<p>SAN DIMAS, Calif. – The $16 billion WesCorp is using the sun to offset energy costs. The nation's largest corporate recently started using a new solar-powered system made up of 154, 120-watt panels. The panels take up 1,900 square-feet of roof space at the corporate's San Dimas, California headquarters. The panels will generate from 14 to 18 kilowatts of power, providing up to 4% of peak usage. WesCorp said it expects an annual $4,000 energy savings. The California Energy Commission paid $67,963 of the total $150,000 price tag for the new system. "The system is designed to be expandable. If energy costs continue to rise, WesCorp can add additional photovoltaic panels and increase its clean energy generation," said Francis Kuhn, VP, Facilities and Administration for WesCorp. California, of course, has had serious energy problems in recent years with rolling blackouts occurring in the summer months.</p>