$SPOW As of 2010, solar photovoltaic’s generates electricity in more than 100 countries and, while yet comprising a tiny fraction of the 4.8 TW total global power-generating capacity from all sources, is the fastest growing power-generation technology in the world. Between 2004 and 2009, grid-connected PV capacity increased at an annual average rate of 60 percent, to some 21 GW. Such installations may be ground-mounted (and sometimes integrated with farming and grazing) or built into the roof or walls of a building, known as Building Integrated Photovoltaic’s or BIPV for short, while BAPV is Building Applied PV -– it’s a retrofit added to the building long after construction. Off-grid PV accounts for an additional 3–4 GW.