Autoclave curing is one of the most energy consuming processes in manufacturing carbon fibre reinforced polymers. In order to improve the energy efficiency, one needs to understand energy usage in an autoclave and factors that influence it. This work presents two thermodynamic based models for estimating energy consumption in an autoclave. The first model is an analytical approach based on simplified heat capacity equation. The second model combines the Multi-Relaxation-Time Lattice Boltzmann method (MRT LBM) with Fourier heat equation to simulate autoclave temperature flow and energy consumption. The output from the two models were compared to energy consumption data collected using a power meter. The estimated values from the MRT LBM method showed a better match with only 1% difference from the experimental value. Since the two models are parametric and scalable, a what-if analysis was carried out to investigate the influence of varying process parameters on autoclave energy consumption. Parameters including cure cycle, autoclave size and loading capacity.