The Lancet Global Health, Volume 9, March 2021

This Viewpoint supports SDGs 3, 6, and 7 by discussing some of the reasons why many of the innovations and technologies for WASH (water, sanitation, and hygiene) and household air pollution developed in recent decades have not led to the expected improvements in health outcomes, and why many of these interventions have either been inconsistently adopted by low-income households, or not adopted at all.
Soiling consists of the deposition of contaminants onto photovoltaic (PV) modules or mirrors and tubes of concentrated solar power systems (CSPs). It often results in a drastic reduction of power generation, which potentially renders an installation economically unviable and therefore must be mitigated. On the other hand, the corresponding costs for cleaning can significantly increase the price of energy generated. In this work, the importance of soiling is assessed for the global PV and CSP key markets.