FES climb rate question.

On Thursday, October 8, 2020 at 1:14:30 PM UTC-7, Mana wrote:
You'll get at least 2m/s dry. But like PF says, better to take a tow to 400m and use the FES straight and level until you find a thermal. It's much more efficient in level flight than climbing.

On the Shark, based on a test flight I think that you will get less than 2m/s as it is a heavier glider than Matthew's Diana 2 :-).

From the FES manual:
5.3.4.1 Rate of climb
The maximum rate of climb is available only for a few minutes with fully charged battery packs. As battery voltage is reduced, the maximum achievable climb rate is lower. The average rate of climb depends mostly on the type of sailplane and its take-off weight. Maximum attainable altitude gain that in standard atmosphere conditions depends on the type of sailplane, its weight and aerodynamic qualities. To achieve the maximum altitude gain, use about 15kW of power. Do not use full power as the efficiency of the system is lower. Usually, 80-85 km/h is best for the climb with positive flap setting (the same setting as used while thermaling). Here are rough numbers:
•1600 m (5200 ft) for UL sailplanes at 300kg take-off weight, i.e.. Silent 2 Electro
•1400 m (4500 ft) for the 18m class sailplanes at 400kg take-off weight (without water ballast), i.e.LAK17A FES
•1200 m (3900 ft) for the 18m class sailplanes at 450kg take-off weight (without water ballast); LAK17B FES, Ventus 2cxa FES, Discus 2c FES, HPH 304ES

Sounds like a very marginal self-launch system and is really just a decent self-retrieve (turbo) setup.

Tom