Solar without the Panels

Investors and utilities intent on building solar power plants are increasingly turning to solar thermal power, a comparatively low-tech alternative to photovoltaic panels that convert sunlight directly into electricity. This month, in the latest in a string of recent deals, Spanish solar-plant developer Abengoa Solar and Phoenix-based utility Arizona Public Service announced a 280-megawatt solar thermal project in Arizona. By contrast, the world's largest installations of photovoltaics generate only 20 megawatts of power.