The rise of renewable energy and battery storage based micro-grids: challenges in techno-economic balance and infrastructural transition, modeled with a real-world case-study

Abstract

The utilization of renewable energy systems and battery storage is a promising solution for remote area electrification. In particular, the integration of renewable energy systems and battery storage units are commonly used to establish discrete electricity generation and stand-alone micro-grids, due to their commercial availability and well-studied electrical behaviour. However, being a highly feasible solution for micro-grid planning, the underlying challenging to find the optimal balance between economics and amenity is often overlooked. The work presented in this thesis aims to use real-world projects to explore the challenges of optimal micro-grid component sizing, by providing an understanding of the key challenges in the process – the techno-economic balance. Potential solutions are provided after identifying the problem, including the utilization of existing infrastructural hardware, incorporation of novel demand management strategies, the establishment of poly-generation to improve generation and storage diversity and reduce the problem of intermittency. It is modeled and shown in this study that the demand management approach of non-critical load deferring could substantially improve network availability in a stand-alone micro-grid, with its effectiveness comparable to loss of electricity – a conventional demand management approach that is significantly more disruptive. A real-world case study project in Bruny Island, Australia is constructed as a mixed integer linear programming model to validate research concepts and provide sensitivity analysis simulations to proposed micro-grid system configurations. Up-to-date utility tariffs and micro-grid component pricings are adopted to reflect both the infrastructural and social environment of the studied area, followed by a series of scenarios configured to map out the potential infrastructural transition of Bruny Island. Furthermore, after the Bruny Island base scenario is established in the model, desalination, electric vehicles and vehicle-to-grid are introduced into the model as methods of increasing generation and demand diversity. It is shown in the modeling results, although each technology intervention contributes in improving the economics of the micro-grid, their impacts may differ due to the local climate conditions and social mix. From the analysis on the model results, this study quantifies the importance of a comprehensive model that utilizes complete cycle, fine-resolution input data, instead of the over-generalized approach. Additionally, this study attempts to provide a novel design mindset for micro-grid infrastructural transitions, to maximize the benefits of existing hardware, reduce interruption and minimize system cost.