{"id":11109,"date":"2016-09-16T13:49:33","date_gmt":"2016-09-16T20:49:33","guid":{"rendered":"http:\/\/cafe.foundation\/blog\/?p=11109"},"modified":"2016-09-16T13:49:33","modified_gmt":"2016-09-16T20:49:33","slug":"e-genius-flies-with-a-range-extender","status":"publish","type":"post","link":"http:\/\/cafe.foundation\/blog\/e-genius-flies-with-a-range-extender\/","title":{"rendered":"e-Genius Flies with a Range Extender"},"content":{"rendered":"

Stuttgart to Barcelona<\/strong><\/h4>\n

Dipl-Ing* Ingmar Gei\u00df, <\/strong>Deputy Project Manager for e-Genius with the Institute of aeronautical engineering at Stuttgart University<\/a> shared the news that e-Genius flew with its range extender for the first time on September 15.\u00a0 He notes that while the battery-powered airplane can manage trips up to 300 kilometers (186 miles), the hybrid engine\/generator pod will enable flights up to 1,000 kilometers (620 miles).\u00a0 This would equal a trip from Stuttgart to Barcelona, Spain, according to the e-Genius web site.<\/p>\n

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\"e-Genius

e-Genius with engine\/generator pod on right wing. Pod is easily attached and detached to allow flight as pure battery-powered craft<\/p><\/div>\n<\/div>\n

As the school explains, \u201cWith [the] e-Genius hybrid most flights of a typical user case can be done in the cost and energy efficient battery mode \u2013 for all longer flights the range extender can be used.<\/p>\n

Generator system control requires no pilot input, everything being done automatically.\u00a0 If the pilot wants to set down at the end of a trip with a certain amount of battery energy on board, e-Genius has an ingenious \u201clook-ahead\u201d feature to modulate the battery to achieve the desired level at the end of the flight.<\/p>\n

Quiet and Efficient<\/strong><\/h4>\n

Already recognized as one of the quietest aircraft on record<\/a> (56-62 dBa in the 2011 Green Flight Challenge), the hybrid craft takes off on battery power alone and switches the engine generator on when the airplane achieves cruise altitude. \u00a0This type of strategy makes e-Genius a good neighbor.\u00a0 As Ingmar reports, \u201cThe system left an excellent impression \u2013 additional noise in the cockpit was barely hearable. So we could still enjoy our silent electric aircraft and didn\u2019t have to use headsets.\u201d<\/p>\n

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\"e-Genius

e-Genius climbing out on pure battery power. Internal combustion engine is turned on at altitude to avoid disturbing people below (not that they would notice any additional noise)<\/p><\/div>\n<\/div>\n

The blog described the hybrid engine\/generator pod last year,<\/a> a compact Wankel engine powering an equally compact generator while consuming only five liters per hour of fuel.\u00a0 Cruising at over 100 mph, the airplane would use only one liter per 20 miles at about 75-percent power (for the engine\/generator), or 1.3 gallons per hour.\u00a0 Fuel consumption would doubtless go down at lower generator outputs.<\/p>\n

Because Wankel engines tend to be thirsty, estimable reader Howard Handelman sent an excellent critique of last year\u2019s entry, including compromises in battery-pack size, different approaches to controlling fuel usage and getting the most out of a hybrid-package.<\/p>\n

\"e-Genius

e-Genius hybrid schematic. Pilot does not notice changes in operation, software combining outputs from alternator and batteries automatically to run motor<\/p><\/div>\n

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A Ground-based Equivalent<\/strong><\/p>\n<\/div>\n

Another German product, the BMW i3, has a range extender<\/a> that allows one to run beyond low battery range.\u00a0 One owner apparently does a lot of local driving and uses only battery power for most of his commuting.\u00a0 \u201cHowever, I have to admit, I thought I\u2019d need to use the range extender more than I actually have. Of my 56,000+ miles, only 1,925 miles have been with the range extender running. I\u2019ve bought 50 gallons of gas (I kept records) and averaged 38 miles per gallon while the range extender was running, just slightly less than the EPA rating of 39 mpg.<\/p>\n

\"Tom

Tom Moloughney’s 1,000 mpg BMW 13 Rex. \u00a0It used less fuel than he drinks in coffee per month, and less tan his gardner’s tractor burns mowing his two-acre lawn each year. \u00a0Charging at home comes from the solar roof on his house<\/p><\/div>\n

\u201cBut just how little gas is that? Well, as I\u2019ve said, I\u2019ve owned the car for 27 months now, so that averages out to me needing to refill the tiny 1.9 gallon gas tank about once every month \u2014 I drink more coffee than that in a month! However, refueling hasn\u2019t been nearly that regular. I\u2019ve gone stretches of four or five months at a time without needing to buy gas. But I\u2019ve also taken the car on a couple of\u00a0road trips of two or three hundred miles<\/a>\u00a0where I needed to refuel three or four times in the same day to complete the journey. In fact, the majority of my REx miles were accumulated on long trips. These trips simply wouldn\u2019t have been possible in an i3 BEV, as charging infrastructure is only now becoming available along the routes I\u2019ve traveled.\u201d<\/p>\n

Such strategies will be the source of endless speculation and controversy until batteries become energy-dense enough to allow what drivers consider \u201cnormal\u201d trips without recharging.\u00a0 Aircraft designers and builders will then have access to power sources that will allow long flights and great performance \u2013 something fairly elusive thus far except for rare aircraft such as e-Genius.<\/p>\n

The e-Genius fuel tank holds 100 liters, so at 5 liters an hour, 16-hour flights (with reserve) would be possible \u2013 too much for any rational need other than record breaking.<\/p>\n

*Dipl-Ing (Diplom-Ingenieur\u00a0(German\u00a0equivalent\u00a0of\u00a0M.S.\u00a0degree, according to Free Dictionary.com<\/em><\/p>\n