Solar could supply SA energy - expert

2012-07-23 10:26

Cape Town - Solar energy could deliver 15 times the current electrical demand in SA if there was sufficient investment in new technology, a researcher has said.

"One of the funny things about solar is that South Africans just don't know it. And it does provide an extremely large potential - much bigger for instance - than wind," Paul Gauché senior researcher and director of the Solar Thermal Energy Research Group (Sterg) in the Department of Mechanical and Mechatronic Engineering at Stellenbosch University told News24.

Gauché conceded that wind power was a maturing technology and even photovoltaic (PV) solar energy was viable with accelerated investment into the sector.

"The potential for PV is immense: If we put PV farms up everywhere we could easily get more than enough power generated in the country, but the problem with both PV and wind is their intermittence," he said.

Gauché is proposing investment into concentrated solar power (CSP) where a set of mirrors concentrate sunlight onto a collector which then acts like a traditional electrical generating plant.


"You use mirrors to concentrate the sunlight and basically what you do is you can then generate steam. The back half of a CSP plant is just like an Eskom [coal-powered] plant in that it's got a steam turbine and a cooling system.

"The front half: What you're basically doing is replacing coal with concentrated sunlight," he said.

CSP is an expensive technology at around R2 per kWh (Kilowatt hour) but in the long term costs would be reduced, especially as supplies of fossil fuels decline.

The technology is a direct competitor to gas turbines that burn diesel fuel which typically cost between R3 and R5 per kWh.

Like wind and solar power, CSP is an intermittent source of energy, but Gauché said that new technological innovations meant that it was more viable.

"The most successful developments are these concentrating solar plants where they actually store the heat energy in salt tanks. The top of the tower actually heats salt and keeps salt molten - these are special salts - and they remain in the molten state all the time," he said.

The additional of the molten salt has seen countries like the US exploring CSP plants and over 400MW of capacity was installed in Spain in 2010.

Renewable energy

SA has been talking about renewable energy alternatives for electricity generation, and Eskom said that during winter electricity supply will be tight as the utility races to complete maintenance programmes.

The government has been lobbied to accelerate the development of independent power producers to generate electricity as opposed to a single entity.

"Over the last 30 years or so, virtually all countries have abandoned that model and now have independent generating and an independent grid, and generating itself has been unbundled into different types.

"We actually happen to think that whether it's private or government isn't the big deal - it's unbundling that's the big deal," said Leon Louw, executive director of the Free Market Foundation.

Eskom has received an African Development Bank loan of $365m that will be used to build a solar plant in the Northern Cape province and the utility is also building coal-fired power stations Medupi and Kusile to meet future demand, despite objections from environmental organisations.

"Medupi may be about to start delivering electricity into the South African grid, but this will come at a huge social, economic and environmental cost, which leaves little to celebrate," Greenpeace said after Eskom successfully conducted a boiler test at the facility.


The utility said that its CSP project in the Northern Cape was serious power station.

"So it's not an experimental project, it will be a real power station. A 100MW is a lot of power - it is scale - it's significant," Eskom spokesperson Hilary Joffe told News24 in 2011.

Gauché said that CSP should be an important part of energy policy over a long-term time horizon.

"It's a very young technology and they [Eskom] are justifiably very uncomfortable with suggesting that they should rely on CSP. I would not rely on CSP today. However, there are nations in the world... where they realise that concentrating solar power is going to be an extremely important part of the mix."

A study done by organisations including Greenpeace, the European Solar Thermal Electricity Association, and the International Energy Agency found that increased investment of €2bn to €92bn into CSP until 2050 would see the technology being able to supply 25% of the world's energy needs.

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  • eddy.deepfield - 2012-07-23 10:43

    Wishful thinking. South Africa cannot afford solar power stations. Try it somewhere else, prove it in practise and then maybe. For now there is nothing other than coal fired stations. We have the coal. Nuclear stations are too scary and dangerous for Africa. Look at Japan.

      Tony Lapson - 2012-07-23 11:56

      They have made transparent, highly efficient solar panels which can be used on all structures and high-rises as windows, while sustaining the buildings electricity needs and actually supplying the grid with more power. Of course, that would defeat the whole purpose of Eskom making profits.

      haydnmay - 2012-07-23 12:54

      South Africa can't afford solar power stations? Yet they are already planning on building 9.6GW of nuclear power at a cost of 100's of Billions of rand? South Africa also has limited coal reserves - something that will make alternatives like solar more attractive. Also, CSP plants have already demonstrated baseload production. The GemaSolar (20MW) plant in Spain has a 78% capacity factor, making it the same (in terms of hours run per year) as a nuclear power plant. Thermal storage will get better and better (and cheaper), making solar thermal plants much more competitive. When you look at the cost of a solar plant, you have to realise that you're paying for 30-40 years of energy, unlike coal and gas and nuclear plants which are subject to fuel cost fluctuations. The sun in an inexhaustible power source. It wouldn't make sense not to use it. The USA are - new Ivanpah 310MW power tower/thermal salt storage plant in California by BrightSource. A company called SolarReserve are building a 110MW power tower as well. Spain likewise has numerous projects in the pipeline.

      Matthew - 2012-07-23 14:11

      The reason they (south africa) cant afford something like this,is because of things like the article from today "3 billion missing from civil servants etc" thats why we cant.Otherwise we probly could and would be halfway there by now.Stupid ANC...bloody agents.thats just my opinion. This IS the best solution and only real way forward for us as a country and human race. Really going to laugh when people kick themselves when the fossil fuels run out "Eish,we should've done that solar power thing.Eish"

      james.rossouw - 2012-07-23 17:51

      US solar Cos like Solyndra bancrupt costs taxpayer +-$546,000,000. German solar Co's ditto, Chinese Co's having problems. Germans are having problems switching to green, forced to import power from Austria.

      andynct - 2012-11-26 12:28

      Solar is still the most expensive electricity there is and that is without the cost of taking into account the fluctuation in availability. The production prices for electricity (NERSA) Concentrating solar power (CSP): R2,51 per kWh Solar photo-voltaic (PV): R1,65 per kWh Wind: R0,90 per kWh Small hydro: R1,03 per kWh Present Eskom production cost: R0.31 per kWh

      rickey.tickey - 2012-12-09 17:08

      Andycnt, I believe your price for solar electricity was taken during peak hours and optimal exposure to the sun. And then their is the big solar secret which most manufacturers try to hide and that is: More carbon is released into the atmosphere during the manufacturing process of a solar cell, than the amount of carbon that cell will save during it entire lifespan.

  • stefan.vosloo.33 - 2012-07-23 11:00

    Would be nice if we dont have to rely on eskom. But then again the goverment would what to have their finger in the pie.

  • chris.shield - 2012-07-23 11:56

    Eskom needs to be unbundled, keep the transmission network as a public utility and privatise the power stations, preferable selling them off to different buyers with strict anti-competition clauses to prevent them all being bought up by 1 or 2 giants which will inevetably lead to price fixing. Allow users to buy their power from whichever one of these producers offers them the best (or greenest) deal and charge a per km surcharge for using the network. And please hurry up with the 2-way meters that allow people with their own small-scale solar or hydro generators to sell their excess back to the producers..

  • badballie - 2012-07-23 12:01

    Africa has the capacity to generate enough solar energy on uninhabitable land to supply the worlds energy needs. The stories of unproven effectiveness are nothing more than b*llsh*t. The high costs involved also have nothing to do with new technology or development costs and everything to do with ensuring the elite's secured revenue streams. Coal is unsustainable and the problem of actually getting it to the power plants remain. The biggest obstacle still remains the need to develop more effective and longer lasting power storage facilities, but this is a problem already faced by conventional power producers and is nothing new. The bottom line is that solar and other greener and cheaper energy sources threaten big business and will be resisted by the major players for as long as possible, through disinformation, outright lies and the continued high profit margins being generated on the sale of the cheaper technology. The answer as always is to take control away from major corporations and put it in the hands of the individual.

  • nicholas.b.wallace.1 - 2012-07-23 12:03

    "It's a very young technology and they [Eskom] are justifiably very uncomfortable with suggesting that they should rely on CSP. I would not rely on CSP today. its been around for along time already. it works! peopele and scientist are to scared to make the jmp from fossil fuels to renewable energy they create disinformation making people think its expensive and cant power everything. with solar you just pay for the technology to make the panel the more panels being made will bring down the cost and create competition which will in turn create jobs and a whole new industry. in the past it used to cost 30$ a watt for solar panels now its under 3$ costs come down efficiency goes up and no harm to the planet.

      piet.strydom - 2012-07-23 14:20

      Nicholas - CSP Solar panels.....

      piet.strydom - 2012-07-23 15:49

      News24 threw away some of my characters. What I posted was CSP is not equal to Solar panels.

      andynct - 2012-11-26 14:01

      There is no reticence from Scientists or Engineers w.r.t. Renewables. Cost is the factor. Concentrating solar power (CSP): R2,51 per kWh Present Eskom production cost: R0.31 per kWh

  • Shane Loxton - 2012-07-23 12:06

    In th USA some states encourage people to install solar power in large quantities, and the energy they dont use gets feed back into the national grid and the get paid out by the Power company for the power. If we had a system like that here instead of just a rebate for a solar heated geezer it might add more enthusiasm amoungst the public. When i was in the US some houses have their whole roof covered in Solar panels and hardly pay a cent for power, and when they go on holiday that power is diverted into the power grid and they get paid when returning back from their vacation. Something to think about?

      piet.strydom - 2012-07-23 14:21

      I believe that that is the best way to do solar - because it can be done in pieces small enough for individual homes, you greatly reduce the need for transmission lines, and you also eliminate transmission losses. You do still have storage losses.

  • giovanni.izar - 2012-07-23 12:28

    Has anyone asked how much of the usable energy we get from the sun will be used? There most certainly is a limit before we start adversely effecting the planet. Absorb enough of the suns energy and the whole system will distort. Air currents, sea currents etc WILL change. The results could be pretty sick.

      giovanni.izar - 2012-07-23 12:31

      Never lose sight of the fact that the land does not belong to you. It is you that belongs to the land.

      Tony Lapson - 2012-07-23 13:09


      piet.strydom - 2012-07-23 14:22

      Uh, where would the solar energy go if not absorbed by the solar panel?

      Cayowin_van_der_Badt - 2012-07-23 14:31

      Hi Giovanni, Just for the sake of it what do you think happens to the energy from the sun that does not get used by solar collectors right now? What would be different if the sun's rays hit a solar panel and not a bit of dirt somewhere in the Karoo.

      aj.coetzee.9 - 2012-07-23 14:34

      First Law of thermodynamics my friend

      aj.coetzee.9 - 2012-07-23 14:36

      PV works on the light available : Photo = light. It will not darken the planet, if thats what you are wondering

      giovanni.izar - 2012-07-23 20:08

      The research has been done. Just look it up before spewing. The sun send out so much energy, the planet is in the path of some of it. The planet uses some of this energy and there is some that is extra. Key word is "Some"

      giovanni.izar - 2012-07-24 07:30

      To those who do not believe...... Read this article.....

  • Ze Don - 2012-07-23 12:46

    100MW on a sunny day is peanuts! Koeberg generates 2x900MW and Medupi will produce 6x798MW... any time of the day or night.

      jason.sole.92 - 2012-07-23 13:21

      At what cost?

      Ze Don - 2012-07-23 13:30

      @Jason: The reality is that solar can't supply electricity 24 hours a day, so it just isn't viable at the moment. Our only choices are coal or nuclear, you choose.

      piet.strydom - 2012-07-23 14:24

      No Don, it is not the only choices we have. The days of having big centralised installations (of anything, not just electricity) is over. We will develop electricity generating energy systems that run in parallel, and use whatever is most economical at the time.

      richard.fahrenfort - 2012-07-23 15:48

      ...there's also wind, tidal and geo thermal. Nuclear power is a dinosaur and its messy and dangerous. There's nothing messy, dangerous, dirty, unsustainable or expensive about solar, tidal, wind and geothermal (aka 'heat mining'). Think about that and then ask WHY we, as a species, dont harness these energies to their full potential. 3 words: Greedy, Energy. Companies.

  • Tawizee - 2012-07-23 13:09

    If you building a house I advice you to put you own solar power system. It costs 7-10 years' electricity but it lasts for more than 25 years.

  • riaan.louw.18488 - 2012-07-23 13:15

    Just do it. The technology is there, its applied in other parts of the world and it works, so why not use it. It can open a whole new industry, allowing for job creation, boosting the economy and teaching people about a having a more sustainable lifestyle - things are going to change in the future, so we might as well start now and adapt before its to late...

      Tony Lapson - 2012-07-23 13:37

      Man-made fiat currency, inked paper, digital figures and profits are just far too important.

      piet.strydom - 2012-07-23 14:26

      @Tony - You can complain all you want about fiat currency, but fiat currency is what has given you and humanity ENORMOUS benefits over the last 100 years. Greatly aided by fractional reserve banking. And it is the excesses of the latter that has caused all the problems that we currently have. But we should not throw out the baby with the bathwater....

      Cayowin_van_der_Badt - 2012-07-23 14:33

      Tony, do you have a viable alternative to money? How would we get there?

  • Galeo Solar - 2013-03-08 22:56

    Solar power definitely starts making sense, even in South Africa. Due to drastic price hikes Oostvallei Retirement Village in Pretoria has decided to switch to a more reliable, renewable energy source. The electrical energy generation at Oostvallei is based on the installation of 31 solar photovoltaic (PV) installations, sufficient to meet the needs of the 120 homes in the estate. With all the homes having north facing concrete roofs, it created an ideal surface for the installation of the individual solar farms. Each of these solar farms produce just over 32 kW/h of electrical energy per day which accumulates to just under 1 megawatt per day for all 31 solar generators. The total generation of clean electricity per month is close to 31 megawatt. The installation was done by Galeo Solar (Pty) Ltd. and is South Africa's only and also largest multi residential solar photovoltaic installation to date. The installation comprises just over 1000 solar panels being manufactured by Suntech Power and uses Kaco-new energy for the inverters and monitoring software. Contact Galeo Solar (Pty) Ltd. to view the installation or for any further details at 0861 228 229.

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