The South Australian parliament has passed the first laws in Australia allowing consumers to make a profit on solar power they generate at home.

Under the new feed-in laws consumers and small businesses using solar power will be paid twice what they are normally charged for any electricity they return to the grid.

Until now any excess power returned to the grid was paid for at the same rate as any power used, providing little incentive for consumers to invest in solar conversions.

The South Australian government hailed the legislation as groundbreaking and expected the federal government to soon introduce similar measures on a national basis.

"South Australia is again at the forefront in tackling the impact of climate change - we continue to lead policy initiatives which deliver real benefits to the environment," Premier Mike Rann said.

The feed-in laws will come into effect in July and will apply to households as well as small businesses, school, churches and other small consumers.

Similar laws have been introduced in 16 European countries as well as seven others outside Europe, including Canada, China and Israel.

The legislation passed in the SA parliament on Thursday night after the government accepted an amendment to extend the scheme from five to 20 years.

South Australian Greens MP Mark Parnell said the changes would encourage the uptake of solar power.

"The 20-year time frame will provide the guaranteed, long-term security that the solar industry is after," Mr Parnell said.

But the SA opposition said the government had to be "dragged kicking and screaming" to extend the length of the scheme.

Opposition energy spokesman Mitch Williams said people required an assurance of long-term financial assistance to encourage them to embrace the installation of solar panels.

He said leaders in the solar industry and the conservation council supported the 20-year time frame.

BP Solar, Australia's largest producer of solar photovoltaic products, said the new laws would allow thousands of householders and businesses to embrace solar power.

"Not only will thousands of South Australian homes have solar systems installed as a result of this policy, but many businesses will now have the opportunity to embrace this technology and turn their roofs into mini-renewable power stations," said BP Solar regional director Brooke Miller.

"By rewarding those homes and businesses who invest in solar power, South Australia can look forward to a future in which the solar industry will drive investment and the creation of new 'green collar' jobs in this state.

"The challenge is now for Australia's other state and territory governments to follow South Australia's lead."