Climate

To view the Climate page, click Climate in the main window's navigation menu.

The Climate page allows you to choose the weather data file that Solar Advisor uses for all simulations in the current case. The Climate page displays a summary of the weather data, and also allows you to view all of the data in the hourly data viewer.

Contents

►	Input Variable Reference describes the input variables on the Climate page.

►	Managing Weather Files explains how to add weather files to the location list and how to include weather data in your project file.

►	About Weather File Formats describes the TMY2 and EPW weather formats that Solar Advisor recognizes.

►	Weather File Data Elements describes the weather data elements used by each of the five technologies that Solar Advisor models.

►	Downloading and Using EPW Weather Files explains how to download EPW files from the EnergyPlus website.

To choose a weather data file:

1.	In the Location list, click the location name.

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If the location you are modeling is not in the list, you can:

•	Check to see whether data for your location is available in EPW format.

•	If you have your own weather data file in either TMY2 or EPW format, add the file to the Location list.

•

Purchase the Meteonorm database and software package, which contains climatological data for over 7,700 global weather stations and can convert the data into TMY2 format. Meteonorm can also import weather data in various formats and convert it to TMY2. The Metonorm website is http://www.meteonorm.com.

Input Variable Reference

Choose Climate/Location

Choose a location from the list of locations. If you plan to use a weather file that is not in the list and want to share your Solar Advisor project with another person who does not have a copy of the weather file, click Copy to user file to include the weather file in your project. (See below for more details on managing weather files.)

Variable	Description	Units
Location	The name of the weather file. A filename preceded by "SAM/" is a standard weather data file included with Solar Advisor and stored in the \exelib\climate_files folder. A filename preceded by "USER/" is a file stored with the SAM file.	--

Location Information

The location information variables display data from the weather file header that describes the location. An empty variable indicates that the information was not included in the header. The location information variables cannot be edited.

Variable	Description	Units
City	The name of the city.	--
State	The state abbreviation.	--
Timezone	The location's time zone, relative to Greenwich Mean Time (GMT). A negative number indicates the number of time zones west of GMT. A positive number indicates the number of time zones east of GMT.	--
Elevation	The location's elevation above sea level in meters.	m
Latitude	The location's latitude in degrees. A positive number indicates a location north of the equator.	degrees
Longitude	The location's longitude in degrees. A negative number indicates the number of degrees west of the Prime Meridian.	degrees

Weather Data Information (Annual Averages)

Solar Advisor calculates and displays the annual average of four of the hourly data columns from the weather file in the weather data information variables. Weather data information variables cannot be edited. You can view graphs and export data tables of the hourly data and statistical properties by clicking View hourly data.

Variable	Description	Units
Direct Normal	The annual average of the direct normal radiation data in the weather file, expressed in watt-hours per square meter.	Wh/m2
Diffuse Horizontal	The annual average of the diffuse horizontal radiation data in the weather file, expressed in watt-hours per square meter. Note that the annual average global horizontal radiation is the sum of the direct normal and diffuse horizontal components.	Wh/m2
Dry-bulb Temp	The annual average of the ambient temperature data in the weather file in degrees Celsius.	°C
Wind Speed	The location's elevation above sea level in meters.	m

Managing Weather Files

Solar Advisor comes with a collection of weather files that it displays in the Location list when you first install and run the software. You can add weather files to the list, as long as they are in one of the two formats that the software recognizes: TMY2 or EPW (see below for a description of the formats). The default location for the weather files is \exelib\climate_files, but Solar Advisor can read weather files stored in any location on your computer. When you add locations to the list, you are simply adding a search path that tells Solar Advisor where to look for the files, not making copies of the weather files.

To add weather files to the Location list:

1.	On the Climate page, click Settings.

2.	In the Library Settings window, click Add.

3.	Navigate to the location on your computer where the weather file is stored.

You can add as many file search paths as you wish.

4.	Click Close to return to the Climate page.

Solar Advisor adds the search paths you added in the Location list.

To remove a search path from the list, click Settings to open the Library Settings window and then click Remove. Note that removing a search path does not delete any weather files.

When you want to share a Solar Advisor Model project with another person, and the project uses one or more weather files that the other person does not have, you can include a copy of the data from the weather files in the Solar Advisor Model file. Including weather data in a Solar Advisor Model file increases the size of the file, but also makes it more portable. For example, the size of the PV sample file with no weather files is 35 kB, with one weather file 274 kB, and with two weather files is 503 kB.

To copy data from a weather file to the project file:

1.	On the Climate page, choose the weather file from the Location list.

2.	Click Copy to user file.

Solar Advisor adds the file to the location list with the "USER/" prefix, indicating that the data is included in the Solar Advisor project file. To remove a file from the list, select it, and click Remove from user file.

About Weather File Formats

Solar Advisor uses weather data files in two formats: Typical Meteorological Year format (TMY2) and EnergyPlus Weather format (EPW). Although Solar Advisor does not read files in the new TMY3 format, you can download them in EPW format from the EnergyPlus website. To learn more about the formats, visit the following websites:

•	TMY2, http://rredc.nrel.gov/solar/old_data/nsrdb/tmy2/

•	EPW, http://www.eere.energy.gov/buildings/energyplus/weatherdata_format_def.html

•	TMY3, http://rredc.nrel.gov/solar/old_data/nsrdb/1991-2005/tmy3/

The TMY2 and TMY3 files are for U.S. locations only. You can download weather data for additional U.S. locations and locations in other countries in the EPW format as described below.

Solar Advisor weather files must meet the following criteria:

•	A text file in TMY2 or EPW format.

•	Filename extension tm2 or epw.

The data in TMY2, TMY3, and EPW files is typical year data, which is determined from long term measured data. Data for individual years (U.S. locations only) is available in the TMY2 file format from the following Beta test versions of NREL websites:

•	Renewable Planning Model test website https://rpm.nrel.gov/rpmentry/

•	Solar Prospector, http://mercator.nrel.gov/csp/

The time convention for Solar Advisor hourly simulations is determined by the convention used in the weather data. For example, TMY2 and TMY3 data both use local standard time, and the radiation data values represent energy received during the 60 minutes preceding the indicated hour. The global horizontal radiation shown for hour 1 represents the total radiation incident on a horizontal surface between midnight and 1:00 a.m. of the first hour of the year. Both data sets assume that there are 8,760 hours in one year and do not account for leap years.

Weather File Data Elements

Solar Advisor uses the data elements from the TMY2 file shown in the table below, depending on the technology being modeled. Note that the generic fossil model does not use data from the weather file.

Table 6. Weather data used for different technologies.

Data Element Name	Description	Units	PV Flat Plate	CPV	CSP Trough	CSP Dish	CSP Power Tower
Latitude	Degrees north or south of the equator of the project site.	degrees	x	x	x	x	x
Longitude	Site longitude.	degrees	x	x	x	x	x
Elevation	Height above sea level.	m	x				x
Local Standard Time	Day of year, month, hour of month, day of month, and hour of day. Used to calculate hour of year.	--	x	x	x	x	x
Direct Normal Radiation	Amount of solar radiation received in one hour within a limited field of view centered on the sun.	W/m2	x	x	x	x	x
Diffuse Horizontal Radiation	Amount of solar radiation received in one hour from the sky, excluding the solar disk on a horizontal surface.	W/m2	x
Wind Velocity	Average velocity of the wind for the hour.	m/s	x		x	x	x
Dry Bulb Temperature	Average dry bulb temperature for the hour.	°C	x		x		x
Dew Point Temperature	Average dew point temperature for the hour.	°C			x		x
Relative Humidity	Average relative humidity for the hour.	%			x		x
Snow Depth	Snow depth for the day.	cm	x

Downloading and Using EPW Weather Files

You can download weather data in EPW format for locations around the world at no cost from the EnergyPlus weather data website at http://www.eere.energy.gov/buildings/energyplus/cfm/weather_data.cfm.

To use EPW weather data in Solar Advisor:

1.	Go to the EnergyPlus weather data website and navigate to the region and location you want to model.

2.	Download the EPW file for the location you are modeling.

If there is not an EPW file for the location, download the ZIP file and extract the EPW file.

3.	On Solar Advisor's Climate page, click Settings.

4.	In the Library Settings window, click Add and navigate to the folder containing the EPW file to add the folder's path to the climate file search path list.

You can remove the search path by selecting it and clicking Remove.

5.	Click Close to return to the Climate page.

The EPW file should now be visible in the Locations list.

For some regions, you can download an EPW file directly for a location. For example, for Bangladesh, you can download the data for Dhaka by right-clicking the blue square next to the word EPW for Dhaka. Be sure to save the file with the epw extension.

SS_Climate-EPW-Blue-Square

For other regions, you must first download a zip file containing the EPW file and then extract the EPW file. For example, for Malaysia, you can download the data for Kuala Lumpur by right-clicking the red square next to the word ZIP for Kuala Lumpur. After downloading the zip file, you can extract the EPW file.

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