This paper focuses on the design issues of a thermo-acoustically driven low-cost linear alternator for the SCORE project. SCORE (www.score.uk.com) aims to improve the quality of life around 2 billion poor people in the rural communities of the developing countries. The advantage of the double Halbach array permanent magnet moving coil alternator structure over traditional loudspeaker as a linear alternator is presented. The theoretical analysis of the linear alternator at different coil configurations with the rectifier circuit is explained and analysed with the finite elements simulation results. The simulation results show that the double coil structure with the smaller number of coil turns would be suitable for this project. The experimental results of the double Halbach array prototype which has been built and tested are discussed and compared with the simulation results.