Photovoltaics: coming of age

The history of photovoltaic development is reviewed. An outline of the potential of the technology as the author views it is given. The challenge to be met to reach this potential is to develop high-efficiency technologies which can be produced at low cost. Three factors suggest this is possible. The first is the latent efficiency still to be recovered with even the most highly developed cell technologies. The second is the recent progress with tandem cells, which suggests that most of the 30-40% efficiency advantage over single-junction devices will eventually be realized. Tandem cells are likely to offer cost advantages in very high volume production. The third is the pyramid of possibilities, the wide range of semiconductors which still have to be evaluated for their photovoltaic potential