A $235 million funding boost for renewable energy only highlights the federal government's lack of action on solar power, the coalition says.

The government committed another $235 million on four commercial-scale renewable energy projects on Friday - two in South Australia, and one each in Victoria and Tasmania.

It's part of the government's Renewable Energy Target of 20 per cent by 2020, and expected to create almost 80 megawatts of renewable energy generation.

The projects involve wave technology, geothermal sources and a mini-grid project involving wind, solar, bio-diesel and storage technologies.

Resources Minister Martin Ferguson said the funding, combined with money from the successful applicants to the program, will deliver about $810 million to the renewable energy industry.

While the coalition welcomed the additional cash boost, opposition environment spokesman Greg Hunt said it proved the government had let stall its push for solar energy.

"Today's announcement is a reminder of how little progress we've seen on the government's much-vaunted Solar Flagships promise," he said on Friday.

"Whatever happened to (its) plan to deliver 1000 megawatts of solar energy?

"All we have seen is a shadow of a promise which is struggling to see daylight."