It was in the country's national interest for the National Energy Regulator of SA (Nersa) to "choose appropriately" when it makes its decision on Eskom's tariff hike, the parastatal's acting chief executive, Mpho Makwana said in Midrand on Thursday.

He was addressing the second last day of Nersa's public hearings on the tariff hike.

Nersa has held public hearings countrywide on the proposed tariff hike of 35 percent every year for three years.

According to Eskom, tariffs have to be raised to help fund its R385-billion expansion plan.

Decision is 'simple'

"I have addressed hearings in eight provinces now and I still say the right decision for Nersa's panel is simple - 35 percent, 35 percent, 35 percent ," Makwana said.

The acting chief executive added that there had been a misunderstanding around Eskom's new coal-fired power station, Kusile.

"At no point has Eskom raised the question of privatisation. We're simply saying that the board of Eskom has given us a mandate to look for private equity players for Kusile."

Makwana said that Eskom had to make up for "a long time of underinvestment".

"We have not invested sufficiently for the future," he added.

Covering costs of energy supply

While Eskom's funding model made use of both tariffs and other funding sources, he explained that tariffs were meant to cover the costs of energy supply.

"In an ideal world - which this is not - power stations should be funded from other sources and not tariffs - and while we are seeking to do this, this is not an ideal world," Makwana said.

"Our building programme should come about from our ability to raise debt.

For that we need to have a reasonable income statement and that is what the tariff increase is about," he added.

Organisations scheduled to address Thursday's hearings include Business Unity SA, environmental agency Earthlife SA, and the SA Chamber of Commerce and Industry.