Page 102 - A Comprehensive Guide to Solar Energy Systems

Chapter 5 • Sustainable Solar Energy Collection and Storage 97

Table 5.2 Globally Installed Stationary Energy Storage Capacity by Battery Type, 2016
Installed Capacity
Battery Technology (/MW) (/GW h)
Li-ion ∼1300 1.27
High temperature NaNiCl 171 1.01
Valve regulated lead-acid (VRLA) 196 0.173
Vanadium redox-flow batteries (VRFB) 114 412

Table 5.3 Comparative Costs of Commercially Available Batteries in South Africa
Over 20-year Lifetime of System
Battery Cost/€(A h) −1 No. Replacements Total Cost/€
VRLA 1.38 4 1726
LFYP 14.21 1 7104
Aquion 6.72 2 5040
LFYP, Lithium-iron-yttrium-phosphate battery; VRLA, valve regulated lead acid battery.
5.7 Carbon Footprint and Lifecycle Impact Considerations

A comparison of carbon footprints of lead-acid and different types of li-ion battery
production for the system is given in Fig. 5.11 (equivalent data for Aquion batteries is
unavailable at the time of writing). When the need for replacement batteries is consid-
ered, lead-acid batteries account for a greater contribution to the carbon footprint of
the system than li-ion alternatives, other than lithium titanate batteries (lTO). lithium-
nickel-cobalt-aluminium batteries (NCA) would contribute least to the carbon footprint
of the system over its lifetime. Using recovered materials in battery manufacturing could
significantly reduce emissions associated with production.
Carbon footprint of batteries production is useful for a comparison of global warming
potential. However, this is a limited picture of the environmental impacts of batteries.
Further consideration of emissions during production from primary resources should be
made; for example, the production of li-ion batteries from primary raw materials results
in considerable SO 2 emissions and water contamination.
Consideration of the hazardous nature of materials within batteries and their potential
impacts if improperly managed during use and end-of-life is also important. Issues relating
to end-of-life of li-ion batteries arise primarily from their metal content: Cobalt is present
in cathodic materials and electrodes are made with the extremely reactive alkali metal li. In
addition, F, As, and sulfonated compounds are present in electrolytes. Improper treatment
of lead-acid batteries at end-of-life results in the release of lead and sulfuric acid to the
environment. These materials can directly impact human health through contamination
of water and soil, and accumulate in food chains when batteries are landfilled or recycled
improperly [39]. This is of particular concern for rural SSA, where batteries are installed in