The main objective of this project consists of an
improvement in PV power forecasts quality, on the road to a smart-grid
management. This is planned to be achieved by developing an innovative
forecasting instrument ASIFOR based on tracking the state-of-the-sky using
all-sky imager data.
ASIFOR includes three interconnected
(1) Radiometric station (RS). RS consists of
minimum two pyranometers one for measuring global solar irradiance (GHI)
and the other for measuring diffuse solar irradiance (DHI). GHI is
straightforwardly exploited for estimating the solar resource, while
post-processed data series of GHI and DHI are used for inferring various
parameters, the topmost being sunshine number (SSN), a binary indicator
stating whether the Sun is shining or not.
(2) Sky monitoring system (SMS). SMS includes
an all-sky imager which will provide a streaming of sky images.
Essentially, all-sky imager defines a
device equipped with 180-degree wide angle lens or mirror optical system
able to acquire time series of hemispherical images of the sky vault.
Post-processing of the sky images streaming is expected to contribute at
increasing the accuracy in forecasting the relative position of the Sun and
(3) Computational system (CS). CS plays
multiple roles: real-time control of the forecasting process, database
management, post-processing data, communication with RS and SMS, providing
forecasts to the grid operator via internet. The forecasting applications
developed within this project will be implemented and run by CS. Sky image
processing will be performed also by CS.
The main objective will be reached through the following
(1) Development of new procedures for image processing
aiming to accurate forecasting of the relative position of the Sun and
clouds. The outcome of this specific objective is the operational SMS
module of the forecasting instrument.
(2) Development of new procedures or enhancement of existing
procedures for accurate solar PV power forecasts. The outcome of this
specific objective is the operational RS module of the forecasting
(3) Establishing a forecasting mechanism for solar
electricity production by joining the SMS and RS information. The outcome
of this specific objective is the operational CS module of the forecasting
ASIFOR itself is the main outcome of the project. It hve to
fulfill three essential characteristics:
(1) The forecasts of PV power are generated at different
horizons of time within one hour;
(2) The forecasts are of high-quality (the mean absolut
percentage error MAPE is less than 20% for all the forecasts generated in a
(3) the forecasting instrument is effectively structured in order to address the needs of grid operators.