Is it possible to harness the power of the sun in order to solve the energy crisis and save the world? It may sound like the plot to The Man With The Golden Gun, but on second glance it is easy to see why some have fallen for it.
With 3,600 hours of sunshine a year, the Sahara is one of the hottest places on earth. As average summer temperatures exceed 40 degrees, sometimes approaching 50 degrees, the Saharan sun is potentially powerful enough to provide the entire planet with solar energy.
A solar powered utopia — or should that be Eutopia?
According to NASA, each square metre of the desert receives on average between 2,000 and 3,000 kilowatt hours (KWh) of solar energy per year. This would mean a single square metre solar panel placed in the Sahara would generate on average 5-7 KWh of energy per day. If we scale up to one square kilometre, it would provide 5-7 gigawatt hours (GWh) per day. If we increase this to 1,000 square kilometres, it would generate 5-7 Terawatt hours (TWh) per day — roughly enough to power Europe’s energy needs.
It sounds impressive right? A solar powered utopia — or should that be Eutopia?
The highest profile attempt was made by a German company called Desertec in 2009. For a few years, Desertec made a number of hyperbolic headlines about providing clean energy for the world. The rationale behind the company was that up to twenty per cent of Europe’s energy needs could be met with solar panels located in the Sahara. Funded by a $500 billion investment, their goal was to develop infrastructure across North Africa and the Middle East in order to transport this vast amount of solar energy to Europe via trans-mediterranean high-voltage power cables.
The problem was that there are only two interconnections between North Africa and Europe — both located between Morocco and Spain. They are both 700 megawatt interconnections, one built in 1998 and the other in 2006, with a third due to be completed in 2030 — totalling 2100 megawatts. To transport enough electricity to meet 15 per cent of Europe’s energy requirements, it has been estimated that roughly one hundred of these interconnections would be required. At $150 million a cable, that would cost 15 billion dollars.
These are not the cables you use to plug in your playstation
These are not basic cables you use to plug in your playstation; these are complex and expensive bits of infrastructure. They must convert high voltage direct current (DC) to alternating current (AC) as it enters the cable, and back to AC as it exits. The challenge is power loss. Three per cent of power is lost per 1000 kilometres and four per cent lost in conversion. Estimates are that roughly €1 million are lost per kilometre of cable.
When you consider a trans-mediterranean cable would have to be extended to the capital of Germany, some 2000 km from Morocco, that’s $1.5 trillion to reach Berlin. Plus €2 million from power loss. It comes as no surprise that with mounting financial costs, the project was scrapped in 2014.
Now it appears the plan has reemerged. With COP26 behind us, there is renewed fervour to reach net-zero carbon emissions as soon as possible. The European Commission’s hydrogen strategy has proposed once again that the EU tap into the Sahara’s huge potential for clean energy. A paper published in March, called the “green hydrogen initiative”, wants to see the EU import 40GW of renewable hydrogen from the deserts of North Africa — via repurposed natural gas pipelines that currently connect to Europe.
This time round transmission will not be by electron; it’ll be molecular. But this approach still faces transportation headaches. The idea of a renewable hydrogen superhighway between North Africa and Europe has attracted criticism. According to Wood Mackenzie analyst Ben Gallagher, hydrogen has low volumetric energy density compared to natural gas. “It would need to be highly pressurised, liquefied [or] turned into ammonia [for] transportation,” Gallagher said. It can be done for small-scale distribution, but “it’s never been done on a large scale”.
Clean nuclear energy is vilified by environmentalists
Martin Lambert agrees with Gallagher’s claims. The senior research fellow at the Oxford Institute for Energy Studies argues, “You need to do some quite deep engineering work to convert a gas pipeline system to hydrogen; hydrogen is quite different stuff to methane, so you can’t convert it easily.” The cost of transporting hydrogen through repurposed natural-gas pipelines would be astronomical.
Even if this financial and logistical nightmare is solved, we then have to store the hydrogen. Britain currently has 20 GW/h of energy storage. Seeing as we consumed 287,000 GW/h of electricity in 2020, this amounts to roughly half an hour’s worth of supply. If we relied on solar to provide our electricity, you’d barely get to finish the latest episode of Eastenders — a price worth paying for some, no doubt.
So, are there any other alternatives? Pop quiz: what form of power produces over half of America’s carbon-free electricity?
The answer is nuclear.
Yet this clean form of energy is vilified by environmentalists. When you apply the concept of availability bias — where rare and emotive events are easily recalled, making them seem more important in decision making — I have no doubt that when I say nuclear, a lot of people will say Three Mile Island, Fukushima and Chernobyl. No one died at Three Mile Island, one at Fukushima and Chernobyl was caused by a faulty Soviet-era design. If we are that scared of radiation, why do cancer patients submit to having their bodies flooded with radioisotopes? In chemotherapy, radioactive substances are used to treat thyroid, bone and prostate cancer.
Measuring by fatalities per Terawatt hour of energy produced, statistically nuclear is among the safest forms of energy: coal — 24.6 deaths; oil — 18.4; natural gas — 2.8. Nuclear, by contrast — 0.07 deaths. It is also cleaner: it produces 3 tonnes of greenhouse gas emissions per gigawatt hour compared with 820 for coal, 720 for oil and 490 for natural gas. Solar energy even produces more carbon emissions than nuclear.
No more Putin lurking by the spigots
As with everything in life, there are of course risks: nuclear energy notably involves the disposal of radioactive waste. But new designs use waste as a fuel source. Fast-neutron reactor plants burn all radioactive material and leave no waste. They also burn waste from slow reactors. As they don’t produce hydrogen, they don’t explode. Nor do they need cooling towers. Their primary fuel is liquefied uranium 238, and they only need refuelling every ten to twenty years.
Reliance on nuclear also removes our dependence on hostile foreign powers. No more Putin lurking by the spigots, turning off the gas flows to Europe.
While nuclear is not perfect — it involves large financial start-up costs — when we’re happily throwing money out of the window for every other carbon-free energy source, why can’t we do it with nuclear energy?
Boris Johnson has ambitious plans to have all our electricity generated by low-carbon sources by 2035, but we can’t rely on renewables alone. Currently solar generates just 1.5 per cent of our total electricity. If he is serious about net-zero, he should invest in nuclear.
Go green, go nuclear.
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