“Adequate” lines or facilities means having sufficient capacity to meet the maximum estimated service requirements of the customer to be served during the year following the commencement of permanent service and to meet the maximum estimated service requirements of other actual customers to be supplied therefrom during such year and to assure such customers of reasonable continuity of service. Facilities or lines are “adequate” even though the electric supplier must increase their capacity if the supplier will undertake to make its facilities and lines meet such service requirements, and can reasonably do so, within such time as meets the customer’s requirements.