Solar rooftop thermal collectors are gaining popularity around the world as a convenient and inexpensive way to heat both water and space.
Cumulative solar water and space heating installations in top 10 countries, 2009.
Source: EPI from REN21,IEA-SHC
Annual solar water and space heating installations in the United States, 2000-2010.
Source: SEIA, GTM Research
Solar water and space heating area per person in top 25 countries, 2009.
Source: Earth Policy Institute