Aeolian removal of dust from photovoltaic surfaces on Mars

Technical Report · Thu Feb 01 04:00:00 EST 1990

OSTI ID:6839042

Gaier, J R; Perez-Davis, M E; Marabito, M

It is well documented that Mars is totally engulfed in huge dust storms nearly each Martian year. Dust elevated in these global dust storms, or in any of the numerous local dust storms could settle on photovoltaic surfaces and seriously hamper photovoltaic power system performance. Using a recently developed technique to uniformly dust simulated photovoltaic surfaces, samples were subjected to Martian-like winds in an attempt to determine whether natural aeolian processes on Mars would sweep off the settled dust. The effects of wind velocity, angle of attack, height off the Martian surface, and surface coating material were investigated. Principles which can help to guide the design of photovoltaic arrays bound for the Martian surface were uncovered. Most importantly, arrays mounted with an angle of attack approaching 45 deg show the most efficient clearing. Although the angular dependence is not sharp, horizontally mounted arrays required significantly higher wind velocities to clear off the dust. From the perspective of dust-clearing it appears that the arrays may be erected quite near the ground, but previous studies have suggested that saltation effects can be expected to cause such arrays to be covered by sand if they are set up less than about a meter from the ground. Providing that the surface chemistry of Martian dusts is comparable to our test dust, the materials used for protective coating may be optimized for other considerations such as transparency, and chemical or abrasion resistance. The static threshold velocity is low enough that there are regions on Mars which experience winds strong enough to clear off a photovoltaic array if it is properly oriented. Turbulence fences proved to be an ineffective strategy to keep dust cleared from the photovoltaic surfaces.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
• OSTI ID: 6839042
• Report Number(s): N-90-19299; NASA-TM--102507; E--5309; NAS--1.15:102507
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
ABRASION
ATMOSPHERES
COATINGS
CONTAMINATION
COSMIC DUST
DIRECT ENERGY CONVERTERS
DISASTERS
DUSTS
EQUIPMENT
MARS PLANET
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PLANETARY ATMOSPHERES
PLANETS
PROTECTIVE COATINGS
SIMULATION
SOLAR CELL ARRAYS
SOLAR CELLS
SOLAR EQUIPMENT
STORMS
SURFACE CONTAMINATION
TURBULENCE
WIND