Chapter 2 Solar Radiation Power Point Presentation Chapter

Chapter 2 — Solar Radiation

Power. Point® Presentation Chapter 2 Solar Radiation The Sun • Solar Radiation • Sun. Earth Relationships • Array Orientation • Solar Radiation Data Sets

Chapter 2 — Solar Radiation A false color image of the sun enhances the turbulent nature of the sun’s photosphere, including a roiling surface, sunspots, and giant flares.

Chapter 2 — Solar Radiation Even over the vast distance, an enormous amount of energy reaches Earth from the sun.

Chapter 2 — Solar Radiation Solar irradiance is solar power per unit area.

Chapter 2 — Solar Radiation The inverse square law states that irradiance is reduced in proportion to the inverse square of the distance from the source.

Chapter 2 — Solar Radiation Solar irradiation equals the total solar irradiance received over time.

Chapter 2 — Solar Radiation The electromagnetic spectrum is the range of all types of electromagnetic radiation, which vary with wavelength.

Chapter 2 — Solar Radiation The wavelength distribution of extraterrestrial solar radiation forms a spectral signature unique to the sun.

Chapter 2 — Solar Radiation Solar radiation in Earth’s atmosphere includes direct, diffuse, and albedo radiation.

Chapter 2 — Solar Radiation Air mass is a representation of the amount of atmosphere radiation that must pass through to reach Earth’s surface.

Chapter 2 — Solar Radiation Peak sun hours is an equivalent measure of total solar irradiation in a day.

Chapter 2 — Solar Radiation Insolation maps rate locations by their average daily peak sun hours.

Chapter 2 — Solar Radiation The atmosphere absorbs extraterrestrial radiation at certain wavelengths, resulting in an attenuated spectral distribution for terrestrial radiation.

Chapter 2 — Solar Radiation A pyranometer measures total global solar irradiance from the whole sky.

Chapter 2 — Solar Radiation Diffuse solar irradiance can be measured by adding a shadowing device to a pyranometer, which blocks the direct component of total global irradiance.

Chapter 2 — Solar Radiation Handheld pyranometers use less accurate and lower cost sensors than precision pyranometers but are more suitable for field measurements.

Chapter 2 — Solar Radiation A pyrheliometer measures the direct component of solar irradiance, which is important when installing concentrating collectors.

Chapter 2 — Solar Radiation Reference cells output a certain electrical current in proportion to solar irradiance received.

Chapter 2 — Solar Radiation The ecliptic plane is formed by Earth’s elliptical orbit around the sun.

Chapter 2 — Solar Radiation The equatorial plane is tilted 23. 5° from the ecliptic plane. As Earth revolves around the sun, this orientation produces a varying solar declination.

Chapter 2 — Solar Radiation The summer solstice occurs when the Northern Hemisphere is tilted towards the sun. The winter solstice occurs when the Northern Hemisphere is tilted away from the sun.

Chapter 2 — Solar Radiation The fall and spring equinoxes occur when the sun is directly in line with the equator.

Chapter 2 — Solar Radiation Standard time organizes regions into time zones, where every location in a time zone shares the same clock time.

Chapter 2 — Solar Radiation The Equation of Time adjusts for variations in Earth’s orbit and rotation that affect solar time.

Chapter 2 — Solar Radiation An analemma shows how sun position, at the same time of day, changes throughout the year.

Chapter 2 — Solar Radiation Solar azimuth and altitude angles are used to describe the sun’s location in the sky.

Chapter 2 — Solar Radiation The sun’s path across the sky at various times of the year can be illustrated on a diagram. The diagrams change for different latitudes.

Chapter 2 — Solar Radiation The solar window is the area of sky containing all possible locations of the sun throughout the year for a particular location.

Chapter 2 — Solar Radiation The orientation of an array surface is described using azimuth and tilt angles.

Chapter 2 — Solar Radiation Energy production at certain times of the year can be maximized by adjusting the array tilt angle.

Chapter 2 — Solar Radiation The average seasonal declinations define the optimal tilt angles for those periods.

Chapter 2 — Solar Radiation The National Renewable Energy Laboratory (NREL) provides solar radiation data for various locations, times of the year, and south-facing array orientations.