/ 5 September 2020

How to stop load-shedding, fast

South Africa could be facing both load shedding and a tariff increase.

Before I get anyone’s hopes up, there is no instant fix to load-shedding. But there is a much faster way than getting Eskom’s major power plants in good shape and building new ones: a rapid roll-out of small-scale solar power.

This is a better solution than relying on fixing Eskom for a number of reasons.

As I outlined previously, large infrastructure projects in South Africa are designed to fail. They fuel patronage and corruption and until the government changes the way they are structured, we can’t expect better. Small-scale solar is completely different — rather than a small number of mega-projects that require top engineering skills, they are a large number of micro-projects that require only ordinary electricians with a little extra training. 

Then there is climate change: our government is supposed to be committed to emissions reduction, and replacing fossil-fuel capacity with solar is one of the most efficient ways to achieve that.

Next, there’s cost. For anyone with money to spare, installing solar is a great investment — particularly as the cost of electricity increases. The payback time of the installation cost is about six years. (I am talking here about photovoltaic panels that generate electricity, not solar water heating.)

Regulatory and practical hurdles

So why isn’t everyone doing it already?

In much of the country, it is not legal to feed excess solar power into the grid. In my home, I installed a solar-plus battery-backup system. If the solar panels generate more electricity than I need, it is wasted — less so during the Covid-19 lockdown because I am working at home more than usual. Adding batteries to the system made it a lot more expensive, so the main gain for me is not losing everything electric when the power is out.

What would it take to allow widespread feeding into the grid? Several elements need to change.

Municipalities need a mechanism to replace lost revenue. A simple approach is to charge a grid-connect fee that is calibrated to make up for the municipal markup on Eskom power. This is fair, because the municipality still has to maintain the grid.

Local substations need to be adapted to allow power input from local sources.

Municipal billing systems and prepaid meters will need to be altered to allow for negative consumption.

Finally, electricians who are not familiar with solar installations will need training to scale up to the required numbers.

None of this is rocket science ― with the right regulatory framework, much of the work will be done locally by small-scale business, the small, medium and micro enterprises (SMME) sector the government has mostly failed to promote.

How the numbers stack up

How far can this scale?

Based on statistics of South Africa’s middle-class and wealthier sectors, up to a million households could install an average of 600W of solar. That adds the equivalent of 600MW to the grid. Even those who could not afford the capital outlay should be able to get a loan because the savings on electricity bills will exceed the interest.

Households with an entitlement to 50kWh of free electricity a month could be given a 300W panel. As a rough average, you get 10 hours a day of the installed capacity. That amounts to 90kWh per month, nearly double the free entitlement. Replacing the free entitlement by solar will pay back the cost of the system. If this is done initially in another million households, this adds 300MW to the grid.

Then institutions — business, academia and so on — can join in. Half a million small businesses could potentially add another 1kW of solar each, adding 500MW. Larger institutions could match that. The numbers I have added up so far come to 1.9GW — the output of a large coal power plant. And that is just the start — when solar power becomes widespread and grid connection is easy, these numbers will increase.

The power of pump storage

What about the intermittency of solar power and its absence in the dark?

Grid-scale storage helps fix that. And that we have more than sufficient capacity for this amount of solar power. Eskom has about 3GW of pump storage — hydro plants that generate electricity when water falls from a high point and store energy by pumping water uphill. If we expand solar significantly — and that requires unblocking the slow pace of licensing independent power producers — more grid-scale storage will be needed.

Existing pump storage was designed to fill the gap at peak demand; aside from system failures, another big cause of load-shedding is the depletion of pump storage, which means Eskom cannot handle peak demand. Large-scale solar power will help to fill that gap because much of the generation is in the daytime, when home use is low.

A lot of work is going into bringing down the cost of large-scale batteries. For the grid, batteries can be surprisingly cost effective compared to a home-scale backup system because grid-scale batteries can be charged when there is an excess of supply and the stored electricity sold at a higher price when energy is in short supply. The alternative is to run expensive peaking plants that can cost up to 100 times the price of cheaper sources of power.

Building more grid-scale storage is for the future; a rapid roll out of small-scale solar will not saturate existing pumped storage and will make a big difference to Eskom’s capacity to meet demand.

We need an inclusive summit 

There are other deep systemic problems in power generation, including massive debt owed to Eskom by delinquent municipalities and nonpaying customers. I was part of a civil society group that took Eskom and the Makana municipality in the Eastern Cape to court to prevent Eskom from shutting off supply. Our court action resulted in a settlement that is still being adhered to.

These problems can be solved with the right will and openness to creating space for the imagination and creativity of the wider society.

My numbers are based on a quick, back-of-the envelope exercise and subject to correction, but a solution this kind is far more doable than fixing Eskom-scale generation. Taking pressure off Eskom will create space to fix its deep, systemic problems and placing generation closer to consumers will also incentivise efficiency — if you use less you can get money back.

What we really need urgently is a summit of all people with expertise in energy to talk through alternatives — not just Eskom and the government, but academics, independent power producers and renewable-energy experts. We cannot continue bumbling along in the hope that Eskom will fix itself soon enough to matter.

Philip Machanick is an associate professor of computer science at Rhodes University. These are his own views.

The views expressed are those of the author and do not necessarily reflect the official policy or position of the Mail & Guardian.