Laser Scribing Promises More Efficient Solar Cells

cylonlover writes "A new manufacturing method that incorporates laser technology may result in thin film solar panels that are less expensive and more efficient than anything presently on the market. Currently, a stylus is used to mechanically etch microchannels into such panels, which electrically connect the individual solar cells and allow them to form an array. Researchers from Indiana's Purdue University, however, are developing a technique in which an ultrafast pulsing laser is used to do the etching. Not only will it hopefully be quicker and cheaper than mechanical 'scribing,' but it should also produce cleaner, sharper microchannels that offer superior performance."

Comments

With all these recent findings...

[Panspechi]

Won't solar panels be so cheap in 5 years that only rich people will burn candles and/or oil?

Re:With all these recent findings...

[SeaFox]

I was thinking something similar. With all these advances in solar technology I keep hearing about from different groups, all with 3-10 year forecasts to be cheaper than conventional fuels, wouldn't it be cool if they all put aside the normal competitive "all-for-us" mentality of businesses and just got together and worked out a way of using all their new ideas in one product? By pooling their resources and know-how we could already be there.

Re:With all these recent findings...

[adolf]

Agreed. I've looked into solar, and even in the best case, it's expensive enough on a household scale that getting off-grid and having it pay for itself is a very far-away proposition: FFS, the roof under the panels is likely to need repaired before the panels themselves have returned their investment... And nevermind ice damage (sure the homeowner's insurance will cover it, but at what cost?) or other acts of God: In Ohio, we gets every sort of weather there is except for hurricanes.

And so, such is the payback period on a big solar array that I often refer to the calculations espoused by solar proponents as being "new math."

That said, solar isn't always big and difficult-to-justify. There are other applications which are far more useful, and some of them are rather small:

I (just the other day) bought a solar panel from Lowe's, for the paltry sum of about $17, despite having shunned solar power for every purpose except for electronic calculators and other toys since I was a kid.

I'm not going to use it to help bring my house off the grid. And I'm not going to use it to solve world hunger.

Instead, I'm going to use it to try to spend less money on car batteries: My daily driver has been consuming batteries about once every 12 months ever since I put a Garmin GPS and keyless entry/remote start into it, and has subsequently twice left me to jump-start the car on very cold winter mornings. (And no, I can't be bothered with turning the GPS off: The time-to-first-fix is sufficiently annoying that such a simple solution isn't really useful to me.)

Sure, I could buy a battery with a longer replacement warranty, but it's a real hassle to get them swapped out, and screwing The Man in this way is (at best) dishonest. I could also get a fancy-pants battery like an Ultima, but that doesn't fit easily into my car, and it's not a solution that is likely to actually save me any money.

For $17, the miniscule several Watts of power produced on the brightest of days should serve well to keep things charged. This will reduce wear on the battery (fewer, or less-intense discharge/charge cycles), and will in turn improve longevity. (I live in the north, and generally park with the rear window facing the south: Rear-deck solar panel == Win.)

I expect to be monetarily paid back within the next year or two, or way more if it means that my existing battery never needs jumpstarted again once it turns cold out and the solar charger prevents me from being late for a job.

I'll likely also take it hiking, if I ever find the time to do any of that again: Keeping a phone charged for the price of a few ounces of photovoltaic strapped to my backpack sounds a whole lot more useful than keeping a bunch of alkalines on hand, and periodic radar maps from the Droid sound like they'd be a really awesome thing in the mountains (along with its battery-powered offerings of proper GPS and a backup magnetic compass in the odd event that I get lost and lose my other compass).

And depending on how my measurements in the car work out, I'll be buying another one for the battery in the lawn mower, since at this price even such a small and cheap battery would be well-served to have a bit of help over the winter and during the days when the grass is growing but isn't ready to cut.

I might even buy one for the 32-year-old Firebird, even though it has no history of battery issues (when I turn it off, it's off), just because it spends most of its days sitting in the driveway and it often goes several weeks (or months, if it's wet/cold out) between runs.

Now, of course: All of these vehicular charging applications would be more-effectively served by just plugging in a small trickle charger whenever they're not in use, but that's a pain in the ass involving extension cords and nonexistent outside outlets, any of which would cost more than this little solar widget did -- and I can't take it with me, plus the installation is would be more difficult and time-consuming than this simpl

Re:With all these recent findings...

[517714]

A low voltage cut-off costs less, it turns off the GPS when the battery hits 10.4 volts which is enough to start the car. It works with covered parking.

Re:With all these recent findings...

[mangu]

A solar thermal system would need a lot of maintenance while PV cells just sit there and push electrons around

As someone who has worked with electronics for over 30 years, I beg to disagree. Imagine the number of bad joints in the billions of cells that would be needed to replace one large electric power plant.

Assuming a size of 10cm x 10cm for each cell, that's a hundred cells per square meter, a hundred million cells per square kilometer, at least two hundred million soldered joints. All that to generate no more than 1000 MW at noon on a sunny day.

With wind slightly bending and moving each panel, dust, dew condensation, oxidation, temperature variations, and all other factors that are always causing electrical contacts to fail, my guess is that PV cells are not scalable to the dimensions needed to replace a significant part of our society's electric consumption.

Re:With all these recent findings...

[necro81]

Also, you have to take into account the energy required to produce and maintain the panels in the first place.

Can we please lay this tired strawman argument to rest? A solar panel will produce many times more power over its lifetime than it took to produce. Spend a few minutes on Google and see the different numbers from dozens of different sources: they all indicate that, yes, solar panels produce more than they require to produce.

If that isn't enough, consider this very basic argument: if it really took so much energy to produce a solar panel, then you would never be able to recoup the investment, because the price of the energy it offsets would never add up to the original price of the installation. Since the financial payback period of a house-sized PV installation is 5-10 years, you can well believe that the energy payback period is something less than that (a handful of years). Given that a PV installation that goes up today will last 20+ years, you should be satisfied that it'll pay for itself in both ways.

Re:With all these recent findings...

[Zerth]

If you're carpeting Arizona with solar cells, you can probably do what Google does: just ignore the failures until enough of a unit is bad to justify the manpower, then pull it.

Blast from the past!

[blind biker]

Laser scribing/ablation has been used since the 80's, for reducing the cost (and hence price) of solar cells. E.g. buried contact solar cells..

Using laser ablation to reduce the manufacturing cost of solar cells is so old news, that I almost don't even remember it, it has been so long ago.

Re:Blast from the past!

[Khyber]

We have much finer lasers now than we had back then, and we can control the pulses much better.

This means much finer channel creation, which means more channels, and thus more area for photon capture.

It may not be new but it has reached a new step.

Re:Blast from the past!

[blind biker]

We have much finer lasers now than we had back then, and we can control the pulses much better.

This means much finer channel creation, which means more channels, and thus more area for photon capture.

It may not be new but it has reached a new step.

When Intel introduces something new in their fabrication process (low-K for high integration, high-K for DRAM, etc.) you don't headline it with "Intel invents the MOS transistor!"

Re:Supply and Demand Problem

[mark-t]

Limited availability of silicon?

On this planet?

Not bloody likely.

The limiting factor will be the limited availability of the production facilities, not the raw materials.

Re:Supply and Demand Problem

[ShooterNeo]

Source? You can pick them up for $0.98 a watt right now, or $1.76/watt for a complete system. Go to sunelec.com for where I found some. Are you telling me these prices were lower 6 years ago? I doubt it.

Re:Supply and Demand Problem

[Anonymous Coward]

Solar panels cost more per watt now than 5 years ago, and their lowest cost per watt was about 6-7 years ago.

Not true. See, for example this data

Re:Supply and Demand Problem

[Isaac-1]

Ok, processed material may be a better choice of words here, in the case of silicon the problem is often lack of purity.

Yeah right!

[vvaduva]

You know, I've been hearing these kinds of announcements from the solar panel industry for over 5 years now. Revolutionary technologies, breakthrough announcements...blah blah blah. Costs have not gone down substantially and I still haven't seen anyone breaking the $1/watt barrier, not unless you buy the panels by the pallet. I will believe them when they deliver.

Germany

[Timtimes]

Kind of funny reading the debate on whether solar is finally ready for prime time since I see it dam near everywhere here in Germany. The country is pumping A BILLION euros per MONTH into solar installations. http://en.wikipedia.org/wiki/Solar_power_in_Germany Pretty impressive what an economy unencumbered by a couple foreign wars can afford to invest in. Enjoy.