The months of blackouts, increased candle use, and frequent mopping of refrigerators are all powerful reminders of the importance of keeping the lights on in South Africa for efficient household and business use. While waiting for Eskom to relieve the shortage of electricity supply in the country, South Africa could follow Mauritius’s footsteps and reduce its reliance on coal by trying out a new electricity source; sugar cane.
Sugar cane is the ninth most valuable crop/ livestock product by value ($57 billion), it is one of the world’s highest yielding crops and it is cultivated on about 23.8 million hectares in more than 90 countries, with a worldwide harvest of 1.69 billion tonnes. Africa only grows about 5 percent of the world’s total production and South Africa leads the production in sub-Saharan Africa.
Mauritius has found a way to light up its city with the cash crop, to the point that power generated from sugar cane now accounts for 14 percent of the country’s electricity needs.
With public utility firm, Eskom, struggling to maintain coal levels at its coal-fired power stations, other options to power South Africa can be used to supplement power generation.
Eskom, which is burdened by debt and corruption scandals, is currently struggling to refinance its maturing debt and is looking for ways to become financially sustainable and profitable enough to maintain regular power supply. Seven out of Eskom’s 14 power stations are old, inefficient and too costly to run.
Although there is a possible bailout option from the government, this may put a strain on the shoulders of taxpayers, thinks economist Mike Schussler. “Loan guarantees from the government to Eskom are put on the shoulders of taxpayers. Eskom does not have the ability to do anything without borrowing. Either way, we as electricity users and taxpayers will bear the brunt,” he stated.
Since November, Eskom has scheduled daily blackouts to avert a total collapse of the grid and these outages are expected to persist pending when Eskom’s new management resolves the company’s maintenance backlogs, construction delays and coal shortages.
A Case for Sugar Cane
To power the country using sugar cane, Mauritius uses the leftover of sugar cane stalks and tips are crushed to produce a dry fibrous material known as bagasse. This bagasse is then burned to generate electricity and unlike other industrial plants that flare their gas, the gas released from the burning of the sugar cane could be captured and used to add fizz to soft drinks.
First, the cane stalks are crushed to extract juice for sugar production, after which they are then soaked to extract more juice before being heated to dry. The final product which has become squashed and dried stalks are then fed into a thermal power station where they burn at 500 degrees Celsius, fueling turbines that produce electricity.
A greener alternative to burning bagasse for electricity production is to convert the fibrous matter into a renewable resource that generates no net carbon dioxide, biogas. Biogas can be converted directly into electricity by using a fuel cell. In most cases, biogas is used as fuel for combustion engines to produce electricity.
Generating power from Sugar cane would not be a challenge for South Africa, given the volume of sugar cane produced to feed its important sugar industry. Sugar cane is grown by approximately 24,000 registered growers in South Africa, who operate mainly on small family farms and produce an average of 19.9 million tons of cane annually.
Presently, around 60 percent of electricity in Mauritius is generated by four sugar companies, each running its own thermal power station from which they put their excess generated power to the national grid to aid in the lighting of the country. Mauritius produces over 100 kilowatt-hours (kWh) of electricity per tonne of bagasse.
With a total world harvest of over 1 billion tonnes of sugar cane per year, the global energy potential from bagasse is over 100,000 Gigawatt hours (GWh) and with the current growers and an excess 372 thousand hectares of farmland the country has specifically for sugar cane, South Africa can address its power challenges using sugar cane.
Luckily, South Africa may not need to build new thermal plants because currently, not all Eskom power stations are operating at full strength and for the main time, some can be converted to aid in the electricity generation from sugar cane.
Eskom’s energy availability factor (EAF) has significantly deteriorated from 78.61 percent in 2017 to 73.74 percent as at September 2018 and there are other factors like the looming coal shortage that could hinder the ability of the electricity supply industry in South Africa to meet its demand in the next five years. This is the best time to consider alternatives and sugar cane could be one of them.