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New Record For Solar Cell Power Efficiency
mdsolar writes "Renewable Energy Access is reporting that a consortium led by researchers at the University of Delaware has achieved 42.8% efficiency with a silicon solar cell. The method uses lower concentration (factor of 20 magnification) than the previous record holder (40.7% efficiency) so that it may have a broader range of applications, since tolerances for pointing the device will be larger. They are now partnering with DuPont to build engineering and manufacturing prototypes. They expect to be in production in 2010. On a roof, such cells would require less than half the surface area to produce the same amount of power as today's standard solar panels, which have an efficiency of about 17%."
...than price per watt. We got plenty of space we can cover with solar cells so it's not important that they are extremely efficient, just cheap enough so it doesn't cost much to cover large areas.
I don't see energy getting any cheaper on this planet, and I don't see energy consumption decreasing.
The problem is it's not just the solar panels: it's the batteries and other infrastructure (and then maintenance!), and the last time I looked at it, it was closer to 20-yrs to pay back a whole system, and the system had a 20-yr life expectancy. That's break-even assuming it makes it to life expectancy.
What I am interested in is directly attaching an AC unit to a solar panel. Where I live it's generally only hot when it's sunny, so the AC would run for free.
Since the AC is one of the most expensive things to run it's win-win-win-win:
If you think imaginary property and real property are the same, when does your house become public domain?
Why are long term trends not taken into account in these reports, for example. It is rubbish to say that we cannot accurately predict climate that far into the future because our short-term predictions are not very good. After all, we cannot predict the little ups & downs in next month's weather, but we can predict that winter will follow summer and autumn, and we know what the trends are in each of those seasons. The long-term trends in global weather can be predicted as well.
On a geological timescale, we are in high summer. Winter is coming, and in 10.000 years we'll be in an ice age. The start of the downward trend in average temperatures is imminent (which means anywhere between now and 1.000 years)... Perhaps that is why the IPCC report does not look any further than the year 2100, the scary hockeystick curve will flatten out after that year, and if you look even further it will drop. Our distant descendants (if any) may even be grateful for the extra CO2 we have released, since it might make the next ice age a little less severe.
But with all that said, conservation and reducing our dependancy on a limited resource is a good thing. But I refuse to join in the mindless panic.
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
Concentration of a larger solar input area onto a smaller solar cell is nearly always better than straight 1:1 reception. The efficiency goes up with these materials, which of course is good.
But also the concentrators are a lot cheaper than the cells. The concentrator is usually a cheap (compared to the cell) lens or mirror. So a 20x concentrator gets 20x the input energy, but for a much lower cost than 20 cells. And that cell is operating at higher efficiency, on 20x the input. So a $10 cell fed by 20 $5 concentrators costs only $110 instead of $200. 5% more efficiency in the cell is applied to all 20 concentrators, not just the 1 cell, for 200% efficiency. So it's double the efficiency at 55% the price, or over 3.6x the $:energy efficiency. In reality, the concentrators are better than 5x cheaper, and the efficiency gains can go higher than 5% greater.
And then there's all the savings from cheaper replacement concentrators, which could even last longer than the cells (though the cells typically last >30 years), and dropping all the other HW from the 19 (or however many) extra cells in favor of "dumb" concentrators. In fact, since concentrators are so cheap, the cells might not require HW to track the Sun for maximum absorbtion, but just array the concentrators in an arc (or bubble) that always leaves an array of concentrators facing the Sun (and the rest off-axis), without consuming energy to move. Or extra parts, or computing, and saving all the maintenance costs, too.
So the more concentration, the better. After all, that's how the engineers thought up this stuff.
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make install -not war
"Now, you could buy solar panels at $5000 per kW (and 20 pounds). Assuming double efficiency is treble the price - you need $15,000 per square meter, so you'll pay $150,000 for solar on your car. Is it worth to drop your fuel consumption 50%? Or completely?"
This is the point where the central market planners jump in and shout that we should subsidize solar panels. But why does that solar panel cost $15,000 per square metre? Because of all the resources, energy, and labour consumed in producing it. Chances are those more than offset the gas you're not burning.
When the manufacturer can make panels efficiently enough to be more affordable than gasoline, it'll be because they're finally less wasteful and polluting overall.
A similar principle holds with recycling, by the way. In the instances where recycling actually saves on energy and raw materials, there is a cost savings as well, and the recycler will pay *you* for your bottles and cans. If the government has to make you do it, it's because the process is not cost-effective overall, and more waste is taking place in the recycling process than the recycling itself saves.
He who lights his taper at mine, receives light without darkening me.
You deliberately buy things that aren't as cost-effective as other stuff, but that reduces CO2-emissions. Unfortunately your money aren't "lost", someone will get rich, such as the bank, or the company CEO, so even this method isn't 100% convincing to me.
Seems like if you deliberately spend money on things that are less polluting than the mainstream offerings, you're helping to make that industry more economically viable. For example: if you buy residential wind turbines, the company that makes them will profit. Yes, some of that money will probably be spent on things that cause pollution, like employee salaries or airline tickets, however it will also be spent on improving and marketing a product that can reduce pollution dramatically.
No institution or individual can ever have zero negative impact on the environment, but they can have a greater positive impact, so that their damage is offset overall. The question becomes, is a supposedly "green" institution really helping the environment more than they're hurting it? Some companies really are, and it's great to give them business, but some are just using environmental concerns as a marketing niche, and giving them money will do nothing but enrich them, and possibly allow them to create more pollution.
I agree with your general sentiment, though. The key is being critical and informed about where your money goes. When you spend money, it doesn't just disappear - it goes on to pay for things that may be destructive or immoral, and couldn't happen without your money. Or, it may go on to pay for things that are constructive and really awesome. Though the amount of money you spend may be similar, the difference between these transactions is vast when you consider the consequences.