Exposure to Precipitation
In the course of the testing, the prototype has been exposed to rain, light hail, and snow. It has also been exposed to condensation especially on days following clear, cold nights.
No adverse effects on the operation of the heliostat have been observed as a result of these exposures. It is likely that the production design will require some form of shielding over the belts and drive gears to prevent ice accumulation (if icing is a possibility in the area of use).
In some cases, precipitation (e.g. snow, rain, or condensation) persists on the clear dome for some period of time into the next sunny period (Figure 9f). If precipitation of this type is likely in the intended use areas, this problem should be addressed in the design. If a material such as DuPont Tefzel is used for the dome in the production design, the dome should shed precipitation
better than the Vinyl
dome used the ability
on the prototype due to to turn the transparent and should be feasible
the “self-cleaning” capability of the dome downward during periods of with a modification of the current
In summary, the heliostat has been exposed to a moderate variety of outdoor conditions with no failures. Some issues have been uncovered (e.g. persistence of precipitation on the dome) which will have to be addressed on a production design, particularly in geographic areas where these conditions occur frequently.
November 24, 2002