I remember reading about another "exciting new breakthrough" that would revolutionize solar because of new high outputs, vaguely something about research from South Africa. And, curiously enough, investment links.
Not that it was an investment scam...that I know of...but it was supposed to be "imminent" and of course, somehow it just never quite has happened yet.
Reminds me of the spams for hot new petroleum investment opportunities that used to go around.
"How they are rated.
Panels are rated in Watts of output. This wattage rating is derived by multiplying the panels peak power voltage times its peak power amperage (Watts = Volts x Amps). These ratings are based on standard test conditions (STC) of 1000 watts/square meter of light input, a cell temperature (not air temperature!) of 25 Degrees C (77 Degrees F), and an air mass of 1.5 (slightly above sea level).These standard test conditions are rarely found in "real world" operating conditions. For example: 1000 watts/square meter of sunlight would only be reached around solar noon, with the panel squarely facing the sun, just after a rain shower has washed all the dust out of the air. [Emphasis mine] "Real world" input is usually around 800 to 850 watts/square meter on a bright day (when you factor in dust and air pollution and consider that the panels are laid flat on the roof and are therefore not square to the sun).
When you consider that solar cells are dark blue to almost black, they soak up sunshine and get quite hot so they are operating at temperatures considerably higher than 25' C (77' F). This increased cell temperature translates into a voltage drop and therefore less output.
The air mass changes as you move from sea level to mountaintop. The atmosphere is thicker at sea level so more sunlight is interrupted by dust and pollution and less gets transformed into solar electricity. Conversely, the same panel operating from a mountaintop will see more intense sunlight and will produce more power.
This is not to imply that panel manufacturers are purposely trying to deceive you. It is because "real world" operating conditions are so variable that they had to come up with some standard test conditions so that all panel ratings "
Panels are rated in Watts of output. This wattage rating is derived by multiplying the panels peak power voltage times its peak power amperage (Watts = Volts x Amps). These ratings are based on standard test conditions (STC) of 1000 watts/square meter of light input, a cell temperature (not air temperature!) of 25 Degrees C (77 Degrees F), and an air mass of 1.5 (slightly above sea level).These standard test conditions are rarely found in "real world" operating conditions. For example: 1000 watts/square meter of sunlight would only be reached around solar noon, with the panel squarely facing the sun, just after a rain shower has washed all the dust out of the air. [Emphasis mine] "Real world" input is usually around 800 to 850 watts/square meter on a bright day (when you factor in dust and air pollution and consider that the panels are laid flat on the roof and are therefore not square to the sun).
When you consider that solar cells are dark blue to almost black, they soak up sunshine and get quite hot so they are operating at temperatures considerably higher than 25' C (77' F). This increased cell temperature translates into a voltage drop and therefore less output.
The air mass changes as you move from sea level to mountaintop. The atmosphere is thicker at sea level so more sunlight is interrupted by dust and pollution and less gets transformed into solar electricity. Conversely, the same panel operating from a mountaintop will see more intense sunlight and will produce more power.
This is not to imply that panel manufacturers are purposely trying to deceive you. It is because "real world" operating conditions are so variable that they had to come up with some standard test conditions so that all panel ratings "
And some people were wondering why we were scoffing at daily outputs that seemed to require perfect output from the SolarStik panels. I've seen how hot the solar panels can get, and mine run relatively cool, since they have a huge airspace beneath them and around them.
Add in the atmospheric dust, air pollution, imperfections in aiming them... and it isn't any wonder why anyone should doubt any results claiming to get more than 100W output from 100 W solar panels.
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Sailingdog Telstar 28
New England
You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.
—Cpt. Mal Reynolds, Serenity (edited)
If you're new to the Sailnet Forums... please read this POST.
Hey, SD, I've got a "Solar Cup" I can sell you. It consists of a rugged mounting pole with one 50-watt rated solar panel on it, and a ten foot diameter mirrored parabolic array that concentrates sunlight 10x on it, so I can get 500 watts out of it.
Now, you're going to protest that's impossible because the heat would make the panel combust, but we've thought of that too, there's a neat liquid-nitrogen cooling tube array integrated into the bottom of the panel, and you can buy liquid nitrogen refill cartridges from us anytime you need them.
Now look what you've done, my Evil Twin Brother has jumped in the thread!
HS... let me guess.. the solar panel cup powers the compressor for the liquid nitrogen cooling system and only uses 450 Watts of power to do it..
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Sailingdog Telstar 28
New England
You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.
—Cpt. Mal Reynolds, Serenity (edited)
If you're new to the Sailnet Forums... please read this POST.
Real world experience: Two friends of mine have just passed through the Suez Canal after sailing in the Pacific since 1997. They have two fixed mount solar panals on the coach roof, subject to frequent shading... I belive they are 1995 vintage 100w Siemens, but may be Arcos. They also purchased two 40w Unisolar flexible panals. For over 7 years, they actually got more power from the Unisolars, because they would move them to whatever location was unshaded.
The Unisolars were delaminating (i think both, but maybe just one) and their output was dropping. They wanted 3 more to replace them, but alas, Unisolar had gotten out of the consumer flexible panal business, and were no longer available. They bought a wind generator.
After reading 51 pages tonight while getting some chores done, i must register my complaint. I've lurked here more than a year, learning a lot, sad to post this.
This site is becoming like sailing anarchy. A newcomer says something that causes a frequent poster to make a personal remark, a fight ensues, and several join the fight to defend their comrade, while other frequent posters try to hijack the thread because everyone is embarrassed.
After a year, i see a trend of more of the above. Tell me that i'm wrong. I still have a lot to learn, and this is still a great place. I hope it stays that way.
I think you can tell someone you think they're a shill with better manners, and certainly less adjectives. How many fights have you been in? Why?
It depends... most boats are best off with a mix of wind and solar, since sunless days often have wind, and some sunny days have no wind. It also depends on what boat you're on. A smaller boat may be better off with two solar panels, if they can find a reasonable way to mount them. Wind generators need to have clearance so that they don't chop the crew in to chum... A larger boat, which generally has a larger electrical bank and higher electrical demands will usually be best off with both, and you can usually accommodate both on it.
Is the area you sail in normally sunny, then get the Solar Panels. If not, then go for the wind generator.
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Sailingdog Telstar 28
New England
You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.
—Cpt. Mal Reynolds, Serenity (edited)
If you're new to the Sailnet Forums... please read this POST.
SD
I am working on the budget for buying the boat, setting it up and sailing from the US to Australia I will be on the boat most of the time (I hope), my only thought is if there is no wind then I will be on the motor no problem, the wind generator will be on a 10' pole at the stern.
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Simon Ericson 39B.
I love my boat S/V GOODONYA Brisbane present location Moreton Bay Queensland
YACHT BROKER
