One of the first solar plants in Switzerland to be integrated to a large urban district heating network has been monitored since its commissioning in 2021. Located in Geneva, this 784 m² solar field, equipped with innovative evacuated flat plate collectors, has confirmed the potential of vacuum solar collectors for industrial and district heating network applications. In 2022, the plant achieved a specific annual production of 684 kWh per m², corresponding to a 45% yearly average efficiency. A dynamic numerical model, developed under TRNSYS and validated against measurement data, allowed investigating the impact of several optimization strategies together with their economic viability. Additionally, a life cycle assessment and a life cycle cost analysis were conducted, confirming that incorporating solar heat into district heating network significantly reduces GHG emissions and non-renewable energy consumption at an energy production cost which is competitive with that of current district heating networks. These findings underscore the potential of solar thermal technology in decarbonating the thermal energy sector, notwithstanding its limited role in the current energy production arena.