/ 17 January 2020

The path to a zero carbon future

Carbon Tax Will Motivate Change
Water, wind and solar energy will not only decarbonise the economy, but it will save trillions.


A request for information (RFI) has always sounded like a rather timid affair. Government departments regularly issue RFIs to the private sector, nongovernmental organisations and the public. It’s a request. Not a demand or a statutory requirement. These requests generally result in a flurry of activity, and a plethora of responses.

Take the recent RFI briefing session held at the Independent Power Producer (IPP) Office of the department of mineral resources and energy on emergency electricity procurement to alleviate the current Eskom crisis. It soon became apparent that the organisers had completely misjudged private and public interest. Staff members were frantically wheeling in chairs to accommodate the throng of respondents. If only Eskom was as quick to accommodate wheeling electricity to the grid as the band of chair-people.

Wouldn’t it be refreshing if the public sector, and state-owned entities such as Eskom were as keen to respond to requests for information. It would save a whole lot of time on issuing Promotion of Access to Information Act requests to get data that would allow for a far more informed response to their RFIs. Data that is routinely posted in real time on utility “dashboards” in countries all over the world.

To the matter at hand: providing information to the mineral resources and energy department.

Best scientific information tells us that by 2050, we had better have fully decarbonised our energy economy. It also tells us that we had better achieve at least 80% of this decarbonisation by 2030. Ten years for the easy parts of the fossil fuel economy, and 20 years for the more stubborn remaining 20%, embedded in things such as long distance air travel.

If this appears daunting, seems impossible or is deemed highly improbable, then savour the following information, a full-on mind-blowing sweetener. If we trundle along in business as usual mode, then the world is set to spend $18-trillion a year on energy in 2050. If we electrify our entire energy economy, this drops to just less than $8-trillion. How is this possible? It turns out to be all about thermodynamics and transfer inefficiencies of one energy form to another.

Burning coal to make electricity is about 33% efficient, meaning that 100 units of energy locked away in coal produce about 33 units of electrical energy. Two-thirds is wasted away as heat, as well as energy to propel small particulate matter into the atmosphere, to wreak their nasty breed of respiratory havoc on those within the range of the pollution plume.

Take the modern internal combustion engine motor vehicle. One would think they’re efficient. If you drive frugally, not too hard on the peddles, you may exceed 20% efficiency in a petrol-driven vehicle, and up to 30% in a diesel-propelled vehicle. The balance is pretty much all waste heat and hot air.

The third big pillar of energy usage — industrial processes such as smelting and large scale heating and cooling — are in fact more efficient. If you burn coal, oil or gas to heat something, then you make use of the energy directly as heat, and you don’t have to go through the transformation to either electricity or kinetic energy in the form of propulsion, as in a car.

So, if we transition to 100% electric, we spend $8-trillion a year instead of $18-trillion a year. Great sweetener.

(John McCann/M&G)

Mark Jacobson and his team at Stanford University, use the term 100% water, wind and solar (WWS) to signify this transition. All electricity is produced from either wind, solar or water (hydro, geothermal, wave, tidal, electrolysis and hydrogen production). So we have two 2050 end members: business as usual or water, wind and solar (WWS).

Some additional information in response to the RFI. If we stick with business as usual, the estimated global health costs predicted by the World Health Organisation are $30-trillion a year by 2050. Translated into human lives, that’s about seven million deaths caused by poor air quality from the combustion of fossil fuels.

As regards climate change marginal costs, conservative estimates for business as usual energy are $29-trillion more than water, wind and solar energy. In other words, the business as usual 2050 total global energy cost is just shy $80-trillion, or 10 times the cost of a switch to 100% WWS.

Jacobson and his team are not thumb-sucking this information. They have modelled WWS energy transition plans for 143 countries, responsible for about 97% of all greenhouse gas emissions. Their global figures are the sum of the detailed country by country models. These models factor in local demand profiles, estimated demand growth, estimated population growth and so forth. Their simulations have been set to accept zero non-delivery of electricity. In South Africa, that translates to zero load-shedding. Nada.

They have a plan for South Africa. But then so does a research group, in Finland of all places. Not much to do during those long winter nights in Finland, they sit in small huddled groups. Someone chips in: “Why don’t we model the South African energy system and dream about sunshine?” They all nod, and get to work. Their model differs in detail, but is uncannily similar to Jacobson’s model. Let’s drink to that.

There is a cry from the backbenchers: “What about the workers?” Globally, there will be 27-million more permanent, direct jobs created than lost. In South Africa, the figure is about 250 000. And that is before you factor in jobs associated with the decommissioning and rehabilitation of coal-fired plants and coal mines. It also takes no cognisance of potential new jobs in, say, the agricultural sector using significant water resources that will be freed up during decommissioning.

Here comes the punchline. If South Africa picks the water, wind and solar route, and transitions to 100% WWS by 2050 (and 80% by 2030), then we need to produce at least four times as much electricity by 2050 as we currently do. Compare this to the Integrated Resource Plan (IRP) 2019 demand estimates and see how wrong they are.

By 2050 we will need just shy of 1 000 terawatt hours (TWh) a year. The IRP 2019 projects a demand of between 360 and 420 TWh, about 40% of the WWS estimate.

A transition to WWS will save us 90% of our energy costs, inclusive of those often ignored externalities. The IRP 2019 focuses on electricity demand in a business as usual case. It takes little or no cognisance of a WWS transition. It is wrong. Why would we fight to have a dirty, harmful, business as usual energy system when we can have a clean energy system at a tenth of the cost? I wouldn’t. Would you?

So, what do we need to construct between now and 2050 to effect the 100% WWS transition?

The exact mix of wind, water and solar, as well as the amount of accompanying energy storage, which includes green hydrogen storage, differs from model to model. Jacobson makes it clear that they present but one of a myriad of models for the transition plan for each country.

The differences in the models are a function of differing proportions of on-shore and off-shore wind, and the splits between residential, commercial and industrial, and utility-scale solar. These ratios are a function of future costs, as well as country specific regulatory and tariff structures. For instance, are flexible rooftop solar installations making up millions of micro-grids to feed surpluses into the distribution networks allowed by the regulators?

So the models are all dominated by wind and solar, and it is mainly the proportions that differ.

I had a crack at modelling a fit for purpose WWS energy mix for 2050 for South Africa. One of the constraints was zero shortages (aka load-shedding). The other key parameter was a least cost mix of storage-backed WWS. We require 240 gigawatts (GW) of solar, 150GW of wind and 90GW/360 gigawatt hours of storage. The average cost of the electricity in 2020 rand terms, before delivery through the transmission and distribution grids is of the order of R0.90 a kilowatt hour. This cost is based on current costs of solar, wind and storage.

For simplicity, if we divide these figures by 30, we need to install 8GW of solar, 5GW of wind and 3GW/12 gigawatt hours of storage a year, each year, forever. There will need to be a continuous rolling replacement build programme after 30 years of usage.

It just so happens that if we construct the new generation fleet at these annual recommended rates, we will be able to retire the entire coal fleet by 2030. It will not be a case of making space to undertake deep maintenance on an ailing coal fleet, in the hope of squeezing some extra TWh out of the older members of the fleet. It will be more a case of allowing between 3GW and 4GW of the coal fleet to be retired each year, and buried with a modicum of dignity.

This then is the recommended solution to the current energy crisis. It is not a panicked knee-jerk, ad hoc response to the state of the coal fleet. It is simply the first step of transitioning to 100% water, wind- and solar energy by 2050.

Clyde Mallinson is a geologist who currently focuses on the energy sector