# PVsyst's forum

Welcome on PVsyst's forum.
 It is currently Tue Feb 25, 2020 2:50 pm

 All times are UTC+02:00

 Post new topic  Reply to topic Page 1 of 1 [ 3 posts ]
 Print view Previous topic | Next topic
Author Message
 PostPosted: Tue Feb 04, 2020 9:12 pm

Joined: Fri Jan 31, 2020 12:44 am
Posts: 2
My runs of PVSyst indicate that, for exactly the same system design inputs, a percent decrease in GHI levels causes about the same percent decrease in energy generation.

So far I have tested 5%, 10%, 11%, 12%, 15%, and 17% GHI decreases by editing my hourly GHI data in PVsyst standard format. In each case, these decreases produce a PVsyst-predicted decrease in solar plant energy generation of about 1% less than GHI was decreased (i.e. a 10% decrease in GHI results in a 9% decrease in energy generation).

Is this conclusion largely accepted by the community of solar energy plant analysts?

If so, and given the mathematical relationship between GHI and insolation, can I presume that the same conclusion can be stated for an insolation decrease by the same above percentages?

Thank you for any insights!

Top
 PostPosted: Fri Feb 07, 2020 10:51 pm

Joined: Tue Oct 18, 2016 3:31 am
Posts: 262
There are more variables to consider on a site specific basis, and when comparing different locations. If you are looking at a single site, and comparing changes in GHI year to year, a decrease in GHI may correlate to an increase in diffuse, lower temperature, etc, which depending on system and equipment, may not give the relationship you've calculated. It also depends on system design. High DC AC ratio site may not give the same result, shading losses may be different, etc. So, not quite, at least we don't, due to the uniqueness of each project.

Top
 PostPosted: Sat Feb 08, 2020 12:01 am

Joined: Fri Jan 31, 2020 12:44 am
Posts: 2
Got it, thank you for your response!

Top
 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Post new topic  Reply to topic Page 1 of 1 [ 3 posts ]

 All times are UTC+02:00

 You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum

Search for:
 Jump to:  Select a forum ------------------ PVsyst SA Announcements (read only)    Latest news - Bifacial Modelling and 3D Drawing    PVsyst's forum rules FAQ (read only)    Installation and use of PVsyst    Meteo data    PV Components    Shadings and tracking    Simulations : parameters    Simulations : results    Standalone and pumping systems Your questions about PVsyst    Howto    Problems / Bugs    Meteo data    PV Components    Shadings and tracking    Simulations    Suggestions    Tutorials : Feedback and requests Links    PVsyst website    YouTube Channel