Benoni has a bright idea
- Ivo Vegter
- 16 Oct 2012 12:08 (South Africa)
Whenever you discuss energy in this country, a plaintive cry goes up: “Why don’t we invest in nice, clean, renewable solar power instead? We don’t need this dirty, evil, fossil fuel stuff that we’re running out of anyway.”
For a start, if or when we run out, the price of coal, oil and gas will rise, and finding alternatives will become economically attractive. That day is not today. Sit down.
The reason we’re not investing overly much in things like solar power instead of large-scale fossil-fuel or nuclear capacity is simple. They cannot, by any stretch of the imagination, provide anywhere near enough energy for South Africa’s needs anywhere in the foreseeable future. And the little they can produce is expensive.
Take Wattville, near Benoni. The Ekurhuleni municipality just unveiled there the first municipal-owned solar photovoltaic site in the country. That’s the kind that uses solar panels to convert sunlight directly into electricity, in order to charge batteries that supply power to the community.
The numbers on this project make for sobering reading. It serves a low-cost housing community of 133 houses. It covers an area of 2,500 square metres. It produces a total of 200 kW. For what is being claimed as a glorious national first, it is surprisingly modest.
Let’s be generous and assume the battery storage system actually works and it can produce this power all day long. Let’s do some division and multiplication.
Its area works out to 18.8 square metres of worth of solar panel per household, which is about half the size of a typical RDP house. One might have suggested sticking it out of the way on rooftops, rather than in a field, but one surmises land is cheap – or government-owned – in this location. Besides, the rooftops of low-cost houses are these days festooned with hideous solar water heaters, also paid for by the government.
Per household, the plant produces 1.5 kW. Now I won’t claim to be well-versed in the arcane arts of electricity grid management, but it strikes me that this is not very much. You wouldn’t want everyone in that little community to turn on the kettle for tea at half time during a football match – to use an image that Energy UK once used to illustrate the worst that can happen to an electricity grid.
The jubilant press release didn’t bother to inform us of the cost of this installation. A call to the Gauteng Department of Local Government and Housing went unreturned yesterday, but let’s give them the benefit of the doubt and imagine they installed it without excessive cost-overruns, bribes and sloppy accounting, at a world-class price of about R30 per Watt. That would amount to R6-million, split 133 ways, or R45,000 per household. By all means, take this as a back-of-the-envelope calculation, but even that conservative number sounds rather steep to me.
It’s not as much as nuclear power would cost, of course. Last I went shopping for a nuclear power plant, I could get (using the phrase “could get” very loosely) a 200 kW Toshiba plant that would fit in my garage for about R20 million. Today, Toshiba is working on 10 MW and 50 MW versions of their micro-nuclear plants. A rival, Hyperion, has a 25 MW unit on sale for about $50 million, which works out to about half the price per Watt of our lovely new solar installation in Wattville. What’s more, it will fit in a single RDP house, instead of the sport-field-sized area the solar panels require.
A far larger photovoltaic project is in the works for Nobelsfontein, 34 kilometres south of Victoria West in the Karoo. When completed, it will have a 50 MW capacity, at a project cost, excluding operations, over-runs and spreadsheet errors, of R1.5-billion. On the back of our envelope, this is comparable to the generous assumptions made about Wattville, and consequently also twice the price per Watt of the nuke-in-the-garage option.
On Twitter, I proposed sarcastically that we respond to this glorious news of solar progress from Benoni by scrapping the over-budget, over-deadline, overly corrupt coal-fired generators, Medupi and Kusile. At 4,800 MW each, they produce 24,000 times the electricity of the Wattville solar plant. Granted, they’re not much cheaper per Watt, but then, if we’re going to complain about the inflated costs of mega projects that run way over budget, it doesn’t sound smart to punt projects that are designed to cost that much from the start.
In response, a sciencey type replied to say I could diss photovoltaics all I liked, but surely I wouldn’t rip into solar-thermal plants? Unlike panels that convert sunlight into electricity directly, solar-thermal power plants work by concentrating sunlight to heat a fluid, usually molten salt, which then heats water to generate steam to drive turbines in the conventional manner.
Solar-thermal plants do seem rather better from the perspective of an electricity grid than dinky little solar panel arrays, which only ever seem good enough for small-scale, decentralised applications like powering a remote cellphone tower, an ocean-going yacht, or an expensive new super-green luxury home.
However, even solar-thermal plants are distinctly limited. Despite their size, each unit only generates about 50 MW. The world’s largest plant employs nine units and says 350 MW on the rating plate. (What the rating plate says and what comes out the working end of a solar power plant are not often comparable.)
Spain has a few neat little plants, which admittedly make science geeks drool. But still, they only produce between 100 and 150 MW each. That means, on average, we’d need 40 of these plants – and they’re not small affairs – blanketing the Karoo, for every big coal-fired power plant we’re not building.
The US Energy Information Administration has estimated future growth in electricity consumption by energy source until 2035, from a historic base going back to 1990. The news is good for renewables, in a way. They lead the pack in terms of growth and will produce more than twice as much energy as we’re getting from renewables today. Nuclear power follows hot on its heels, by that measure. However, by share of power produced, renewables will only account for 14%, and nuclear for 7%, of the total energy produced, up from 10% and 5%, respectively, in 2008. The rest – 85% in 2008 and 79% in 2035 – will continue to be made up by fossil fuels.
The solar power market, globally, isn’t all it’s cracked up to be, either. Recipients of loan guarantees in the US are dropping like flies, often having gobbled up the government’s subsidies without producing a single product, thanks to domestic inefficiency and over-competitive, state-subsidised production in China. The US has responded to the Chinese threat by slapping self-serving trade tariffs on it, betraying much about whether it really wants a cleaner environment or is just interested in sustaining a faltering crony-capitalist patronage state.
Cool technology – if you’ll permit me to describe 800-degree molten salt as “cool” – doesn’t pay the rent. If we want an efficient and cleaner alternative to the coal we’re burning today for the bulk of our electricity, getting all excited about solar power seems futile. It will take decades before solar becomes truly competitive, if it ever does. The same is true for wind, which brings with it a can of worms of its own, not least of which is the awesome superpower weapon they deploy against small flying creatures: barotrauma.
Nuclear can be rather expensive on a large scale and is limited to base-load power generation rather than catering for variable peak loads, but it’s a mature, well-understood and very safe technology. And face it, a nuclear power station in your garage would we way cooler than a solar-thermal plant out in the sticks.
It would be great to see some work done on the possibility of developing liquid fluoride thorium reactors in South Africa. These puppies are even cooler than car-sized nuclear reactors. If we devoted some engineers to them, South Africa would soon be world leaders in what may well prove to be the true alternative for a post-fossil-fuel world. They appear to make a lot of financial sense, if some recent books – and Daily Maverick comments – are to be believed. Sadly, I don’t expect to see one in operation in South Africa before I’m old and grey.
If I were a betting man, I’d put my money for our medium-term energy future on natural gas. It’s cheap, clean and efficient, and we have a potentially vast supply right here in South Africa. And frankly, compared to solar plants of either variety, the Karoo landscape would look better for it.
But let’s not get distracted and let reality take anything away from that field of dreams in Ekurhuleni. Congratulations, Benoni, on your 200 kW solar panel project. I’m sure it’s very nice. DM