This paper presents the development of a tool that aims to help stakeholders make informed decisions to invest in renewable energy and understand the impact of different tariffs on the economic viability of renewable energy investments. This includes evaluating the costs and benefits, and assessing the impacts of different tariff structures on the economic feasibility of those options. Furthermore, the tool can help in identifying the potential risks and challenges associated with renewable energy integration projects, such as market and network charges fluctuations. Therefore, this tool provides various evaluations to inform users about their energy consumption in relation to sport market energy prices, network tariffs, and retailer charges. It enables the assessment of a site's economic operation over specific timeframes, calculates potential energy savings from on-site renewable sources, and determines economic indicators based on life-cycle cost analysis. The tool has been designed and validated with data from the Australian energy market, focusing on investment decisions for renewable energy projects in Victoria state. It adheres to the Australian Energy Market Regulations and incorporates feed-in tariff rates particular to the Victorian energy market and its regulatory framework.