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Garage_Hermit

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Reply with quote  #11 
With regard to Dan's message at #4 above:

solarelectricityhandbook.com/solar-irradiance.html

contains an error in that it states "Measured in kWh/m2/day..."

It should state "Measured in kWh/m2" (period).

The displayed information is erroneous because the figures shown are not daily totals...

Taking an example from the site, for my own locality:
according to the link, for January, I receive "1.43 kWh/m2/day"

Therefore if my collector is 10 square meters, it receives 14.3 kilowatt-hours per day.

However, using Gary's tables at HERE... http://www.builditsolar.com/References/SolRad/Lat48.htm
the daily total for a vertical mount is 1478 BTU per square foot.

Multiplying this by 10.76 gives 15,900 BTU per square meter over the day,
/3412 = 4.66 kW

which is 3.25 times MORE...

Thus IMO Gary's tables are better, in that they speak of "global irradiance" and use the correct units - "BTU per hour per square foot"

per THIS... http://www.3tier.com/en/support/solar-prospecting-tools/what-are-units-solar-irradiance/

Quote:
The total amount of solar energy that falls over a given time is called the insolation. Insolation is a measure of energy. It is the power of the sun added up over some time period.


In effect, POWER is ENERGY described as a function of TIME (and not as a function of... TWO TIMES) (viz. an hour, and a day...).


 
 
 

Solar Irradiance Figures

Select Country: 
  
Select Town/City: 
Solar Panel direction: 

[solar-angle-vertical]

Rennes
Average Solar Insolation figures

Measured in kWh/m2/day onto a vertical surface:
JanFebMarAprMayJun
1.43
 
2.11
 
2.51
 
2.72
 
2.75
 
2.75
 
JulAugSepOctNovDec
2.79
 
2.95
 
2.84
 
2.27
 
1.77
 
1.28
 

Click on the images below to see irradiance figures for different angles:

Vertical Surface Optimal Year Round
  42° angle
 Adjusted throughout the Year
 
Best Winter Performance
  27° angle
 Best Summer Performance
  57° angle
 Flat Surface

Dan, in view of the above, and provided U (and other members) agree with my reasoning, it might be a good idea to simply dump the link in question

G_H

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solardan1959

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Reply with quote  #12 
Hermit,
   Give me two dollars and I'll remove it.  (my attempt at making money from solar)  Also, no Francs or Euros excepted but I do take gold and paypal.  I'm normally not that ornery but I'm feeling bad since I got that link from a questionable source anyway.

Dan
Garage_Hermit

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Reply with quote  #13 
Dan, I'll pay you in *water* (a US gallon being the equivament of "8 pound something"...) [biggrin]
(or 10 euros / 12 USD!)

G_H

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(2) It's wrote, "voilà" unless talking musical instruments...
solardan1959

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Reply with quote  #14 
Hermit,
  8 pounds of water, you pay the  shipping cost, plus customs, if it gets through it sounds like a deal....done!

Dan
mattie

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Reply with quote  #15 
Plot the position of the sun at any location in the continental United States.
http://www.solarplots.info/
Garage_Hermit

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Reply with quote  #16 
Nice tool ! The "daylight saving" button is a neat feature for determining solar noon !  (for my own part, I sometimes get dyslexic !)

Interesting to see that Minneapolis is only 4 minutes behind  me !

G_H

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(1)  "Heat goes from hot to cold, there is no directional bias"
(2) It's wrote, "voilà" unless talking musical instruments...
solardan1959

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Reply with quote  #17 
The sustainable by design link quit working apparently because the site was moved, here is the info for a new link and the place it should end up.
I also added this in the main post (#post # 1)

On Feb 15, 2015, at 6:03 AM, Daniel Sargent wrote:

> Chris,
>     Found your site and toolbox through Gary at build it solar and found them useful and informative.  I noticed the link does not work any more and was wondering if you just moved on or moved somewhere else. (also noticed there is a sustainable by design furniture co. so that is awkward)

Hi, Dan...thanks for writing!  I moved to a new web host, and apparently http://www.susdesign.com
isn't working right now, so I'll get that fixed.  This works right now, though:

        http://susdesign.com

Thanks for letting me know!

Cheers,

Christopher
Gonçalo Sousa

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Reply with quote  #18 
For people in India, a recommend this specific calculator: 

http://indiagoessolar.com/solar-calculator/
electrodacus

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Reply with quote  #19 
I'm an electrical engineer new on this forum.
I live OffGrid moved two years ago and I do have quite a bit of knowledge about solar and efficient house design.
I studied option for heating my small house that is in Canada Saskatchewan with long and cold winters.
And my decision will be to heat with electricity from solar PV panels at the moment the most cost effective method for me.
When I designed the house about 3 to 4 years I will say that is a bad idea but the price on PV drooped so much that is really the best option for me.
Not sure I will be alowed to post a link to a calculator is the PV Watts version 1 search for that if there is no link http://rredc.nrel.gov/solar/calculators/pvwatts/version1/
That seems to be one of best tools to calculate solar energy available at your location and has most locations around the world so you can compare with others.
It is extremely precise for PV based on my experience and it works for thermal solar if you know how to take and use those values.
This online calculators are good for the statistical data they have collected you need to know what to expect and how to calculate the amount of energy that you will need and produce and also the amortisation cost for unit of energy that is quite important.
If you are building a new house do not forget to incorporate thermal storage in to design it will cost almost nothing and is extremely valuable is like a thermal battery for your solar energy.
viracocha

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Reply with quote  #20 
Found this one the other day.


http://suncalc.net/#/44.9833,-93.2604,14/2015.08.29/10:03
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