links for 11/12/2011

• Compared assessment of selected environmental indicators of photovoltaic electricity in OECD cities (PDF)

  Interesting facts about photovoltaics. via @doctorkarl
  – The energy pay-back time (EPBT) of a complete PV system (not only panels, but also wires and electronic connexion devices) is, depending on the solar irradiation of its location, in the range   of 19 months (just over one year and a half) to 40 months (three years and 4 months) for a roof-mounted system, and from 32 months (2 years and 8 months) to 56 months (4 years and 8 months) for a PV-façade. 
  – Based on a commonly admitted 30 year-long commercial life cycle, the energy return factor (ERF) is between 8 and 18 for roof-mounted systems, and between 5.4 and 10 for façades.
  – Varying widely from one country to another, using the energy   production mix from each country, 1 single kW of PV    panels (roughly 10 square meters) can avoid up to 40 tons of Carbon dioxide (CO2) during its whole commercial life cycle – 23.5 for a façade. 

  tags: photovoltaic energy pay-back time

Posted from Diigo. The rest of my favorite links are here.