We all use a lot of energy. So why don’t we generate it where we consume it, in our cities and in our buildings?
This simple efficient optical tracker offers three major advantages when compared with conventional systems: a higher absorption of solar flux, less tilt loss in vertical facades and a reduction of at least one axis for solar tracking purposes.
The scalable system consists of three principle components that can be easily configured, to provide maximum flexibility: a ball lens, an absorbent body (static or uniaxial) and a solar energy converter.
The ball lens can be manufactured worldwide by the glazing industry, for example from PV panels, as a complete glass ball, or –for windows– as a liquid-filled hollow glass sphere. In terms of surface area, it is one of the biggest lenses, so that the aperture receives 57% more solar flux than a flat aperture with the same two-dimensional measurements per square meter. The refractive index and the associated concentration factor are easily calculated and emissions can be optimized for all solar energy converters, including photovoltaic and solar thermal ones. Concentrations ranging from 3 to 10,000 times can be achieved and may be established by adjusting the distance to the absorber body. Additionally, the hollow sphere permits the use of selective filters that enhance performance by benefitting from albedo and internal reflections.
The absorber is the body that carries the energy converter. 365 days of absorbed perpendicular direct-beam energy give it the very highest performance. When compared with a planar aperture, the static version –without a mechanical tracking system (Image 2)– has an almost identical overall surface area, but offers the advantages that the amount of radiation emitted is 57% higher and that the system supports all inclinations from 0-90° without tilt losses. The version with a high concentration ratio (Image 1+3) is configured on the focal plane, so that a single-axis tracker control (azimuth) is sufficient to absorb the radiation. This arrangement provides an affordable option for sun tracking, and permits multiple integration options and optimized land use or heavy wind and snow calculations.
Different solar converters are suitable for use with the system, such as all photovoltaic cells types (crystalline, thin film, CPV, etc.) and solar thermal types, including absorber tubes, thermal receivers and simple water absorbers. The Fire Ball can be coupled with single or hybrid cogeneration systems to generate heat and electricity (using a III-V Semiconductor with a Stirling engine) at the same time.
The system is a great choice, both ecologically and aesthetically, for optimized energy production in urban areas. Its price will be determined by demand. The Fire Ball is a “brilliant” option if you want performance in the future. Keep our nature green and our cities clean!