We have analyzed the major activities carried out for geothermal electricity generation since WGC2005. New data have been taken from \WGC2010\ country update reports, private communications from \IGA\ members and affiliated organizations. Other updates have been collected from websites of private and public organizations involved in geothermal development. Plants commissioned in 2010 (after WGC2010) have been included in the installed capacity, even though their produced energy has not been accounted for. An increase of about 2 GW (herein we use \MW\ and \GW\ for the electrical capacity and \MWth\ and \GWth\ for thermal capacity) in the five year term 2005–2010 has been achieved (about 22%), following the rough linear trend of approximately 400 MW/year, with an evident increase of the average value of about 200 MW/year in the 2000–2005 period (Bertani, 2005a,b, 2006, 2007). The most significant data to be highlighted from this paper are:• a total of 24 countries now generate electricity from geothermal resources; • the total installed capacity worldwide is 10,898 MW, corresponding to about 67,246 GWh of electricity (early 2010 data); • Germany, Papua – New Guinea, Australia, Turkey, Iceland, Portugal, New Zealand, Guatemala, Kenya, and Indonesia have increased the capacity of their power plant installations by more than 50% with respect to the year 2005; • the top five countries for their electricity production are USA, Philippines, Indonesia, Mexico and Italy; • five countries realized an increase above 100 MW with respect to 2005: USA, Indonesia, Iceland, New Zealand and Kenya. The prospective for growth during 2010–2015 are good, with a strong possibility of realizing a big increase in the installed capacity up to 19 GW, if all the currently identified projects would be realized all around the world.