FOR REAL SPREAD OF PHOTOVOLTAIC RESIDENTI AL SYSTEM

Photovoltaic system is very suitable for residential use from its feat ures, and PV residential system is expected to play a main part of PV system. Cost reduction of PV system is the most important subject for the system to realize the real spread. In a short term, cost reduction of current Si-crystal solar cell is required. In a middle term, thin- film solar cell is necessary to become practically used and mass-produ ced. And in a long term, next-generation, low-cost solar cell is indis pensable to cope with future self-supporting market. Spread process of PV residential system is considered as follows: the first step is mar ket formation based on gavernmental subsidy, the second step is market expantion. In this period, roof integrated PV module will be practica lly used and adopted in pre-fabricated house in large quantities. Futu re, cost-reduction of PV system will be achieved owing to technologica l development and mass productions effect. Power cost of PV system wil l become equal to that of commercial power and thus consequently the r eal spread of the PV system, the third step, will appear.