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New Material for More Efficient Solar Cells
PunkerTFC writes "Space.com has an article on a new material that could create relatively cheap solar cells which are up to 50% efficient. This is much better than the 25% efficient silicon solar cells (most common) or the 36% efficient multi-junction solar cells (very expensive). The material was created by "forcing oxygen into a zinc-manganese-tellurium crystal" creating more band gaps, which allow the cell to create electrical energy with three seperate frequencies of light. This could lead to cheap, high-output solar cells in the future, but it will take at least 3 years to assess the feasibility of the new technology, according to the researchers."
Solar cell technology seems to be getting more and more advanced. When will the time come when we are able to use it to effectively power a complete house?
This has been released very recently - it's based on PbSe crystals instead - at Los Alamos but also through University of California.
...but until it progresses to the point where we don't need a surface of cells an order of magnitude larger than the structure they will power to use them, they're still impracticle for primary energy needs.
I don't think we'll ever see solar cells as primary terestrial energy sources though. Cloud cover and night ruins their feasibility, but I'd wager money on them being used to augment other alternative energy sources in the future. Maybe power will go the way of Intel's new chips, multiple sources at lower power instead of one giant one at greater.
Oil reserves appear to be running out (looking at the recent problems Shell had with its overstated reserves, and seeing how some of the other large oil companies make even larger estimates than Shell's old ones). The future of energy production is going to be nuclear, wind, and solar. So it's very timely news.
Personally I think the collapse of the oil supply within the next 15-20 years will be the most traumatic event in recent human history.
Solar cells will help a lot in some ways but they won't be enough to stitch together a modern society built on the motor car and cheap fuel.
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You have false notions about the feasability of solar. You would be speaking of cheap solar whereas (as it is now) there ISsolar technology that:
A) Doesn't have to cover the entire structure - but really is mute point - if you want solar - why not maximize its production - installation and deployment is 1/4 the cost - once it's being installed, install as much as possible - your goal is to "overproduce" if possible - did you know that your local energy untility has to BUY BACK power that you could place onto the grid if you overproduced?
B) The GM solar race car is a marvel of engineering, is as fast as most street legal cars and it looks cool too!
C) Cloud cover and night are of no consequence. Cloud cover only reduces production - besides power IS STORED in batteries anyway - it doesn't go straight from the sun to your light bulb or TV.
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This was already covered by /. a few weeks ago, but this new space.com article does seems tohave more details.
The solar constant (see for example here is about 1.somethin kW per Square meter.
That simply means you need quite some substantial area irradiated by bright sunlight to obtain a given amount of energy.
I think this is a limiting factor for many interesting ideas out there..
perl -e 'printf("%x!\n",49153)'
One alternate plan is to use cheap titanium dioxide to make less efficient solar cells that are significantly less expensive. Titanium dioxide is used to tint paint white and is available cheaply in bulk. While researchers are working on increasing the efficiency through nano particle techniques, do it yourselfers have made progress.
Solar sales are up 30-40% every year, and have been growing at such a steady pace for a long time.
Naturally, this is a positive feedback loop. Lower prices mean it's affordable for more niches, which means more people buy, which in turn scales larger. At this point, it's pretty much unstoppable. It is useful in too many niches, especially where customers aren't connected to a power grid.
There are now many countries that have more cell-phones than landline phones. It's likely that in 10 years, some countries will have more customers getting electricity from solar than from a central grid. Naysayers will say it's not ready... but then again, 15 years ago cell phones weren't either. What matters is not the absolute numbers, but the growth rate of the industry and the evolution of the technology.
Of course, as the market matures, more people are doing R&D to find cheaper ways to build PV systems, which is only going to accelerate this momentum.
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Tellurium is about $14/lb. Gallium, by comparison, is about $1000/lb, which is why gallium-arsenide photocells, which can reach 30% efficiency, aren't widely used.
World production of tellurium is only about 100 metric tons. Gold production is 25 times larger. Tellurium is cheap because it is produced as a byproduct of copper smelting. Nobody mines tellurium directly at present. So there may be a supply problem if demand increases substantially.
And on that same page, they do mention that PV prices can go as low as "$3.58 Watt: thin film and $3.16 Watt: crystalline." $5.85 is an average, which includes PVs that are designed for different systems. In my case, I only care about cost per watt as I will have a sufficient surface, others have to worry about squeezing the most energy out of a limited space. Different needs, different models and different prices.
The most promising route will probably be solar rooftops, where solar cells are integrated with construction materials. For new construction or re-roofing, this makes a lot of sense because you don't have to pay much more for installation. With net metering, you also wouldn't need the expensive batteries. Of course, that assumes you're on the grid; if not, connection charges can be more than going the cost of going solar, including battery array.
Solar is still expensive for now, and this has led most people that consider it to use every trick in the book to lower their energy consumption. Better lighting, appliances, windows, insulation... if it cost less money to conserve than generate, it only makes sense to spend money on efficiency. You probably do not need 564kWh/month- you should be able to reduce that by at least a third, with a payback in under 2 years.
There are other applications too where cost alone is not a huge issue. If reliability is important, being able to have your own power supply, batteries, and a net metering arrangement with the grid could be a cheaper solution than most UPS, and give you far more autonomy.
While you may not see it as rosey, it's hard to argue with the fact that sales are still growing, year over year. And I can't think of anything that could stop that in the next 20 years: it's all but inevitable.
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