Solar Panels Reach $1 a Watt 381
ZosX writes "An article over at Popular Mechanics announces that, for the first time, solar cells have been manufactured for the much sought-after figure of $1/Watt. They also talk about a new study of the cost of the particular raw materials used in different manufacturing processes. The conclusion is that the company that just achieved the $1/W milestone, using cadmium telluride technology, may not prove to be the long-term winner capable of meeting demand when it rises into the terawatt range."
Wow (Score:5, Interesting)
TCO (Score:5, Interesting)
So, their goal is to get the cost of manufacturing down to about 60-70 cents a watt, and the cost of installation down to $1 a watt. I didn't realize the hidden cost of installation was so high.
Chilling effects. (Score:1, Interesting)
What happens when we line the world's deserts with endless fields of solar panels and tip past the breaking point of global cooling? Where's your God now?
Tellurium (Score:4, Interesting)
Volume production will outstrip the world Tellurium supply in the near future so this isn't going to be a cost effective technology for long.
Re:Wow (Score:3, Interesting)
Re:TCO (Score:2, Interesting)
IAAE (I am an electrician) and I can tell you that the major cost consideration of a on-grid PV system (after the panels themselves) is the grid tie inverter. They are SERIOUSLY expensive. The off grid equivalent would be a battery bank which is just as expensive and a potential environmental disaster in the making.
If you want to save money, energy and the environment then I would suggest a vacuum solar hot water system any day of the week. Much cheaper, much more efficient and still does some dam useful work.
Why $1 per watt is important (Score:3, Interesting)
The reason why $1 per watt is important, which isn't mentioned in the summary, is not just that it's a nice round number, but the capital cost of electricity for most major industrialized nations averages about a buck a watt. Some more, some less, depends on the cost of land and the economic conditions when the plants were built, technology level, pollution controls, etc, but your local electrical power company happily pays about a buck a watt to build a traditional non-solar plant.
Solar only works half the day, but probably much lower maintenance, slower depreciation, and no fuel costs at all.
So, it now costs "about the same" to build a 1 GW coal, a 1 GW natgas, a 1 GW nuke, OR A 1 GW SOLAR ... Which brings solar into the corporate boardroom.
Re:TCO (Score:1, Interesting)
Re:Why $1 per watt is important (Score:4, Interesting)
You mentioned that solar only works half the time, but you seemed to dismiss it as irrelevant.
Total capacity is a very misleading metric to measure power stations by, and is meaningless without information about it's utilization.
Obviously solar panels only generate when the sun is shining, just like wind plants only generate when the wind is blowing. A very good wind farm will get 40% utilization. A very good solar farm will get maybe 25% utilization.
And that's not the whole story either. It's also interesting to look at the demand weighted generation. This is a way of accounting for generation being more useful when demand is higher. In general, solar panels have a higher DWG in hot climates (air-con when sun is shining), and a lower DWG in cold climates (heating when sun isn't).
Current installed prices are about $5/Wp, and I'd be suprised to see %1/Wp before 2015.
CdTe is a direct band-gap material, Si is indirect (Score:1, Interesting)
The article seems to have a shallow understanding of the physics involved here... it presumes that extraction costs are the limiting factor:
Almost certainly, the reason CdTe has won this particular race is that it's one of the compound semi-conductors, all of which are direct band-gap materials [1], and Silicon is an indirect band-gap material. With an "indirect" band-gap, for a photon of the right energy to be absorbed it has to hit the lattice at the same time as a phonon, but for a "direct" band-gap, the photon alone is enough -- this tends to limit the efficiency of photo cells made of the much simpler, more abundant Silicon... and unfortunately the compound semi-conductors are all composed of much rarer and more poisonous elements.
Since this is slashdot, I will hazard an uninformed guess that there may be some tricks out there to get Silicon to act as efficiently as a direct-band gap material (e.g. an odd, nanoscale surface texture) -- but these tricks will up the cost of manufacture, and won't achieve wide-spread use. There's no free lunch, and the name of the game in ground-based solar power is to gather an extremely diffuse source of energy -- it's just not an easy problem (despite the repeated, proud announcements of Breakthroughs from it's enthusiasts).
[1] When last I looked -- which was some time ago -- no one really knew why the compound semi-conductors were all direct band-gap materials, and the elemental ones were indirect.
Re:Wow (Score:5, Interesting)
To plug into the grid you need a Synchronous Inverter.
You are not suppose to dump square wave on the grid either.
Some guerilla solar ppl who do not understand this do it anyways.
The grid uses generators that generate sinewave power.
To connect cleanly and correctly you need a Sinewave based
Synchronous Inverter and that is not cheap.
Also if you live in a heavy lightning storm area then you run
the risk of your huge investment going up in smoke by being
attached to the grid.
Your best bet is to get off the grid.
Some ppl do it a little at a time by converting all their lights
to LED lighting and have wind and or solar charging some used
forklift batteries that are stored outside in a fireproof box.
forklift batteries are not the best, but used ones are cheaper
by a huge amount than the very best made new for this purpose.
Over time as they get more of their own power made they can
move circuits over to the off grid system.
The killers are central heat and air, electric dryer, fridge,
hair dryers, vacuums, electric ovens, and microwaves.
Re:Wow (Score:4, Interesting)
Most(and I mean MOST), grid-tie systems shut off when the grid power goes out. This is to protect the system and line workers.
For an extra $1k or so you can have a system that works more like an automatic transfer switch, when the main power goes out, the system will automatically power circuits depending on priority and available power. IE put the dryer last, the computer first. ;)
http://www.oasismontana.com/Xantrex-xw-inverter.html [oasismontana.com] - but I'd want to read the documentation carefully before getting one. It's listed as working in either mode, but not both at the same time, or being able to switch automatically.
Re:Wow (Score:5, Interesting)
Found a better one, lists that capability as standard:
http://www.infinigi.com/beacon-power-m5-inverter-5-kw-gridtied-battery-backup-p-104.html?ref=100 [infinigi.com]
Only 5kw though. At $5k, it'd take 4 years of eliminating my electric bill to pay for the inverter alone, much less solar cells, wind turbine, or install.
By my back of hand figuring on the basis of using ~1000kwh a month, I'd need a 4-5kw inverter anyways.
1000kwh/month = 33kwh/day, 1.4 kwh/hour, 1400 watts average load. Times 3 for rough guess on usable/production periods vs max, 4.2kw minimum load needed. BTW, my water heater/stove/dryer are all electric, but heat is propane. I pay ~.10 cents per kwh, decreasing if I use a lot.
Re:Wow (Score:3, Interesting)
Answer: Nope.
Re:Tellurium (Score:2, Interesting)
As a summer internship, I had the opportunity to work for one of the only refiners of Tellurium in the US, they happen to be a large copper refinery.
Tellurium is indeed a rare element, but the value of tellurium was nearly nill only a few years ago. Refineries that were capturing the tellurium were literally throwing it away. Their rate of recovery hardly reflected the $200/lb that it currently trades at in the US.
In other words, while I know that it is still a very rare element, I also know that we have the capability to recover a far higher percentage of tellurium if the demand stays high.
Re:thats nice (Score:2, Interesting)
I get the feeling he was being clever...
http://en.wikipedia.org/wiki/Prometheus [wikipedia.org]
Re:thats nice (Score:4, Interesting)
Tellurium is extremely rare, one of the nine rarest metallic elements on Earth. It is in the same chemical family as oxygen, sulfur, selenium, and polonium (the chalcogens).
In a previous life I worked as a Metallurgist for a copper refinery. One project I worked on was refining / recovery of Tellurium from our anode slimes. From a technical point of view it wasn't difficult to recover. I was able to easily get > 99.96% purity in the lab.
At the time we had around 10 Tonnes / year of Tellurium in our slimes. Considering that the total world production is < 40 Tonnes, that was significant.
Even at > $100,000 / tonne, it just wasn't worth our while to go to the trouble of recovering it.
In the end we sold our slimes 'raw' and took the price hit for the impurities (included Copper and Tellurium)
It's not expensive, because no-one's using it. But if you start mass-producing anything with tellurium in it that cheapness will disappear sooner than you can say "exhausted supply".
It would probably be a very good investment to buy (right now) a ton or so of tellurium and put in your basement. Perhaps a bit unorthodox an investment, but before 20 years pass it will be many times more valuable than gold or platinum. Right now it costs between $70 and $100 per pound. You can reasonably expect that to become at least several thousand within the next ten years.
That price is still > $200,000 / Tonne
If the demand (and then price) really do go up, many of the refineries (or the precious metals companies that purchase their slimes) may be induced to actually recover their Tellurium, thus increasing supply.
NB. The major use of Tellurium is currently as a free machining agent in steel (it makes it easier to drill / machine)