The role of modified diesel generation within isolated power systems

Traditional engine load limits restrict a diesel engine's range and its ability to load share. Accordingly, to achieve high renewable penetrations, diesel generation is conventionally turned off, positioning diesel in competition with variable renewable generation. While this approach maximises renewable penetration (environmental gain), it is uneconomic, requiring costly and complex enabling technologies such as battery storage. For many isolated communities the commercial, technical and social barriers associated with storage integration prove insurmountable. A stalemate results, with owners unable to transition to renewable generation due to inflexible diesel technologies. In this respect, it is easy to view diesel generation as an obstacle to renewable integration. Thankfully, modified diesel technologies can offer improved flexibility without the cost or complexity of energy storage. This paper details the development and testing of both low load and variable speed technologies, each able to improve the performance of diesel generation. Two isolated power system case studies are modelled, with Cape Barren island increasing renewable penetrations to between 41.3% to 58.0% compare to conventional penetrations of 7.7% to 10.1%. For Lady Elliot island the modelled range is 26.7% to 28.5% in comparison to a base of 5.3%. The results serve to recommend modified diesel application as a precursor to battery storage integration.