TMY, The key to estimating the long-term resource of an renewable energy plant.

Before building a farm, the project developer must know the deposit of a territory in order to optimize the choice of land, the capacity of the plant and its profitability. Forecasting this production in the very long term (often 25 years) assumes that the deposit of the last 10 to 30 years is representative of the energy potential of the decades to come.

More concretely, time series of solar data (solar irradiance on the ground on a horizontal or inclined plane, also called irradiance) or wind turbines (wind speed and direction) on an hourly scale, from observations and models, are used to statistically obtain a representative year of the deposit, called a “Typical Meteorological Year”.

The TMY is constructed by selecting the most representative months among the available series (the most typical of January, February, March, etc.) which are finally concatenated into a single artificial and representative year.