8' diameter Power Dish
Reflectec polymer film
vacuum deformed to focus sunlight
Dish weight = 65 lbs.

U.S Patent # 7,374,301
Test Receiver for Boiling Water
8' diameter dish focuses to a 20 sq. in.  spot-
insulated SS pot holds 1 gal of water
18' best focal length
350 suns concentration.
Maximum temperature 922C @ 987W/M2 solar insolation
4500 watts energy delivered

(from ASAE Standard X580) W= (Tfinal-Tinitial)MCv/S, where

W= watts
Tf=  Final temperature in degrees C
Ti-    initial temperature in degrees C
M=  Mass of water  (and mass of pot)
Cv=  Specific heat of water (and SS pot)
S  =  Seconds
Heliostat Dish Design Progression
                                                        Completed

light weight
repeatable performance of over 100 suns
low vacuum leakage                                                       

Verify manufacturability of design with low
production factory runs                                                 

Scale up to 8' diameter, and test                                  

Begin outdoor tests with weatherable film  
(10 year life goal)                                                             

Replicate performance of first 8' dish --
pilot run of 2 additional 8' diameter dishes.               

Vacuum seals improved-  hold time improves
from several hours to  several days                           

Design 1/4 scale model of tracking structure
for 4 dishes that also provides both active
and passive stowage modes for high wind ,
dust, and hail events.                                                      

First Vacu-Seal Patent issued
U.S Patent # 7,374,301                                                   

Two-dish tracker developed for solar cooking                                                      
A Better Focus Co.
Large Power Dishes
Best Cost Concentration-



Solar energy is plentiful, but diffuse.   The concentration of
solar energy enables a wide array of applications, including  
industrial steam,  process heating, air conditioning, sterling
engines, concentrating photovoltaics, etc.
Solar concentrating systems also offer the hope of being the
most cost-effective method of capturing and utilizing solar
energy, but the fact remains that traditional
combustion-based generation of thermal and electrical
energy is still considerably less expensive for the typical
industrial user.
One method of closing the cost gap between traditional and
solar power generation is though the use of film-based
reflective materials, as opposed to traditional glass mirrors.  
The first patents for this technology were allowed in the late
1960's, and several systems were developed over the
following 2 decades.   A large field of mirror film trackers with
integral Sterling engines was placed in southern California
by LaJet/Cummings in the early 1990's.  The site was
abandoned  after brief operation, primarily because of poor
durability of the film material made by 3M Corp., who then
abandoned the manufacture of reflective film.   Also, to
prevent wrinkling of the film,  an underlayment of stainless
steel sheet was typically used by designers,  which
increased the cost and weight of the sun-tracking
structures.  The combination of dish weight and heavy
sterling engines required a heavy tracking structure.
Dish/Engine design settled on glass mirror reflectors, which
again required increased weight of the sun-tracking
structures.

Better reflective film materials were researched at NREL,
and at Reflectech Solar, now part of Skyfuels/Sunshine Kadi
Group.  Film durability has improved significantly, and will
likely continue to improve.  



ABF Solar's technology uses no underlayment material, but
instead uses a patented floating batten and  solar
tensioning systems to inhibit wrinkling.  

A lightweight yet strong dish design enables a very low mass
for the tracking structure to move, but the film must still
survive periodic high winds.   ABF Solar has developed a  
weathervaning stowage mode which protects the dishes
from high wind and hail events.  The prototype survived 9
years prior to failing last winter.  An improved tracker design
will provide a minimum of 25 years of service.

A big advantage of vacuum deforming film is the ability to
dynamically adjust focal length, which offers flexibility in
implementation, and also provides the ability to quickly
return dishes to a safe unfocused condition in the event that
tracking control is lost.


Looking for Partners
We are looking for a user/partner to build a 20KW
dish-thermal system:
Do you have a year-round need for hot water or low
pressure steam?
Are you located in a region with good solar resource?
Do you have an interest in participating in the development
and testing of the next-generation of high-energy solar
systems?
Intellectual property of new developments will be shared.


Expressions of interest can be forwarded to  Doug Simmers
at www.doug@abetterfocus.com.
Reflectechsolar.com
8' diameter dish focuses light to a
5" dia. spot on receiver pot for
heating water. Max Temp of 922C
1/4 Scale model of a 4-dish thermal
system focusing on a insulated plate
with thermocouple mounted
A Better Focus Co. is proud to announce the allowance of our first patent         
for our VacuDish concentrating technology, U.S Patent # 7,374,301, and a
subsequent patent for weathervaning wind stowage mode, US Pat. #
8,210,162 B2
Partner Query
Performance Testing
Questions and answers
mirror-reflective film for concentrating solar energy