A brief Project on Solar Impulse helps to understand you quickly about it:-)

5. 3rd and the Final Model
(HB-SIA)

7. Bertrand Piccard and
50 aeronautical engineers, physicists
and technicians
80 technological partners
Main partners (Solvay,
Omega, Schindler )
100 advisers
and
suppliers

9. Cruise speed: 70 kilometres per hour (43 mph)
Endurance: 36 hours (projected)
Service ceiling: 8,500 m (27,900 ft) with a maximum altitude
of 12,000 metres (39,000 ft)

10. Problem on the spar
In the summer of 2012, during the final structural test
of the wing spar, a problem was encountered and the
spar broke. After the initial shock, the team got
together, analyzed the problem and concluded that an
additional year was gained for new Solar Impulse
adventures.

11. The construction of Solar Impulse 2 or HB-SIB
started in 2011, incorporated much lessons learned
from the previous HB-SIA, but with more spacious
cockpit enabling the pilot to fully recline during flights
of 4-6 day duration. It will have an increased
payload, isolated electrical circuitry to enable flights
in rain, and improved reliability through system
redundancy.

12. 140 million Swiss Francs
over 12 years including the
construction of two airplanes and
the salaries of an 80 strong team
and also other 80 companies
supported.

13. 2003: Feasibility study at the École
Polytechnique Fédérale de
Lausanne
2004–2005: Development of the
concept
2006: Simulation of long-haul flights
2006–09: First prototype (HB-SIA)
2009: First flight of prototype
2009–11: Manned test flights with
prototype
2011–12: Further test flights
through Europe and North Africa in
7 legs
2011–13: Construction of second
prototype (HB-SIB)
2013: Continental flight
across United States(Mission
Across America)
2014: First flight of HB-SIB (2 June)
2015: Planned world tour in
several stages

14. The historic moment on 8 July 2010
resulted in, not one, not two, but three world
records for HB-SIA and its pilot! The prototype
aircraft was awarded records (in “Solar-Powered
Aeroplane” category) for “Gain of Height”
(8744m), “Duration” (26h 10min 19s) and
“Absolute Altitude” (9235m).

15. 2015 will be the year Solar Impulse has
been working towards: the attempt of the First
Round-The-World Solar Flight. Bertrand
Piccard and André Borschberg, the two Pilots
and Founders, will fly around the world with no
fuel, rising up to technical, human and
operational challenges that have never been
faced before.