Consolidated Edison Inc. said late Thursday that one of its subsidiaries has agreed to buy a Sempra Energy subsidiary for $1.5 billion. The Sempra Energy unit owns renewable electric-production projects, including projects jointly owned Con Edison units and development rights for additional solar and energy-storage projects. The deal is expected to close at the end of the year, Con Edison said. Con Edison expects to fund the deal using a combination of $715 million of equity and $825 million of long-term, non-recourse debt, it said.