We propose a probabilistic, energy-aware, broadcast calculus for the analysis of both connectivity and energy consumption of MANETs. The semantics of our calculus is expressed in terms of probabilistic automata driven by schedulers to resolve the nondeterministic choice among the probability distributions over target states. We first develop a probabilistic observational congruence together with a bisimulationbased proof technique. Then we define an energy-aware preorder semantics. The observational congruence allows us to verify whether two networks exhibit the same observable probabilistic behaviour in terms of connectivity, while the preorder makes it possible to evaluate the energy consumption of different, but behaviourally equivalent, networks. We show our calculus at work both by modelling the Location Aided Routing (LAR) protocol for large MANETs and by evaluating the energy cost of a Go-Back-N protocol with respect to a Stop-And-Wait in a network with mobility.