Over the past decade metal halide perovskites (MHPs) have emerged as potentially transformational materials for enabling low-cost high efficiency photovoltaics (PVs). This is due in part to the defect tolerant nature of these hybrid semiconductors. At the same time understanding the defects is critical to enabling them in a range of applications including PV. In addition to defect tolerance the labile nature o the halide systems are interesting opportunities to reconsider what we want and can realize in a semiconducting material. Finding new ways to measure and interrogate these unconventional semiconductors without inadvertently modifying rather than measuring them is critical to their use in technologies. Current topics in PV research will be touched upon to indicate the challenges and associated research required to translate the potential of these material in to promising new technologies and sustainable products that can have impacts at the TW scale.