The next generation of solar devices with higher conversion efficiencies, compared to conventional single junction silicon solar cells, will be based on emerging PV technologies (e.g. perovskite-on-silicon tandem). In the field of Industry 4.0 applications the use of indoor-PV is gaining momentum. However, there is still a lack of measurement capabilities that realise performance measurements with low uncertainties for emerging PV applications. This project will reduce the reference solar cell calibration uncertainty that successively affects all subsequent calibrations and performance measurements in the traceability chain. In addition, international standards will be developed, including measurement procedures for emerging PV technologies. The uncertainty of the PV calibration chain will be reduced and thereby, in a wider perspective, the financial uncertainty of investments.