h a l f b a k e r yA dish best served not.
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
browse anonymously,
or get an account
and write.
register,
|
|
|
Please log in.
Before you can vote, you need to register.
Please log in or create an account.
|
International shipping is energy efficient, but rather dirty because ships use high-sulfur bunker fuel.
My concept is a revolutionary clean energy idea that blends solar power into the shipping logistics chain.
You know today's container ships are really humongous boaties. Huge! [See link, where
it says: huge.]
-The idea is to design a software system that computes the way in which containers are placed on a ship and the exposure of each face of each container to sunlight during the particular voyage of the ship from one port to the other.
-With these data, you can clip on solar panels on the containers that face the sun most during the voyage. You have only tree sizes in the panels: those for the top of a container, those for the long side, and those for the front.
-You clip on the solar panels, stack the containers in the right, pre-determined order, and connect them to a ginormous battery that co-powers the ship.
Let's have a look at the potential.
-A phenomeninormous container ship like the one in the picture carries some 11,000 standard containers measuring 12 x 2.35 x 2.4 meters (40 x 7.8 x 7.9 ft).
TOP LAYER:
-let's assume that the top face of all the containers at the top row receive sunlight. The number of containers in this layer: 20 x 15 = 300. The top surface area of a container is: 12 x 2.35m = 28.2 m² (40 x 7.8ft = 312 ft²).
The total surface area would be: 8460 m² (93,600 square feet).
-total power: efficiency of solar cells = 15%; 6 hours of okay sunshine per day @ 150 watts per square meter = 7,614,000 watts!!!
SIDES:
-the sides are roughly 20 long, 6 high in length, and 15 long, 6 high in breadth. We have two length-sides, and one frontal breadth side.
-total surface area of length sides: 20 x 12m x 2.4m = 576 m² times 2 = 1152m²
-total surface area of front side: 15 x 2.35m x 2.4m = 84.6m²
-total surface area of all sides = 1236m²
-total power: efficiency of solar cells = 15%; **only 2 hours of okay sunshine per day on these panels** @ 150 watts per square meter = 370,980 watts!!!!
When the containers arrive at their destination, the solar panels are clipped-off and used on others. Click, and deliver clean energy for ships on other routes.
Of course, the solar panels may receive a special coating to protect them against the saline environment of the ocean voyage. But clicking them on is a fully automated process and could revolutionaritize the entire shipping industry!!!
!!!
It is truly gigantuous!!
http://i3.photobuck...l/hunormousboat.jpg
Huge. [django, Sep 08 2008]
SkySails - kite more powerful than PV cells
http://www.skysails.info/
Much, much, much, much, much, much, much more powerful. Much so!! [django, Sep 09 2008]
U.S. Solar Radiation
http://rredc.nrel.g...srdb/redbook/atlas/
US insolation maps [MechE, Sep 09 2008]
[link]
|
| |
//7,614,000 watts!!!//
A mere 1/150th the power required to drive a half-decent DeLorean.
Bun anyway.
sp. "metre" |
|
| |
So a half-decent DeLorean car sports hundreds of thousands of horse power? |
|
| |
Someone is making a mistake here. Could be me, cause I'm not good at maths. :-) |
|
| |
Yeah your arithmetic is wacky. |
|
| |
TOP: 8460x150x(6/24)*0.15=47587.5W average for a 24 hour day...not 7614000!!! as claimed. |
|
| |
SIDES: 1236x150x(2/24)*0.15=2317.5W average for a 24 hour day...not 370980!!! as claimed. |
|
| |
So yeah, it's actually 0.6% of what you claim. |
|
| |
It's also only 50kW, i.e. the same power as a 1.3L Honda. |
|
| |
The power is completely inadequate to make the idea float. |
|
| |
Texticle, wait, then I have a totally wrong idea about the potential of solar power. |
|
| |
If a series of panels spread out over the surface area of a really humongous, gigantous mega-container ship, yields only the power equivalent of a tiny car - then how can it ever have a future? |
|
| |
I though solar power had a future. Sad me! |
|
| |
/Optimal solar energy load on a square metre is roughly 1kW. Peak efficiency of PV panels is about 40%. Let's assume 10 hours/day at 65% energy load, averaged./ |
|
| |
650W/m² insolation for 10 hours on a given day?! The brochure may say something like that, but those things are written by salespeople. |
|
| |
Also 40% is a bit of a stretch outside of the lab. |
|
| |
Yes [django], PV panels are generally a poor choice where other forms of energy are available. |
|
| |
Compared to PV panels, the simple technology of a kite seems to yield much, much, much, much, much, much, also: much, more power. |
|
| |
See this link, about the SkySails. The company says its kites can perhaps cut fuel consumption of a large ship by 30%. |
|
| |
And it would be much, much, much, much, much, moreover: much, cheaper than PV panels. |
|
| |
In any case, perhaps when future solar power panels are like a plastic sheet and dirt-cheap, one can use it in my clip-on system. Just for the show and the greenwash, not so much for the power. |
|
| |
But why not put those solar panels somewhere on land where they can stay fixed and get the same amount of sunlight. The cost of moving them around, essentially reinstalling them, every few weeks must get expensive. |
|
| |
//may run as high as 2400W/m2// on *this* side of the atmosphere ? I thought it was more like 500w/m2 at the equator, hmm... gotta check that... |
|
| |
[edit] insolation at the *top* of the atmosphere at the solar-plane equator is 1366w/m2 (over the elliptical course of a year)... still looking for a decent ground-level figure, but 1kw/m2 at the equator on a sunny day at noon seems to be the concensus. |
|
| |
Solar panels will come into their own as the price per watt installed comes down. While these ships are giant for a man-made mobile structure, your numbers show that they actually cover less than a square kilometer. In the areas with the highest insolation there tend to be lots of vacant square kilometers. (Arizona/Nevada, Saharan Countires, etc.) Additionally, once the cost is brought low enough, there is no reason not to install them on the roof of all new construction, for instance. In that case, the use of them in conjunction with diesel electric systems may indeed make sense. |
|
| |
Oh and as far as insolation, yes, peak value on a flat plate collector is 1kw/m^2. What I suspect UB was refering to was daily values which, in the US range from as low as 1-2 kwH/m^2/day average in Alaska, to 5-6 kwH/m^2 in the desert southeast. Thus, even in Alaska, 18m^2 will provide enough power to offset the average US residental (~1000kWh/year) usage. And yes, I realize that Solar isn't going to work in Alaska in the winter, I'm just pointing out that solar does have potential. Even in January, most of the country would be adequately served with a similar sized array and storage batteries to cary over through the night. (I aologize for the US-centrism, that's what I had the numbers available to hand for) |
|
| |
//So a half-decent DeLorean car sports hundreds of thousands of horse power?//
Oh yes - one point twenty-one gigawatts! |
|
| |
/..Thailand and central Australia may run as high as 2400W/m2/ |
|
| |
This is crazy talk, as per the 1366W/m² insolation figure that [FlyingToaster] has mentioned. |
|
| |
[MechE], if your daily values are correct (are they refering to beam insolation, as they seem kind of high for a fixed collector?) I think you are neglecting all the inefficiencies in the system. The collectors themselves are only going to be 15% efficient, then you've got to store the energy, and then you've got to invert it for use/distribution. Factor in the signifcant capital cost throughout, and the payback period will by far outlast the expected life of the components. Clearly a much bigger collection area will also be required. (Also I think you dropped a zero in your US residential annual usage figure). |
|
| |
Those numbers are accurate for a flat
plate collector. A 1 or 2 axis tracking
collector can do significantly better. I
did just use 15% for the efficiency, but
the total losses in a grid tied system are
typically only another percent or two,
with maybe another percentage point
loss for battery storage (of the total, so
10-13% of insolation), so at most
27m^2 still within most roof sizes. |
|
| |
A solar installation is not cheap, as I
mentioned the cost of panels (And
inverters) needs to come down. Even
now, however, it is not completely
impractical. At present a solar
installation in the southeast will pay for
itself (flat, not TVM, and without
incentives) in about twenty years. Since
the stated life of such systems is about
that time, it gives a flat payback.
However, every long installed system I
am aware of has continued operating
well past its stated life, barring
catastrophic damage. |
|
| |
And your right, should be
10000kWh/year, but that is the number
I used in my figures. |
|
| |
[MechE], where is the 15% in your calculation? 1.5kWh/m² per day times 18m² with 100% efficiency is 27kWh/day or 10000kWh/year. Your conclusion that such an Alaskan panel could supply a household implies use of a 100% efficiency factor. |
|
| |
[Textile] Right again, sorry don't know where my brain was on the math. So an Alaskan household would need between 120 and 180 m^2 to completely offset its usage, which I'll admit is getting excesive. |
|
| |
Panels tilted at lattitude, or even lattitude-15% which would be ~ a 45 degree angle, so practical for rooftop mounting on a south facing roof, provide somewhere between double and triple the input. Which does cut it to ~40-60 m^2. So under the absolute worst possible conditions, a household can still carry clost to enough solar to completely offset it's usage. And again, I'll admit that Solar is not practical in Alaska due to extremely low (non-existent in the further north) production during the winter. |
|
| |
Under the conditions that apply for most of the rest of the country, however, a relatively minor reduction in the cost of a solar installation (panel cost, primarily, although again, the inverters make up a significant percentage of the installed cost) will be enough to bring them entirely into the practical range. |
|
| |