RED ROCK ENERGY Solar Power Heliostat Arrays.

* 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 http://www.talkshoe.com/tc/40649

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

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.

HELIOSTAT or CENTRAL RECEIVER SYSTEM:

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.

mechanical
Early Mechanical Heliostats and Coelostats
And some modern ones for illustration.
heliostats

Foucault4 Foucault BC = BM   North

Cloesen1 Foucault ALT/AZ Cloesen North

Foucault1 Foucault Spin/Tilt   North

Foucault2 Foucault ALT/AZ Foucault South

Foucault3 Foucault ALT/AZ Foucault South

Etsy1 Foucault Spin/Tilt Foucault North

Dublin1 Foucault ALT/AZ Foucault North

Kubel1 Foucault ALT/AZ Foucault North

Kubel2 Foucault ALT/AZ Foucault North

Gambey2 Gambey BK = BM     North	Gambey1 Gambey Spin/Tilt Gambey North Folded Up	Pistor2 Gambey Spin/Tilt Pistor North	Tubingen1 Gambey Spin/Tilt   North	Schmidt1 Gambey Spin/Tilt Stoney North	Stoney1 Gambey Spin/Tilt Stoney North	Stoney2 Gambey Spin/Tilt Stoney North	Stoney3 Gambey Spin/Tilt Stoney North	Stoney4 Gambey Spin/Tilt Stoney North Picture
Harvey1 Gambey Spin/Tilt Stoney North With base	Harvey2 Gambey Spin/Tilt Stoney North In Case	Harvey3 Gambey Spin/Tilt Stoney North Label	Harvey5 Gambey Spin/Tilt Stoney North In Case	Harvey6 Gambey Spin/Tilt Stoney North In Case	Harvey7 Gambey Spin/Tilt Stoney North	Harvey8 Gambey Spin/Tilt Stoney North
Yeates1 Gambey Spin/Tilt Stoney North Base missing	Yeates2 Gambey Spin/Tilt Stoney North Base missing	Yeates3 Gambey Spin/Tilt Stoney North	Yeates4 Gambey Spin/Tilt Stoney North	Yeates5re Stereo Gambey Spin/Tilt Stoney North Relaxed Eyes	Yeates5ce Stereo Gambey Spin/Tilt Stoney North Crossed Eyes
Fuess1 Gambey Spin/Tilt Fuess North	Fuess2 Gambey Spin/Tilt Fuess North	Fuess3 Gambey Spin/Tilt Fuess North	Fuess4 Gambey Spin/Tilt Fuess North	Fuess5 Gambey Spin/Tilt Fuess North Folded	Fuess6 Gambey Spin/Tilt Fuess North	Fuess7 Gambey Spin/Tilt Fuess North	Fuess8 Gambey Spin/Tilt Fuess North
Fuess10 Gambey Spin/Tilt Fuess North Improved	Fuess11 Gambey Spin/Tilt Fuess North Improved	Gertner1 Gambey Spin/Tilt Gertner North

Silbermann13 Silbermann Spin/Tilt	Silbermann12 Silbermann Spin/Tilt	Silbermann1 Silbermann Spin/Tilt	Silbermann3 Silbermann Spin/Tilt	Silbermann4 Silbermann Spin/Tilt	Silbermann6 Silbermann Spin/Tilt	Silbermann7 Silbermann Spin/Tilt Parts missing	Silbermann9 Silbermann Spin/Tilt	Silbermann10 Silbermann Spin/Tilt
Silbermann11 Silbermann Spin/Tilt	Silbermann2 Silbermann Spin/Tilt	Browning1 Silbermann Spin/Tilt	Duboscq01 Silbermann Spin/Tilt	Duboscq02 Silbermann Spin/Tilt	Duboscq03 Silbermann Spin/Tilt	Duboscq04 Silbermann Spin/Tilt	Duboscq05 Silbermann Spin/Tilt	Duboscq06 Silbermann Spin/Tilt Parts missing
Duboscq07 Silbermann Spin/Tilt	Duboscq08 Silbermann Spin/Tilt	Duboscq09 Silbermann Spin/Tilt	Duboscq10 Silbermann Spin/Tilt	Duboscq11 Silbermann Spin/Tilt

Brashear1 Coelostat Type 1 Secondary Mirror Missing	Brashear2 Coelostat Type 1	Hilger1 Coelostat Type 1 Adam Hilger, London circa 1910	Ives1 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
Ritchie1 Coelostat Type 1	Transylvania1 Coelostat Type 1	PolarCoelostat Coelostat Type 1	Tornaghi Coelostat Type 1	Tornaghi Coelostat Type 1	Gertner2 Coelostat Type 1

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 South, (in the northern hemisphere).
6. Note! It's possible to operate with the primary mirror alone where a telescope is, itself, aimed at the rotating mirror.
    It's a bit simpler to mount the primary mirror as it doesn't need to be on rails.

Coelostat2 Coelostat Type 2 Horizontal output

Coelostatmg18 Coelostat Type 2 Vertical output

Baidu1 Coelostat Type 2 Horizontal output

Prazmouski Coelostat Type 2

Coelostatnsosp2 Coelostat Type 2

Astropalma1 Coelostat Type 2

Sirius1 Coelostat Type 2

helliostatcoelostatmay1 Coelostat Type 3

heliostatcoelostatsonnen1 Coelostat Type 3

tpole
National Solar Thermal Test Facility (T Pole Design)
Solar II Central Receiver (T Pole Design)

esolar
ESolar Central Receiver (T Pole Design)

practicalsolar
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.

lfr
singleaxisheliostat1
"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.

kaluta
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.

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.

lfrose
* 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.

lfrcalcs
* 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.

hdsolar
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.

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

clfr
singleaxisheliostat2
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
singleaxisheliostat3

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.

2/3motion
singleaxisheliostat4

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

2/3cooker
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:
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 Solar Heliostat: A device capable of reflecting sunshine to a stationary target throughout the day (Receiver Axis Design)
Sundog Lighting Heliostat (Receiver Axis Design)
Steve Baer's Zomeworks has a receiver axis heliostat.

dish
DISH:
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
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.

trough
TROUGH:
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.

troughew
 Sandia East-West Horizontal Axis Trough (Horizontal)
 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.

rotaryinsulation
 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.

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

cpc
  * 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.

hyperbolicparaboloid
hypar
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.

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

sunshinerecorder
Sunshine Recorder
A sunshine, CampbellStokes, recorder is a device that records the amount of sunshine at a given location.

rawlemon
Rawlemon Solar Devices
A CampbellStokes 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.

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

up970331
Update of Heliostat arrays 970331.
Arrays&nbsp Computer&nbsp Costs&nbsp Description&nbsp Divergence&nbsp Front&nbsp Furnace&nbsp Lighting&nbsp Neat&nbsp Odeillo&nbsp Plan&nbsp Side.

up980301
Update of Heliostat arrays 980301.
1997&nbsp 3M SMF1100 Solar Film&nbsp Axis&nbsp Bridge&nbsp Challenge&nbsp Computer&nbsp Converters&nbsp Costs&nbsp Cover&nbsp Deflandre&nbsp Diodes&nbsp Dish&nbsp Efficiency&nbsp Engine&nbsp Fresnel&nbsp Heliostat&nbsp Hinge&nbsp Horizontal&nbsp Richard J. Komp, Ph.D.&nbsp Mylar&nbsp Polar&nbsp PV&nbsp Sayre&nbsp Size&nbsp Software&nbsp Thermal&nbsp TPole&nbsp Tracker&nbsp Trough.

Many links have a single word in very small sized characters next to them. These are used to find this location in the page. If you want to jump directly to that location in the page include that word in the URL: for that page. Here is an example to jump to this "link" text:
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see how the "#links" was added to the basic page URL:

	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.
	moshier aa * 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.
	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 Graphic position of the Sun in realtime.
	analemma * The Analemma Key to astronomical and solar tracking mathematics. * Red Rock Analemma Page A bunch of links to solar astronomical info.
	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.
	pfts * Power From The Sun A very nice solar book on the net.
	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
	mrsolar * Mr. Solar. Your contact point for information, products and services about every aspect of solar, wind & water power. * PV panels sorted by power.
	sspence * "Steve Spence" <sspence@green-trust.org> * green-trust.org Steves website has a wealth of alternative energy topics.
	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.
parabola	amsi * Drawing a parabola with a T square.
	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. Example: 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 * 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.
	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.
	parabola1.1 * "mscir@yahoo.com" <mscir@yahoo.com> Another parabolic CAD drawing program * Download parabola1.1 here including the Visual Basic 6 source code.
	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>
	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 * 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 History
	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 * 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.
	warrior * The Energy Warrior
	SMF1100 mylar acrylic * 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 mylar * 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. Mylar & Plastic Coverings
	reflectech * Reflectech. Long Life Acrylic Film Mirror materials.
	sohara * Sohara. Directable Mirrors - A Better Way To Focus The Sun.
	beaty * William Beaty Infinitely large solar furnace.
	event * Event Horizons. * Ken Kolbly is working on heliostats.
	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>
	air * Jim Brown's main page. * Air transfer solar collector on Jim's house.
	cooker * Solar cookers.
	steveharris * SUNSHINE TO DOLLARS By Steven Harris * Reel time temperature measurements of his solar oven.
	spiral * Spiral Concentrators by Steenblik
	sunspot * SunSpot Making good use of the Sun. Fresnel Solar Cooker Design by Ed Norman
	cleardom * ClearDome Solar cooking reflectors.
	mealy * Webb Mealy's Solar Cooker Webb has several nice videos of his project. * An Excel spreadsheet to set mirror angles. WebbMealy1.xls
	newton * 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 * Helikon Solar-Powered 3D Printer by Markus Kayser Experimental 3D printing method using the sun to melt sand into useful objects.
	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 * 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.
	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>
	gerst * Leo Gerst's Heliostats. This is an example of an "in line" solar tracker driving a "T Pole" heliostat mount.
	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 * CiraLight's Smart Skylight Lighting Heliostats. Ciralight's SunTrackerDaylighting 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 * Karl Roth's Cassegrain Dish Lighting System.
	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>
	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.
	rossen * Erik Rossen's Mini-Heliostat page. (Erik has extensive bookmarks to many subjects.)
	domestat * Inflaitable Heliostat by Gary Reysa
	ostergren * The Heliostat Team Dr. Warren Ostergren * An interesting heliostat with a gimbol mount, moved by weight shifting.
	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
	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 * Otherpower The Cutting Edge of Low Technology * All Wooden Wind Generator * Experiments * Wonder Magnet * Amazing Magnets
	elcheapo * El Cheapo Passive Solar Tracker. (Propane mass transfer activated). Simillar to Zomeworks.
	poulek * Traxle Poulek Solar Polar mount with tracker. One of my competitors.
	living eddy * 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!!!
	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 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.
	smallpow * Small Power Systems Trackstar Small Power Systems is a company in search of answers to the world's energy and environmental Problems. <George@smallpowersystems.com> One of my competitors.
	windsun * Wind & Sun by Warren Lauzon. One of my competitors.
	led3 redrok tracker XOR 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 * Red Rock Energy LED3X tracker The LED3X is a series of solar trackers that can be used with single and dual axis applications.
	solarstalker XOR 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. (919)556-0159 Youngsville, NC 27596 <sales@solarstalker.com> One of my competitors.
	stracker * Sun Tracking These guys seem to have disappeared.
	sunlink * Sun-Link Tracker One of my competitors.
	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 XOR 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.
	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.
	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.
	tag * The Analog Guy Solar Trackers: ST2-48V5A SINGLE & DUAL AXIS SOLAR TRACKER 56V 5A MAX ST2-12V DUAL AXIS SOLAR TRACKER 18V 0.5A MAX <info@theanalogguy.com> 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.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 * 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 XOR Type Tracker * SBE, LLC 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.
	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 * SOLENER TRACKING SYSTEMS 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.
	envirotech * Envirotech's SSI-200W Grid-Tied Inverter SSI, Smart Sine-wave Inverter. Rated at 200W. However, it is not UL approved yet. $289us 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.
	homepower * Home Power Magazine
	ata * Renew Magazine
	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.
	webring * The Renewable Energy Webring.
	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.
	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.