Solar cell performance parameters (open circuit voltage, short circuit current, fill factor and efficiency) are derived for different solar cell types for the irradiance range 0.1–1000W/m2. Also it is demonstrated how spectral mismatch factors for indoor lighting conditions are calculated. The presented methods and particular results may aid product designers in selecting appropriate solar cells for Product Integrated PV (PIPV) operated indoors and allow for more certainty in energy balance estimations of PIPV design concepts.