Life cycle water usage in CdTe photovoltaics

Abstract

Life cycle water withdrawal for cadmium telluride photovoltaics (CdTe PV) ranges from approximately 382–425 L/MWh, with only ∼12% from direct on-site usage. The remainder is related to indirect waterwithdrawal from the use of grid electricity and raw materials throughout the product life cycle. Approximately half of life cycle water withdrawal is associated with module manufacturing, one-third from balance of systems (BOS), and the remainder from takeback and recycling. Primary contributors to life cycle water withdrawal are the use of grid electricity, glass, and on-site water during manufacturing; steel, copper, inverters, and on-site water in the BOS; and electricity, chemical use, and transport during takeback and recycling. During manufacturing, water consumption is approximately one quarter of withdrawal and is due to cooling tower water evaporation and site irrigation. When deployed in the U.S. Southwest, a CdTe PV array can provide net displacement of life cycle water withdrawal of over 1700–5600 L/MWh relative to grid electricity.