Solar Impulse 2 Soars Over The Pyramids

It took 50 hours and 50 minutes for Solar Impulse 2 to fly from Seville, Spain to Cairo, Egypt. Only one leg remains in its historic flight around the world solely on electric power supplied by the sun. The airplane is constructed of carbon fiber. Its wingspan is larger than a 747 at 236 feet. It weighs just 5,100. Its wings are covered with 17,248 solar cells that provide electricity to four 38.5 kWh batteries. Solar Impulse 2 has four electric motors rated as 17.5 horsepower each. In flight, it cruises at between 45 and 60 mph.

André Borschberg, cofounder and CEO of the Solar Impulse 2 venture, says, “This flight across Europe… [touched] a large number of countries, very diverse in terms of culture, climate and geography. But in addition to all being on the shore of the Mediterranean Sea, they have a common denominator: the potential benefit of using renewable energies and clean technology.”

In the 15 months since Solar Impulse 2 left Abu Dhabi, solar panel and electric motor technology have improved dramatically. Reports of other electric airplanes are beginning to appear in the news. The Sun Flyer looks like a convention trainer aircraft but has solar panels and an electric motor. NASA is experimenting with electric flight. Siemens says it has created a new electric motor that is lighter but 5 times more powerful than any before. It is working in cooperation with Airbus on electric powered commuter aircraft.

Solar Impulse 2 is similar to the original aircraft flown by the Wright Brothers at Kitty Hawk. It is a harbinger of things to come, many of which are inconceivable at the present time. Modern aircraft are marvels of engineering, but they also create significant carbon emissions, which are injected high in the atmosphere where traditional carbon absorbers such as land masses and oceans cannot contain them.

Electric flight will be a critical part of meeting the carbon emissions reductions needed to keep global warming from exceeding the 2° C threshold that climate scientists believe is the tipping point beyond which rising temperatures will spiral out of control, doing massive damage to the environment.

So a well earned salute to Solar Impulse 2 and the team that made its around the world flight possible. It is now just 1,471 miles away from Abu Dhabi, where the journey began. We will be sure to share that historic moment with you. In the meantime, enjoy the video of the flight from Seville to Cairo.

Source: CleanTechnica

Integrated Propellers Could Power Electric Airplanes

In the same week when the Solar Impulse 2 — an electric airplane powered by the sun — began its quest to circumnavigate the world, NASA announced it has developed a new design that integrates many slow turning electric motors into the wings of light aircraft. The result is that electric airplanes may actually fly someday, although they will only be 1 or 2 passenger planes to begin with.

Integrated propellers provide a 60 percent boost in wing efficiency and a significant reduction in drag. The NASA project envisions 32 electric motors — 16 on each wing — turning small propellers. Each motor can be placed precisely on the wing for maximum efficiency and reduced drag, reports Jalopnik.

The pilot would have many options during flight never before possible. Each motor could be operated independently at different speeds to optimize performance, depending on the phase of flight. In cruise mode, some motors could be shut down and their propellers folded to reduce drag even further. Computers could determine the optimum speed for each motor from takeoff through landing. Having so many motors available would provide critical redundancy and emergency backup in case of failure.

With the government penchant for cool sounding acronyms, NASA is calling the project Leading Edge Asynchronous Propeller Technology (LEAPTech). NASA has mounted the wing on a specially modified truck at Edwards Air Force Base, where it can operate on a dry lake bed at speeds up to 70 mph. The truck has its own acronym, of course. It is known as the Hybrid-Electric Integrated Systems Testbed (HEIST). Researchers are focusing primarily on the takeoff and landing phases of flight.

After the initial research is complete, NASA plans to mount its experimental wings on an Italian-built Tecnam P2006T. Using an existing airframe will allow engineers to compare the performance of the flight demonstrator with that of the original P2006T. Because the technology is easily scalable, it could then be applied to small passenger planes and eventually be tried on commercial aircraft.

Will we be flying to the Bahamas on vacation aboard electric airplanes any time soon? Probably not. But when you consider that commercial airliners spew enormous amounts of CO2 emission behind them everywhere they go, the NASA research could prove to be enormously important for the environment.

Images: NASA