Berkeley Achieves New Highs in Thermophotovoltaic Efficiency

Dean Sigler Announcements, Electric Powerplants, Solar Power, Sustainable Aviation Leave a Comment

Researchers at University of California at Berkeley announced a record in thermophotovoltaic efficiency, now at 29 percent, but with a few tweaks, soon to be at 50 percent.  This is great news for small drones, which could stay up for days, but possibly not a be-all, end-all for larger, more conventional electric aircraft.  Let’s examine the potential and the pitfalls involved. The researchers’ “groundbreaking physical insight” and “novel design” applies thermophotovoltaic principles that are “an ultralight alternative power source.”  Eli Yablonovitch, professor of electrical engineering and computer science (EECS), wrote in a paper published in the Proceedings of the National Academy of Sciences, ““Thermophotovoltaics are compact and extremely efficient for a wide range of applications, from those that require as little as 100 watts, [such as] a lightweight unmanned aerial vehicle, to 100 megawatts, [providing] electricity for 36,000 homes. In comparison, a 100-megawatt combined cycle power plant is massive,” Expanding on work he and his students published in 2011, Yablonovitch …

Coots and e-Gulls at Oshkosh

Dean Sigler Batteries, Electric Aircraft Components, Electric Powerplants, Sustainable Aviation 1 Comment

Lead image shows Mark Beierle in the Soaring Gull of his design with which he accompanied Richard Steeves to Oshkosh. As many readers know, Richard Steeves, a physician and teacher at the University of Wisconsin – Madison is also a builder and long-time advocate for an amphibious aircraft called the Coot.  He publishes the Coot Builders Newsletter and stages a recurring AirVenture event, a yearly get-together of fellow Coot builders.  Recently, he got into electric aviation and has built and flies Bravo, an e-Gull designed by Mark Beierle.  Richard’s newsletter now features articles about amphibians and electric flight. Mark showed up at Richard’s hangar at the Sauk Prairie Airport, a lovely stretch of green bordered by hangars and bisected by a concrete runway pointing south toward Madison and north toward the Wisconsin Dells. Beierle “worked very methodically and precisely to optimize Bravo beyond my dreams,” according to Richard. The Coot Builder’s Newsletter reports, “Mark Beierle showed up at the Sauk …

Another e-Gull takes flight

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Richard Steeves is an oncologist in Madison, Wisconsin, on the faculty of the University of Wisconsin School of Medicine and Public Health, and has hosted your editor’s visits to AirVenture in 2013 and 2014. He recently took delivery of the e-Gull he helped finish at Mark Beierle’s airport workshop near Santa Margarita, California.  The airplane was a pre-owned craft that was rebuilt for electric power in Mark’s shop.  Richard had been a speaker at a symposium on thorium reactors, a subject important to this cancer-fighting radiation specialist, and then vectored over to Mark’s field to see his “new” airplane. Multiply skilled, Richard previously built a beautiful example of Molt Taylor’s Coot amphibian, and spent many happy hours flying along the Wisconsin River near his home.  He writes and edits the Coot-Builders’ Newsletter, and has published three books intended to help newcomers to the Coot family – The Coot Story, The Coot in a Nutshell and The Essential Coot.  His interest in electric aircraft …

ElectraFlyer’s New ULS – A Different Kind of Boomer

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Randall Fishman must have a wall of medals, trophies, and award plaques for his many breakthroughs in electric flying.  He was the first to astound Oshkosh attendees with the flight of an electric airplane, his ElectraFlyer C with a brushed motor and controller configured by Fishman.  He picked up not only prizes, but magazine and newspaper column inches and Internet hits.  His developments since then have diverged onto two paths, a two-seater and a pair of ultralight motorgliders. Randall sold a kit last year for his ElectraFlyer X to Richard Steeves, a physician from Madison, Wisconsin (look for an upcoming entry). and has been providing technical and material support. The X  should take to the skies soon. ElectraFlyer’s Ultralight development took two turns in the last seven months. At the Sebring, Florida Light Sport Aircraft Expo in January, your editor saw an adaptation of a single-seat motorglider, displaying a new motor of Fishman’s design housed in a scooped air intake. The …