1. Solar Cooking and Beyond- Pursuing Best Cost Solar Concentration
Presented at the 2017 American Solar Energy Society Conference in Denver, Colorado
Doug Simmers
ABF Solar, LLC.

2. ABF Solar, LLC.
Manufactures point-focus solar dishes for cooking applications
And also pursues scaling of this technology for power applications

3. Goal- Best Cost Concentration
A Better Focus Co. is dedicated to designing and manufacturing a “best cost” concentrating solar dish
Lowest materials cost
Superior performance to glass mirror or polished metal systems
Good weatherability (for thermal power applications)

4. Directed Energy Cooking
Long focus system
Infinitely variable focusing from 10’ to 25’
Requires slight dish adjustment as the sun moves
Many Cooking Accessories

5. Safety Considerations greater power requires greater diligence to safety
Wear sunglasses when looking at the focused light.
Misdirected focused light can start a fire. Always cover dishes when unattended
As with any type of cooking – cooking surfaces are HOT

6. Re-inventing vacuum-deformed mirror film dishes
- Reinventing point focus dishes utilizing mirror film instead of glass mirrors
- vacuum deformed to focus sunlight.
offers much lower cost than glass mirrors
provides sufficient concentration
light weight dishes enable lightweight tracking structures
Infinitely variable focal lengths between 10 and 30 feet
rapid defocusing for safety.
Re-inventing vacuum-deformed mirror film dishes
Mirror-reflective film is stretched across a perfectly round frame

7. This results in a string of focal points that are not the ideal parabolic shape, but results in temperatures of over 850F at stagnation
Vacuum hold time is typically 2+ hours

8. Previous “stretched membrane” systems have had a checkered history
Learning from the past
Problem- Poor film durability
Solution- New films provide similar performance and service life to glass mirrors - Reflectech Solar, Div. of SkyFuels
Note: cooking dishes use less expensive reflective mylar, and must be stored indoors
Problem- Film wrinkling- past systems utilized stainless steel sheets or other heavy underlayments to inhibit wrinkling
Solution- Annular floating batten with thermal tensioning
Film wrinkling inhibited by
internal floating battens,
and thermal film tensioning
US pat. # 7,374,301 B1
Film wrinkling typical,
without underlayment
Failed LaJet/Cummings Project
Wrinkling inhibited via
internal “floating battens”
US pat. # 7,374,301 B1
Wrinkling inhibited via
internal “floating battens”
US pat. # 7,374,301 B1

9. Learning from the past- Previous “stretched membrane” systems have had a checkered history
Problem- Weatherability- high winds and abrasive particulate (again, cooking dishes would be brought inside during high wind events)
Solution- Weathervaning tracker, rotates away from oncoming wind.
Dishes flip up to reduce incident dish area. Prototype has survived outdoors for 9 years
Haboob approaching Phoenix
Note: cooking dishes use less expensive reflective mylar, and must be stored indoors
Weathervaning tracking structure
Dishes turn their backs to oncoming wind
Dishes flip up, reducing incident area to the wind
Failed LaJet/Cummings Project
Wrinkling inhibited via
internal “floating battens”
US pat. # 7,374,301 B1
Wrinkling inhibited via
internal “floating battens”
US pat. # 7,374,301 B1

10. Latest Developments
More precise concentrated spot- 850F + at stagnation
Improved ability to project focal point
20’
25’
15’

11. Latest Developments
Professional cooking system with two dishes, and sun-tracking frame
Automated sun tracking
Expanded to 4- dishes
Enables small Power applications
Spring, 2018
Looking for partners with a 3-5 kw (thermal) need

12. Summary
ABF Solar dish technology is an effective and cost competitive method of concentrating solar thermal energy.
Basic cooking systems offer many cooking methods
Professional cooking systems offer manual sun tracking
Automated sun tracking will be available in 2018
Scaling to 8’ diameter has been tested, and offers potential for future thermal power applications
Cooking systems are being demonstrated in front of St. Cajetan’s church today, and tomorrow.
Questions?