"A PV market of 300 GW/a by 2025 definitely seems possible, corresponding to an installed capacity of about one TW by the end of that year and producing about 6% of world electricity — about the same level as in Germany in 2012. The economics will be very favorable for residential and commercial systems with the German experience showing that such penetration levels pose few problems. Increasing resistance from market incumbents, such as we are now seeing in Australia, is likely to be the main impediment. On the technology front, I would still see silicon maintaining its dominance, with polysilicon prices continuing to drop, directionally solidified ingots becoming larger and also largely monocrystalline, sawing costs decreasing and efficiencies on the resulting very thin wafers approaching the UNSW lab record of 25%. Perhaps some of the newer technology our group is now working on, aimed at growing thin film crystalline tandem cells on top of standard silicon cells, will have found its way to the market by then, providing a path to above 40% efficiency."