Lukas,
You're correct. I think that was also what I written in my original post, i.e., that the TimeHourOffset should be -0.5 for North American convention solar data from -1:00-0:00. What's confusing to me is that TimeHourOffset was added only recently, so if you don't specify it in the def file, it will use a default of -0.50. In any case, the solar position has to be consistent with the solar data in your weather file. I actually think the TimeHourOffset is much more needed in EnergyPlus than in the WeatherConverter, so you don't have to do things like the longitude shift when running EPlus with European convention weather files. In the WeatherConverter the only benefit with the TimeHourOffset is if you're using the WC to calculate DNI from GHI in European convention, and even then you're still stuck with having to shift the longitude when using that file in EnergyPlus. I suggested adding this parameter to the EnergyPlus Team a couple of years ago and although the suggestion was well received I never heard anything since. BTW, how does IDA-ICE deal with this difference in convention?
Sent from my iPhone
Joe Huang
White Box Technologies
346 Rheem Blvd Suite 108D
Moraga CA 94556
(o) 1(925)388-0265
(c) 1(510)928-2683
On Feb 6, 2016, at 7:08 AM, "lukas.rokka@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
Hi Joe
If all solar data are on the full hour, I think "moving 7.5 degrees westwards" and setting TimeHourOffset=0 is the correct thing to do (for Energyplus, not for e.g. IDA ICE).
But in the case of having GHI and DNI as -1:00-0:00 data, and wanting the Weather converter calculate DHI as -1:00-0:00 it' seems that TimeHourOffset=-0.5 is the right way to go for correctly formatted epw files.
Regards,
Lukas
__._,_.___
Posted by: Joe Huang <yjhuang@xxxxxxxxxxxxxxxxxxxxxxxx>
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
The primary EnergyPlus web site is found at:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
Attachments are currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
__,_._,___