A Doctor's group says the Solar Thermal Power Plant process in Port Augusta is taking too long.
Last Week Alinta Energy announced the first results of the feasibility study.
The company has determined a stand-alone solar-thermal power plant is technically feasible.
Doctors for the Environment's South Australian spokesman says it's taken over four years to even get to this stage.
There are nearly 40 of these solar thermal plants in operation worldwide and a further 20 being built right now.