pvlib.iotools.read_tmy2#
- pvlib.iotools.read_tmy2(filename)[source]#
Read a TMY2 file into a DataFrame.
Note that values contained in the DataFrame are unchanged from the TMY2 file (i.e. units are retained). Time/Date and location data imported from the TMY2 file have been modified to a “friendlier” form conforming to modern conventions (e.g. N latitude is postive, E longitude is positive, the “24th” hour of any day is technically the “0th” hour of the next day). In the case of any discrepencies between this documentation and the TMY2 User’s Manual 1, the TMY2 User’s Manual takes precedence.
- Parameters
filename (str) – A relative or absolute file path.
- Returns
Tuple of the form (data, metadata).
data (DataFrame) – A dataframe with the columns described in the table below. For a more detailed descriptions of each component, please consult the TMY2 User’s Manual 1, especially tables 3-1 through 3-6, and Appendix B.
metadata (dict) – The site metadata available in the file.
Notes
The returned structures have the following fields.
key
description
WBAN
Site identifier code (WBAN number)
City
Station name
State
Station state 2 letter designator
TZ
Hours from Greenwich
latitude
Latitude in decimal degrees
longitude
Longitude in decimal degrees
altitude
Site elevation in meters
field
description
index
Pandas timeseries object containing timestamps
year
month
day
hour
ETR
Extraterrestrial horizontal radiation recv’d during 60 minutes prior to timestamp, Wh/m^2
ETRN
Extraterrestrial normal radiation recv’d during 60 minutes prior to timestamp, Wh/m^2
GHI
Direct and diffuse horizontal radiation recv’d during 60 minutes prior to timestamp, Wh/m^2
GHISource
See 1, Table 3-3
GHIUncertainty
See 1, Table 3-4
DNI
Amount of direct normal radiation (modeled) recv’d during 60 mintues prior to timestamp, Wh/m^2
DNISource
See 1, Table 3-3
DNIUncertainty
See 1, Table 3-4
DHI
Amount of diffuse horizontal radiation recv’d during 60 minutes prior to timestamp, Wh/m^2
DHISource
See 1, Table 3-3
DHIUncertainty
See 1, Table 3-4
GHillum
Avg. total horizontal illuminance recv’d during the 60 minutes prior to timestamp, units of 100 lux (e.g. value of 50 = 5000 lux)
GHillumSource
See 1, Table 3-3
GHillumUncertainty
See 1, Table 3-4
DNillum
Avg. direct normal illuminance recv’d during the 60 minutes prior to timestamp, units of 100 lux
DNillumSource
See 1, Table 3-3
DNillumUncertainty
See 1, Table 3-4
DHillum
Avg. horizontal diffuse illuminance recv’d during the 60 minutes prior to timestamp, units of 100 lux
DHillumSource
See 1, Table 3-3
DHillumUncertainty
See 1, Table 3-4
Zenithlum
Avg. luminance at the sky’s zenith during the 60 minutes prior to timestamp, units of 10 Cd/m^2 (e.g. value of 700 = 7,000 Cd/m^2)
ZenithlumSource
See 1, Table 3-3
ZenithlumUncertainty
See 1, Table 3-4
TotCld
Amount of sky dome covered by clouds or obscuring phenonema at time stamp, tenths of sky
TotCldSource
See 1, Table 3-5
TotCldUncertainty
See 1, Table 3-6
OpqCld
Amount of sky dome covered by clouds or obscuring phenonema that prevent observing the sky at time stamp, tenths of sky
OpqCldSource
See 1, Table 3-5
OpqCldUncertainty
See 1, Table 3-6
DryBulb
Dry bulb temperature at the time indicated, in tenths of degree C (e.g. 352 = 35.2 C).
DryBulbSource
See 1, Table 3-5
DryBulbUncertainty
See 1, Table 3-6
DewPoint
Dew-point temperature at the time indicated, in tenths of degree C (e.g. 76 = 7.6 C).
DewPointSource
See 1, Table 3-5
DewPointUncertainty
See 1, Table 3-6
RHum
Relative humidity at the time indicated, percent
RHumSource
See 1, Table 3-5
RHumUncertainty
See 1, Table 3-6
Pressure
Station pressure at the time indicated, 1 mbar
PressureSource
See 1, Table 3-5
PressureUncertainty
See 1, Table 3-6
Wdir
Wind direction at time indicated, degrees from east of north (360 = 0 = north; 90 = East; 0 = undefined,calm)
WdirSource
See 1, Table 3-5
WdirUncertainty
See 1, Table 3-6
Wspd
Wind speed at the time indicated, in tenths of meters/second (e.g. 212 = 21.2 m/s)
WspdSource
See 1, Table 3-5
WspdUncertainty
See 1, Table 3-6
Hvis
Distance to discernable remote objects at time indicated (7777=unlimited, 9999=missing data), in tenths of kilometers (e.g. 341 = 34.1 km).
HvisSource
See 1, Table 3-5
HvisUncertainty
See 1, Table 3-6
CeilHgt
Height of cloud base above local terrain (7777=unlimited, 88888=cirroform, 99999=missing data), in meters
CeilHgtSource
See 1, Table 3-5
CeilHgtUncertainty
See 1, Table 3-6
Pwat
Total precipitable water contained in a column of unit cross section from Earth to top of atmosphere, in millimeters
PwatSource
See 1, Table 3-5
PwatUncertainty
See 1, Table 3-6
AOD
The broadband aerosol optical depth (broadband turbidity) in thousandths on the day indicated (e.g. 114 = 0.114)
AODSource
See 1, Table 3-5
AODUncertainty
See 1, Table 3-6
SnowDepth
Snow depth in centimeters on the day indicated, (999 = missing data).
SnowDepthSource
See 1, Table 3-5
SnowDepthUncertainty
See 1, Table 3-6
LastSnowfall
Number of days since last snowfall (maximum value of 88, where 88 = 88 or greater days; 99 = missing data)
LastSnowfallSource
See 1, Table 3-5
LastSnowfallUncertainty
See 1, Table 3-6
PresentWeather
See 1, Appendix B. Each string contains 10 numeric values. The string can be parsed to determine each of 10 observed weather metrics.
References