The assembly government is expected to say that Wales has the potential to generate twice its electricity needs from renewable sources within 15 years.
Environment Minister Jane Davidson will make a statement on energy later.
The assembly has previously set a target of seven terawatt-hours (TWh) of green energy by 2020, but Ms Davidson will say the potential is far greater.
Environmental campaigners have said the assembly government is being "unrealistic and over ambitious".
The assembly government began consultation on its so-called Renewable Energy Route Map in 2008 as part of the coalition One Wales agreement between Labour and Plaid Cymru.
Monday's announcement will set out how it intends to deliver a low carbon energy policy.
Ministers initially had set themselves the target of producing 4TWh of electricity from renewable resources such as wind and wave power by 2010, and 7TWh by 2020.
A terawatt hour is equivalent to one billion kilowatt hours and is commonly used to express the energy production and consumption of businesses and countries.
In a written answer to a question last month, Ms Davidson confirmed that at present Wales was only hitting the 3TWh mark.
However, she added: "There is considerable interest from developers in relation to the spectrum of new technologies including biomass, onshore and offshore wind, wave and tidal.
"I am confident that considerable additional capacity will come on line over the coming years to significantly exceed the 2020 7TWh target."
But Monday's announcement could go much further.
Cutting carbon
The environment minister is expected to say that Wales has the potential to generate twice its electricity needs from renewable sources before 2025.
At present, Wales uses around 24TWh of electricity a year, from a mix of fossil, nuclear and green methods.
Climate change experts have been quick to point out that any claims that Wales could produce double the electricity it needs from renewable means would mean a massive jump.
Gordon James, president of Friends of the Earth Cymru, said producing 48TWh of electricity from renewable sources was "unrealistic and over ambitious".
He said: "A goal of generating all of Wales' electricity from renewable sources by 2025 would be much more achievable and would be a big step forward and a tremendous achievement.
"That was what they suggested in the Renewable Energy Route Map and we would welcome that."
'Biggest obstacle'
However, he warned there were considerable challenges to be faced if the assembly wanted to meet that commitment.
"The biggest obstacle currently is that permission for generating more than 50 megawatts, through a wind farm, for example, lies with Westminster and not the assembly."
Part of the move towards greener energy supplies is being driven by pledges to cut greenhouse gas emissions.
But research published by the assembly government last year demonstrates just how high the green electricity mountain could be to climb.
In 2007, the study found that 29% of all carbon dioxide greenhouse gas released in Wales came from traditional electricity generation.
In fact, in that year, the overall emissions from electricity production in Wales actually increased by 0.1%.
The same report also noted that in this period, Wales produced 13.1 tonnes of carbon dioxide per person - nearly five tonnes of the gas more than produced per person in England and Scotland.
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