In the United States, one of the largest utilities, Pacific Gas & Electric Company, has been a leader in using cost-effective PV-powered systems throughout their service territory; by the end of 1991, they had over 1100 installations in operation [37]. A number of other utilities each have about 100 such installations. An Electric Power Research Institute (EPRI) study has identified over 60 separate types of cost-effective PV applications for utilities and their customers [38]-[40]. These systems usually serve
a single type of load, such as T&D sectionalizing switches, cathodic protection, environmental monitors, communications installations, and water pumping. By early 1992, over 50 US. Electric utilities had these cost-effective systems in operation and preliminary market estimates for these cost effective applications are in the few 10s of MW over the next five years (see [34]).
When accurate costs for extending utility transmission or distribution facilities or for installing fossil-fueled engine generators are known. PV-powered systems can compete economically; in many cases, this is true for both first cost and life-cycle costs.