HELIOSTATS
Each Heliostat includes an aluminum mirror frame with stabilizer (shipped unassembled). Mirror frames and stabilizers are assembled by the user or installer. The mirror frame is designed to carry eight standard 12" x 12" (30.48 cm x 30.48 cm) glass mirrors, also called “architectural tiles”. Mirrors are not included (see
Miscellaneous Materials).
Mirrors are secured to the mirror frame using a high quality, outdoor, silicone-based adhesive caulk. For many applications (e.g. natural lighting) the mirrors can be installed flat. The user has the option of individually focusing each mirror by tilting it slightly on the beads of caulk before the caulk sets. Using this technique at a distance of 75 feet (23 meters) from the target, one can achieve a round Sun spot 18-20" in diameter – a 3-4x Sun concentration per Heliostat.
The Heliostat Housing tracks the movement of the Sun by rotating within a "C" bracket on both its vertical axle (to move left/right) and its horizontal axle (to move up/down). Rotation is digitally controlled to an accuracy of 0.11 degrees, equivalent to 4" in 100 ft. Each Heliostat is individually targeted and controlled with the system software, and any Heliostat can be reprogrammed for a new target in minutes. Unlike other heliostat systems that must be installed in a particular pattern because they are mechanically linked, Practical Solar Heliostats require no installation pattern.
The "C" bracket can be quickly and easily mounted onto a pole. A mounting pole would be installed into the ground with concrete footing or affixed to a stable structure. Properly installed and targeted, the movement of the Heliostat is never encumbered.
Features and Advantages
Extremely rugged, maintenance-free design includes a high gear ratio and limited duty cycle.
Each Heliostat delivers about 3000X more energy than it consumes. Power consumption is less than 0.1 watts on average per Heliostat.
External parts are stainless steel, aluminum and glass – all rust free and extremely durable against the elements.
Mirrors require little or no maintenance in most locations. Accumulation of dust and debris is diminished by the natural cleansing effect of rain so that mirror reflectivity is not significantly diminished over time.
Installation is accomplished with household tools.
Heliostat is stable in high winds.
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Mirror frame and stabilizer are shipped in a compact tube and assemble in minutes.
Heliostat Specifications
| Reflector area |
8 ft2 (0.75 m2) |
| Reflectivity |
>85% average over visible and infrared regions at normal incidence |
| Weight |
18 lbs (8 kg) includes mirror mount, excludes reflectors |
| Electrical interface |
2-conductor AWG cable, stranded, unshielded, overall jacket (see
cable gauge guide in
Miscellaneous Materials) |
| Electrical power consumption |
<100 milliwatts (0.1 watts) average; <1 watt-hour/day |
| Positioning accuracy |
0.11 degrees |
| Rotational limit |
+/- 60 degrees Azimuth; + 50/-5 degrees Altitude |
| Operating temperature range |
-20°C to +50°C (-4°F to 122°F) |
| Operating humidity range |
0-100% relative humidity |
| Maximum wind speed (operation) |
80 kilometers/hour (≈50 MPH) |
| Maximum wind speed (structural) |
150 kilometers/hour (≈90 MPH) |
HELIOSTAT LIST PRICE (including Mirror Frame and Stabilizer): $ [ contact us ]
Heliostats
