| The concern about the global warming and the worldwide energy crisis has brought about the need for quantitative estimates of alternative energy technologies life-cycle net impacts of energy production and emissions reduction. These estimates are useful for systematic comparison among other supply and demand side management strategies to avoid Greenhouse Gas (GHG) emissions. The GHG emissions of grid-connected photovoltaics (PV) systems mostly occur during their manufacture, but the embedded energy in the materials and the CO2 emissions are paid back in 3 to 5 years in Massachusetts in avoided fossil fuel combustion to generate the equivalent electricity.; Herein is a compilation and comparison of the different technologies and manufacturing processes used in commercial photovoltaics system production and use. Case study examples are examined of PV systems installed in Green Buildings in Massachusetts based on empirical data. |
