Refurbishing ageing coal-fired power plants while allowing independent power producers (IPPs) to contribute to the grid to make up the difference is the way forward for South Africa’s energy generation capacity, says advisory firm XMP Consulting senior coal analyst Xavier Prevost.

The answer to the country’s power-generation concerns is not to convert wholly to renewable energy, even though it has a role to play, he tells Mining Weekly.

“Why should we move to renewable energy when coal is cheaper?” Prevost muses.

He notes that a number of State-owned power utility Eskom’s plants that are scheduled for decommissioning need not be wholly abandoned, but should rather be refurbished.

Most of these older plants have a thermal efficiency rating of about 35%, owing to older technology installed in the 1960s. What this means is that for every 100 MJ of heat generated from coal, about 35 MJ becomes electricity. The rest is released into the atmosphere as carbon dioxide. Essentially, 65% of the potential energy in coal is wasted.

The latest in coal-fired electricity generation technology, however, allows for up to 65% thermal efficiency, Prevost explains.

He comments that this would almost double the electricity output from the old plants while maintaining Eskom’s coal demand levels, thereby sustaining the coal industry, which many South Africans depend on for continued employment.

Refurbishing these old plants to be more efficient would also be less expensive and quicker than building new ones, with the construction of new coal-fired power plants unlikely to be financially viable, given Eskom’s financial woes, Prevost adds.

To make up the difference in terms of energy capacity, Prevost states that several IPPs have been ready to contribute to the grid for over a decade but have been thwarted by bureaucratic red tape.

Decentralised Power

The advantages of using coal-based IPPs are numerous.

Eskom would not be saddled with the risks of large initial capital expenditure to build them or with maintaining them, as this would be the responsibility of the IPPs.

Further, conveyors would most likely be used to transport coal to the plants because they would be situated at or near mines. This would be less expensive, and more environment friendly than bulk trucking endeavours.

The use of coal-based IPPs will sustain employment levels and help to buoy coal prices.

New renewable-energy installations might be helpful in filling capacity-generation gaps; however, Prevost states that it simply is not economically sensible to consider converting the whole economy to renewable energy for at least the next 100 to 200 years.

“I have much research to show, and many colleagues who agree, that the alarmist environmental activism surrounding coal emissions is mostly political manoeuvring. Much of it is sensationalism and it is not always grounded in proper scientific and economic research.”

Moreover, Prevost notes that the impact of renewable energy on the environment is not zero. Renewable-energy solutions often need expensive batteries to store power to ensure consistent energy delivery. All these components and technologies require mining, beneficiation, smelting, manufacturing and transportation. Solar and wind installations also have large geographical footprints.

He claims that a large-scale shift towards renewable energy will drive energy prices up, citing Germany as an example, where this has led to economic difficulties, and trade disparities between it and neighbouring countries.

However, developed countries, such as Germany, have the economic buoyancy to sustain such difficulties, whereas a developing country, such as South Africa, does not.

He sees improvements in technology potentially leading to cleaner uses for coal-based energy, which South Africa could truly benefit from, such as the conversion of coal into hydrocarbons through coal-to-liquids, which continues to be implemented by petrochemicals and energy company Sasol.

Further, hydrogen for clean energy purposes can be produced through the gasification of coal.