The state’s main energy efficiency program has boosted the instant rebate for compact florescent light bulbs to $1.40 from $1 for a limited time to encourage residents to replace their old incandescent bulbs.

A household can as much as $100 a year by swapping out the old bulbs with CFLs, said Ray Staring, Hawaii Energy Program manger. CFLs use 75 percent less energy than incandescent bulbs and last nearly 10 times longer, he said.

Hawaii Energy administers the energy conservation and efficiency program for Honolulu, Hawaii and Maui counties. The program is funded mainly through a fee paid by electric utility customers.

In addition to the CFL rebate, Hawaii Energy is funding a Blue Planet Foundation program that allows residents on Maui and Hawaii island to trade their incandescent bulbs for CFLs.