One of the most encouraging aspects of the current PV scene is the steady reduction in costs. Continuing improvements in cell and module efficiencies are making a substantial contribution; but above all it is the sheer volume of production in state-of-the-art factories using highly automated facilities that is driving down costs. Right back in Section 1.4 We introduced the
'learning curve' concept to illustrate how, for a wide range of manufactured products, costs tend to fall consistently as cumulative production rises. Figure 1.11 confirmed that PV costs have fallen for more than two decades by around 20%
for every doubling of cumulative production and the trend continues. the long-held, almost cherished, ambition of the PV community to produce modules at 'one US dollar per watt' was finally achieved in 2009 in the case of high-volume thin-film CdTe manufacturing, with rival cell technologies not far behind.