What directions do the horizontal total radiation intensity, horizontal scattered radiation intensity and vertical direct radiation intensity of solar energy represent respectively? Is there an inclusion relationship? The total horizontal radiation intensity of solar energy-including radiation in all directions. There are direct and scattered.

Intensity of scattered radiation in the horizontal plane-includes scattered radiation in all directions.

Normal direct radiation intensity-this has nothing to do with the horizontal plane, indicating the direct radiation received on the plane perpendicular to the radiation direction. It also includes direct radiation reaching the plane from all directions.

The first one contains the second one.

The third one has nothing to do with the first two, but discusses different planes. Normal direct radiation intensity refers to the radiation power per unit area perpendicular to the radiation direction, which is generally very large.