The Democratic Alliance on Sunday warned that Eskom's mandatory savings plan could prove expensive.
Last week, Eskom said that due to the tight power supply situation and the need to do routine maintenance at several power plants, some large industrial consumers will be expected to consume less electricity over the next few months.
DA spokesman on energy David Ross said he would ask Eskom CEO Brain Dames to disclose how expensive these savings agreements would be.
Demand market participation agreements dictate the rate at which Eskom reimburses large industrial consumers for productivity losses due to power cuts.
Power outages are likely to take place over the next few months and this would be expensive, Ross said.
He called for these agreements to be transparent, particularly with regards to the compensation rate for lost productivity.
On Thursday, Public Enterprises Minister Malusi Gigaba warned that electricity supply would become increasingly tight until the end of 2012.
This is when Eskom's new base-load power stations start to deliver power into the grid.
Gigaba said the next challenge facing electricity supply security would be the summer maintenance season for Eskom. - Sapa