Andrew Richards, executive manager of corporate affairs at Pacific Hydro, said EnergyAustralia and Origin Energy, which control more than half the national electricity market, had halted the signing of long-term power purchase agreements with wind and other renewable energy suppliers, in effect blocking developers from securing loans for new projects.

''For whatever reason, they're just not contracting,'' Mr Richards said. ''Unless they start contracting, you just simply can't get the finance - particularly non-recourse project finance - to build these projects.''