Efficient production and operation of geothermal systems, aimed at minimizing total costs, emissions, and environmental footprints, are crucial for the global adoption of geothermal energy. Operational challenges like scaling, corrosion, and equipment degradation significantly impact operational expenditures (OPEX). Mitigation measures often negatively affect the environmental footprint. Therefore, proactive monitoring and mitigation considering multiple objectives are vital for sustainable geothermal asset performance. Digital twin technology, proven in industries like chemical, manufacturing and petroleum, offers a solution for optimizing operations and reducing emissions. This paper demonstrates the development and application of digital twin technologies for real-time monitoring, performance optimization, and multi-objective process control in geothermal systems. The developed framework deploys open-source tools to create an open-source digital twin framework for the sector. The proposed architecture, real-time data integration, and functionalities such as process monitoring, event detection, forecasting, and optimization are further discussed in this publication.