Will You Be Able to Print the Solar Cells for Your Wings?

Dean Sigler Solar Power, Sustainable Aviation Leave a Comment

That may sound like a silly question, but thin-film solar cells are pushing the boundaries of lightness and efficiency that will make them viable candidates for use on aircraft.  Looking back at earlier achievements demonstrates the great things that can be done with limited resources.  Eric Raymond, for instance, made a solar-powered flight across the United States in 1990 on amorphous solar cells that were only about two percent efficient. His Sunseeker Duo, which he flies around Italy and Switzerland with Irena, his wife and co-builder, has modern thin-film cells that are 23-percent efficient – a ten-fold gain.  Before that, the earliest two solar-powered flights were charged by big, round solar cells, not terribly efficient and lacking full coverage of a wing because of the gaps between cells.  Fred To in England and Larry Mauro in America did what they could with these disadvantages and managed successful, but short, flights after hours of charging small on-board batteries (also relatively inefficient). …

Solar Sails for Ultralights?

Dean Sigler Electric Aircraft Materials, Sustainable Aviation, Uncategorized 1 Comment

Ultralights have done many spectacular things, including topping Mt. Everest and crossing the English Channel.  Gerard Thevenot flew the Channel under a La Mouette wing powered by an Eck/Geiger motor driven by three fuel cells in 2009 – six years before the recent flights with faster electric craft.  For that matter, Paul MacCready and his team flew a solar-powered aircraft from near Paris to an RAF runway on the eastern English coast in 1981. Hang gliders, paramotors, and other rigid and non-rigid-wing craft might benefit from new sailcloth that incorporates flexible solar cells into its makeup.  Used on sailboats, the solar fabric helps run auxiliary motors and can help extend the cruising range of a boat when the sails are furled. A French company named UK Sailmakers France has started a new company, SolarClothSystem®, to make mainsails with “a film containing high efficiency photovoltaic cells.”  The solar cells can be used on sails that will be rolled or folded, as …

Direct Conversion of Sunlight to Hydrogen – Cheaply

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

We’ve witnessed several attempts to produce an “artificial leaf,” a device emulating the photosynthesis of plants, but providing hydrogen and oxygen that could power fuel cells in electric vehicles instead of plant sugars to make trees and flowers grow.  One of the biggest problems so far has been the rare and costly materials necessary to generate hydrogen. Ècole Polytechnique Fédéral de Lausanne (EPFL) scientists have come up with a low-cost alternative, using abundant materials called perovskites and budget electrodes to produce hydrogen from water with a 12.3 percent conversion efficiency – a record for fairly common materials. Perovskites are a calcium titanium oxide mineral that come in a variety of colors and can be bog-common or extremely rare, approaching rare earth mineral status.  The CaTiO3 used by Michael Grätzel is of the common variety, but that doesn’t seem to detract from its performance as a hydrogen-production agent. That, and the inexpensive materials used in the device’s electrodes cause Jingshan Luo, a post-graduate …

Solar Impulse 2 Makes Premier Flight

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Solar Impulse HB-SIB, the second aircraft from the program headed by Andre’ Borschberg and Bertrand Piccard, took to the skies early this morning piloted by Markus Scherdel.  Taking off from Payerne Airport at 3:38 Greenwich Mean Time (GMT) Solar Impulse 2 climbed to a randomly orbiting path within a 20-mile compass of the airfield to the southwest, Lake Neuchatel to the north, and Belleville to the northeast. At about 4:01 GMT, and about 5,300 feet, Scherdel reported a slight vibration and briefly leveled off until determining that it was probably an aerodynamic vibration – not a motor issue, but possibly from a hatch door.  He continued climbing and performed a bank angle test of 5° at varying airspeeds and “a steady heading sideslip” to determine that controllability and stability were OK. At 4:47 GMT the team’s web site reported, “Flight Director is quite happy: no problem has been detected on the electrical and propulsion system, stability of airplane is good.  …

Cambridge, MIT Chasing Room-Temperature Hydrogen

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

News from Cambridge University shows some promise for inexpensive production of hydrogen, an elusive process considering the lightest element in creation is also the most common, said to make up 90 percent of the visible universe.  On earth, it readily combines with oxygen to form water, a handy thing to have around for the benefit of our species. Getting hydrogen out of the water so that we can burn it in our cars and airplanes is a frustrating process, though, often requiring more energy for the extraction than can be obtained from its combustion. According the National Renewable Energy Laboratory, “To make [hydrogen] usable in fuel cells or otherwise provide energy, we must expend energy or modify another energy source to extract it from the fossil fuel, biomass, water, or other compound in which it is found. Nearly all hydrogen production in the United States today is by steam reformation of natural gas. This, however, releases carbon dioxide in the …

MIT Solar Findings Mirror Those of 13 Year Old’s Tree Research

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

A recent report from MIT, replete with computer algorithms and graduate level insights, made your editor dip back into a story about a young naturalist who saw a model in nature that could lead to more efficient solar arrays.  Both produced works of genius and give us hope for some real breakthroughs in solar power deployment. The Massachusetts Institute of Technology announced that, “Innovative 3-D designs from an MIT team can more than double the solar power generated from a given area,” and suggested that models of their new approach, “show power output ranging from double to more than 20 times that of fixed flat panels with the same base area.” Jeffrey Grossman, the Carl Richard Soderberg Career Development Associate Professor of Power Engineering at MIT and leader of the research team, reports in a paper published in the journal Energy and Environmental Science that the greatest improvements came in “locations far from the equator, in winter months and on cloudier …

Solar Power Cheaper than Diesel Generators – in India

Dean Sigler Electric Powerplants, Sustainable Aviation 3 Comments

Care2.com, a catch-all web site that distributes free e-greeting cards and a blend of new age health care, pet care, and environmental news, caught this editor’s attention with the news that solar power is now cheaper than Diesel-generated electricity in India – without subsidies – and by the manner in which private industry and government agencies are adapting to this. Two giants on the industrial side have thrown their substantial resources behind solar.  BHARTI, the largest mobile phone company, is using the sun to power rural cell towers.  Jaine Irrigation, the world’s biggest mango puree producer, is building an 8.5 megawatt solar power plant, according to Care2. On the governmental side, Sustainable Business.com explains the reverse auction approach that helps India get cheaper power than other countries manage. “In India, those that bid the lowest in a reverse auction win the right to build solar plants up to 20 megawatts (MW) and sell the electricity under a 25 year contract. “Winners are …

Making Good Use of “Underutilized Space”

Dean Sigler Sustainable Aviation Leave a Comment

Airports and air bases occupy lots of space, especially if they have crossing runways.  The acreage consumed to protect the public from the long narrow strips of asphalt or concrete can be considerable.  Making good use of the “waste” space might make airports more economically viable.  Arizona’s Luke Air Force Base is planning to use its space to generate electricity through solar power, just as Nevada’s Nellis Air Force Base has since 2007.  According to the Associated Press, the “Arizona Public Service Co. has announced plans for the largest solar installation on U.S. government property.”  The 15-megawatt solar power plant will be 1 mW larger than the system at Nellis, and will be online by next summer.   52,000 tracking solar panels located on 101 acres on the Base will supply about 50 percent of the facility’s electrical needs, or the equivalent required for 3,750 Arizona homes. The project will create 550 jobs and remove 19,000 tons of carbon dioxide emissions per year, according to …

QinetiQ Zephyr Breaks Official Record for Solar-Powered Endurance

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

According to BBC News and GlobalFlight.com, QinetiQ’s Zephyr, a 22.5 meter (72 feet) unmanned, solar-powered aircraft has been in the air for more than a week over the Yuma, Arizona Proving Grounds, and program managers intend to keep it there for a total time of at least fourteen days.  Having flown since 6:40 a.m. July 9, its endurance is now four times that of any other unmanned aerial vehicle.   A US Global Hawk holds the current official world endurance record for an unmanned aerial vehicle (UAV) of 30 hours, 24 minutes.  Zephyr’s record is being certified by the Federation Aeronautique Internationale, the world air sports federation. Jon Saltmarsh, Zephyr’s project manager, says the craft, “Is basically the first ‘eternal aircraft,’”  a name once given to AeroVironment’s Helios and related aircraft.  The 50 kilogram (110 pound) unmanned airplane emulates the flight pattern followed by Andre’ Borschberg in taking the Solar Impulse to a world record for manned solar-powered airplanes.  Its thin solar cells power the twin …

Ultra in the Key of E

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Protoplane, the French manufacturer of the Ultra ultralight two-seater, has big plans for increasing the efficiency of an already efficient aircraft. Their petrol-powered, 450 kilogram (990 pound) all-up weight monoplane can cruise, according to the company, at 220 kilometers per hour (137 miles per hour) on only 12 liters (a little more than 3 U. S. gallons) per hour, achieving 43 miles per gallon.  At slower speeds, the plane can stay aloft for nine hours on its 90 liters of fuel. Protoplane hopes to market the first electric two-seater in 2010, basing the design on improvements in “weight, aerodynamic efficiency, batteries, motors and propellers.” Their web site sets forth Protoplane’s objective. “Making an electric aircraft is very difficult, because one pound of mogas stores the same energy as 54 pounds of the best space designed Lithium-Ion battery cells ; So Ultra-e focus[es] on the objective of running 280 km (174 mi) at 160 km/h (100 mhp) with 21 kWh, equivalent to …