Re: [EnergyPlus_Support] Re: A question about using real-time weather data to do a simulation

Ke,

Single year actual hourly weather files in EPW format (called AMY or actual meteorological year files) with all of the required variables including solar radiation are available for any of the 8,000 global ground stations or the closest Weather Analytics virtual met station one every 35 Km around the globe. These files are available for direct order online at www.wxaglobal.com (click get a weather file). The files are not free ($75) but quick and easy and local and you cna chose full calendar years or a custom cros calendar year.

Hope this helps, Chuck from Weather Analytics

From: Ke Xu <xukevin24@xxxxxxxxx>
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Sent: Tuesday, April 10, 2012 2:48 PM
Subject: [EnergyPlus_Support] Re: A question about using real-time weather data to do a simulation

Linda,
I recalled this question today, and looked into the E+ AuxiliaryPrograms document, it is stated that
"Real-Time weather data is available from the EnergyPlus web site. From the web site:
"Hourly weather data from stations across the world is continuously collected and stored into
a local database. The data is available through this web interface. Most stations have
information for dry bulb temperature, wet bulb temperature, wind speed/direction,
atmospheric pressure, visibility, cloud conditions, and precipitation type. Data may not be
available for all stations and may not be contiguous for time period selected." The data is
available in two output formats: CSV and IWEC. Note that their CSV is not the same as
EnergyPlus CSV format. If you wish to get weather data from the real time sources, it may be
easier to use the IWEC format with the EnergyPlus WeatherConverter program; HOWEVER,
they do not collect solar data and, currently, the WeatherConverter cannot generate solar
data for these data files."
And I also checked the document "Real-Time Weather Data Access Guide" downloaded from http://apps1.eere.energy.gov/buildings/energyplus/pdfs/weatherdata_guide_34303.pdf
It indicated that the IWEC format file contains the following variables:
Entry Units/Notes
Local Date and Time YYYYMMDDHH
Dry Bulb Temperature Tenths of Degree Celsius
Dew Point Temperature Tenths of Degree Celsius
Wind Direction Degrees (0Âº = North)
Wind Speed Tenths of Meter Per Second
Altimeter Hundreds of Pascals
Visibility Tenths of Kilometers

Therefore, I think that the original data sets-either .IWC or .CSV doesn't contain solar radiation as a variable, is WeatherConverter adding the solar information somehow during the translation?

Thanks.

Ke

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Linda Lawrie <linda@...> wrote:
>
> I believe the real time weather site includes "global horizontal"
> solar. If you put that through the EnergyPlus Weather Converter it
> will use an algorithm to split the global into direct and diffuse
> that EnergyPlus needs.
>
> At 08:04 PM 9/25/2011, Ke Xu wrote:
> >Hello,everyone,
> >
> >To my understanding, the real-time weather file only includes
> >outside air dry bulb temp, dew point temp, wind direction and speed,
> >etc., but there is no solar radiation information. My question is,
> >without the solar radiation information, how does E+ calculate the
> >hourly cooling load and if it is necessary to incorporate the solar
> >radiation data, is there any public resources that I can reach? and
> >how can I incorporate that into EPW file?
>