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The excessive depletion of fossil fuels and increasing environmental concerns have led to the need to explore alternative sources of power for aircraft. This has spurred various stakeholders in the aerospace industry to explore hybrid electric propulsion technology and fully electric vehicles. Airships are aerial platforms based on lighter-than-air systems technology. They have several unique features compared to other vehicles, chiefly their being more environmentally friendly due to low fuel consumption. Among airships, lifting-body dynastats are the most suitable configuration for implementing different levels of hybridization in propulsion systems owing to their large surface-to-volume ratio. The present study deals with the relevance of a hybrid propulsion (conventional engine + electric motor) system and its comparison to conventional ones. An objective function based on envelope volume is formulated to achieve an optimal configuration of a tri-lobed dynastat to carry 10 tons of payload over a 500 km range for specified operating conditions powered by conventional fuel and batteries. The design space is explored assuming a predicted future battery technology level with specific energies ranging from 250 to 750 Wh/kg. Three case studies based on the source of power are investigated: fuel alone, fuel + batteries, and fuel + batteries + solar array. It is seen that the airship can be fully electric with zero carbon emissions but at the expense of a longer length (+18%) and higher envelope volume (+63%) compared to the baseline model.

In recent years, hybrid airships have been identified as promising alternatives for high altitude, long endurance missions. In this study, a design methodology to study the feasibility of a winged hybrid airship powered by solar energy is presented. The proposed methodology involves five disciplines of the airship, viz., geometry, aerodynamics, environment, energy and structures that have been coupled in order to develop an optimum design which incorporates the maximum advantages of the modules. A total of fourteen design variables have been finalized, which are required to carry out the sizing of the envelope, wing, and solar panel layout. The Particle Swarm Optimization (PSO) algorithm is implemented to carry out optimization of a user-defined fitness function for given user-defined operating conditions. The optimization study is subjected to general constraints of weight balance and energy balance. Optimal solutions have been obtained for two different configurations. These are—conventional airship and winged hybrid airship. The solutions have been obtained for four different days of the year, in order to analyse any potential benefits and pitfalls of the two configurations for the varying conditions over the course of one year. The results obtained are generally found to be in excellent agreement with the imposed constraints. The winged hybrid airship configuration was found to have offered no significant benefits in comparison to the conventional configuration. The analysis of the key parameters and data values readily supports this conclusion.