Techno-economic performance analysis of grid-tie and standalone PV system in Victoria

Nowadays, more attention is given for the development of renewable energy to prevent the environment from greenhouse gas emissions, which is due to the fossil fuels and their effect on climate changes. Several countries are working on improving their energy policies as a step of moving towards renewable energy resources. As a part of this movement in Australian, Victorian government has released several initiatives for rebates like small trading certificate (STC) for the Grid-connected rooftop solar, battery rebates, other rebates for a standalone system. Due to rapid decline in the price of the PV system, Australia is experiencing massive growth in rooftop PV. The question arises in everyone’s mind is to stay connected to Grid or going off-Grid? Now, both the systems have its pros and cons, but the lack of accurate analytical design approach resulted in a significant amount of oversizing, high costs is involved in the project and wastage of the resources. Hence, the installation of Grid-connected system has been increased a lot in the market and due to this oversizing of the system, excess solar feeding into the Grid, understandable it is beneficial because, it reduces the emission from the fossil fuel generators by displacing but the local electricity distribution network might be unable to digest these excess exports which are happening and confirmed by several residential households when they discovered their grid voltage is higher (i.e., 255 V ~ 260 V) than the nominal voltage 230 V. This resulted in PV system generating less than it should, and the consumers ended up getting higher bill than before solar installation. So, the networks are started to tighten their PV connection agreement by export limiting the system partially or entirely zero export. This paper presented a decision support tool for the assessment of feasibility of staying connected to Grid or off-Grid by carrying out numerous economic and technical analysis using the Hybrid Optimization Model for Electric Renewables (HOMER) simulation software.