A reinvigorated AGL Energy has flagged a smaller-than-expected drop in earnings this coming year and announced $250 million of battery and solar acquisitions as it seeks to accelerate its build-out of clean energy and prepare for the exit of coal power.

Shares in the giant electricity and gas supplier, whose biggest investor is tech billionaire Mike Cannon-Brookes, rose 2.3 per cent after it reported vastly improved results for the year ended June 30, including a near-trebling in core profit that beat its own twice-upgraded guidance.