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. |
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 |