Skip to comments.New solar-cell efficiency record set
Posted on 09/16/2009 8:17:13 AM PDT by canuck_conservative
Here's a seemingly simple solar power fact*: the sun bathes Earth with enough energy in one hour (4.3 x 1020 joules) to more than fill all of humanity's present energy use in a year (4.1 x 1020 joules). So how to convert it? In the world of solar energy harvesting, there's a constant battle between cost and efficiency. On the one hand, complex and expensive triple-junction photovoltaic cells can turn more than 40 percent of the (specially concentrated) sunlight that falls on them into electricity. On the other, cheap, plastic solar cells under development convert less than 5 percent.
In between, ubiquitous photovoltaicsthe multicrystalline silicon solar panels cropping up on rooftops across the country and, indeed, the worldstruggle to balance the need for (relatively) easy manufacturing and low cost with technology to get the most electrons for your solar buck.
Yesterday, Spectrolab announced that its newest triple-junction solar cells had achieved the world record in efficiency, converting 41.6 percent of specially concentrated sunlight into electricity. All told, a tiny cell just 0.3174 square centimeters turned the sunlight equivalent of nearly 364 suns into 4.805 watts. That kind of efficiency is why 60 percent of satellites in orbit today bear earlier iterations of the technology; that's a total of roughly 640 kilowatts of Spectrolab cells circling Earth.
Those cells cost 40 cents per watt, according to the manufacturerif you happen to have the sunlight equivalent of 500 suns streaming down while enjoying a temperature of 25 degrees Celsius. In reality, only specialized applications like satellites (and government contractors or agencies like NASA) can afford the technology.
More Earth-bound photovoltaics, like Suntech's Pluto line of multicrystalline cells, which boasts 17.2 percent efficiency converting one sun's light into electricity, or Suniva's ARTisun single silicon crystal cells that can convert 18.5 percent of the sunshine into electricity, cost more than $2 per watt. Installation roughly doubles that price.
Bringing the cost of just the photovoltaic cells down to about $1 per watt is the magic number solar manufacturers are aiming for, figuring that will make them cost-competitive with electricity produced by burning natural gas. Some manufacturers of thin film cells (less efficient but cheaper), such as First Solar, claim to have reached that mark, with efficiencies around 10 percent. Finding a way to further boost the ability to convert sunlight into electricity while also lowering costs to this level would herald the true dawn for solar powersomething anticipated since photovoltaics were discovered.
Jimmy Carter suspects racism is what is driving this.
It is a no brainer. It makes no economic sense at this point in time. There is no ROI - ever.
And by way of comparison internal combustion engines ( as well as diesel and turbines) are scalable. Solar energy is still a pipe dream. Tell me what you do at night? What do you do when it is cloudy? How are you going to store any of that energy for later distribution and consumption?
Solar is useful for space craft period. oh and heating your water for a shower
Bringing the cost of just the photovoltaic cells down to about $1 per watt is the magic number solar manufacturers are aiming for, figuring that will make them cost-competitive with electricity produced by burning natural gas.
I wonder if the cost they talk about takes into account the fact that you have to replace them all every 10 years or so.
I don't have a recent bill in front of me, but IIRC, my home uses 1600 watts a month. If the solar manufacturers attain their goals, I can power my home for just $1600 a month!!
Such a deal.
Well of course, its not usable at night or when it’s overcast. Just like wind power can’t be used when it’s calm.
But they ARE there at times, free and available to augment to on-demand electricity supply.
The technology may be pricey at the moment, but it’s changing quick.
Yea the maintenance aspect is always overlooked in these stories. If they came up with a technology that produced electricity at $0.001 per kilowatt-hour, but you had to replace them once a week, that still wouldn’t be a very good deal would it?
No, the solar panels are a one time capital cost, not a recurring cost.
Your electric bill probably has 1600 kilowatt-hours per month which is an average power of 2222 watts if spread evenly over the month. Figure at 1/4 usage (my wild ass guess) for nights and clouds you would need 8888 watts of panels, or a one time cost of $8,888. Plus you need installation and storage. But those are one time costs. Now compare that to your monthly bill and see how long your payoff time is.
They are not FREE. If you actually think that then you need to go back to science school.
Pricing for these technologies will not come down anytime in the foreseeable future -— nor should they. This is the same type of madness that drives people to food into fuel. Augmentation is not a main source and hence will never be lower in cost. If you want really consistent power then look to things such as shale, tar sands, nuclear, and coal
On my grandparents’ farm before electricity they generated gas from carbide and lit the house with that. I understand that was not uncommon. Wonder if that is still possible today for remote locations like yours?
There is a way to convert solar energy into electric power at a reasonable cost. Make the Gulf of Mexico your solar energy collector, and tap that energy via the Gulf Stream as the moving ocean current passes through the Florida Straits.
Turbines located beneath the ocean surface would not conflict with visual appeal or vessel traffic.
I've been hearing that since about 1973....
No, the solar panels are a one time capital cost, not a recurring cost.
Current generation - I think I accidentally make a joke.
Well I meant the “source” is free - you still have to pay for the equipment, whether its solar or fossil fuel, duh - but after that, solar is free.
Fossil fuel isn’t.
Hey, neat, we could surround the earth at 50,000 feet with hundreds of giant magnifying glasses and power our cars. Of course, it might be a little risky.
The solar panels will last a lot longer than that, if you use a battery bank to store excess energy for use at night then batteries will need replacing every 10-15 years depending on the quality and how they were cared for. But panels will outlast a roof.
Of course fossil fuel is free -— after all it is just sitting in the ground. Rather like sunlight just sitting around in the air. The trick is to extricate it, use it, and do it all for a reasonable price. Currently that means oil, gas, and coal.
Get the solar panel installed cost with a storage system (or a cost neutral way of pumping my daily excess into the grid and back out at night) down to $0.10/kWh amortized over the life of the panels and I'll order some. If they are much more than that I'll just stay with the grid.
At $1/watt and my wild ass guess of 6 hours average per day it will be about $0.05/kilowatt-hour before installation, energy storage and maintenance if spread over ten years. That number is in the ballpark for replacing power from the electric company.
That would have to be 1600 kilowatt-hours. Watts if power. Kilowatt-hours is energy. Energy is what you pay for.
I happen to work in the field you loon.
What you so lightly describe as easy things to accomplish ( ie storage that is efficient and can handle high distribution loads) is not. My mind is completely open as yours apparently is not. I have already cited shale, tar sands, nuclear, and coal as currently available sources of stable energy.
We can and probably should continue to work on the others. Wind is most useful while actually at sea ( in the propulsion of large cargo ships), not so useful on land. Solar as an actual source of large ampunts of energy poses greater risks due to the concentrators than even some of the nuclear plants out there.
Again, keep trying.
Oh and please pay enough attention that what they got was 4 friggin Watts. When a small sized town uses megawatts that should be easily scalable.
Did some quick googling. Looks like there was a problem with the plastic coating discoloring and reducing the efficiency. They claim they’ve overcome this problem. Guess we’ll see if that’s true in a few years. I’m not a materials engineer but seems the cells themselves would last near forever.
You really are nuts. You don’t even read what you write. Generators are NOT free. getting the sunlight properly collected and out of the generator is NOT free. the land that the concentrators sit on is NOT free. The same costs for getting the product exist. I will grant you that the cracking is additional cost for oil but compared to the pricey natural of large scale photovoltaics you are not going to win that cost battle. To say that eventually PV will come down in price is nice but it also avoids the realities of manufacturing large PV.
You really do not know the science so quit while you are behind
Ther's nothing more inovative than an ice fisherman trying to make his shanty more comfortable and home like.I know many that have tried. The costs and the tech. aren't there yet. I'm talking about one room maybe a TV and a DVD player and lights.The honda gas powered generator is still the holy grail out there. Battery tech. seems to be the biggest problem. along with cold temps andd snowy cloudy days. thes are men that are used to living amp by amp. and i just don'y see it yet.
Don’t know if you’re against these new technologies because you consider them “Obama’s babies”, or you’re stuck in a rut, or what ....
And if you’ve forgotten the power of science to innovate - ironic, considering all the moon-landing specials this summer, but whatever - then remember this quote from a century ago, by one of the then-”experts” in science:
“No balloon and no aeroplane will ever be practically successful.”
You're confusing cost to install (capital) with cost of operation. The $1/watt is the cost to install the cells.
Since the vendors are guaranteeing their cells for 20 years, I think you point is "invalid".
Complete replacement guarantee or pro-rated?
The above is true for photovolataics, but not solar thermal. For solar thermal is possible to store the energy AS HEAT to continue to generate power at night. With eight hours worth of heat storage capacity, a solar thermal plant can provide all energy needs and match the "day-night" demand cycle exactly, without ANY need for fossil fuel "backup".
Cells down to about $1 per watt. Ok now what is the battery cost to keep the lights on until midnight?
Prorated, but the pro-rating is acceptable:
"Kyocera Solar Panels come with a 20 year warranty on the power production of their panels. Because there are no moving parts, the only wear-and-tear these systems see is from daily sun exposure, year after year. This is factored into the 20-year warranty, which states that by the end of the twelfth year, the panels should still be producing at 90% of their initial capacity, and that by the end of the 20th year, they should still be producing at 80% of their rated power."
Nanosolar, which is already selling cells for $0.99/watt, offers a 25 year warranty.
How well do they hold up in hail?
Importantly, if you want the most bang for your buck from solar energy, you have to use it for *marginal* applications, *passive* effects, and *multiplying* effects. Let me use three examples.
To start with, the bulk of your household energy is inexpensive grid power. It is great for this. However, when you get into periods of “peak demand” (in summer or winter, depending on where you live), you enter the “marginal” zone, where suddenly the price of grid power jumps, because its demand jumps. If you can use solar power just to stay *out* of the marginal zone, you save a bundle, and solar power becomes very efficient.
In the hot desert southwest in summer, a home air conditioner in the heat of the day sucks down energy like a sponge, but for the wrong reason. Say it is 115F out, and you want it to be 76F inside your home. What most people don’t realize is that their a/c doesn’t just cool down the inside of their home, but it has to contend with cooling the crawlspace above their home as well. And crawlspace temperatures can get over 140F, easily.
But a little, solar powered fan, that blows the hot air out of the crawlspace, lowers its temperature to “only” 120F. But this 20 degree difference radically lowers the load on the a/c. So a little solar powered fan can save you a $75-100 a month.
Pretty darn efficient. An excellent “marginal” use for solar power.
As a second example, that of “passive” solar energy, works in just the opposite direction. One of the biggest energy use appliances in a home is the hot water heater. Typically, it has to heat cool city water (say 75F) to perhaps 120F. But just diverting the city water to a “passive” roof solar water heater, just a stainless steel tank painted black, it raises the temperature of city water to maybe 100F or more.
And throughout the warm months this can save a huge amount of money. In winter, a simple bypass valve means that the empty tank doesn’t freeze.
“Multiplying solar power effects” still need a lot of development, but can be anything from a solar still to recover fresh water, to using solar powered water electrolysis to get hydrogen and oxygen, both of which are otherwise expensive, but very useful.
I looked into it a few years ago. Same result: makes no economic sense. Two years ago, a solar salesman admitted to me that it’s only for rich people - even with subsidies.
I’d love to have solar power. I hate being on the grid. But I ain’t rich. So until they solve the economics, I ain’t buying.
Thanks Canuck for the link, I’m starting a class next Monday to become a Certified Photovoltaic Practitioner. At present I’m an unemployed licensed electrician, the only jobs out there right now are from out of state firms looking to parachute here to do business in photovoltaics. Basically they lack the licenses, I lack the experience, though I am ahead of the curb having wired two systems out of the 102 commercial systems installed last year in Massachusetts.
So I think come the Spring of 2010 I’ll be ready to install some systems on my own.
I don’t consider myself a “Green” but I hate seeing all of our nation’s profit going to the Middle East, quite sick of it in fact.
I like to see a huge push to nuclear power, then coal, then renewables, seems pretty sensible to me.
A couple of things folks are overlooking when they consider photovoltaics (vs thermal solar) is that it works quite well in the winter, and it introduces energy into the grid exactly when the demand is peak during the day.
“So until they solve the economics, I aint buying.”
If you look at the post above, you’ll see that a very basic system can reap huge rewards. A attic fan can be installed to a module or two, independent of any other system - no batteries, no grid tie in. The sun shines - the fan keeps your attic cool(er), thus the house, cutting the demand for the AC running all day. Just a couple hundred bucks to install.
Look up some of the stuff that I actually work with
flexotricity for example.
I am not AGAINST any of these. I am merely pointing out that what you claim is not currently factual. it is not based on any thermodynamics nor electrochemistry nor materials science. I am not saying it won’t ever happen. I merely pointed to things that already exist. Why won’t you address those????
Actual the solar thermal plants that exist DO have fossil fuel backup .....your understanding of solar thermal comes from reading a few articles not actual experience
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