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Solar Panel Efficiency
Optimizing the output of my solar panel
Sat December 18 2021  7:26pmMisc.


sine = efficiency
You remember, of course, all the trigonometry you learned in school, and its practical applications to daily life. Well, here's another example:

The solar panel is at its peak efficiency when directly facing the sun: that is, when the panel is perpendicular to the rays from the sun. This corresponds to the sine value of 1.0 for a 90° angle, as the graph illustrates. When the panel is parallel to the rays of the sun (0°), or away from the sun, the efficiency drops off to practically nothing. At angles between these two extremes, the maximum relative efficiency changes as a sine function of the angle. For example, sin(65)=.9063, so at an angle of 65° the maximum potential efficiency of the panel will be a bit more than 90%.

The practical importance is that I can expect to harvest more of the sun's light if I can keep my panel facing the sun, like a sunflower. It needn't be exactly 90°; anything close to the top curvature in the graph will be fine. The aforementioned 65° sounds like a reasonable goal. If my panel never strays more than 25° in any direction from the sun, that gives me 50 total degrees of tolerance for inexactitude, while still attaining 90% efficiency or better.

Now, this is fun math, but only as an approximation or a hypothetical ideal. Even on a sunny cloudless day, earth's atmosphere diffuses a certain percentage of the sun's light, so that light is coming from all directions, not just from the point of the sun. Were it not so, our sky would be completely black, as in outer space. So the efficiency is not 100% at 90°, and is not zero at 0°. On overcast or rainy days (LOTS of those in Nicaragua), the diffusion is even greater and the efficiency curve much flatter. Nevertheless, this seems to be an idea worth pursuing. I hope to follow with another blog article or two, in trying to implement the above to improve my solar panel system.

 
Solar Panel
Harvesting the sun for my house
Sat January 30 2021  11:43amMisc.


solar panel

Have recently purchased and installed a solar panel with its various components. Not motivated primarily by ecological nor economic concerns. The grid for large areas of Nicaragua gets its power from a well engineered and environmentally friendly hydroelectric dam just north of Jinotega. My monthly light bill is typically between $U10 and 15 for around 80 to 100 kilowatt hours of energy consumption. But Disnorte is poorly administered and unreliable. Besides, I like the idea of being a bit more independent. Call it a learning experience, if nothing else, and a possible hedge against future needs.


batteries, inverter, etc.

This initial modest experiment isn't intended to make me energy independent. As a beginning, only one of the house's three circuits are solar powered: the most critical circuit containing both refrigerator and computer. The entire system consists of a 300 watt solar panel mounted in an open area on the roof, three 12 volt batteries for night time and other standby power, a 1200 watt inverter to convert the solar and battery DC current into 120 volt 60 Hz AC house current, a controller and cables to connect all these, all located indoors in a spare room, and a double throw knife switch (in a different room, not pictured) to switch the circuit back and forth between solar and Disnorte, if needed.

Speaking of learning experience, I've already learned that the inverter's internal circuitry is particularly sensitive to short circuits and reverse polarity (blush!) Am also still learning how the panel, controller, and inverter interact, and hope to perhaps take better advantage of the panel's full capacity. To that end, am supposing that the panel is most efficient when facing the sun more or less directly. The panel as pictured is mounted at an angle of 24.5° to the south of horizontal. For late January in Nicaragua, this is not too far from ideal, but that angle ought to vary from time to time for greater efficiency. You might be interested in a javascript routine that I wrote to help in this regard.

Perhaps more articles to report on any progess or regress.

  2 comments
rev. Feb 12 2021  8:31pm
 
DePyper
Honoring the name my father gave me
Thu October 24 2019  4:33pmMisc.

Am planning some small website changes soon, but first want to publicly clarify another matter that is of great personal import and may also have a slight impact on the planned website changes.

My family name is DePyper, a compound, two-part surname of Belgian origin. Am not sure of the etymology; it may originally have meant something like 'the piper', as in the village flute player, or, more likely, 'of (the town of) Pyper'. Either way, 'Pyper' was the important part, and 'De' (or 'de') merely the prefix.

I grew up learning to write my family name as DePyper, but also to recognize and accept De Pyper and de Pyper (read article)

  1 comment
rev. Nov 26 2019  6:40pm
 
Unrest in Nicaragua
The crisis in Nicaragua: A foreigner's viewpoint
Wed July 4 2018  3:23pmMisc.

It started out in April as a peaceful protest of Daniel Ortega's proposal to cut social security benefits, and of his tyrannical repression of dissent. So say the news reports. But from the beginning it has involved looting, burning, and extracting 'donations' from motorists who want to pass through. And when Ortega quickly renounced his social security proposals, the protests only intensified. For a couple months now these 'peaceful' demonstrations have been occupying marketplaces and interfering with transportation (including transportation to and from the hospital). Many of the youth manning the roadblocks are recognized as local thieves and loafers, no job, no schooling, still living (read article)

  7 comments
rev. Dec 4 2018  10:48am
The law will never make men free; it is men who have got to make the law free.
- Henry David Thoreau

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12/18/21Solar Panel Efficiency
1/30/21Solar Panel 2
10/24/19DePyper 1
7/4/18Unrest in Nicaragua 7
Copyright (c) 2017-2022 Gerald DePyper - Jinotega, Nicaragua, C.A.
rev. 2021.12.15