Certain aspects pertain to a combination sensor comprising a set of physical sensors facing different directions proximate a structure, and configured to measure solar radiation in different directions. The combination sensor also comprises a virtual facade-aligned sensor configured to determine a combi-sensor value at a facade of the structure based on solar radiation readings from the set of physical sensors.

Certain aspects pertain to a combination sensor comprising a set of physical sensors facing different directions proximate a structure, and configured to measure solar radiation in different directions. The combination sensor also comprises a virtual facade-aligned sensor configured to determine a combi-sensor value at a facade of the structure based on solar radiation readings from the set of physical sensors.

A photovoltaic system's configuration specification can be inferred by an evaluative process that searches through a space of candidate values for the variables in the specification. Each variable is selected in a specific ordering that narrows the field of candidate values. A constant horizon is assumed to account for diffuse irradiance insensitive to specific obstruction locations relative to the photovoltaic system's geographic location. Initial values for the azimuth angle, constant horizon obstruction elevation angle, and tilt angle are determined, followed by final values for these variables. The effects of direct obstructions that block direct irradiance in the areas where the actual horizon and the range of sun path values overlap relative to the geographic location are evaluated to find the exact obstruction elevation angle over a range of azimuth bins or directions. The photovoltaic temperature response coefficient and the inverter rating or power curve of the photovoltaic system are determined.

A photovoltaic system's configuration specification can be inferred by an evaluative process that searches through a space of candidate values for the variables in the specification. Each variable is selected in a specific ordering that narrows the field of candidate values. A constant horizon is assumed to account for diffuse irradiance insensitive to specific obstruction locations relative to the photovoltaic system's geographic location. Initial values for the azimuth angle, constant horizon obstruction elevation angle, and tilt angle are determined, followed by final values for these variables. The effects of direct obstructions that block direct irradiance in the areas where the actual horizon and the range of sun path values overlap relative to the geographic location are evaluated to find the exact obstruction elevation angle over a range of azimuth bins or directions. The photovoltaic temperature response coefficient and the inverter rating or power curve of the photovoltaic system are determined.

Methods and systems for predicting irradiance include learning a classification model using unsupervised learning based on historical irradiance data. The classification model is updated using supervised learning based on an association between known cloudiness states and historical weather data. A cloudiness state is predicted based on forecasted weather data. An irradiance is predicted using a regression model associated with the cloudiness state.

Methods and systems for predicting irradiance include learning a classification model using unsupervised learning based on historical irradiance data. The classification model is updated using supervised learning based on an association between known cloudiness states and historical weather data. A cloudiness state is predicted based on forecasted weather data. An irradiance is predicted using a regression model associated with the cloudiness state.

A solar irradiance intensity estimation apparatus has an estimation model generation unit that generates estimation models of solar radiation intensities at a plurality of observation points based on observed cloud state data and solar radiation intensities observed at the plurality of observation points, an estimation model interpolation unit that generates an estimation model of a solar irradiance intensity at a target point based on the estimation models of solar radiation intensities at the plurality of observation points, and a solar irradiance intensity estimation unit that estimates a solar irradiance intensity at the target point based on a reflection intensity at the target point obtained from the cloud state data and the estimation model of a solar irradiance intensity at the target point.

A solar irradiance intensity estimation apparatus has an estimation model generation unit that generates estimation models of solar radiation intensities at a plurality of observation points based on observed cloud state data and solar radiation intensities observed at the plurality of observation points, an estimation model interpolation unit that generates an estimation model of a solar irradiance intensity at a target point based on the estimation models of solar radiation intensities at the plurality of observation points, and a solar irradiance intensity estimation unit that estimates a solar irradiance intensity at the target point based on a reflection intensity at the target point obtained from the cloud state data and the estimation model of a solar irradiance intensity at the target point.

Infrared cloud detector systems and methods for detecting cloud cover conditions.

Infrared cloud detector systems and methods for detecting cloud cover conditions.