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Solar Power Heliostat Arrays.
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* theenergydude's Community Call
Gary Carmichael, The Energy Dude, will be interviewed me about solar trackers.
We discussed solar tracking advantages and disadvantages for a number of applications.
He asked me about my life, times, and interests, it was great fun.
He interviewed me on Saturday 2009/03/21 01:00 PM EDT

LED3X for sale
* LED3X Solar Tracker
A simple, accurate, low cost, single axis electronic solar tracker based on using green LEDs as photovoltaic light sensors.

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I Last edited this page on 20170521
Alternative energy systems for the home or small property owner who is interested in Natural Energy or Solar Power.
    I want to use these web pages as a forum for:
  1. The interchange of ideas related to the production of natural energy.
  2. Heliostat (mirror) based concentrator solar collectors.
  3. Solar trackers.
  4. Electric vehicles (battery powered).
  5. Pneumatic vehicles (compressed air powered).
  6. Hybrid vehicles.
  7. Neat patents.

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I have many interests ranging from amateur radio and astronomy to auto racing and mechanics. One general thread is the use of electronics and computers to devise low cost smart solutions to many of the problems I encounter.
Heliostat Information.

1. A heliostat is, generally, a one or two axis solar tracking flat mirror that reflects sunlight onto a fixed receiver or target.
2. Furthermore, the geometry between the Sun, Mirror, and Receiver is constantly changing throughout the day or year.
2a. There is a special case, the Type 1 Coelostats, where light is sent along the polar axis where the geometry
    is approximately fixed throughout the day and parabolic concentration can be used as in the Scheffler Reflector.
See the Scheffler Reflector.
This appears to violate #2, but it doesn't. In this case the geometry changes throughout the year, not just throughout the day.
3. In general, the mirror is aimed normal to the bisector between the sun and receiver.
X Many mistakenly call "Direct Solar Trackers", such as Dishes, Troughs, and Lenses as heliostats.
They are not. Generally, these things are aimed directly at the Sun which violates #2 above.
Here are some "Dictionary" definitions:
A. Dictionary.com: An instrument consisting of a mirror moved by clockwork, for reflecting the sun's rays in a fixed direction.
B. Collins: An astronomical instrument used to reflect the light of the sun in a constant direction.
C. Merriam-Webster: An instrument consisting of a mirror mounted on an axis moved by clockwork by which a sunbeam is steadily reflected in one direction.
D. Webster's New World: a device consisting of a mirror slowly revolved by clockwork so as to reflect the sun's rays continuously in a fixed direction.
E. American Heritage: An instrument in which a mirror is automatically moved so that it reflects sunlight in a constant direction. It is used with a pyrheliometer to make continuous measurements of solar radiation.
F. Wiktionary: A device that includes a plane mirror which turns so as to keep reflecting sunlight toward a predetermined target, compensating for the sun's apparent motions in the sky. The target may be a physical object, distant from the heliostat, or a direction in space, and is almost always stationary relative to the heliostat, so the light is reflected in a fixed direction.
G. British Dictionary: Instrument used in solar telescopes to orient and focus sunlight along a fixed direction. A typical heliostat consists of a flat plane mirror and a curved parabolic mirror. The plane mirror is mounted along an axis parallel (i.e., equatorial) to the Earth and rotated slowly by a motor to reflect light from the Sun. The parabolic mirror focuses the reflected rays into the telescope along a fixed direction while the Sun traverses the sky. Therefore, as the telescope's field of view rotates, different celestial objects move quickly into view
And others.

The problem for us in the Solar Field is these definitions are just too general or so specific they exclude many real heliostats. And the British Dictionary definition is just plain wrong.
Ok, to be fair, my definition is clearly slanted towards "Solar Heliostats".

Archimedes Archimedes
in ancient Syracuse, Sicily
It's been reported Archimedes destroyed ships in the harbor with a death ray, or heat ray.
While "technically" feasible the practicality of such a weapon is doubtful. The physics just don't make sense. The harbor is at least 2 miles wide and 1 mile wide at the entrance. Sending light a distance of 1/2 mile from a line, or several lines, of many mirrors on the shore just can't set the ships on fire.
As the MythBusters say, BUSTED.

Early Mechanical Heliostats and Coelostats
And some modern ones for illustration.
Heliostats (pronounced [HE·LEE·o·stat]), generally, reflect light onto a stationary target.

William Jacob s'Gravesande coined the word heliostat in a textbook in 1742 from the Greek words for Sun and Stationary.

They cover a range of devices such as Coelostats (pronounced [SEE:low:stat]) and Siderostats (pronounced [sid:er·o·stat]).

However, we usually consider heliostats as having 1 mirror while coelostats and siderostats have 2 or more mirrors.

All have a primary clock drive moving the main axis and is aimed at the celestial pole. These rotate once in 24 hours.
(This is not precise, as the length of the day varies throughout the year, but close enough over a days time and would be reset each day anyway.)

None have a drive for the secondary DEClination axis. The secondary axis is always manually adjusted each day their used.

The distinguishing differences between the Foucault, Gambay, and Silbermann single mirror heliostat types:
1.  The Foucault (pronounced [fou·cault]) or (Cloesen) type's mirror drive bar is oriented normal, (or perpendicular), to the mirror's plane surface and usually out the back. The mirror motion is usually in AZimuth/ALTitude although there are examples that move in Spin/Tilt (Receiver Axis). There is often another bar off to the side which prevents the mirror from rotating and binding at certain angles. Note, this second bar is not part of the geometry calculation, just a device to prevent binding at certain extreme angles.

The sliders on the drive bars must be able to articulate in all three motions of pitch, yaw, and role in addition to slide. This is the equivalent of a "Ball Joint" as opposed to a "U-joint". These motions must be dead centered in the main slider. The Spin/Tilt (Receiver Axis) line passes through the Receiver, Mirror Ball Joint, and the clock Drive axis.

Foucault1 looks like it's AZimuth/ALTitude but its actually Spin/Tilt (Receiver Axis). The mirror rotates on a bearing on it's back side. (Difficult to see in the image.)

Etsy1 has a yoke that operates in Spin/Tilt (Receiver Axis).

In the diagram, points BCM form a triangle with two sides BC & BM are equal in length with side CM is variable in length depending on the time of the day. Side CB points to the DEClination angle of the sun, +-23.5°. Angle CBP = 90° + the current DEClination.

Usually the angle from vertical BY to side BM is 90° so the light leaving the unit is horizontal. However, the Foucault1 and Etsy1 examples have mechanisms that allow the exit angle to be adjusted in ALTitude as well as AZimuth.

In Foucault1 the mirror mount is adjustable in height. A link near the base maintains the side BM length constant and equal to BC, a parallelogram, no mater the light exit ALTitude angle.

Be careful, some of these examples don't maintain the BM length so there will be some error unless the light exits horizontally.

In Etsy1 the mirror mount is adjusted by moving in an arc about point B.The radius of the arc maintains the side BM length constant and equal to BC. There is no error for any light exit ALTitude.

(Jacobus Van der Cloesen's heliostat predates Léon Foucault's design by many years, at least from 1730, but the eminent Foucault gets the credit because he completely described the operation in the literature. Go figure???)

2. The Gambay (1823) type's mirror drive bar is oriented parallel to the mirror's plane surface and off to the side. The axis of the drive bar must pass through the center of the mirror's gimbol mount.

The mirror motion is always in Spin/Tilt (Receiver Axis).

The sliders on the drive bars must be able to articulate in all three motions of pitch, yaw, and role in addition to slide. This is the equivalent of a ball joint as opposed to a U-joint. These motions must be dead centered in the slider.

A particularly nice compact version was designed by Johnstone Stoney (1869) in a small wooden box.

Of note! Stoney's version uses a simplified yoke shaped mechanisms which was much lower in cost and eaisier to make. However, Stoneys basic design was not adjustable in AZimuth, i.e. light must exit either in a North or South direction.

Later, Rudolf Fuess (1879) uses Stoney's yoke mechanisms and made a very accurate although expensive versions of the Gambay type heliostats. These are probably the most elegant looking examples of all the mechanical heliostats.

In the diagram points PKM form a triangle with two sides BK & BM equal in length and side KM is variable in length.

Side BK points to the daily DEClination angle of the sun, +-23.5°.

The angle formed by the polar axis and side PK = 90° + the daily DEClination.

In the diagram side PM is shown horizontal so the light leaving the unit is horizontal. However, many examples have mechanisms that allow the exit angle to be adjusted in ALTitude, as well as AZimuth, by moving in an arc about point B. Moving in arc always maintains a constant PM length.

The radius of the arc maintains the side BM length constant and equal to BK.

3. The Silbermann type's employ a mechanical angle bisector mechanism and the mirror motion is always Spin/Tilt (Receiver Axis).

J. T. Silberman invented this design in 1843.

4. Note! Any of the heliostats that employ Spin/Tilt (Receiver Axis) can have a bendable mirror to concentrate sunlight, somewhat, as long as the exit is along the polar axis.

The curvature must me done along the Tilt axis. This curvature adjustment is dependent on the current DEClination angle.

Further, this mirror could be a Toroidal dish as in the Scheffler Reflector. However, the exit axis must be along the Polar Axis.

5. As a practical mater! Foucault types tend to work better when positioned between the celestial pole & target and the Gambay types when positioned opposite the celestial pole & target.

I.e. in the northern hemisphere, the Foucault is on the northern side and the Gambay on the southern side.

North side heliostats tend to require smaller mirrors than south side heliostats.

Silbermann types can be placed in any location, although generally north side is preferred.












Folded Up








With base

In Case

In Case


Base missing

Base missing


Yeates5 Stereo
Yeates5 Stereo

Base missing
















Parts missing





Jules Duboscq1











Type 1 coelostat:
1. Rotate the main mirror once in 24 hours around the polar axis directly in Right Ascension.
2. The main mirror has a seasonal "Tilt" in DEClination to reflect the sunlight along the polar axis.
3. The secondary mirror, if used, reflects light in any desired direction away from the polar axis.
4. The primary mirror needs to be about 2.6 times as wide as the desired beam width.
5. The double mirror heliostat was invented by Young in 1807 and re-invented by Müller in 1894.
    It was then produced commercially by Max Kohl in about 1906 and a little later by Hilger.
6. In general, the output beam is best sent to the South, (in the northern hemisphere).

Coelostat Type 1

Coelostat Type 1

Coelostat Type 1
Adam Hilger,
London circa 1910

Coelostat Type 1
Max Kohl Chemnitz 1

Coelostat Type 1
Parts missing
Max Kohl Chemnitz 2

Coelostat Type 1
Parts missing
I own this one

Coelostat Type 1

Coelostat Type 1

Coelostat Type 1

Coelostat Type 1

Coelostat Type 1
Type 2 coelostat:
I think this Type 2 coelostat was first described by Willem Jacob 's Gravesande about 1742.
Later Foucault also described this in 1862.

1. Rotate the main mirror once in 48 hours around the polar axis in Right Ascension.
2. The main mirror in not tilted at all. The plane of the mirror is parallel with the polar axis.
    Sunlight is reflected away from the polar axis at an angle equal to the suns seasonal DEClination.
3. The secondary mirror is positioned to reflect light in any desired direction.
    This mirror has a seasonal positional movement as well as a seasonal tilt.
    (Note! The diagram says the secondary is fixed but it isn't.
    It must tilt a bit depending on how far the primary mirror's base has moved.
    Either the main or secondary mirror mount must be moved to adjust the geometry seasonally.)
4. The primary mirror has a width of about 1.1 times as wide as the desired beam width.
    The width of the secondary mirror is similar in width but is also dependent on the direction where the light is sent.
5. In general, the output beam is best sent to the North, (in the northern hemisphere).
Type 2 Coelostat2

Coelostat Type 2
Horizontal output
Type 2 Coelostatmg18

Coelostat Type 2
Vertical output
Type 2 Baidu1

Coelostat Type 2
Horizontal output
Type 2 Prazmouski

Coelostat Type 2
Type 2 Coelostat2

Coelostat Type 2
Type 2 Astropalma2

Coelostat Type 2
Type 2 Sirius1

Coelostat Type 2
Type 3 coelostat:
1. The Type 3 Coelostat has the main and secondary mirrors set to exactly 45°.
2. Rotate the main mirror once in 24 hours around the polar axis directly in Right Ascension.
    Note! This sends the light directly along the polar axis.
3. The secondary mirror has a seasonal "Rotate" in DEClination to reflect the sunlight along the polar axis.
4. The tertiary mirror, if used, reflects light in any desired direction away from the polar axis.
5. All mirrors have a width of about 1.4 times as wide as the desired beam width. The width of
    the tertiary mirror width, if used, is highly dependent on the direction where the light is sent.
Type 3 May1

Coelostat Type 3
Type 3 Sonnen1

Coelostat Type 3

Sandia Heliostat Array National Solar Thermal Test Facility (T Pole Design)
Central Receiver Solar II Central Receiver (T Pole Design)

ESolar ESolar Central Receiver (T Pole Design)

Practical Solar Inc. Practical Solar, Inc. (T Pole Design)
I own a set of 10 of these I got on ebay from Light Manufacturing.

They have a new multiple heliostat design. Take a look!!!!
I don't think I would call the new design a T Pole though.

"Linear Fresnel Reflectors", LFRs, are, in general, long Mirror Slats oriented in the North/South direction with Linear receivers, also generally, oriented in the North/South direction, (but not always). They are tracked in only 1 axis, and since they are Heliostats they move at 1/2 the speed of the Sun.
This is an example of a "Single Axis Heliostat".
This concentrator IS a form of heliostat as it fits the definition of a heliostat.
1. It redirects the light to a stationary target.
2. The geometry changes throughout the day.
3. And is aimed at the bisector angle.

1. One basic characteristic is the length of the receiver is oriented "Parallel" to the mirror slat rotation axis. While being parallel is desirable it's not a requirement:

Technically, the centric axis of all the mirror slats and the receiver must radiate from a common point. Parallel lines do this assuming the radiating point is at a great distance. Think of railroad tracks that appear to be converging on a distant point.

All examples I have found have the receiver oriented horizontally. This is also not a requirement for an LFR. If the radiating point is close and the receiver is higher than the horizontal slats the receiver must be oriented at an angle.

If that radiating point is much closer to the slats and receiver, instead of the slats being long rectangles, could be trapezoidal in shape. Clearly not parallel.

2. North/South axis LFRs is clearly the most efficient orientation, i.e. has the shortest slat length and operates for the largest portion of the day.
However, other orientations are possible for special applications. See Kaluta bellow:

3. As with all heliostats the angular motion of, after being initially aligned, all the elements is always the same. Therefore, only a single motor drive is required to drive all the mirror slats. Al least for the LFR.

The related device called a CLFR is slightly different. The motion of each slat is the same, but when a slat switches from one receiver to the other that angle of "SWITCHING MOVEMENT" is NOT the same as the other slats. This kind of complicates the slat driver mechanics.

Anthony Kaluta's LFR example places mirror slats on the West side of a North/South vertical greenhouse wall facing West. It looks like the slat orientation can be oriented NNE/SSW. The intention is to maximize reflected light to the greenhouse in the morning and early afternoon during the cold half of the year, (Northern hemisphere description).
This instalation is in New Mexico at over 7000' altitude.
The slat and receiver axes radiate from a point that is rather close on the north side so are clearly not parallel.
Experimental LFR Mirror Slat A little larger Mirror Slat Daytime view of the Greenhouse Wall Greenhouse Western Wall Greenhouse Western Wall
Single Axis tracker 2 to 1 gear mechanism 2 to 1 gear mechanism View along main axis Back Side

Another is a single horizontal Mirror Slat in front and below the window's sill to reflect light upward through the window onto the ceiling which scatters the light throughout the room. Generally the slat should be at least twice as long as the window is wide. This works well as the light is not usually reflected into ones eyes.

Another is a pair of vertical Mirror Slats to either side of the window jam's to reflect light upward through the window. I don't like this method as the glare of the reflected light is uncomfortable to look at. Note! This could also use the 2/3rd Motion mechanism but still not desirable.

3. A simple tracker mechanism for LFRs is the 1/2 speed motion geared type like those I used on a "Receiver Axis Heliostat" mount except the tracker is a single axis type. Or you could use a single axis computational tracker.

LFR on Instructable * There is an Instructable based on the LFR concept.
In this case their design is used to produce hot water or steam. The receiver has secondary concentration based on Dr. Roland Winston's CPC or Compound Parabolic Concentrator.

The controller they are using is an Arduino driving multiple, 20, stepper motors, one for each mirror slat. However, there is no need for multiple drive motors, just a single motor is requiresd. All the slats would be mechanicly linked with something like a pair of gears for each slat or a cable and pulley on each slat.

LFR Calculations * This is an "Excel" spreadsheet to do some LFR Calculations on a large scale thermal heating project I'm designing.

SFERA * SFERA Linear Fresnel Collectors
A Technology Overview
A fairly thorough presentation on LFR systems including geometric mathematics.

HD Solar HelioDynamics (LFR) Design
Linear Fresnel Reflector, LFR, instead of CLFR because each mirror slat always aims at a single line receiver.
I think these guys went away.
Ijeit Design and Analysis of Rooftop Linear Fresnel Reflector Solar Concentrator (LFR) Design
Linear Fresnel reflectors, as shown Fig 1 use long, thin segments of mirrors to focus sunlight onto a fixed absorber located at a common focal point of the reflectors.

Apparently the LFR concept was first described by Leonardo Da Vinci:
Leonardo Da Vinci LFR Leonardo Da Vinci in one of his notebooks on solar concentration.

CLFR Compact Linear Fresnel Reflector, CLFR (CLFR Design)
The University of Sydney School of Physics
This is the new kid on the block.
This is an example of a "Single Axis Heliostat".
This concentrator is a form of heliostat as it fits the definition of a heliostat.
1. It redirects the light to a stationary target.
2. The geometry changes throughout the day.
3. And is aimed at the bisector.

An interesting variation of a heliostat using linear movable mirror strips or slats, something like a Venetian blind. This concept only tracks in one axis. In this case I believe it satisfies the definition of a heliostat even though the second axis movement is not required. Movement of the image does occur along the line of the stationary receiver so the slat length is extended a bit to keep the receiver fully illuminated.
A new and unique design, although not fundamentally new as Leonardo Da Vinci described it centuries ago. This has the potential to make large heliostat systems truly cost effective. The design is highly scalable. In other words as the size goes up the component cost to power ratio, installed $/W, actually goes down.
T Pole heliostat costs go up as size increases mainly due to exponentially increasing bending moments in high winds.

The "Compact" part of the CLFR, of which they got their patent, stems from the method they use to aim the mirrors at one of two receivers at different times of the day. They do this to prevent a mirror slat from "Shadowing" its neighboring mirror slat. This results in a more "Compact" design. As with the LFR The motion of each slat is the same, but when a slat switches from one receiver to the other that angle of "SWITCHING MOVEMENT" is NOT the same as the other slats. This kind of complicates the slat driver mechanics.

Russell Concentrator
Russell Concentrator Russell Concentrator (Russell Concentrator) Design
The Russell Concentrator is similar to the "LFR" except the mirror slats are stationary and the linear receiver moves in a circle.
This is an example of a "Single Axis Heliostat".
This concentrator is a form of heliostat as it fits the definition of a heliostat.
1. It redirects the light to a stationary target.
2. The geometry changes throughout the day.
3. And is aimed at the bisector.

Water Cooled PV 2/3rd Motion Heliostat
2/3rd Motion With the Mirror Away Steve Baer's sketch Steve Baer (2/3rd Motion Heliostat) Design
"2/3rd Motion Heliostat", Steve Baer first described this type of heliostat motion in "Notes on Tracking May 2008" in an internal Zomeworks paper.
I'm fond of saying "There is little fundamentally new in the field of solar tracking". This may have proved me wrong!!
(If anyone knows of examples prior to May 2008 please inform me. I want to be complete here.)
This is an example of a "Single Axis Heliostat".
This concentrator is a form of heliostat as it fits the definition of a heliostat.
1. It redirects the light to a stationary target.
2. The geometry changes throughout the day.
3. And is aimed at the bisector.

Nick Pine, on the SolarHeat Forum, has been designing a hybrid water cooled PV panel system. Essentially, 30 feet of panels are mounted flat in a row in an East-West direction. They must be flat to the horizon because of the water hybrid element. On the North edge a mirror, equal in width ( 39" ) to the panels and extended in length past the ends of the panel array, is hinged to move in a North-South direction. This mirror is used to reflect light onto the panels.
This can be called a "Single Axis Heliostat" like the LFR although there are severe restrictions on placement and geometry.

I was trying to develop a tracker for this. I tried to move the mirror in "MirrorAngle" to do bisector or 1/2 speed motion as other heliostats do. This was not working out well as the mirror width needed to be excessively wide.

Nick showed me the mirrors should move in "MirrorAngle" with 2/3rd the motion of the sun's "SunAngle". This motion is an inherent property of isosceles triangles, triangles with at least 2 sides of equal length. One side being the mirror and the other the PV panel. Note! In my example drawings the 2/3 motion is implemented using 2 gears or pulleys. The primary one is stationary with the secondary mounted on the mirror. The secondary gear or pulley is exactly 2 times the diameter of the primary.

Note! "SunAngle", or SA, is not the same as "ALTitude". SunAngle is the angle above the horizon at a point normal, perpendicular, to the mirror axis. It starts at 0° at the horizon and goes to 90° at the zenith and extends over the top to 180° on the other side.
Similarly,"MirrorAngle", or MA, is not the same as "ALTitude". MirrorAngle is the angle above the horizon at a point normal, perpendicular, to the mirror axis. It starts at 0° at the horizon and goes to 90° at the zenith and extends over the top to 180° on the other side.

An alternate location for the sensors is near the edge of the panel opposite the main axis. However, this location, which uses reflected light is not nearly as accurate as the other method which looks directly at the sun.

2/3rd motion, huh? What gives? All solar tracking motions are supposed to be either 1/1 or 1/2. I never heard of this before! But it does work!! Neat huh!!!

After studying this we realize that a N-S orientation with 2 mirrors works even better. Geometrically, there are no restrictions as to orientation of the fixed receiver. The orientation where the line of PV panels are mounted on the polar axis will have the most gathered energy per day. Or say, directly on a south facing roof. Of course, we often have engineering restrictions, (such as Nick's requirement for the PV panel be mounted flat), that limits optimal mounting.

All this is a bit hard to explain in words so study the images. You can call me at (651)583-2265 if you have questions.

Anyway, this looks like a truly new concept. It does have some warts though.
Here are the pros & cons.
1. Concentration is limited to 2X or less, with some orientations much less.
2. Energy gained per day is always more than a fixed mount panel without a mirror of the same orientation.
3. The PV panel or other active receiving device is easily mounted and doesn't move.
4. A simple sensor based tracker can be used. Of course, computational tracking can also be done.
5. The sensor is mounted on a simple 2/3 gear, or cable, mount so the sensor aims directly at the sun. A big plus as it can't be confused looking back through the mirror as in an inline tracker!!!
6. Of course, since the mirror tracks the sun in only one axis there will also be "COSINE Loss" when the sun is not normal to the mirror in a direction along the main axis.

Further work:
It is not a requirement that the mirror meet the panel at the edges. The only requirement is that the plains of the mirror and panel meet a common vertex of the isosceles triangle.

The implication is the mirror can be mounted away from the panel, for engineering reasons, if a gap is needed.
You might ask, can extra sets of mirrors on the same side be added to increase concentration?
The answer is no.
All the reflected light from the extra mirrors will be shadowed by the inner mirror.

It occurred to me the inverse of all this also works. Basically, the mirror and PV panel exchange places. Now the panel moves and the mirror is fixed. This has limited use and I would call it trivial.

I wrote an Excel Spreadsheet to see how this all works. I also tried using 3/4th and 4/5th motions. I found 2/3rd motion is superior in every way to the other motions in these applications.
The spreadsheet calculates:
1. The exact flat mirror width for each SunAngle. Of course, you will choose the largest calculated width for a desired SA range if the motion is other than 2/3rd.
2. The sun concentration factor contribution for the PV panel and each wing mirror for each SA.
3. The gear ratio for the solar tracker mount.
4. The basic difference angle between the 2 wing mirrors.

Related a bit, but not exactly:
Solar energy concentrator system Patent:US4316448 Solar energy concentrator system.
This has movable film mirrors. The geometry is not exact but close enough for many applications.

Solar Tracking With A Box-Style Cooker 2/3rd Motion Solar Tracking With A Box-Style Solar Cooker.
"James W. Thomasson, PhD
wrote this article.
James described the exact 2/3rd motion. And then goes on to describe a simple drip tracker and a cable scheme to move the mirrors for a solar cooker. The geometry of the cooker version is not actually 2/3rd motion. The linkage works OK, and good enough for the box cooker.

Added info:
Solar Concentrator Truss Assemblies Patent:US2010-0206303 Solar Concentrator Truss Assemblies.
Non movable mirrors set to 60° on a moving frame.

hinge Hinge (Hinge design)

receiveraxis Receiver Axis (Receiver Axis design)
(Can be called "Receiver Axis", "Target Axis", "Spinning Elevation", "Spin Elevation", "Spin Tilt", or "Rotation Elevation" heliostat mount.)
Heliotrack Heliotrack Solar Heliostat: A device capable of reflecting sunshine to a stationary target throughout the day (Receiver Axis Design)
Sundog Sundog Lighting Heliostat (Receiver Axis Design)
Steve Baer's Zomeworks has a receiver axis heliostat.

A dish is a two axis solar tracking mirror that reflects sunlight onto a receiver, often circular in shaped, that is in alignment with the sun and the central axis of the mirror.
Sandia Dish Sandia Dish
Yang­Sui Yang­Sui translates to solar ignitors, or burning mirrors.
Possibly the oldest solar device at 6000 years ago. Used to ritualistically ignite fires in seconds. Made of bronze with a polished inner parabolic surface.

A trough is a solar tracking mirror, either one or two axes, that generally reflects sunlight onto a linear receiver that is perpendicular to and is in alignment with the sun and the central axis of the linear parabolic mirror. A variation is the use of linear lens elements.

NS Axis Trough Sandia East-West Horizontal Axis Trough (Horizontal)
NS Axis Trough Practical Field Alignment of Parabolic Trough Solar Concentrators (Horizontal)
Technically this test facility trough is mounted on a large turn table, a kind of Lazy Susan, so actually the main axis of rotation is vertical and the secondary axis is horizontal.

E/W Horizontal Axis Trough Horizontal Axis Trough with Rotary Insulation (E/W Horizontal Axis)
This trough uses an innovative high efficiency transparent rotary insulation system. When spinning colder, heavier, air is forced to the peripheral surface of the drum through centrifugal force. The hotter, lighter, air is forced to the interior surface of the concentrator through centripetal force.

Air is a good very good insulator. In normal insulation the air can convect from the hot surface to the cold surface reducing its effectivness. Of course, materials such as fiberglass help to prevent this convection. However, these materials prevent light from passing through. Rotary insulation is highly effective as virtually no convection will occure.

Apparently Jeroen van Luijtelaer invented this concept.
Rotating solar boiler (2005)
Build It Solar has a DIY artical by Luijtelaer this:
The Rotating Solar Boiler -- A NEW Idea.

Polar Axis Trough Polar Axis Trough (Polar Axis)
Ron Smith's Polar Axis Trough Ron Smith's Polar Axis Trough (Polar Axis)

Arctic Solar's Compound Parabolic Concentrator  * Arctic Solar's Compound Parabolic Concentrator (CPC)
This type of concentrator is based on Roland Winston's basic, long expired, patent US3923381.
Unlike conventional parabolic concentrators which require relatively accurate aiming CPC troughs can accept much wider acceptance, or off axis, angles.

The wider acceptance angle can be a good match with Linear Fresnel Reflector, LFR, arrays.

Hyperbolic Paraboloid Hyperbolic Paraboloid Hyperbolic Paraboloid (Hypar design)
This concentrator is technically a trough as the focal zone is a line, although it uses a Hyperbolic Paraboloid reflector.
Its also is technically a heliostat as the geometry changes throughout the day.
The 3D curves are built up from strait lines.

Sandia Solar Furnace Sandia Solar Furnace (T Pole Design)
Four Solaire Solar Furnace Four Solaire Solar Furnace (T Pole Design)
Odeillo Solar Furnace Odeillo Solar Furnace (T Pole Design)

Sunshine Recorder Sunshine Recorder
A sunshine, Campbell–Stokes, recorder is a device that records the amount of sunshine at a given location.

Betaray 180 Rawlemon Solar Devices
A Campbell–Stokes device that concentrates sunlight on photovoltaic cells.

Pyrosphere Pyrosphere
Clayton Bailey's sunshine recording device.

Pyranometer Pyranometer
A pyranometer is a type of actinometer used to measure broadband solar irradiance on a planar surface and is a sensor that is designed to measure the solar radiation flux density (in watts per metre square) from a field of view of 180 degrees.

Heliostat design concepts 960301.
Absorptivity  Black Crystal  Chemistry  Complaint  Concepts  Costs  Cover  Efficiency  Emissivity  Fridge  Future  Greenhouse  Heliostat  Light Measurements  Lighting  Lumens  NREL  Phase Change Materials  Power  Radiometric & Photometric Terms  Reflectivity  Solar Spectrum  Solec  Stasis  Storage  Thermal Connection.  Thermal Properties of Materials.

Update of Heliostat arrays 970331.
Arrays  Computer  Costs  Description  Divergence  Front  Furnace  Lighting  Neat  Odeillo  Plan  Side.

Update of Heliostat arrays 980301.
1997  3M SMF1100 Solar Film  Axis  Bridge  Challenge  Computer  Converters  Costs  Cover  Deflandre  Diodes  Dish  Efficiency  Engine  Fresnel  Heliostat  Hinge  Horizontal  Richard J. Komp, Ph.D.  Mylar  Polar  PV  Sayre  Size  Software  Thermal  TPole  Tracker  Trough.

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blank wells
* "David N. Wells" <laseraxe@erols.com>
* The Northside Company.
* Davids concentrator is similar to the Russell patent# US4148564.
This is a Power Point slide presentation.

* The same thing in HTML.
The Helix Nebula moshier
* Astronomy and numerical software source codes by
* "Stephen L. Moshier" <steve@moshier.net>
* aa-56.zip Self contained Ephemeris Calculator.
This is a neat program that can be run as a subroutine. Its written in C.
Keith Burnett burnett
* Keith has written codes for the Position of the Sun.
They're based on page C24 of the 1996 Astronomical Almanac.
He presents it in the forms of Formulas, QBasic ( works with Power Basic ), and Excel 97 Spreadsheet.
* "Keith Burnett" <kburnett@btinternet.com>
SunCalc suncalc
* SunCalc
Graphic position of the Sun in realtime.
analema analemma
* The Analemma
Key to astronomical and solar tracking mathematics.
* Red Rock Analemma Page
A bunch of links to solar astronomical info.
Borealis Power Technology borealis
* Borealis Power Technology
They hold patents on an exciting now type of electric power generation technology called Power Chips.
They operate on the electron thermionic emmmision principal.
See: * Borealis on my patent page.
Power From The Sun pfts
* Power From The Sun
A very nice solar book on the net.
Solar Mike's mike
* Solar Mike's Photovoltaic web page.
I'm still alive but my personal website isn't. It took a lot of time to maintain and I've taken a job with Array Technologies, Inc. I did pick up the URL http://www.solarmike.com but have not done anything with it. Any specific questions...drop me an email
"Solar Mike, Michael Reed, Sales Manager" <mreed@wattsun.com>

Array Technologies, Inc.
3312 Stanford NE
Albuquerque, NM 87107, USA

PH: 505-881-7567
FX: 505-881-7572
URL: www.wattsun.com

Mr. Solar mrsolar
* Mr. Solar.
Your contact point for information, products and services about every aspect of solar, wind & water power.
* PV panels sorted by power.
Mr. Solar sspence
* "Steve Spence" <sspence@green-trust.org>
* green-trust.org
Steves website has a wealth of alternative energy topics.
Dew Point dew
* Dew Point, dew.exe
I have a useful program for calculating and converting between Dew Point, Relative Humidity, and Ambient Temperature.
Click on this line to download the program.
* Drawing a parabola with a T square.
Focal Length Calculation focallength
Parabolic Focal Length Calculations
The focal length and image size of a parabola can be calculated with some simple measurements.
Measure the Radius distance of the parabola from the rim to the central axis and Depth of the dish.

R  = Radius
D  = Depth
FL = Focal Length
S° = Solar diameter in degrees of arc. About 0.5°
I  = Ideal Image Size formed by a perfect parabola.

The Radius of a 10' satellite dish in inches = 60"
Depth = 21"

R^2   / (D   * 4) = FL
60"^2 / (21" * 4) = 42.9" Focal Length

TAN(S°   / 2) * 2 * FL    = I
TAN(0.5° / 2) * 2 * 42.9" = 0.37" in diameter
Of course a real 10' satellite dish is not nearly
that perfect. They have a focal zone diameter of
about 3". 
The rule of thumb is the Ideal Image diameter of
the Sun is about 1% of the Focal Length.
centroid centroid
* Calculate the Parabolic Curve that has its Centroid at the
same location as the Focal Point for a Trough.

The Centroid is the center of gravity of an object, the balance point.
Ok. normally this is done on a 2 dimensional plane figure. In this case
it's the centroid of a 2 dimensional line. Is this still a centroid?
Close enough for me.
Anyway, this centroid calculation is done only on the trough reflector.
Any other hardware needs to be balanced to the same focal point
to completely balance the system.

In addition this Excel spreadsheet assumes the reflector is
made from a flat sheet of material bent into the parabolic shape.
I.e. it calculates the actual width obtained from a standard sheet width.
It calculates the reflector area efficiency, i.e. the captured light width
v.s. the sheet width.

This spreadsheet can also be used with any arbitrary parabolic curve.

Parabola using a string Parabola using a Rotozip tool
CdS solar tracker demartile
* "Rich DeMartile" <rich_demartile@prodigy.net>
was kind enough to provide some CAD drawings on a method of producing a parabola. Thanks Rich.

* Rich also has posted a schematic of a solar tracker and mount based on a pair of CdS photo cells.
mscir parabolic CAD drawing program parabola1.1
* "mscir@yahoo.com" <mscir@yahoo.com>
Another parabolic CAD drawing program

* Download parabola1.1 here including the Visual Basic 6 source code.
Jeremiah Chace Jeremiah Chace
* Jeremiah Chace's web page.
* Jeremiah has a shareware program to plot parabolas. troughs8.exe
Click on this line to download the program.

* "Jeremiah Chace"  <jeremiahchace@wildblue.net>
Shadowing calculations shadow
* Download an excel spreadsheet to calculate spacing, or shadowing, between unit elements in a tracking solar array.
I wrote this to assist in comparing methods and orientations. There is always a compromise between keeping the elements closely spaced and the resultant energy loss due to shadowing.
Sunflower sunflower
* Doug Wood
* "Sunflower" <fox@harbornet.com>
Doug Wood makes very interesting low cost parabolic dishes. They are based on long strips of glass mounted on a truss frame.
SunFlower's 35 year Dish Concentrator HistorySunFlower's 35 year Dish Concentrator History
Teton Engineering Inc teton
* Teton Engineering Inc.
A Tracking Solar Concentratorfor for the home experimenter.
This concentrator, based on 1 square foot mirror tiles, is the first solar system I studied. It was, I think, the one presented in Mother Earth News many years ago.
Ra Energy FDN ra
* Ra Energy FDN
The Solar Hydrogen Economy is the Gandhi strategy, the missing part to civilization's greater puzzle and the key to the elusive paradigm shift.
Raleigh Myers <ramyers@igc.org> describes an interesting off axis parabolic trough constructed from concrete.
The Energy Warrior warrior
* The Energy Warrior
3M SMF1100 SMF1100

* 3M SMF1100 <http://www.taindustrial.net/renewable-energy-market/3m-solar-mirror-film-1100-1/>
They sell 3M SMF1100 which appears to be the replacement for the venerable SA-85 acrylic film mirror material. These films use Silver as the reflective surface. Acrylic films have a much longer lifetime than Mylar. Also, the reflective surface is imbedded between the acrylic film further enhancing the weathering lifetime.
Nielsen Enterprises nielsen

* Nielsen Enterprises <http://www.mirrorsheeting.com/>
3019 S. 256th St.
Kent, WA 98032
(253) 941-7281
They sell good quality reflective aluminized mylar in a variety of sizes.
Hydrobuilder hydrobuilder
* Hydrobuilder.
Mylar & Plastic Coverings
Reflectech reflectech
* Reflectech.
Long Life Acrylic Film Mirror materials.
Sohara sohara
* Sohara.
Directable Mirrors - A Better Way To Focus The Sun.
Beaty beaty
* William Beaty
Infinitely large solar furnace.
Event Horizons event
* Event Horizons.
* Ken Kolbly is working on heliostats.
Pine Associates Ltd. nick
* Nick Pine is expert at solar thermal calculations.
* Nick designs Solar Closets and Sunspaces and has an extensive FAQ.
* He has a program to kerf cut wooden ribs for parabolic troughs. kerf.bas
Click on this line to download the program.

* "Nick Pine" <nick_pine@verizon.net>
Jim Brown's house air
* Jim Brown's main page.
* Air transfer solar collector on Jim's house.
Solar cookers Solar cookers
Gujarat Gujarat
* Solar cookers.
Steven Harris steveharris
* Reel time temperature measurements of his solar oven.
Spiral Concentrator spiral
* Spiral Concentrators
by Steenblik
SunSpot sunspot
* SunSpot
Making good use of the Sun.
Fresnel Solar Cooker Design
by Ed Norman
Clear Dome Solar cleardom
* ClearDome Solar cooking reflectors.
Webb Mealy's Solar Cooker mealy
* Webb Mealy's Solar Cooker
Webb has several nice videos of his project.
* An Excel spreadsheet to set mirror angles. WebbMealy1.xls
Dish Turbine
Gear Box Track
* C. Christopher Newton
This is a beautiful example of a Solar Dish Steam Turbine Electric Generator.
This was his masters thesis project.
Attached is a copy of his thesis paper which is on a concentrated solar thermal steam system.
In the appendices of the paper, you will find the diagrams for the steam turbine.
With the proper amount of steam supplied, the turbine is capable of 5 hp.
Helikon Solar Sintering helikon
* Helikon Solar-Powered 3D Printer by Markus Kayser
Experimental 3D printing method using the sun to melt sand into useful objects.
Axel's Helioworm axel
* Axel's Helioworm Heliostat.
Helioworm - DIY Heliostat drive with self made worm gear.
The worm gear wheel is made from the white plastic of a cutting board.
The stepper motors and the gears are taken from an old printer.
All moving parts and the control electronics are located in the housing and are the weather proof.
The control unit is based on an Atmel Mega168 micro controller.
Electronic board and control program.
Practical Solar, Inc. practical
* Practical Solar, Inc.
They have developed a new, proprietary concentrating solar power system (CSP system) to harness energy from the sun:
a small-scale heliostat system that can direct up to 300 square meters of sunlight onto a single square meter. This concentrated solar energy can be used to produce heat, light and power for a virtually unlimited number of applications, at only a fraction of the cost of other solar technologies.

I own a set of 10 of these I got on ebay from Light Manufacturing.

They have a new multiple heliostat design. Take a look!!!!
I don't think I would call the new design a T Pole though.

Helio Track heliotrack
* Helio Track
Solar Heliostat: A device capable of reflecting sunshine to a stationary target throughout the day.
This is an example of a "Receiver Axis" heliostat.
* "Justin Bruen" <sales@heliotrack.comm>
Leo Gerst's Heliostats gerst
* Leo Gerst's Heliostats.
This is an example of an "in line" solar tracker driving a "T Pole" heliostat mount.
Solenica's Heliostats solenica
* Solenica Heliostats.
This is an example of an "in line" solar tracker driving a "U-Joint" type heliostat mount.
Instead of rotary drives as in my example Solenica uses linear actuators and links.
This is basically in Italian, however, the Internet translators don't seem to work on this site.
CiraLight's Smart Skylight Lighting Heliostats ciralight
* CiraLight's Smart Skylight Lighting Heliostats.
Ciralight's SunTracker™Daylighting Device.
Ok, mot exactly a heliostat. It does turn in AZImuth, but is not tracked in ALTitude.
It's a compromise as it reflects much of the light down to a difuse light scatering hemisphere.
SolarTech Solar Lighting solartech
* Karl Roth's Cassegrain Dish Lighting System.
Home Heliostat homeheliostat
* Home Heliostat
This is a bit hard to categorize.
It has a sensor section that operates essentially as a "Receiver Axis" mount where
the sensors aim directly at the sun. The mirrors are mounted on "Azimuth Altitude"
axes. There is a gimbaled linkage between the two.
The area is about 1/2 square meter and reflects up to about 400 watts of light power.
Ok, actually about 200 watts of visible and 200 watts of infrared light.
That's equivalent to about 3000 watts of electrically driven incandescent light bulbs.
Cool, and costs about $400us.
* <contact@wikoda.com>
Light Manufacturing lightmfg
* LightManufacturing LLC's AZimuth ALTitude Heliostat
Unique low-cost heliostats for industrial and architectural applications. About $1349us.
The mirror is tensioned reflective film and microprocessor controlled.
Interesting concept of "Solar Thermal Rotational Plastic Molding".
* LightManufacturing's H1 specifications.
Erik Rossen's Mini-Heliostat rossen
* Erik Rossen's Mini-Heliostat page.
(Erik has extensive bookmarks to many subjects.)
Suntenna domestat
* Inflaitable Heliostat
by Gary Reysa
* The Heliostat Team
Dr. Warren Ostergren

* An interesting heliostat
with a gimbol mount, moved by weight shifting.
Magaldi magaldi
* Magaldi Group Concentrated Thermal Transfer & Energy Storage Using Sand
This is a very interesting technology using sand as both the thermal transfer medium and thermal storage.

I remember "Solar I" doing something similar years ago using Hawaiian black obsidian sand.
I did some experiments with something similar.

Here are some preliminary search links:
* Renewable Energy World
* google Search
* Getty Images
* CSP Today
* Google Patents, WO2011027309

Steve Baer zomeworks
* Zomeworks
Pasive Energy Products and Heliostats. A leader in the development and manufacture of passive energy products since 1969.
* Universal Track Rack™.
* A paper written by Steve Baer.
Heliostats--Sameshine vs Sunshine
woodmill woodmill
* Otherpower
The Cutting Edge of Low Technology
* All Wooden Wind Generator
* Experiments
* Wonder Magnet
* Amazing Magnets
Solar Tracker elcheapo
* El Cheapo Passive Solar Tracker.
(Propane mass transfer activated).
Simillar to Zomeworks.
Poulek poulek
* Traxle
Poulek Solar
Polar mount with tracker.
One of my competitors.
LivingOnSolar living
* Living On Solar
Jim Eddy has a Polar Axis Solar Tracker based on a TV antenna rotator, it's controller box, and a Sony remote control.
He has complete plans on how to do it.
Cool idea!!!
Sun Energy sunenergy
* Sun Energy
Sun Energy is based in Minnesota. Owner Jerry Lilyerd attended Iowa's first Annual Energy Fair in 1990 and found himself hooked for life. He then attended and helped at many subsequent energy fairs during the next 4 years. After realizing that his personal 'hobby' had him working full-time, Jerry founded Sun Energy in 1994. He had been installing solar and inverter systems, as well as working full-time at NSP (Northern States Power). Jerry reports that he has been booked solid ever since!
All of Sun Energy's business comes from referrals. Jerry and his experienced team of energy professionals handle small to large installations-commercial and residential. <lilyerd@gmail.com>
Wattsun wattsun
* Wattsun Solar Trackers
Wattsun Trackers provide you with more solar power for less money.
Your power is harvested in a smooth dawn to dusk flow.
Wattsun Trackers maximize your investment in solar power.
* And a bunch of solar data including Excel Spreadsheets.
* Excel spreadsheet to graphicly show the shadowing effects of multiple tracked panels. This one is for 40° of latitude.
Small Power Systems smallpow
* Small Power Systems
Small Power Systems is a company in search of answers to the world's energy and environmental Problems.
One of my competitors.
Wind & Sun windsun
* Wind & Sun
by Warren Lauzon.
One of my competitors.
LedSHex3 led3

Dual XOR Solar Tracker ConceptXOR Type Tracker
* Red Rock Energy LED3 tracker
I make a simple, low cost, single axis electronic solar tracker based on using green LEDs as light sensors.
I no longer make this XOR type tracker as it has been replaced with the LED3X works better in many ways.
Led3x led3x
* Red Rock Energy LED3X tracker
The LED3X is a series of solar trackers that can be used with single and dual axis applications.
Solar  Stalker solarstalker
Dual XOR Solar Tracker ConceptXOR Type Tracker
* LPC, Laser Precision Crafts
DIY Solar Trackers

Based on one of my earlier designs, (LED3), that used 4 LED sensors per axis.
Be aware, they are using a Microprocessor which has not passed the FCC radio emission tests so would be illegal to use in the US and other parts of the world.
Youngsville, NC 27596
One of my competitors.
Sun Tracking stracker
* Sun Tracking
These guys seem to have disappeared.
Sun Tracking sunlink
* Sun-Link Tracker
One of my competitors.
Fusion Seeker fusionseeker
* Fusion Seeker
Solar Tracker Controllers. These are "single axis" and "dual axis" FUSIONSEEKER solar trackers. They can be used in all applications that need solar tracking (solar panel trackers, water heating solar collectors, any sort of solar concentrators, daylighting systems, etc).
Be aware, they are using a Microprocessor which has not passed the FCC radio emission tests so would be illegal to use in the US and other parts of the world.
Made in Slovenia.
One of my competitors.
SunTura suntura
Dual XOR Solar Tracker ConceptXOR Type Tracker
* SunTura by WindyNation
Solar Tracker Controllers. These are "dual axis" SunTura solar trackers.
They have both solar trackers and tracking mounts.
Be aware, they are using a Microprocessor which has not passed the FCC radio emission tests so would be illegal to use in the US and other parts of the world.
One of my competitors.
SIA Electric siaelectric
* SIA Electric
Solar Tracker that is a close copy of my LED3X made with a PIC microcontroller.
Be aware, they are using a Microprocessor which has not passed the FCC radio emission tests so would be illegal to use in the US and other parts of the world.
Made in Romania.
One of my competitors.
Solar Electronica solarelectronica
* Solar Electronica
"The SOLARTRACK is a microcontroller-based system, ECU (Electronic Control Unit), which has been designed to follow up on two axes with high precision.
It is suitable for all types of PV or CPV modules, including photovoltaic panels, concentration systems and heliostats.
The control modules, working in close loop, calculate the position of the Sun, Elevation and Azimuth, with a precision less than 0.01°, by means of a patented solar sensor designed by us."
Be aware, they are using a Microprocessor which has not passed the FCC radio emission tests so would be illegal to use in the US and other parts of the world.
Made in Mallorca, Spain.
One of my competitors.
The Analog Guy tag
* The Analog Guy Solar Trackers:
Be aware, they are using a Microprocessor which has not passed the FCC radio emission tests so would be illegal to use in the US and other parts of the world.
One of my competitors.
CampaTracka CampaTracka.com
* CampaTracka
Dave Harvey makes solar trackers loosely based on my LED5 low power solar trackers.
He uses mechanical relays to increase output current to 3 amps. <dave@campatracka.com>
One of my competitors.
Unfortunately, I think he has gone away.
MTM Solar Tracker Kit mtm
* MTM Scientific, Inc
Solar tracker kit.
They uses mechanical relays to increase output current to 3 amps.
Note! This tracker is not suitable for use with higher current actuators as the relays are prone to contact damage. A number of people who have had troubles with the MTM trackers have replaced them with my LED3X trackers.
Basicly for school and light duty applications.
Be aware, they are using a Microprocessor which has not passed the FCC radio emission tests so would be illegal to use in the US and other parts of the world.
One of my competitors.
SBE Solar Tracker sbe
Dual XOR Solar Tracker ConceptXOR Type Tracker
Single axis tracking systems for light duty applications.
They use LED type sensors circuits similar to those I developed in the LED3 trackers which have 4 LEDs on each axis.
Be aware, many of their products are using a Microprocessor which has not passed the FCC radio emission tests so would be illegal to use in the US and other parts of the world.
One of my competitors.
Home CSP csp
* Home CSP
They have a number of devices for solar tracking.
They use LED type sensors circuits similar to those I developed in the LED3 trackers which have 4 LEDs on each axis.

One of their trackers, the "Track'n Park", has the ability to park in a "Face Up" or "Tabled" position. While this is interesting, I highly discourage this practice for several reasons.:
1. Leaving PV panels in the tabled position overnight in heavy snow or sleeting conditions can take longer to melt when aimed at the sun in the morning. Parking in the east with the edge upward minimizes these problems.
2. While the tabled position may reduce the wind loading, this is actually a false security.
The worst survivable winds that are encountered are those caused by "Downbursts" or "Microbursts". These are unpredictable and happen in seconds. There is just not enough time to move into the safer position.
I recommend making the tracking mount strong enough to take these wind with any orientation at any time without notice.
3. The tabled position has greater susceptibility to "Hail".

Be aware, many of their products are using a Microprocessor which has not passed the FCC radio emission tests so would be illegal to use in the US and other parts of the world.
One of my competitors.

Solener Solar Tracking solener
One and two axis tracking systems which are now entering the stage of commercialisation. Grid-connected system incorporating two-axis tracking systems and high wind-speed protection.
Be aware, they are using a Microprocessor which has not passed the FCC radio emission tests so would be illegal to use in the US and other parts of the world.
SSI-200W Grid-Tied Inverter envirotech
* Envirotech's SSI-200W Grid-Tied Inverter
SSI, Smart Sine-wave Inverter.
Rated at 200W. However, it is not UL approved yet.
This inverter connects between a PV panel, or other power source, and the 120V 60Hz grid. It operates the PV panel at the MPPT, Max Power Point Tracking, mode to get the most energy transfer per day.
Home Power homepower
* Home Power Magazine
Renew Magazine ata
* Renew Magazine
ME3 me3
* Minnesotans for an Energy-Efficient Economy (ME3).
NESEA nesea
Northeast Renewable Energy Association aims to strengthen the economy and improve the environment by bringing clean electricity, green transportation, and healthy, efficient buildings into everyday use.
Renewable energy webring webring
* The Renewable Energy Webring.
Midwest Renewable Energy Association mrea
* Midwest Renewable Energy Association
Their Mission: The Midwest Renewable Energy Association is a nonprofit network for sharing ideas, resources, and information with individuals, businesses, and communities to promote a sustainable future through renewable energy and energy efficiency.
American Solar Energy Society ases
* American Solar Energy Society
is a national organization dedicated to advancing the use of solar energy for the benefit of U.S. citizens and the global environment.
Arizona Solar Center arizona
* Arizona Solar Center
Your source for information on solar energy in Arizona.
National Database of State Incentives for Renewable Energy (DSIRE) dsire
* State Programs and Regulatory Policies Table.
EnergyPlus energyplus
* EnergyPlus
EnergyPlus is a new building energy simulation program for modeling building heating, cooling, lighting, ventilating, and other energy flows.
National Reneuable Energy Laboratory nrel
* National Renewable Energy Laboratory
* Solar Radiation Data Manual for Flat Plate and Concentrating Collectors.
The Hybrid Optimization Model for Electric Renewables.
NASA nasa
Surface meteorology and Solar Energy Data Set (release 3)
RETSCREEN retscreen
* Canadian based solar data.
PVGIS pvgis
* PhotoVoltaic Geographical Information System (PVGIS)
Solar data for Europe and Africa.
SolarGIS solargis
* Solar Radiation Database Geographical Information System (SOLARGIS)
SolarGIS: High-resolution solar radiation database
Time series in 15 minutes time steps, representative meteorological year, longterm averages, temperature, Solar radiation data for India, Middle East, Africa, South America and Europe.
Langley langley
* Surface Solar Energy Data Set
Monthly Averaged Regional Data.
This is a monthly solar energy data set for the whole earth. They have a lot of data about sizing and orientation for solar systems.
Meteonorm meteonorm
* Meteonorm
Global Meteorological Database for Solar Energy and Applied Meteorology.
They sell a CD of world meteorological data with hourly resolution.
Paul Scherrer Institute psi
Paul Scherrer Institute.
Renewable Resource Data Center rredc
Welcome to the Renewable Resource Data Center.
Stretched Membrane Heliostats saic
* Solar Power Technologies
* Stretched Membrane Heliostats.
CRACKED cracked
by Donald E. Simanek
A very humorous treatise.
CREST crest
Center for Renewable Energy and Sustainable Technology.
Note, Crest has had some problems migrating to a new URL address. If dificulties are encountered make sure the link starts with "http://sol.crest.org/...." instead of "http://solstice.crest.org/....".
Greenpeace greenpeace
* Greenpeace
I don't agree with much of what Greenpeace stands for. However, they have commissioned a study of PV manufacturing plants for the future. This study has been well received.
This report proposes constructing large PV manufacturing plants to compete evenly with conventional fossil fuel power plants.
* Solar Energy: from perennial promise to comprehensive alternative.
It's a 63 page document in Adobe .pdf format.
Concentrated Sunlight Consortium weizmann
* Weizmann Institute
Concentrated Sunlight Consortium.
PIX pix
The Photographic Information eXchange.
Midway Labs midway
* Midway Labs Inc.
* Concentrating photovoltaic concentrators.
* This is the most efficient and cost effective commercially available concentrating PV that I know of.
Unfortunately they may have gone out of business.
DNP Group scicenter
* Solar Electric Solutions
Energy Efficiency specializes in designing and installing photovoltaic (PV) solar energy solutions, small or large, freestanding, or interconnected with the power grid.
* Midway Labs
A solar Fresnel concentrator.
Solar-Focus solarfocus
* Solar-Focus
DNP Group dnp
* DNP Group
Manufacturers of large Fresnel lenses in Denmark.
Cerebral Meltdown Computational Solar Tracker Software cerebralmeltdown
* Cerebral Meltdown Computational Solar Tracker Software
Gabriel Miller

Arduino based Solar Tracking by computing the position of the sun.
Can do direct tracking as well as Heliostats.
HXS10 SolarR Tracker hxs10
* Yokogawa HXS10 SolStation
Solar Positioning Controller?

This is a very nice high end solar tracking controller.
Capable of direct and heliostat control.
Mainly useful for larger scale solar tracking applications.
Intelligent Sun Tracking Heliostat Systems and heliostat solar illumination.
(One of my competitors.)
Sun Tracking Controller trak
* Solar Trak
Timothy M. Leonard, President
Enhancement Electronics, Inc.
Dual-Axis, Open Loop Sun Tracking Controller.
We do Mirrors but not Windows.
(One of my competitors.)
Four Solaire De Mont-louis solceram
* Four Solaire De Mont-louis
Solar ceramic furnace.
Acro Solar Lasers acro
* Acro Solar Lasers
Solar dishes and trackers.
Unfortunately they may have gone out of business.
Solcomhouse solcom
* Solcomhouse
The solcomhouse website will also provide information to everyone on how to do your part to save the planet. The Goals of solcomhouse are to provide the people of the world housing that is in sync and in harmony with the environment. * International Solar Collectors, Inc.
Parabolic trough collectors.
Hydrogen Information hion
* H-Ion Solar Inc.
Specializing in Hydrogen and Oxygen technology for sustainable energy systems.
Ecomall ecomall
* Ecomall
A Place to Help Save the Earth.
HyperPhysics hyperphysics
* HyperPhysics
Hosted by the Physics and Astronomy,
Georgia State University.
The Engineering Tool Box engineeringtoolbox
* The Engineering Tool Box
All kinds of Engineering info.
Bizarre Stuff bizarre
Bizarre stuff you can make in your kitchen.
Fun Science Gallery funsci
* Fun Science Gallery
a collection of scientific instruments and experiments.
Electronics Lab elab
* Welcome to Electronics Lab!.
Here you can find useful circuits with full description, diagrams and PCB, electronics articles, links and downloads.
Popular Scirnce Magazine. popsci
* Popular Science
The official Web site of Popular Science Magazine.
Junk Science Home Page. junksci
* Junk Science Home Page
"All the Junk That's Fit to Debunk."
The Free Energy Archive. free
* The Free Energy Archive
Skeptical investigation of free energy concepts.
Fun site.
PicoTurbine pico
* PicoTurbine
They provide plans, books, and kits for renewable energy education and homebrew projects.
Projects are available for fifth grade through adult.
* Subscribe to the Renewable Energy Newsletter.
Martindale's The Reference Desk calculators
* Martindale's The Reference Desk
All the online calculators you could ever need.
* Calculators.org

Online Conversions and Constants.
* Mortgage Rates

Student Resources: Measurement and Calculation Tools.
The Visible Human Project visible
* A Guided Tour of the Visible Human
The Visible Human Project has generated over 18000 digitized sections of the body. The animations and images in this tour use a few of these images to demonstrate planes of section and other introductory concepts in anatomy.
Science wiens
* Ben Wiens Energy Science Cyber-pages.
Williamson Labs williamson
* Williamson Labs
Look no further. You'll find it at Williamson Labs!
Learn Electronics for FUN and Profit, Painless Tutorials on Electronics, from the Basics Electronics to Electrical Engineering.
Science Toys scitoys
* Science Toys
Make toys at home with common household materials, often in only a few minutes, that demonstrate fascinating scientific principles.
* ITEK Energy
Itek energy, based in Washington, has a PV panel manufacturing facility in Minnesota.
They have "Made In Minnesota" certified PV panels in the 250W class.
2746 31st Ave S.
Minneapolis, MN 55406
Ph: (612)318-6369
Paul Krumrich, General Manager
Silicon Energy siliconenergy
* Silicon Energy
Silicon Energy, based in Washington, has a PV panel manufacturing facility in Minnesota.
They have "Made In Minnesota" certified PV panels in the 250W class.
P.O. Box 376
8787 Silicon Way
Mt. Iron, MN 55768
47.521513, -92.606573
Ph: (218)789-1710
Erin Shea, Inside Sales & Support
The Solar Cell Net
* The solar cell co.
They carry; New, full, and broken solar cells, Thin films and small solar panels.
Sun Power Corp sunpower
* Sun Power Corp.
Putting Light to Work
SunPower is the premier manufacturer of ultra high-efficiency silicon solar cells. SunPower's current solar cell products include the world's highest efficiency concentrator solar cells, which are designed to work with a lens or mirror that concentrates the sunlight many fold.
Electronic Goldmine goldmine
* Electronic Goldmine
They have small PV panels and bare cells.
* Plastecs
Plastecs Company manufactures small Solar Panels as well as providing Crystalline Photovoltaic Solar Cells, cut to size in small or large quantities.
Home of Solar Energy daniels
* Daniel's Home of Solar Energy
How to Cut your Energy Bill with Solar Energy
And Hybrid cars.
Solatron Technologies solatron
* Solatron Technologies
These are new high efficiency monocrystalline solar cells that were purchased from Tecstar Inc., a Southern California based manufacturer of solar cells for use in space based technology such as satellites and the international space station.
Cell Si Co cellsico
* cellsico,inc.
manufacturer solar cells,equipment for production solar photovoltaic panels,single crystal ingots,wafers for semiconductor and solar photovoltaic,vacuum coating equipment,component.
Practical Photovoltaics Richard J. Komp, Ph.D.
* Practical Photovoltaics
by Richard J. Komp, Ph.D.
This book describes how to make solar PV concentrators to produce electricity and hot water. The concentrator is based on CPCs, Compound Parabolic Concentrators, by Dr. Roland Winston.
Build Your Own Solar Panel pjhurley
* Build Your Own Solar Panel
by Phillip J. Hurley an Ebook author.
All the information you need to build your own photovoltaic panel to generate electricity from the sun.
Rocky Mountain Institute. rmi
* Rocky Mountain Institute
A nonprofit research and educational foundation with a vision across boundaries.
Its mission is to foster the efficient and sustainable use of resources as a path to global security.

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To use the mailing list send a message to a single address which is reflected to all the subscribers of the list. Very efficient huh?

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Heliostat Array Project.
Heliostat Project.

Arrangement  Frame  Plan.
Arc Heliostat Array Project.
Arc Heliostat Project.

software analemma
Analemma. The solar tracking software Project.

Analemma  Books  Links  Moshier
Water Distillation and Pumps.
Water Projects.

Airlift  Army  Bowjon  Dams  Distillation  GAIATECH  Greenhouse  Humidification  Hydraulic  Hydro  Pasteurization  Pumps  Ram  Still.

Heat Engine Projects.
Heat Engine Projects.
Ø Converter  3Ø Generator  3Ø Motor  Alternator  Atlas Copco  Bash  Bio Diesel  Boiler  Brayton  Capstone  Choosing  Copeland  Definitions  Denso  Diesel  Expander  Federal Energy Regulatory Commission  Fuels  GE Microgen  Grid Intertie  Home Power Magazine  Henry Engines  IGTI  Kornich  Liquid Metal MHD  Mitsubishi  Net Metering  Nigel Smith  NSP  Omnion Power  Physics  Piston  Propane  Refrigeration  Rotary  Rubber  Sanden  Scroll  Sterling Rankine  Stirling Engine  Stirling Animation  Thermionic  Thermodynamics Class  Thermoelectric  Turbine  Vane  Watt-Hour Meters  Wooden Windmill.
Electronic Projects
Electronic Projects

Actuator  Brad's-Trough  CDS Sensor Tracker  Chace Tracker  Charger  Charging Temperature  Damage  Rich DeMartile  Diversion1  Efficiency  EWB  IO  LED Solar Trackers  MPPT  Demoing my Tracker at the MREA Energy Fair  New LED Solar Tracker  NREL Maps  Patent5622078  Making PC Boards  PWM  Relay Tracker  Shunt1  Shunt2  Shunt3  Solar Trackers  Surface Mount Codebook  Terminals  Tracker Economics  Traxle  TriPod Mount  Under-voltage.
Electric Vehicle Project.
Electric Vehicle Project.

Advantages  Battery Info  BatPack  Calculations  IGBT  Motor  Operation.
Pneumatics, Vehicles & Engines.

Engine  Nitrogen  Vehicle  Westminster.
Miscellanous Projects 1.
Other Projects.

Caution  Copper Properties  Dehumidifier  Differential Temperature Sensors  Hubbard  Enertron  Heat Pipes  Propane Tapper  Thermacore.
Amateur Radio APRS Remote Weather Monitoring.

Call-Signs  CASI  Radio  Update.
Mathamatical & Physical Formulae
Mathamatical & Physical Formulae

Thermal Formulae
Neat Patents.
Neat Patents.

Awnings  Bearings  Brayton  Candles  Compressor  Concentrators  Cooling  EMI  Engines  Flat Plate  Heat Pipes  Hydrogen  Internal Combustion  Ignitor  Instrumentation  Insulation  Don Lancaster  Lighting  Mechanical  Medical  MHD  MPPT  Optics  Pneumatic  Dennis Polla  Power  Pumps  PV  Pyrolysis  Rankine  Receiver  Refrigeration  Robotics  Scroll  Stereolithography  Stirling  Storage  Sundial  Thermionic  Thermoacoustic  Thermoelectric  Trackers  Vane  Vehicles  Wacko Patents  Water  Wind  Xerography.
GOES Current Satellite Weather Photos from GOES.
MPX Weather.
Web Wolf.
Web Wolf Web Wolf, web page design and hosting.
Virgiles Flight Simulator.
Flight Simulator A really neat personal flight simulator.
Vinz Decals Vinz Decals
Rob Phillip's placeVacation at Rob Phillips' place, in Maui!
The Acronym FinderThe Acronym Finder.
Edit+ EditPlus is an Internet-ready, 32-bit text editor for Windows. I use this full featured text editer to write all my web pages. And only $20 to boot.
Currency Converter
Edit+ Currency Converter.
Picture Gallery.

It's Me
Hi all! This is my mug shot.

     Home of the $35 Solar Tracker     Receiver
    http://www.redrok.com/led3xassm.htm     [*]
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