U.S. President Barack Obama's call for sweeping investment in clean energy and for carbon cap-and-trade legislation won praise from analysts and the renewables industry, saying it is a rallying call for other nations.

In his first speech to a joint session of Congress, Obama said that to truly transform our economy, protect our security, and save our planet from the ravages of climate change, we need to ultimately make clean, renewable energy the profitable kind of energy.

I ask this Congress to send me legislation that places a market-based cap on carbon pollution and drives the production of more renewable energy in America, he said in comments that are in marked contrast his predecessor's stance on climate change.

He said China had launched the largest effort in history to make their economy energy efficient and that it was time for America to boost investment in companies and jobs in the clean energy sector.

President Obama is to be commended for inspiring the American public to step up to the plate on climate change, Australian Greens Deputy Leader and climate change spokesperson, Senator Christine Milne, told Reuters.

His next challenge is to encourage laggard nations, including Australia, to move with urgency and determination to tackle climate change, energy security and the global financial crisis with common solutions.

BILLIONS TO INVEST

Obama said his budget proposal to be released on Thursday will invest $15 billion a year on wind and solar power, advanced biofuels, clean coal and American-built cars and trucks that are more fuel efficient.

He also said thousands of miles of power lines would be built to carry new energy to cities and towns.

Obama is quite right to be directing concerted investment in renewable energy and transmission infrastructure, to bring these new wind and solar power sources from where it is generated to where it is used, said Barry Brook of the University of Adelaide, in South Australia state.

But Brook said while putting a price on carbon was necessary, it was not enough.

Will the world's future energy mix be entirely renewable, and is it appropriate to frame energy alternatives in narrow terms? I think not, said Brook, director of the Research Institute for Climate Change and Sustainability in Adelaide.

Obama's speech showed strong leadership in the move toward a more sustainable future, said Simon Troman, vice-president of the Australia and New Zealand Solar Energy Society.

The renewable energy and energy efficiency industries world wide have been consistent with the message that dollar for dollar, renewables and energy efficiency provide more opportunity for job growth, Troman told Reuters.

If we had any issues with Obama's statement, it would be in the change from pre-election talk of a carbon tax to now talking of a market-based cap on emissions. These types of caps do not automatically result in more renewable energy use, he said.

(Additional reporting by Tom Doggett in Washington; Editing by David Fox)