Solar panels are still a rarity in most communities in the United States. You might ask, why are there so few? But given the true economics of solar power today, it makes more sense to ask, why are there so many? These economics might be changing. While traditional solar technology keeps getting more efficient, the cost of the silicon semiconductor technology that underpins traditional systems keeps costs high. But silicon is not the only semiconductor that can transform sunshine into electric current. A startup, Konarka, uses titanium dioxide powder (more commonly used as white pigment) instead. TiO2 is photovoltaic — it turns photons (light) into electrons (electricity). Konarka dyes the TiO2 dark, so it will absorb more light, and melds the powder into a uniform substance that conducts electricity. (The powder by itself does not.)