# PreComp Theory

**URL:** <https://forums.nlr.gov/t/precomp-theory/2246>\
**Category:** Computer-Aided Engineering Software Tools\
**Created:** [May 9, 2020, 5:07am UTC](https://forums.nlr.gov/t/precomp-theory/2246 "2020-05-09T05:07:53Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Arka.Mitra](https://avatars.discourse-cdn.com/v4/letter/a/b3f665/32.png) [@Arka.Mitra](https://forums.nlr.gov/u/Arka.Mitra)\
**Post date:** [May 9, 2020, 5:07am UTC](https://forums.nlr.gov/t/precomp-theory/2246/1 "2020-05-09T05:07:53Z")

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Hi,

I would like to know the underlying theories in PreComp calculations. Is it possible to provide any kind of theory manual?

Thanks in advance,  
Arka Mitra

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**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\
**Post date:** [May 11, 2020, 1:03pm UTC](https://forums.nlr.gov/t/precomp-theory/2246/2 "2020-05-11T13:03:50Z")

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Hi Arka,

I’m not aware that a PreComp Theory manual was ever written, and Gunjit Bir–the developer of PreComp–is no longer employed at NREL. The PreComp User’s Guide references the following journal publication, although it specifically says “PreComp has been developed anew and offers features not available in the earlier code”: [asmedigitalcollection.asme.org/ … Structural](https://asmedigitalcollection.asme.org/solarenergyengineering/article/123/4/372/461484/Computerized-Method-for-Preliminary-Structural). Regardless, this publication may be a good place to start.

Best regards,