With 100 watt incandescent bulbs being phased out, how to the alternatives that provide 1600 lumens compare. Here's a straightforward graphic from Scientific American.

Lester Brown reports on the proliferation of solar rooftop water heaters at Sustainablog:

The pace of solar energy development is accelerating as the installation of rooftop solar water heaters takes off. Unlike solar photovoltaic (PV) panels that convert solar radiation into electricity, these “solar thermal collectors” use the sun’s energy to heat water, space, or both. Source: sustainablog (http://s.tt/14T9R)

The cost of solar power is collapsing to the point that its use is about to explode across the United States, according to Kees Van Der Leun at Grist:

[T]he fact that 30 pounds of silicon, an amount that costs $700 to produce, is enough to generate a lifetime of household electricity baffled me. Over 25 years, the family would pay at least $25,000 for the same 100,000 kilowatt-hours (kWh) of electricity from fossil fuels -- and its generation cost alone would total over $6,000!

[P]rogress in solar panels has been so dramatic and sustained that, as a blog post at Scientific American put it, “there’s now frequent talk of a ‘Moore’s law’ in solar energy,” with prices adjusted for inflation falling around 7 percent a year.