Concentrating Solar Collectors

Concentrating solar collectors use shaped mirrors or lens to provide higher temperatures that flat plate collectors.

 

Heliostats are tracking mirrors that reflect solar energy onto a fixed target.

 

This page "concentrates" on providing links, information and plans for Build It Yourself  concentrating collectors and heliostats.

 

- Concentrating Solar Collectors

- Heliostats

 

See also the Solar Cooking section for more concentrating designs ...

 

Questions? 
Report Broken Links ...

 

Concentrating Collectors
RedRok

Duane Johnson

www.RedRok.com

 

Duane's RedRok site is information central for DIY Heliostats and  concentrating solar collectors.  There are good designs here that can be built on a budget and without exceptional mechanical skills.   The site can be a bit of a challenge to find stuff on, but its worth the effort.
A parabolic trough solar collector you can build

George's website with information on the parabolic collector and other interesting projects...

George's blog -- experiments and tests on concentrating collectors, LED lighting, ...

 

Good Youtube Videos on the collector...

George's very clever parabolic collector cleaner...

A very nice set of ganged, parabolic, tracked, concentrating collectors used to heat water. 
Can be made with common shop tools.

George has just released a generation 2 version of plans and documentation for his collector system. Its a major update that includes design changes, more detail, lessons learned and more. It is an exceptional set of plans and a reference on concentrating collectors. These were .my thoughts on the first version -- the 2nd version is even more impressive.

George has done some really interesting and well executed testing of flat plate and parabolic concentrators both tracked and not tracked...

Generating steam with George's parabolic trough collector... steam generation from sunGeorge has been doing some interesting experiments using his parabolic trough collectors (just above) to generate steam.

It will be interesting to see where this leads.
The Aquaflector

http://www.aquaflector.com/

 

 

This is a new and very interesting design for a simple and potentially large area concentrating collector.  Potential applications include generating steam, or concentrating PV cells.

 

 

Looks like a very simple, buildable, well thought out design.

Manual Making of a Parabolic Solar Collector,
Gang Xiao, Laboratoire J.A. Dieudonn'e,
Universit'e de Nice, Nice France

Manual Making of a Parabolic Solar Collector... (pdf)

Quite a detailed set of instructions on how to build this parabolic trough style solar collector by warping a think flat mirror sheet into a parabola.

Lots of detail.

Solar Fire Project

http://www.solarfire.org/

 

 

Solar Fire provides detailed plans and how-to instructions for building three different sizes of concentrating solar collectors.

The materials are easily obtainable and the design is simple and straight forward -- the concentrators can be made with readily available materials and simple tools.

The Helios collector provides about 3 KW output and temperatures up to 950C.  Several potential applications are discussed.

Inflatable Heliostat

Download full report pdf (3.5 mb)

Mithra and Gary

Mithra (the inventor's) website:
http://www.ricenterprises.org/

Another interesting inflatable idea ...

An experimental, low-cost heliostat design that uses air pressure to focus and support the mirror.
 

Home Made Solar Water Distiller

 

http://www.thesietch.org/projects/distiller/index.htm

 

This is an interesting design for solar water distiller.

I've included it in the concentrating  solar collectors are because the mirror design is interesting and simple, and may have variety of concentrating solar applications.

Roasting Coffee on Sunshine

How to get articles from Home Power ...

Issue 105 Home Power Magazine

How to build a 1200F solar coffee bean roaster.

Certainly one of the highest and best uses for solar power!

A concentrating Collector made from 116 mirrors of 1 sqft each

 

http://www.ida.net/users/tetonsl/solar/page_iii.htm

 

 

"Teton Engineering's Tracking Solar Concentrator is an array of 116 mirrors, one square foot each mounted on a framework and arranged to reflect sunlight on a "collector", figure 1. The concentrated sunlight can raise the collector temperature to about 1200F"

A very detailed set of plans are included -- !! be careful !!

Understanding Solar Concentrators

VITA paper on concentrating solar collectors

 

VITA paper provides a good deal of information on how a wide variety of concentrating solar collectors work.
SunSpot -- Fresnel Mirror Concentrator

http://www.sunspot.org.uk/ed/

 

 

 

A concentrating Fresnel mirror.

Used as a solar cooker here, but might be used for other concentrating applications.

Scheffler Concentrators -- Large, Concentrating Cooking Collector with Storage

Barli Development Institute
http://www.barli.org/solar-storage.html

Another Version in Nepal
http://spot.fho-emden.de/hp/weiler/itahari.html

Good description of Scheffler Reflector Design:
http://www.solare-bruecke.org/ ...

David Delaney article on the Scheffler heliostat cooker design
http://www.geocities.com

These Scheffler heliostats concentrate the sun onto a fixed cooking vessel, or onto a heat storage device that provides for cooking after sunset.

This type of  concentrator can be built with common materials and ordinary skills.   The daily tracking can be by a simple clockwork mechanism, and seasonal tracking can be manual.
The Ultimate Solar Cooker

http://www.inhabitat.com/ ...

How it works:
http://www.solare-bruecke.org ...

 

Solar cooking on a large scale.  84 parabolic concentrators of 9.2 sq meters each.  Capable of cooking 20 to 40 thousand meals a day!

This type of  concentrator can be built with common materials and ordinary skills.  
Solar Sphere -- Concentrating Solar Power

http://www.seao2.com/solarsphere/csp.htm

 

 

An interesting collection of concentrating solar collectors.
Parabola Drawing Tool

http://home.germany.net ...

 

An easy to make tool for drawing parabolas as used in concentrating collectors.
Compact Linear Fresnel Reflector
A concentrating scheme using flat or nearly flat mirrors

Full size prototype test (pdf)

Several papers from Ausra -- a commercial developer of the concept:
http://www.ausra.com/technology/reports.html

An approach that maintains some of the advantages of trough collectors without the need for hard to form parabolic mirrors.
Optics Experiments On The Cheap

http://www.youtube.com/watch?v=uX9Z-nsUHiA

 

This is a very clever and simple test setup for experimenting with curved mirror shapes.

It allows you to quickly and easily fully visualize how a given mirror shape will do in focusing incoming sun.  It allows you to very quickly see the effect of mirror shape changes.

While the video is aimed at refining solar cooker designs, the technique could be used for any kind of concentrating solar application.

Performance of Concentrating Collectors

Test Results SEGS LS-2 Solar Collector,
Dudley, Kolb, Sloan, Kearny
Sandia Labs, 1994

http://sopogy.com/
Look in the "Solutions" area

 

 

There is not a lot out there on the  performance (efficiency) of concentrating collectors.  These two sources provide some material on parabolic trough style collectors.
The 1994 paper gives tested efficiencies for the very sophisticated SEGS LS collector that uses a selectively coated heat receiver enclosed in an evacutated tube, but is helpful because it gives performance with and without the vacuum and the tube.
The Sopogy site gives some performance data on their collector. 
Bear in mind that both of these collectors are built to very high precision.
If you are aware of other sources for concentrating collector performance, please let me know.
Heliostats
Light Manufacturing Heliostats

http://lightmanufacturingsystems.com/heliostats/
Light Manufacturing HeliostatThese commercially available heliostats use a 2.3 sq meter tensioned film mirror.  The control system tracks the reflected sun from the heliostat onto a fixed target, such as a non-sunfacing window in a building.  Prices start around $1300.

These heliostats are part of a solar thermal powered rotational molding system offered by the same company.  This molding system uses far less energy than conventional rotational molding systems and also costs less.  A fascinating application of solar to an industrial process with larger energy needs.  See the first video on this page for a description...
HELIOTRACK.COM

http://www.heliotrack.com

 

 

A very good website on building heliostats and concentrating solar collectors.

Good practical design and experimental data and even some kits to help with the tracking.

The Wikoda Sunflower Heliostat...
sunflower heliostatA new commercial heliostat aptly named the Sunflower.

The tracker, which is also sold separately is right in the center of the petals.

The Practical Solar Heliostat System

http://www.iwilltry.org/b/projects/build-a-heliostat-for-solar-heating-and-lighting/

I Will Try Homepage...

 

An interesting new commercial heliostat product.  The 8 sqft of mirrors are tracked to reflect sunlight on a fixed target using software running on your PC.
The mirrors can be adjusted to provide concentrated or diffuse light.  One PC can guide many heliostats.  Many applications, including reflecting light and heat into windows that do not ordinarily get sun.
While the product is new, units have "endured several years outdoors with no damage, even during severe winter weather and winds in excess of 80MPH."

How to Build a Heliostat for Solar Heating and Lighting,
Rob, www.IWillTry.org

http://www.iwilltry.org/b/projects/build-a-heliostat-for-solar-heating-and-lighting/

 

Rob's heliostat -- reflects solar light and heat into a window in your house.
An interesting idea if your house is lacking in south windows.
Some detail provided on the construction.

Inflatable Heliostat

Download full report pdf (3.5 mb)

Mithra and Gary

 

 Surya -- a cylindrical tracking inflatable concentrating PV solar collector...

Patent for the Surya...  (pdf)

An experimental, low-cost heliostat design that uses air pressure to focus and support the mirror.
 

 

 

 

NEW This is the follow on version of the inflatable heliostat design that uses a tracking inflatable reflector to concentrate energy on a line of PV cells --->

RIC Enterprises ...

 

This is the site of my friend, co-worker, and very creative inventor -- Mithra.  We have worked together on several projects, including the inflatable heliostat just above.

The Inventions page on Mithra's site has some very interesting ideas.
Mirror gives Italian Village Its Place in the Sun


http://www.gizmowatch.com

news.bbc.co.uk/2/hi/europe/6189371.stm#map

"ROME (Reuters) - A village in the Italian Alps is finally basking in winter sunlight thanks to a giant mirror installed on a mountain top to reflect the sun's rays into the main square."

They use a heliostat to reflect sun into the town square.  I've thought about doing this (on a much smaller scale) to reflect light into my east facing living room windows.

Cable supported heliostat from Solaflect Energy



http://www.solaflect.com/
For power generation stations that use a central tower to collect sunlight reflected from a field of heliotstat, the heliostats are the major cost element, so simpler and cheaper heliostat designs have a big payoff.

This new design by Solaflect Energy supports the heliostat mirrors using mostly tension cables rather than the traditional heavy bending structure.

Working on more efficient heliostat designs seems like a good backyard inventor challenge.