ParabolicTrough

=== mirror designs ===
 
https://web.archive.org/web/20060212135003/https://www.homepower.com/files/solarice.pdf Working with the S.T.E.V.E.N. Foundation (Solar
Technology and Energy for Vital Economic Needs), we
developed a simple ice making system using ammonia
as a refrigerant. A prototype of this system is currently
operating at SIFAT (Servants in Faith and Technology),
a leadership and technology training center in Lineville,
Alabama. An icemaker like this could be used to
refrigerate vaccines, meat, dairy products, or
vegetables. We hope this refrigeration system will be a
cost-effective way to address the worldwide need for
refrigeration. This icemaker uses free solar energy, few
moving parts, and no batteries. See Heliostat_Mirrors#osesolar for alternative using fresnel long slats. 
=== Georgeplhak ===
The troughs are connected in sync with spring loaded linkages 
https://georgesworkshop.bigcartel.com/ book purchase $35 
http://georgesworkshop.blogspot.com and book http://www.ffwdm.com/solar/gen2-book.htm ISBN 098658111-9 
https://www.youtube.com/watch?v=Ek-iYH67kEQ Description of a self built solar tracking parabolic trough water heater by the designer/author. Detailed plans are offered. Made mostly with local materials and common shop tools. from https://www.youtube.com/user/georgeplhak . Solar printing https://georgesworkshop.blogspot.com/2020/02/solar-printing.html by Markus Kayser. Links to https://www.homepower.com/account/archive-download and https://lm.solar/ 
http://www.ffwdm.com/solar/solar-index.htm 
Timelapse videos of the system in operation: youtube.com/user/georgeplhak
Frequently asked questions: http://www.ffwdm.com/solar/FAQ.htm 
https://www.builditsolar.com/Projects/Cooking/StoredHeat/StoredHeat.htm The concentrator is a 1,3m (4ft) diameter scrap satellite receiver dish and stand. The dish is covered with (glued on) bits of scrap glass mirror from the local glazier. Iron locator rods attach a galvanized sheet metal sleeve and open-ended piston arrangement I had made at the local metalworkers. The piston contains a 10x10 bundle of 1 cm (0.4") square-section steel rods, all 20 cm (8") in length. The bundle is secured inside the piston with fencing wire, and the one end (blackened with soot) is presented to the focused sunlight. At the other end of the piston is a handle to grab when moving the heated steel core. 
https://thefraserdomain.typepad.com/energy/2006/10/vertigro_algae_.html 
Housing#walrus for link to housing design 
=== arctic ===
http://www.redrok.com/main.htm#mechanical&gsc.tab=0 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.
=== sopogy ===
Sopogy trough Could hack patent. 
Wims parabolic trough No patent 
Matalon energy Use optical and temperature sensor to align trough. Uses foam blocks to construct trough. Innovative idea to HackPatents. 
http://solarcooking.wikia.com/wiki/Helios_Array 
http://www.builditsolar.com/Projects/Concentrating/SOLRCONC.HTM 
http://www.solarfire.org/tech/helios/helios.html Best idea yet 
http://www.builditsolar.com/ 
http://www.redrok.com/main.htm 
http://www.builditsolar.com/Projects/Projects.htm 
http://www.builditsolar.com/Projects/Concentrating/concentrating.htm Links to links 
http://www.solarfire.org/Helios,36 Design with bent mirrors plans given 
http://www.tinytechindia.com/steampowerplan.htm 
=== silverized mirrors ===
http://www.nextag.com/flexible-plastic-mirror/search-html 
http://abacused.com.au/shop/products/1808,143 
=== BoinBoingSolarOven ===
http://boingboing.net/2009/04/13/7-solar-oven-design.html 
http://www.cnn.com/2009/TECH/04/09/solar.oven.global.warming/index.html 
Bohmer's contest win notwithstanding, solar cooking with a cardboard oven isn't new. Two American women, Barbara Kerr and Sherry Cole, were the solar box cooker's first serious promoters in the 1970s. They and others joined forces to create the non-profit Solar Cookers International -- originally called Solar Box Cookers International -- in 1987. 
http://www.medwelljournals.com/fulltext/jft/2009/12-19.pdf Journal paper 
=== Arched Fresnel Lens - Entech Solar ===
Entech Solar - http://www.gizmag.com/entech-solar-energy-hybrid/12509/?utm_source=Gizmag+Subscribers&utm_campaign=e6e668ca37-UA-2235360-4&utm_medium=email
- 26 patents on stretched Fresnel lenses over photovoltaic cells increasing their efficiency by a factor of four by focusing and concentrating the incoming suns rays. 
https://patents.google.com/patent/WO2016098337A1/en?q=(entech+solar)&oq=entech+solar See journal paper references links to https://www.sciencedirect.com/science/article/abs/pii/S0927024810003235 and https://opg.optica.org/ao/abstract.cfm?uri=ao-52-35-8586 
Fresnel lens designs from Entech Solar. Further details on Helios array mirrors here . 
http://www.patentstorm.us/patents/6111190/fulltext.html Inflateable Fresnel lens 
https://solarcooking.fandom.com/wiki/Minimum_Solar_Box_Cooker 
=== post ===
http://groups.google.com/group/sci.energy/browse_thread/thread/d09162094a59d76d/7634ce1b00ef26b9?q=%22solar+turbine%22#7634ce1b00ef26b9
>The only way we know how to generate large scale energy is to get something
>hot to increase its pressure and then expand it through rotary or
>reciprocating devices (save the use of potential energy from solar energy in
>hydro-generation). I don't see that changing much very soon ...
I do:
Another quality solar thermal design from feklar.
-------------------------------------------------------------
A supercharged heated air solar turbine.
North side: parabolic solar trough reflector.
South side: clear structural glass enclosure, either at ground level
or elevated on cast structural glass pylons.
Let's use a 40 foot long section for example purposes. Also for the
enclosure internal dimensions lets use, say, 2 feet high and 10 inches
wide (N/S), by 40 feet long (E/W). Open to the air at the top @ 10
inches by 40 feet. Maybe with a little roof suspended a few inches
over the top of the opening to keep the rain out.
Inside the enclosure, install a pipe and bearings, say 9 bearings for
approximately (a little less than) 5 foot sections of pipe between
bearings.
For the pipe, use, say, an 8 inch diameter. Made of clear structural
glass, but with the inner surface coated with heat storage mass
material. Or instead, have a rod of heat storage material affixed
inside the center of the clear pipe, running the length of the pipe.
Given this setup, there will be approx. five feet of pipe between each
bearing. The bearings are there because the pipe will rotate inside
the bearings. Consider the interior of the enclosured shaped not as
an extruded rectangle @ 2' x 10" x 40' but as an extruded 'd' or 'b'
shape, with the pipe rotating in the round area and the air pipe being
represented by the line. So maybe a 10 inch diamter circle of the 'd'
or 'b' shape, the upright section is approx. two feet high by 8 inches
wide, and the length, 40 feet.
When making the pipe, slot it. Cut slots in it so air can pass out of
the pipe, and arrange the slots so they run in the direction of the
length of the pipe, between the bearings. Orient or angle the slots
so that if heated air escapes out of them at high velocity, the pipe
will rotate, and the pipe will only be able to rotate in one
direction. Your very basic, very elongated turbine.
Now take the approximately 20,000 solar watts you will get with about
a 7 foot wide 40 foot long reflector trough, and focus it upon the
heat storage mass material coating on the inner diameter of the pipe
(or upon the inner rod if using a rod).
Cool air will be sucked into the open ends of the pipe as the heat
storage mass material heats up and the air will be heated and escape
out of the slots to the airspace within the enclosure. As the mass
constinues to rise in temperature, the air flow because of the
pressure increase of the heated air will increase and the pipe will
begin rotating from the turbine arrangemnt of the slots and the force
of the escaping heated air. Use shrouds on the open ends of the pipe
to act as venturis or pressure enchancers to dictate the correct
direction of airflow through the pipe. Obviously, you don't want a
lot of the hot air to be blown out the ends of the pipe. While the
pipe would be (in this example) 8 inches, the ends of the pipe may
have reducers and convoluted entrance pathways (a small length of 1"
diamter coiled pipe the replacement cool air must travel through, for
example) to create smaller and more effective end openings than that.
The top of the enclosure is open to the air, and here the heated air
escapes. At the top of the enclosure, install a "supercharger" Or in
other words, a roller cage blower type fan running the length of the
enclosure, or other type of exhaust fan system. Link the rotating
pipe mechanically with structural glass welded pulleys at 2X rotation
speed with the fan drive, probably as simple as using a v-belt at each
end of the enclosure. As the fan rotates, the hot air is helped to be
forced out of the enclosure. This should either guarantee the correct
direction of airflow (out the top of the enclosure), or amplify it
once it is established since it will improve the pressure /
temperature gradient between the heated air and the replacement cool
air. It will evacuate the waste heat from the exhaust area. It will
lower the pressure within the enclosure and therefore assist in a
higher rotational speed via the greater pressure differential between
the enlosure and the heated inside of the pipe (which is why the term
"supercharger" is appropriate). Note that the use of 2X exhaust fan
speed is used here as an example, rather than a given. Note also that
the cool air resupply is introduced into the ends of the pipe, never
into the enclosure.
Next to each bearing, or every other bearing, or at just the two end
bearings, install a magnetic stator onto the pipe and affix it into
place so it rotates with the pipe. Then have sliding generator
windings that can slide past the bearing to control the rotational
speed. The higher the speed, the more of the windings are slid over
the areas where the stators are rotating, and the more power is
produced, and the more mechanical braking action on the pipe as a
result.
This one probably has to be kick-started in the morning to get it
running. Given the weight of the pipe and the friction of the
bearings, there is considerable initial resistance at first, even with
the windings disengaged from the stators... Not a problem if it is
connected to the power grid, just reverse the power flow and use the
windings as motors to spin the pipe up enough to overcome the
resistance, then disconnect, reverse, and reapply as a generator
(using fewer windings, at first).
It is highly likely that an impressive rotational speed can be
achieved this way, once it really warms up. The bearings could be
magnetically levitated, but I would think the method itself lends
itself more to air pressure levitation using the same principle. Have
small sections of the reflector trough focus additional energy on
small heat storage masses inside the bearings with a venturi for an
air supply inlet, and use many small air holes in each bearing surface
for the pressurized heated air to escape, like an air hockey table.
Given the high initial resistance to rotation, it is probable that
sufficient pressure to raise the bearings will be applied before
enough force is available to rotate the pipe. Another approach would
be to not slot between the bearings, but only at (inside) the
bearings, so that the escaping pressurized air from the pipe would
levitate the bearings.
This might be an excellent choice to use in conjuction with structural
glass biomass production greenhouses, since these greenhouses do not
require 100 percent of the incident solar energy. In this case,
install the setup on the roof of the greenhouses. Instead of a single
large trough, use three panel reflector troughs with a foot or half
foot or so if empty space between each trough, and instead of
orienting striaght east and west, be off by ten or fifteen degrees.
This will ensure adequate insolation inside the greenhouse, at the
cost of a slight loss in power production efficiency.
This only applies if you want to get maximum land use efficiency. The
angle of 10 or 15 degrees affects the insolation of the greenhouse
just to the north of the trough. For maximum land use you want to
pack the setups together east and west and north and osuth, so from
sourth to north you would have greenhouse, trough,greenhouse,
trough,greenhouse, trough,greenhouse, trough, etc... with as little
space as possible between each pair. For large scale biomass / solar
terraforming, in other words. For a backyard effort, obviously this
probably isn't an issue.
At the ends of the pipe where cooler air is being sucked in, it may
also be possible to install wind generators at each end to further
brake the rotation and provide more power output.
The only specific potential problem issue here that I can see that
needs further addressing is the bearing issue. Obviously, prolonging
the lifespan of the bearings is of considerable importance. I do not
claim to have produced the best possible approach by suggesting air
levitation.
For the time being, just assume that I know a way to make everything
out of structural glass for a ridiculously low cost. The troughs, the
supports, the pipe, the exhaust blower fans, even the bearings.
Everything except the iron ferrite and steel stator cores, and the
copper windings of the armatures. Assume that no other construction
materials can come close to being as inexpensive.
So don't discard it out of hand because it would cost too much or
"more appropriate" materials would be available that would also make
it cost too much for what the output and efficiency might be.
http://www.angelfire.com/empire2/ptaak/images/mexwench.jpg
=== links ===
https://patents.google.com/patent/US4784700A/en?oq=us4784700, Point focus solar concentrator using reflector strips of various geometries to form primary and secondary reflectors Fresnel Dish, from http://redrok.com/neat.htm#US3923381 
https://www.youtube.com/watch?v=xWozY15WA40 from https://www.youtube.com/@kevinjennings4494 
https://www.youtube.com/watch?v=abDlCsNO6UI by The XCPC parabolic evacuated tube non tracking solar thermal collector brought to you by Articsolar.com. Just a simple test showing the steam pressure generated even on the cloudiest days. The UV index was low, I don't have an exact number but it was no more than 300w/m2. Follow the link if you are interested in more information. 
https://web.archive.org/web/20180224045301/https://articsolar.com/
https://www.youtube.com/watch?v=AX0IBl_mR-w 
https://www.youtube.com/watch?v=MMOFDZZ1Plo this is my first system based on George Plhak design. Book availabe at 
SolarLinks#Georgeplhak 
Category:Sasecurity
Category:Energy
Category:Heliostat
Category:Solar reflective material
Category:Solar energy