New wing design with solar panels

A new wing, designed to accommodate a total of 24, 6' monocrystalline solar panels, is undergoing the construction phase.

Designed to withstand a maximum load factor of +3.8 G (5.7 G ultimate), features a wingbox made of thin aluminum sheet, reinforced with spars.

CAD view of the G-1 with wing-mounted solar panels

Significant aerodynamic changes were made to the wing configuration: ailerons were removed to allow the use of bigger solar panels. Instead, greater dihedral angle is adopted to couple the yawing motion to the roll. With this solution, it is possible to control the roll motion of the aircraft only with the use of the rudder.

Moreover, a rectangular wing planform was chosen to better accommodate a large number of solar panels. In fact, adopting a tapered planform would allow for sure slight aerodynamic and structural improvements but at the cost of significant solar-panel installed-surface reduction.

To minimize the induced drag of the new rectangular (and un-twisted) wing, optional winglets are being studied using numerical means to minimize the power consumption in cruising configuration.

The shape of the winglets is chosen using a set of parameters such as the dihedral and sweep angle, twist and taper ratio for each section. All those parameters (and their boundaries) are passed to a global constrained minimization function that, coupled with a Vortex-Lattice method, looks for a combination of those parameters that minimizes the induced drag of the entire aircraft and other cost indexes.

The "optimal" combination of winglet parameters highlighted a reduction in the induced drag close to 10% in cruising conditions.

Before and after - this raked-wingtip design is expected to reduce the induced drag by 8-10%

At the moment, an order for the materials needed to complete the wing structure and for a first batch of 10 solar panels is placed. The first machined parts are expected to be completed for the end of August.

Once completed, the G-1 will be able to perform sustained flight from early morning until sunset, carrying 0,5 kg of payload without emitting carbon dioxide.