The Sunday Mail (Zimbabwe)

Getting off grid becoming trendy

- Prof Hartmut Winkler ◆ Hartmut Winkler is a professor of Physics at the University of Johannesbu­rg

SOUTH AFRICANS have been battered by power shortages for several years. These have worsened to the point that towards the end of 2022 the country’s electricit­y utility, Eskom, had only half of its power generation capacity operationa­l.

This has forced Eskom to escalate its rotational power cuts.

By mid-January 2023, users were typically without electricit­y for eight to 10 hours a day.

The situation is unlikely to improve much in the short to medium term.

It is expected that this year, especially as power demand increases in winter, the country’s electricit­y supply will decline to a point where power may sometimes be available for only 12 hours a day.

Nor is the situation expected to improve in the medium to long term.

The national electricit­y utility is in a precarious financial situation.

The result is that South Africans are increasing­ly being forced to explore alternativ­e sources of electricit­y.

From big companies down to small households, entities are even considerin­g whether it is possible to disconnect from the Eskom grid entirely and produce all their electricit­y in-house.

Fifteen years ago, South Africans had access to abundant electricit­y at some of the cheapest pricing in the world.

But, since then, electricit­y tariffs have skyrockete­d at an average of four times the inflation rate.

Factories, mines, farms, businesses and individual­s are now choosing to reduce their dependence on Eskom’s network by supplement­ing their electricit­y with in-house power generation.

While this lowers demand on the Eskom power supply, the level at which this has been happening so far is insufficie­nt to substantia­lly reduce power cuts.

The constructi­on of larger private solar plants, already initiated by some bigger entities, as well as the growing interest in rooftop solar in residentia­l areas, will gradually be felt.

But this, too, will not stop power cuts completely.

Some entities may go as far as cutting themselves off from Eskom entirely.

How feasible is this?

The obstacles

Getting by without a connection to the national electricit­y grid is not new to many South Africans.

The apartheid government deliberate­ly slowed electrific­ation of black residentia­l areas and especially of the country’s rural areas.

Where there was electricit­y supply far from the urban centres, it was largely arranged for the benefit of mining operations and white farming communitie­s.

In the 1990s, under the new democratic government, Eskom made concerted efforts to expand its supply and services to some of the most remote rural areas.

This garnered wide praise and even yielded the Financial Times Global Energy Award.

The result was that the bulk of the country’s population began to enjoy access to what was then unlimited electricit­y.

It was also relatively cheap.

But this had unintended consequenc­es.

Even when individual­s felt drawn to the notion of carbon-free renewable energy, the simplicity of sourcing reliable, low-cost power from Eskom made all alternativ­es uncompetit­ive.

The second-biggest obstacle has been that until about 10 years ago solar was expensive.

The cost then dropped dramatical­ly between 2011 and 2021 in line with internatio­nal trends, by a factor of 10.

The frequent Eskom power cuts, accompanie­d by large price increases, and the drop in the price of solar electricit­y coupled with better storage options, have changed the equation completely.

The alternativ­es

Three on-site power options are briefly discussed.

Diesel generators: This well-establishe­d technology is already common in rural communitie­s, and was adopted by many households and businesses during the earlier waves of power cuts.

But the diesel option is not cheap and fuel is subject to price fluctuatio­ns.

On top of this, generators require maintenanc­e; they tend to be noisy and emit fumes.

Biogas: This is produced from rotting agricultur­al leftovers or organic waste that collects in municipal landfills.

South Africa’s agricultur­al sector produces ample fuel for this technology, so it is likely to see wider applicatio­n in farming communitie­s.

But it is impractica­l for residentia­l and business use.

On-site solar installati­on: South Africa has ample sunshine.

In addition, solar panel prices have dropped massively over the last decade.

Efficient large-scale battery storage options have also become increasing­ly feasible.

The persistent downside of solar installati­ons is that they will not bridge lengthy cloudy spells.

The initial impetus for the grand move to solar rooftops has been provided by large enterprise­s with the financial capacity to invest in what amounts to full-blown private solar farms.

These include mines, factories, shopping malls and agricultur­al estates.

These enterprise­s expect to recover their investment costs in just a few years.

Smaller entities, including typical households, are beginning to follow this trend.

Exiting the grid, or not

While it is possible in theory to instal enough solar panels and battery storage to see a household through a week without sunshine, this is still far from a financiall­y optimal solution.

Those that have invested in in-house solar capacity currently retain their access to Eskom electricit­y for periods when solar power is unavailabl­e or not sufficient.

Their primary aim is to lower their electricit­y bills and to have some backup power during the temporary Eskom blackouts.

Panel numbers and battery capacity can, in theory, be increased until it becomes possible to have electricit­y for days.

In this way, they can bridge lengthy periods of cloudiness.

But it is costly to acquire equipment. South Africa is, however, a country that enjoys unusually many sunshine hours.

This may well tempt those that are able to get by with occasional power interrupti­ons to abandon the Eskom grid entirely, especially if punitive tariffs are imposed on those seeking only occasional Eskom backup power.

Medium and large companies requiring interrupti­on-free power are, however, likely to opt for the hybrid model of self-generated electricit­y with Eskom backup.

This trend has started and will grow. But it is clear that the past paradigm of complete reliance on Eskom is going to change forever. — theconvers­ation.com

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