Global horizontal irradiance

Global horizontal irradiance, usually shortened to GHI, is the solar irradiance received on a horizontal surface. It is reported in watts per square meter, and monitoring gateways list it as the 'Irradiance Global' sensor type. Weather stations and data loggers expose GHI as a measured register value, and some systems archive the raw reading as an interval average with a scale factor applied. Installation guidance for GHI sensors covers how far they must sit from nearby obstructions, because shading of the sensor distorts the reading. Some O&M literature uses the same abbreviation for global horizontal insolation, which is the energy accumulated over time.

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• sentence 1: support check: partial - Passages give the GHI abbreviation expansion but not the definition of irradiance received on a horizontal surface.
• sentence 4: support check: partial - The figure title shows guidance on distance from obstructions, but the shading-distorts-reading rationale is not stated.
• sentence 5: support check: partial - GHI is listed as global horizontal insolation, but the 'energy accumulated over time' definition is not stated.
• sentence 1: review: partial - The passages expand GHI to Global Horizontal Irradiance but never define it as the irradiance received on a horizontal surface.
• sentence 4: review: partial - The figure titles show guidance on how far GHI sensors sit from nearby obstructions, but the claim that shading distorts the reading is not stated. -->