The US$ 80 billion (UK£ 40 billion), Grand Inga project, which will be sited in the Democratic Republic of Congo, would generate twice as much energy as China's Three Gorges dam.
According to the BBC, it is hoped the dam will boost Africa's electricity supply by a third. However, opponents doubt it will help the poorest Africans without electricity.
The World Energy Council, (WEC) which hosted the two-day meeting in London, said the Grand Inga project would help the estimated 500 million Africans without access to electricity.
"We have to raise the level of access to commercial energy all through Africa and other parts of the world, where poverty is faced," WEC secretary general Gerald Doucet told the BBC.
"We can't do it without building these projects, but of course, on a sustainable basis that takes into account the social, civil and environmental issues. And I can say that in the past, mistakes have been made, but WEC is here to make sure those mistakes are not repeated," Mr Doucet said.
Power could be transmitted to other countries via a giant new distribution system to Egypt in the north, Nigeria in the west and to South Africa.
For construction to start as planned in 2014, the WEC is asking for finance for a feasibility study to be done as soon as possible.
The Grand Inga project is expected to be constructed on the Congo river, alongside two existing hydroelectric plants. It should begin operating between 2020 and 2025, said the WEC.
The plans include a 205 m-high dam, 15 km-long reservoir and a plant with the capacity to produce 320 TW hours of electricity annually.
The idea for the project was first conceived in the 1980s, but political turmoil in the DR Congo meant that the plans could not proceed, said the BBC report.