Immediately after the 20 per cent renewable energy target belatedly passed the Senate yesterday - after the Opposition secured bipartisan support for a substantially increased industry compensation package - it came under attack from backers of geothermal and large-scale solar energy.

They warned they risked being left on the shelf as wind farms and rooftop solar power - neither clean baseload solutions in their own right - met the target more cheaply in the early years.

The Australian Geothermal Energy Association's chief executive, Susan Jeanes, said energy drawn from kilometres underground was expected eventually to be the cheapest alternative to heavy-polluting coal-fired power.

But she said it would first need support to reach 300 megawatts capacity - roughly a third the size of a coal-fired plant.

John Grimes, the chief executive of solar industry body ANZSES, joined her in calling for part of the renewable energy target to be quarantined for technologies that could eventually provide baseload power.

The Opposition proposed setting aside a quarter of the target to come from renewable sources for emerging baseload technologies, but was rebuffed by the Government.

''I don't think the design has been well thought through to make sure these technologies mature,'' Mr Grimes said.

The criticism was at odds with the reaction of the Clean Energy Council, which said the ''landmark'' legislation could lead to $20 billion in clean energy projects over the next decade, creating 28,000 jobs.

The Climate Change Minister, Penny Wong, has said the Government would support the likes of geothermal through other budget measures.

But Ms Jeanes said geothermal drilling had received only $50 million and the Energy Minister, Martin Ferguson, had said there was unlikely to be more. Yet, she said, $3.5 billion would go to development of carbon capture and storage technology.