The roll-out of grid-connected solar photovoltaic (PV) systems has increased. A report by Lawrence Berkeley National Laboratory summarized trends in the installed cost of grid-connected PV systems in the United States from 1998 through 2008. Key findings of the analysis are as follows: • The capacity-weighted average installed cost of systems completed in 2008 – in terms of real 2008 dollars per installed watt (DC-STC)4 and prior to receipt of any direct financial incentives or tax credits – was $7.5/Watt, a decline from $7.8/W in 2007 following several years (2005-2007) during which installed costs remained relatively flat. From 1998 to 2008, installed costs declined by about 3.6% (or $0.3/W) per [...]  Meer...