Page 94 - A Comprehensive Guide to Solar Energy Systems

Chapter 5 • Sustainable Solar Energy Collection and Storage 89

FIGURE 5.6 Average daily hours (±1 SD) of sunlight across sub-Saharan Africa. * Indicates a country with less than 3
monitoring stations available.

Growing recognition of these benefits, rising/volatile resource prices [22], global re-
source criticality concerns [23], and rising production costs, have made circular economy
an attractive prospect, particularly for manufacturers who rely on supplies of critical raw
materials. Material criticality issues and environmental impacts associated with the use
of toxic materials in devices can also be mitigated with appropriate circular practices. Ad-
ditionally, intangible company assets such as brand value may be enhanced as consumers
become increasingly environmentally aware [22]. To take an example from the PV world,
First Solar, the company that produce CdTe PV, have adopted business models that unlock
the power of circular economy and generate value through the development of appro-
priate recycling technologies, long product lifecycles, and linking value chains with other
industries and supply chain partners.
The commercial viability of PV is based on the levelized cost of electricity generation,
determined by the power conversion efficiency, cost, and lifetime of PV products. resource
efficiency benefits afforded by circular economy can potentially reduce the economic and
environmental costs of module production, enhancing commercial viability and increasing
competitiveness with alternative renewable energy technologies. In an African context,
where cost of systems has been a barrier to adoption of PV, this is of great importance.
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Energy payback time, emissions associated with electricity generation [CO 2 eq (kW h) ],
−1
and the cost of energy generation (US$ Wp ) can all be reduced through adoption of
circular practices. Studies have shown that the energy payback time for Si wafer-based PV
technologies is reduced by half through use of recycled materials [24]. For CdTe PV, it has
been predicted that, as power conversion efficiency improvements are made, and avail-
able volumes of end-of-life modules increase, demand for CdTe for PV could be satisfied