BATON ROUGE, La. — Louisiana taxpayers who added solar panels to their homes have until Aug. 31 to claim a tax credit for residential solar energy systems installed through 2015.

Lawmakers set aside $5 million a year, up to $15 million over three years, to clear a backlog of credits that went unpaid when the state abruptly capped and ended the tax break program as a budget-balancing maneuver.

The revenue department says taxpayers who purchased qualifying systems — and didn’t previously submit tax credit claims — must file their claims electronically.

Taxpayers who previously submitted claims but were denied because of the cap don’t need to refile. But if they didn’t get a letter from the revenue department about the tax credit, they should call 855-307-3893.

More information is on the revenue department’s website .