LIPA and the state’s top solar-industry group on Monday reached a tentative agreement to develop a road map that would make time-of-use electric rates a standard offering on Long Island within three years, while phasing in a new fee for first-time solar customers over three years instead of one.

LIPA chief Tom Falcone called the prospect of a new standard time-of-use rate, which would provide discounts to those who shift electric use away from peak-demand times, crucial to cutting carbon emissions while reducing costs—savings that would be passed on to ratepayers.

The New York State Solar Energy Industries Association, which has been pushing hard in recent weeks for a rollback of what some members called a solar tax planned for Jan. 1, is expected to vote on the plan on Tuesday, said NYSEIA board chairman, David Schieren.