Hawaii island has reached the limit on the amount of rooftop solar energy systems that can send excess power into the grid for a credit.

Darren Pai, spokesman for Hawaiian Electric Co., said the Big Island’s Hawaii Electric Light Co. reached the cap Tuesday.

In October the state Public Utilities Commission ended a popular incentive program that offered owners of solar energy systems a credit equal to the retail rate for the excess energy that their systems send into the grid and replaced it with two less attractive programs.

Only one of the two programs, called grid-supply, allowed customers to continue exporting excess energy to the grid.

The grid-supply program credits solar owners 15 cents a kilowatt-hour for the extra energy, roughly 8 cents less than the retail rate that had been offered through the original program. The PUC also put a 35-megawatt limit on the amount of energy generated from the grid-supply program statewide. The limit for Hawaii and Maui counties was 5 megawatts. Oahu’s limit is 25 megawatts, and the island has roughly 5 megawatts of space left.

The other program, called self-supply, encourages customers to buy battery systems because under this option owners of solar energy systems are not allowed to send any excess energy into the electric grid.

Now Hawaii island residents who want solar have to register for the self-supply option if they want to remain connected to the grid. Self-supply does allow customers to use energy from the grid.

Maui Electric Co. said in June that solar customers hit the county’s limit for grid-supply systems.