for ultra-pure silicon is taken from the raw material (not so pure silicon) used for silicone production.

Anyway, smelting silicon creates large volumes of CO. CO (carbon monoxide) is highly flammable, on the order of natural gas, and usually burns off to C02 at the top of the furnace bed. (CO could be used as a fuel like natural gas, but it is so poisonous it is not really safe to do so.) Since coal and charcoal are used in the process, other carbon by-products are also released, mostly in gaseous form. E.g. like the stuff that makes up tars and such... a little nasty... but quite small relative to CO and CO2 since the high temperature tends to atomize them. However, some of the coal and charcoal does burn away in the upper part of the furnace (where it is relatively cooler) and before it gets a chance to react. As well as producing some not so nice gases, it is a very energy intensive process. Silicon is never found in elemental form in nature. It must be separated from SiO2, which requires a lot of power, which in turn needs to be produced at generating stations.

As far as silicon used in semi-conductors goes, I'm not sure if they use electrolysis to refine it to ultra-pure levels. Maybe in some sort of deposition process from a gasous phase, but I am just guessing from what I have read in general chemistry related articles. The details of that type of processing are usually very top secret so I am not sure who could or would comment on that. And I mean either industrial secrets and likely in a military sense as well (it is probably of strategic value).

Re:Slicon Shortage

[K8Fan]

Took some serious hitting with a sledge hammer and a vice to put any kind of a bend in the metal. Impressive stuff.

Want to see something really cool? Check out "Liquidmetal". It's an alloy of titanium and other metals and has some really amazing properties. For one, it can be cast and does not form crystals like titanium, has a low melting tempature compared to it's component metals - it can actually be injection-molded. It's twice as strong as titanium by weight and much more flexible. There's a bounce-test video on their web site that it a hoot.

Right now it's being used for the hinges in that new Motorola Razor phone, various sporting goods and military applications. Cool stuff.

Re:Slicon Shortage

[dbIII]

The problem is that it has a high melting point, and is very difficult to forge and to machine.

It is difficult to forge and machine due to the oxide layer - which is very hard and one of the reasons we use it in the first place (it's mostly used in chemical plants). It isn't really a good choice for a laptop since it costs so much to make and is very difficult to do anything with - and aluminium conducts heat better and can be formed while soft for the aircraft grades - the stuff the early 20th century airships were made out of.

The metal itself has a high strength and hardness, but there are plenty of steels harder than it. The oxide layer is very hard, and as soon as you chip some away it forms again. A slightly harder compound, titanium nitride, is the gold coloured stuff you see plating the tips of cutting tools.

If the oxide is being used in these cells the process may be surprisingly cheap, since the hard bit is reducing the oxide to metal. If it's something else, there may be ways of making it cheaply from an ore - a mineral sand. If a vapour is being sprayed onto a substrate it might not cost a lot either.

I'm not a materials scientist anymore, but for a while when I was I used to teach engineering students how to break things under controlled circumstances - and find out why stuff broke under uncontrolled circimstances.

Re:Slicon Shortage

[theshowmecanuck]

It's possible. It could be a type of co-generation. The idea is used in a lot of places, but usually it involves using excess heat to produce steam, or waste steam. It would be a good idea.

Something to think about: in order to be flammable you need concentrations of at least 5% CO in air (about the same as needed for natural gas). That's 50000 ppm. To put it in perspective if you were in a room with 800 - 1000 ppm CO for several hours, you would likely end up dead. If you walked into a room with 4000 to 5000 ppm CO, you might not even know what hit you as you hit the floor. It wouldn't be long before you died. So basically, if you used it for a fuel source, it would really suck if the pilot light went out. Maximum OSHA allowable limits in the workplace is 35 ppm. In the middle of typical rush hour traffic (I measured it with a portable meter): 50 ppm! Mind you in industry you are usually indoors where it can concentrate, and often there are very high levels behind it (our offgas lines had 75 to 80 % pure CO... even small leaks were dangerous... we had monitors and venting systems and escape air bottles everywhere).

To silicon or not to silicon, that is the question

[eviloverlordx]

Of course, once we decide, we'll need to find out what 'to silicon' actually means...

I gotta say...

[SparksMcGee]

I confess I've always had a problem with power sources that do silicon. Snooty bastards, what with their made up verbs and their rock music...

How does this compare?

[AtariAmarok]

How does this compare to what is used as solar cells in spacecraft now? Sounds interesting. Imagine, not a beowulf cluster, but a solar-sail type of spaceship in which the sun pushes against a huge sail made of this stuff, and also sends electricity to the ship.

This is big news.

[TheGuano]

It could lead to some very promising developments. I was trying to collect solar energy today, but ended up siliconing so bad that I couldn't sit down for hours. It still smarts...

Oh great...

[Kjuib]

Now I have to upgrade from my Tin Foil hat to a Titanium Foil hat... I hate expensive upgrades!

Better than tinfoil?

[14erCleaner]

Now you can get power and protection from UFOs with one convenient hat!

price?

[soupdevil]

...cost effective for specialized military, homeland security and commercial applications.

In other words, ridiculously overpriced, and unavailable to the average consumer for the next decade.

Price per kilowatt hour...

[MisterLawyer]

The way this question is posed demonstrates a common misunderstanding of the costs and benefits of investing in alternative energy sources.

Obviously, the marginal price per kilowatt hour is $0. The difference between obtaining 100 kilowatt hours and 101 kilowatt hours is nothing. You would simply have to wait for enough sunlight to hit the solar panel to generate that extra 1 kilowatt hour.

The true cost of investing in solar energy is in the intial cost of manufacturing and setting up the panel.

Thus, the actual cost per kilowatt hour depends on how long you use the solar panel. The longer you use the panel, the cheaper each kilowatt hour becomes.

Re:Price per kilowatt hour...

[soupdevil]

That's assuming zero maintenance costs, and that waiting costs you nothing.

good for the horta

[AtariAmarok]

"which, unlike almost all the cells currently in use, does not silicon."

Good development. The decline in the demand for silicon should help the threatened horta population to bound back. At least until Pamela Anderson Lee pursues more expansion.

You know...

[nmb3000]

That's what they get for using Office's grammar checker.

Unobtanium foil, better still

[winkydink]

but I hear it's really hard to get

Solar cells from biology

[Bifurcati]

At University of Queensland (in Australia) where I study, we're developing solar cells out of "solid solids" - flexible polymers/plastics. The hope is that as well as being even more efficient, they'll be easy to use - they're flexible, and can be bent, twisted, shaped, etc.

One possibility is to use melanin - the skin pigment that gives our skins colour. Being in Australia, of course, researching melanin is of significant interest to us! It's yet another example of biology helping to make really cool physics - more details are available on UQ's physics blog.

can't get something for nothing

[kebes]

Food for thought: if your solar sail is using photon pressure, then by coating it in a photoelectric, you're halving its efficiency as a solar sail. Why? Well if your solar sail is a perfect reflector, then the photons bounce off and reverse direction, so the momentum change is twice the initial photon momentum (yes photons are massless but they do have momentum). If the sail is absorbing the photons for electricity, then they are not reflecting, so you merely absorb their momentum, making your forward impulse half what it would otherwise have been.

But, as we all know, solar sails work both by exploiting photon pressure, and solar wind (particles emitted by the sun), so the situation is maybe not that bad.

sweet deal

[SuperBanana]

DayStar Technologies (NASDAQ:DSTI) today received confirmation that the State of New York has awarded the University at Albany College of Nanoscale Science and Engineering (CNSE) at the Albany NanoTech research complex a $750,000 Technology Transfer Incentive Program Grant to work with DayStar in the development of optimized substrate templates for CIGS solar cell applications.

[...]

Over a two year period, both DayStar and Albany NanoTech will each contribute $375,000 and NYSTAR will contribute $750,000.

Nice. So, basically, The state of NY puts in three quarters of a million dollars because DayStar promises not to go elsewhere and to graciously donate $350,000 to research that...will directly benefit them and pretty much nobody else.

I'm sorry, but I'm getting really sore for public funds being used to bankroll essentially private R&D done by public, for profit companies. Of course, it's not nearly as bad as the biotech industry, which whores itself out like nobody's business. Did you know we give the biotech industry about $30 billion (yes, billion) a year? Just GIVE it away? No strings attached? That exceeds -estimated- TOTAL tax (local, state, and federal) collected by around $6BN. Virtually 100% of all biotech related R&D is paid for by you and me, while the industry rakes in well over $200BN a year.

And to think they have the gall to whine about how expensive drug research is, or how risky it is! They're NOT PAYING FOR IT!

solar schmolar -- CROPS are the real solar energy

[CFD339]

Plants user solar energy. They don't move. Things that move, need to eat plants, or eat animals that eat plants.

Why? There isn't enough energy in the sunlight to sustain the metabolic rate required for movement. In billions of years, nature hasn't figured out how to covert enough sunlight into energy to sustain an animal's movement other than by concentrating it first into vegetable matter which can be eaten.

For humans to make use of energy, we pretty much have to burn something. We have to release solar energy stored as food, then in most cases concentrated in the form of hydrocarbons.

Fission energy, fancy as it may be, is still about just making water hot. For that matter, if they get there, so will fusion energy be.

We humans are stunningly good at burning things and making excuses for the things we do that are essentially asocial. Aside from that, we're not exactly all that and a bag of chips.

There's no such thing as free energy. The trick we need to find is how to tap bigger forces. Tidal forces with tethered floating generators which rise and fall with the tides and capture that motion as energy would be good. Finding that so called vacume energy between particals would be a fairly useful trick as well.

Making giant solar panels which turn sunlight into energy at less efficiency than plants, then waste most of it in transmission and storage overhead is ultimately not going to win.

More near term, we need to find or engineer a crop which is ideally suited to concentrating sunlight into a hydrocarbon or sugar that can be stored, transported without sigificant loss, then burned.

Unless one of you /. people has found a really efficient ENDOTHERMIC reaction. That would be very cool. :-)

Re:This has all been gone over before...

[TFoo]

Umm, I could be missing something, but your initial statement that "Photoelectric won't work, won't solve even a small fraction of our power needs, not remotely" seems to be completely wrong.

A quick Google search shows that on earth every square meter receives about 4.2kwh of energy per day over a 24 hour period.

A quick look at my electric bill says I use about 20kwh/day as a rough average -- another Google search suggests that the average US household uses approximately 25kwh/day

...So, finishing the math: using 15% efficiency solar cells, the Average US Household needs only 40 square meters (430 square feet) of solar cells to cover all its energy needs. Heck, I could use 5% solar cells on my roof in downtown San Francisco, and STILL have 2x extra capacity to sell back to the grid!

Don't get me wrong: Solar won't solve everything, particularly in applications like transportation where energy storage is an issue --- and cheap Fission IS something we should have figured out a long time ago --- but please don't resort to misinformation to make your points, it only weakens what you are saying.

Re:This has all been gone over before...

[rcw-home]

Photoelectric won't work, won't solve even a small fraction of our power needs, not remotely.

Don't confuse photoelectrics with photovoltaics.

For example, Sandia Labs has a plant currently in operation that produces 5MW in 9 acres, by focusing light onto a tower that heats molten salt which drives turbines. It can produce energy 24 hours a day.

The United States' generating capacity a few years ago was 813 gigawatts, so at .55 MW per acre you'd need 1.4 million acres for all of the US's energy needs. That's about 2300 square miles or 6000 square kilometers, or about 1.5 Rhode Islands. We have many deserts that are larger than that.

Realistically, you don't need a power generation mechanism to be able to handle the entire United States energy needs before you put it in production. You just need it to be cheap (and cheap after the costs of fighting NIMBY lawsuits are factored in).

Sandia's web site doesn't say what their cost per megawatt hour is, but they do say the entire facility is currently worth $120 million. Since this type of system uses nothing exotic, I would expect economies of scale to change the numbers quite a bit. Assuming a life of 30 years, they'd have to be able to reduce the cost by about a factor of 10 to be competitive with today's rates. It could happen.

Re:This has all been gone over before...

[nadaou]

To clear up some common misconceptions you listed:

* Wind: Dead birds, intermittency in many areas, large surface areas, noise

Dead bird thing is mostly a myth. You will kill a thousand times more birds of prey by putting in a highway & getting them hit while munching on roadkill. Radio towers and bridges are just as dangerous as wind tubines to birds.

see http://www.homepower.com/files/birds.pdf
"Wind Generators and Birds: Power Politics?"

Large surface area: most wind farms are dual use, cows still munch the grass, only a small percent of land is lost to use, and that is mostly from access roads.

Noise: true for 1970's turbines. All new turbines are geared and rotate quite slowly. I've stood under one of the new 200' tall versions in 40mph winds.. you just hear a gentle swoosh. From a 1/4 mile away you don't hear it at all.

* Solar: Sigificant chemical wastes, large surface areas

just to note the really nasty galium arsenide solar cells are a tiny fraction (ie only NASA & similar use them). Most solar cells are made from recycled Si from the chipmaking process. That waste is already being made by computer chip makers; the solar cell manufacture process actually reduces existing industrial waste!

* Tidal: Beach erosion, corrosion of power units

Beach erosion? Please explain how dampening waves causes beach erosion? I just don't see it. Even if you unmix "tides" with "wind waves". Tide power is fairly hard to harness unless you live in an area of freak tidal range.

* Hydroelectric: Large loss of land, high greenhouse gas releases

The "high greenhouse gas releases" is a misleading arguement at best. Long and the short of it is that methane from anoxic lake sediment is not a net change to the carbon budget. Burning fossil fuels is.
see this comment for a fuller justification: http://science.slashdot.org/comments.pl?sid=144076 &cid=12073778