License to Print Money
cringely.com
cringely.com
I'm not an expert in solar panels by any stretch, but my understanding that the two major breakthroughs we need are a) how to make the solar panels themselves more efficient over a long life-span. Typically they lose 2-4% of their efficiency every year, meaning 20 years down the road, they've lost 50% of their energy power. b) a more efficient converter from the DC generated by the solar cells to the AC we put back into the grid.
In others words, design it with replacement by do-it-yourself homeowners in mind. I looked up the spec for one and it was 1250x800 mm (~4x3 ft) and weighted 12 kg (~25 lbs). That's a little awkward for one person to cart up a ladder, but what if they were half the size and had a strap handle on the side? What if they used quick disconnects for mounting? If you set out with these as design goals, then I'm sure a feasible solution could be found.
Smaller panels can make it easy to replace gradually, acouple here, a couple there...
In practice such things are not common at all, people don't have friends who will just go up on roofs and do serious work. The best you can hope for is something as easy as installing Christmas lights (which doesn't even require getting on the roof itself, just up to the eaves).
$1000 every two years is less than $50 month.
I'd happily pay $50/month for all my electricity.
Roof area of an average new house: maybe 100 m^2?
Peak solar flux: 1 kW/m^2
Take into account the existence of night, cloudy days, and the fact you're probably not at the equator: divide that by four.
Efficiency of these solar cells: they have a "goal" of 10%, so let's optimistically assume they make it.
So we're collecting, on average, 0.11001000/4 =2.5 kW.
Actually, y'know, when I started this calculation I was anticipating something ridiculously small, but that's a not-insignificant fraction of your usage. Am I missing a factor somewhere?
Use the power grid as your battery.
Another big one not mentioned yet: ever noticed how dirty your car looks after being left outside for a couple of weeks? Well have fun washing your roof as often as you wash your car.
That's still somewhat optimistic; about 10--20% of peak is more realistic, based on what we've seen with existing solar installations. It's closer to 20% in sunny places, and closer to 10% in places with less sun.
However, that still leaves us with a respectable amount of electricity. Good for them.
Of course, the panels themselves are not the whole cost. There's other electrical equipment needed to make that energy usable, for example, and someone has to install and maintain the solar panels. I think the next big source of money in this market, after they get the cost of manufacturing the panels down far enough, is streamlining installation and maintenance. Perhaps someone could make durable "solar shingles" that are relatively easy to put on a house, or some such thing.
Longer-term, solar photovoltaics look like they could provide a pretty hefty amount of energy cheaply, if we solve a lot of engineering issues. Where they fall down is producing power reliably, close to where it's needed. One way of dealing with this is to have the solar panels in space, but obviously that's pretty tricky. Another way of dealing with it is to use something else to provide the base load of your electrical grid -- nuclear could handle this with cheap green aplomb -- and use the solar power for things which can easily soak up cheap intermittent power, such as charging the batteries of electric or plug-in hybrid cars. Theoretically, it could also be used to power interesting energy-hungry chemical processes, like ammonia synthesis or aluminum refining. Making this financially viable is another big engineering challenge, but definitely a worthwhile one if it works out.
Note: these are not cost competitive with "regular" CSI panels - they are mostly for people who put a premium on appearance.
Just because of day and night divide by three. (2 for day night, plus some extra due to twilight).
Then for upper latitudes divide by 2 again, and then finally divide by 3 because only part of the roof will face the sun. So your factor should be 18 not 4, i.e. your numbers are 4.5 times larger than they should be.
BTW your multiplication symbols turned the number inside it italic.
They just have the minor hitch of not, in fact, existing.
kWh/day is even worse -- it's a unit of power made by dividing a unit of energy by a unit of time, multiplying it by a second unit of time, and dividing it by a third unit of time!
And now if you'll excuse me, I'm going to go for a jog at 0.11 meter days per hour per second.
For comparison 1kWh = 3.6 MJ.
How would transparent solar cells work? Would the light coming in be part of the <90% of the light not being converted to electricity?
It seems like a "disposable society" solution to solar power, and I'm not convinced unless it comes with a clear recycling program.
Not to worry though. If these are used in any kind of large installations then the scrap value of the expired cells will be part of their profit. At the very least they might be fuel for cement kilns. If they can burn tires (when not in anyone's backyard) then thin sheets of plastic should be easy.
http://www.konarka.com/index.php/power-plastic/material-char...
the materials used are 100% recyclable.
I recently finished "The World Without Us" by Alan Weisman, and his discussion about the long-term impacts of our reliance on plastics struck me as a very under-appreciated burden on the environment - a huge amount ends up in the ocean, where it breaks apart but doesn't actually go away - it just becomes bite-size for smaller and smaller organisms, with predictable effects along the food chain.
I am wary of a "race to the bottom" in terms of cost/watt because it undervalues other aspects of energy production, where the "good enough" mentality hasn't turned out very well in the past (nuclear and coal in particular). This particular technology seems aimed more at being financially-sensible, and I am concerned that the long-term environmental impacts are not being weighed heavily. It's important to factor in the cost, convenience, and logistics of the whole life-cycle of a technology, not just the cost/watt for a limited time frame.