Talk:Air mass (solar energy)

Antiplano or altiplano?

I'm ignorant... Is it an antiplano with an incorrect internal reference or altiplano with a typo? 129.67.19.65 (talk) 10:22, 14 April 2010 (UTC)

Consider merging "Airmass" and "Air mass coefficient" pages?

I notice that two pages - this page "Air mass coefficient" and "Airmass" cover similar territory. However I also see that keeping them separate has value:

• this "Air mass coefficient" page to:
  • define the term "Air mass coefficient" and
  • as a practical summary for practitioners in the solar industry

• whereas the "Airmass" page provides a more theoretical and comprehensive coverage of the atmospheric physics at play, the various models that have been developed, and usage in other contexts, i.e. optical astronomy.

However, someone might like to reflect on merging the pages. In the meantime, I've added cross-references between the two pages, so you can easily notice both regardless of which one you land up on first. Hope this helps. —Preceding unsigned comment added by Anmclarke (talk • contribs) 02:22, 30 April 2011 (UTC)

I’d keep the articles separate. I agree that there′s a fair amount of common ground, but the approaches and styles are quite different. We undoubtedly could merge them (assuming we could agree on which to follow), but nonetheless, the very different ways in which astronomers and solar engineers seem to approach the subject (e.g., a simple quantity symbol such as X vs, the mnemonic AMn favored in solar engineering) might be confusing for the reader.

We might want to consider more systematic naming, including deciding whether “airmass” is one word or two. We then might have something like Air mass (atmosphere) for the current Airmass and Air mass (solar energy) for this article. JeffConrad (talk) 20:25, 15 May 2011 (UTC)

Thanks Jeff. Makes sense. Being very much a newcomer I didn't feel it was my place to change the names of articles other people had created (and nor would I know how to). It seems that astronomers do tend to use the one word "airmass" form and others don't??? But it gets worse: there's also a 3rd related article! - the "Air mass" (meteorology) article. And a <space> seems hardly enough to differentiate two article names. A general readership is most likely to want the meteorology article. So what about something like: Air mass becomes Air mass (meteorology); Airmass becomes Air mass (theory); Air mass coefficient becomes Air mass (solar energy); leaving the way open for someone to write a more detailed article about Air mass (astronomy). - anmclarke 11:09, 16 May 2011 (UTC) —Preceding unsigned comment added by Anmclarke (talk • contribs)

I think Air mass (theory) may lose a few people, because it doesn’t provide context, especially to contrast it with meteorology. Perhaps atmosphere isn’t quite right, because it’s obviously an atmospheric phenomenon for solar energy applications as well. I had thought of astronomy, because most of the citations are from astronomers, but it doesn’t say much about actual observing. Conceivably, it could apply to other areas, such as photography (How bright is the Moon? It depends . . .); offhand, I don’t have any good sources, but it’s straightforward to determine a zenith–horizon difference in EV from any of the various formulas. All things considered, I still lean toward atmosphere, but perhaps someone else has a better idea—it’s hardly something that needs immediate resolution. JeffConrad (talk) 14:59, 16 May 2011 (UTC)

I don't know about the others, but this one is specifically for solar cell research, and those reporting or reading about efficiency. It is the same atmosphere that the others are about, but the reasoning, and so emphasis, is different. Gah4 (talk) 00:41, 4 May 2019 (UTC)

Correction of solar intensity for site altitude

For equation I.2, the page refers to reference [18] (Laue, The measurement of solar ... irradiance at different terrestrial elevations, 1969) for the source of the correction term h/7.1. However, Laue’s paper does not suggest this, but applies an alternative correction, where air mass (AM) is corrected with the ratio (local pressure)/(101325 Pa). Ref. [18] should therefore be removed from I.2 — Preceding unsigned comment added by Peter.schild (talk • contribs) 12:54, 18 September 2012 (UTC)

I'd like to add that Eq. (A.4), $AM={\sqrt {(r+c)^{2}\cos ^{2}z+(2r+1+c)(1-c)}}\;-\;(r+c)\cos z\,$, assumes, implicitly, that the density of air is a constant throughout the layer of the atmosphere, but this assumption is not correct. --Roland (talk) 02:18, 8 March 2022 (UTC)

AM2

Years ago, when I was working with a lab doing solar cell research, we used AM2 for tests, and had actual glass filters to approximate AM2 illumination. I believed at the time that this was usual for US research, given the US average latitude. This article doens't seem to make AM2 seem so popular as I remember. Did things change over the years? Gah4 (talk) 05:01, 4 April 2019 (UTC)

More specifically, it seems to suggest that now AM1.5 is used for solar cell researchers. When did it change from AM2 (in 1981) to AM1.5 (now)? Gah4 (talk) 00:39, 4 May 2019 (UTC)

temperature a black body of the same size must have to yield the same total emissive power

The article says: temperature a black body of the same size must have to yield the same total emissive power. I would have expected it to be based on the spectrum, not the emissive power. Gah4 (talk) 00:44, 4 May 2019 (UTC)