Innovation in photovoltaics (PV) is mostly driven by the cost per kilowatt ratio, making it easy to overlook environmental impacts of technological enhancements during early research and development stages. As PV technology developers introduce novel materials and manufacturing methods, the well-studied environmental profile of conventional silicon-based PV may change considerably. Herein, existing trends and hotspots across different types of emerging PV technologies are investigated through a systematic review and meta-analysis of life-cycle assessments (LCAs). To incorporate as many data points as possible, a comprehensive harmonization procedure is applied, producing over 600 impact data points for organic, perovskite (PK), dye-sensitized, tandem, silicon, and other thin-film cells. How the panel and balance of system components affect environmental footprints in comparable installations is also investigated and discussed. Despite the large uncertainties and variabilities in the underlying LCA data and models, the harmonized results show clear positive trends across the sector. Seven potential hotspots are identified for specific PV technologies and impact categories. The analysis offers a high-level guidance for technology developers to avoid introducing undesired environmental trade-offs as they advance to make PV more competitive in the energy markets.