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Typical Meteorological Year Data

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Typical Meteorological Year (TMY) data products are designed for use in simulation software that computes the electricity yield of a solar energy system. The TMY is derived from hourly time series covering all range of available data (22/17/9 years). The TMY is constructed by concatenation of representative months into a Typical Meteorological Year. The selection of representative months depends on the type of solar energy application under consideration.

    In general practice, two data sets are derived from the time series – one for P50 and one for P90:
  1. The P50 TMY data set represents, for each month, the average climate conditions and the most representative cumulative distribution function, therefore extreme situations (e.g. extremely cloudy weather) are not represented in this dataset.
  2. The P90 TMY data set represents for each month the climate conditions, which after summarization of GHI/DNI for the whole year result in the value close to P90 derived by statistical analysis of uncertainties and interannual variability, i.e. to the conservative value of GHI/DNI. Thus TMY for P90 represents generally a conservative estimate, i.e. a year with the annual GHI/DNI value, which is close to the lowest identified within the time series covering 22/17 years.

Sample data

    Download ZIP files and examine SAMPLE DATA:
  • TMY P50, calculated from hourly data for a period Jan 1994 to Jun 2012 (ZIP, 121 kB)
  • TMY P90, calculated from hourly data for a period Jan 1994 to Jun 2012 (ZIP, 121 kB)
  • Sample data refers to a site Plataforma Solar de Almería (PSA), Spain.

TMY vs. Synthetic Hourly Time Series

Some popular simulation software are able to generate synthetic hourly time series from long-term monthly averages. This is a widely used approach. However, it generates a distorted representation of time series. Mathematical models for generating synthetic time series have been tuned for few specific sites in temperate climate. The performance of these models is not validated in other climatic zones such as rain tropics or arid deserts. Hence, the resulting synthetic time series deviates significantly from the actual time series.

Typical Meteorological Year data are closest to real time series as they include 12 fragments of real data that describe a climate more realistically based on the given selection criteria. Energy Yield simulations using TMY data represent better accuracy compared to energy yield simulations done using synthetic time series data.

Compatibility with Simulation Software

We can deliver TMY data in a format that is compatible with most popular simulation software on the market.
Instructions of importing SolarGIS TMY data to PVsyst simulation software can be found here.

Purchase TMY Data

Hourly TMY data can be purchased using climData online shop.
For customised solutions i.e. site-adapted TMY, sub-hourly TMY data sets, etc. please contact us.



Visualisation of 9 characteristics in TMY P50 dataset.
x axis represents days in a year, y axis hours in a day.


Data available

solargis.info

DNI

Direct Normal Irradiance/Irradiation

GHI

Global Horizontal Irradiance/Irradiation

GTI

Global Tilted (in-plane) Irradiance/Irradiation

DIF

Diffuse Horizontal Irradiance/Irradiation

TEMP

Air temperature at 2 m

RH

Relative humidity

WS

Wind Speed at 10 m

WD

Wind Direction

Geographic

Terrain, Landcover, Population

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