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 photovoltaics—the multicrystalline silicon solar panels cropping up on rooftops across the country and, indeed, the world—struggle 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 manufacturer—if 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 power—something anticipated since photovoltaics were discovered.
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.
/johnny
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.
Keep trying
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.
bump
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.”
-Lord Kelvin
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".
Racist capitalist.
Complete replacement guarantee or pro-rated?
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