Imagine covering your electric airplane with a light-collecting, energetic coating that generates enough juice to extend the battery-only range of your electric airplane. That possibility comes to mind from seeing recent articles about Heliatek’s organic solar cells, which demonstrated a solar-collecting efficiency of 13.2 percent. That’s only about one-third of what the best silicon solar cells can do, but those tend to be relatively thick, heavy, and brittle. Heliatek has managed to make a six-layer thin-film cell in which the active layers are only 250 nanometers (0.00000984252 inches) thick. Sandwiched within protective layers and weighing less than a kilogram per square meter (a few ounces per square foot) HeliaFilm™ can be wrapped around a radius of 10 centimeters (just under four inches). Performance figures are for opaque cells. Transparent cells which could be placed on windows or canopies have a transparency level up to 50 percent and an efficiency of six percent. HeliaFilm® is available in lengths from 0.3 to 2.0 …
On a Clear Day, I Can See My iPad
Dr. Brien Seeley, President of the CAFE Foundation, shared the news of an exciting breakthrough that could make the see-through parts of an airplane’s solar collectors. Most solar collectors have a black or near-black look because they are absorbing light in the visible spectrum. Pulling energy from infrared or ultraviolet spectra invisible to the human eye allows Ubiquitous Energy’s Clearview Power translucent film of to be laid over iPad and Kindle screens and keep them charged constantly. Consider the possibilities of such films covering the Plexiglas or carbonate canopies on aircraft. Even those portions could then be energy collectors. On craft such as electric sustainer motor powered sailplanes, the glazed area comprises a large part of the total fuselage surface area. According to the MIT Technology Review, “…The transparent solar cells are made of various organic layers, deposited one at a time on top of a glass or film. This process could easily be integrated into thin-film deposition systems found …
Sunexelec – Recharging in Flight
The Club d’Ultra Léger d’Alsace is a group of French enthusiasts in Strasbourg, on the German border about halfway between Luxembourg and Switzerland. They have been building ultralight aircraft since 1983, tackling technological innovations such as carbon fiber leading edges, motorization, electrification, and now solar power. They were the first to motorize a Swift, and with one of their craft electrically powered, mounted strips of photovoltaic cells to the upper wing surface. Finding that worked to boost battery duration, the group went on to mount 6.1 square meters of solar cells on an Alpaero Exelec, an ultralight self-launching sailplane. After making 60 flights on battery power between May and April of this year, the group installed the solar cells on the wings, flying 18 times on solar assist between May 21 and July 20. These included eight launches in which the solar cells recharged the airplane’s LiFePO4 batteries during the flight, making the possibility of endless cross-country flight a realizable …
Solar Cells Can Never Be Too Thin
AirVenture’s unofficial prize for the most popular aircraft at each year’s fly in – the brown grass award, named for the trampled turf around the much-thronged craft, had a CAFE Foundation equivalent at this year’s Electric Aircraft Symposium. That would be the crumpled carpet prize for the circles around Dr. Joseph (Joe) Armstrong, Chief Technical Officer for Ascent Solar, a Thornton, Colorado-based firm. Wearing a bandolier-like ribbon of extremely thin, flexible solar cells at the end of his talk, he was surrounded by break-takers eager to get a closer look at his impressive array of photovoltaics. Commercial production modules of the copper indium gallium (di)selenide (CIGS) cells have been verified at an industry-high10.5-percent efficiency by the National Renewable Energy Laboratory (NREL). The cells are created using thin-film deposition on a plastic substrate; this monolithic integration of the cells and their flexible backing permitting their draping over curved shapes. An integrated manufacturing process using “laser pattern interconnect printing” forms PV modules, 20 volt …