The new fund will hold AGL's recently completed solar power projects in western NSW and will be partly owned by AGL, the Sydney-based energy supplier announced on Wednesday in its first-half results.

The earnings report saw AGL slump to a first-half loss of $449 million after writing down the value of its gas exploration and production business, as it flagged last week.

But first-half underlying earnings rose 24.2 per cent to $375 million, beating Citigroup's estimate for first-half core profit of $350 million, which it said was 2 per cent above the consensus estimate.

AGL forecast at its annual general meeting in late September that full-year core net profit should be between $650 million and $720 million, and said on Wednesday that it expected the result to be within the upper half of that range, "subject to normal conditions" for the rest of 2015-16.

Chief executive Andy Vesey said the strong performance of AGL's core business "highlights that we are well positioned to capitalise on the evolution occurring in the energy sector."

Mr Vesey said part of that evolution involved supporting the country's transition to a lower carbon generation portfolio and the launch of the Powering Australian Renewables Fund, which he had hinted at several times late last year.

The fund will develop at least 1000 megawatts of large-scale renewable energy projects at a cost of $2 billion to $3 billion, with AGL contributing about $200 million. A "small number" of parties will be invited to partner AGL in the fund, with a broad mix of funds and banks to contribute debt, AGL said.

AGL has also made a $US20 million equity investment in the California-based developer of rooftop solar and battery systems Sunverge, Mr Vesey said.