TuNur, a joint-venture company between NurEnergie, a solar power plant developer based in England, and a collection of Tunisian investors, has seized upon the unmet export market of solar energy from Tunisia to Europe.

Squinting in the sunlight, Maurizio Scaravaggi checks his watch and uses his shadow to find north. He turns to look west, out over a featureless landscape to the horizon. "That is ours," he says, picking up a handful of sand and letting it run through his fingers.
Rjim Maatoug, this patch on the northern edge of the Sahara, is not the dramatic landscape of a Hollywood desert, but a wide, sandy plain, punctuated every few metres by dried shrubs. A few kilometres away an oasis has been turned into a commercial palm-oil plantation, the only industry in this desolate region of Tunisia. "We won’t have to clear the land," he says. "The mirrors won’t need much space, and the bushes will hold the sand."
Scaravaggi works for Nur Energie, an Anglo-Tunisian enterprise that is close to securing the surface rights to 100 square kilometres of this desert. Here, the company intends to build a 2GW concentrated solar power (CSP) plant to export energy to a European market that is facing a huge potential shortfall as Germany takes its nuclear reactors offline.
The project, called TuNur, is one in a long line of schemes that have been discussed for years: solar-power projects have turned up as proposals on the sidelines of Mediterranean energy conferences for more than a decade, and almost every recent co-operation agreement between Europe and North African states has included a pillar on renewable energy and climate change. In the wake of the Fukushima nuclear disaster, momentum has gathered, both in Europe and in Asia. If the vision is realised, it could be one cell in a solar mega-grid stretching around the Mediterranean from Morocco to Greece, using the Sun to power the industrialised nations of northern Europe.
It falls to Scaravaggi to solve TuNur’s most taxing challenge: extending a transmission cable from this patch of desert, up 600km of rough terrain, to the Mediterranean and across to its landing point in Montalto di Castro, 90km north-west of Rome.
A taciturn, bespectacled engineer and a veteran of the Italian energy sector, Scaravaggi has spent a quarter of a century managing the complex electromechanics of building networks. But this job, he admits, requires constant re-evaluation of the technologies and logistics used in the industry. Handling those logistics will be Fethi Bel Hadj, 45, from Nur Energie’s local partner, Top Oil Services. Bel Hadj, a jovial bear of an oilman, handles a Land Cruiser as if it were an extension of his body and seems to know every centimetre of the country’s roads and pipelines — many of which he has had some hand in building or maintaining.
While Scaravaggi deals with the complicated theory and electromagnetic-engineering challenges, it is Bel Hadj who will have to turn the design into a reality, finding ways to move the machines and massive lengths of cable into position, and to navigate the land and passage rights.
The pair, along with a small crew of surveyors in a chase car with a gaffer-tape-secured GPS jutting from the passenger window, are searching for an accessible route out of Rjim Maatoug and to the north coast of Tunisia. It is a journey that has taken them down the west coast, on a crowded highway where overhead lines already jostle for space; across the Chott El Jerid, a Martian salt lake where the water runs red around glistening crystal islands; and then north, up the Algerian border, where on the roadside diesel smugglers sell plastic bottles of fuel at knock-down prices, and where Bel Hadj frets about the safety of his cars.
Artist's impression of CSP clusters in desert area (Source: BrightSource Energy)
"If we leave them here, they will be in Algeria by tomorrow," he says, as the team abandons their plan to stay overnight in Thelepte while following a potential corridor that would have the line cross the chott (the Arab name for a Saharan salt lake), and over the mountains, past the frontier towns of Gafsa and Métlaoui. There, skeletal conveyors are draped across the blunt peaks. Phosphate mines throw tonnes of dust into the air, adding to the sandstorms that are common in the spring.
This route, a combination of B-roads, existing service tracks left by the oil and gas industry and bone-jarring off-road jaunts through the rocky desert, seemed on the map to be the most promising. The altitude is a challenge, but the route offers advantages: the lack of urban development should ease planning issues, and the route will pass the Jendouba substation. This would allow the company to plug into the Tunisian domestic network and repay some of their deals with the government and monopoly operator, the Société Tunisienne d’Electricité et Gaz — STEG — with power, rather than cash.
The alternatives — a longer route to the west, either alongside the coastal highway or up a secondary road further inland — add some practical problems. The total breadth of a buried cable corridor, which would be needed if the team build near the road, is around 12 metres — two cable trenches of three metres each with a six-metre service road in the middle. The cable rolls must be transported horizontally in 40-tonne, 1km-long rolls with a diameter of five metres — twice the width of a standard truck, and wider than most roads. Bel Hadj thinks they can jerry-rig one of the huge low-bed trucks used by the oil and gas industry with a specially designed holder that could bring the cable reels upright.
At the port of Gabes, he says, there is a "Fajoli", a vast, 750-tonne-capacity vehicle that could carry multiple reels. The logistics, he says, should not be dictating the design. Whatever the design requires, they can fix it. An overland solution would be far cheaper, but it would need to use alternating current because the electrostatic effect of direct current would attract sand to the lines. Once the cable reaches the sea, there is a whole new problem. The undersea laying technology only works at depths of up to 1,600m. Off the coast, the sea bed drops sharply to 2,000m. The sheer weight of the cable hanging free two kilometres in the water behind a ship would probably capsize it. Unless a new, lighter material can be used — and Scaravaggi thinks that Spectra, an alloy developed to spin into ropes for racing sailing boats, is a possible alternative — then the team may need to modify one of the enormous catamarans used to lay oil pipes.
There is little discussion of the power plant itself. This, Scaravaggi admits, is partly because it has become customary to delay such decisions, to squeeze the best deal out of potential suppliers. "I know of one project in America where they changed from CSP
[to photovoltaics, PV] on the last day," Scaravaggi says, hinting that he might consider incorporating PV in Rjim Maatoug. A different technology in the mix uses heliostats, or mirrors, that project the Sun’s energy to a boiler on top of a tower, creating high-pressure steam that can be integrated with conventional power-plant components to create energy.
Scaravaggi knows that it is not the generation technology that poses his greatest challenge, but the transmission. The problems are solvable, but this will take time. After securing building permits, completing the design and tendering, manufacturing the components and putting them in place, final completion could take seven years. Still, generation will be modular, and Scaravaggi believes it is feasible to bring 1GW online by 2017, which would make TuNur one of the earliest, if not the first, to market. This kind of solar-for-export project has finally found a window of opportunity.
Building utility-scale solar power for export is not a new idea. Enthusiasm for renewable energy as a serious alternative to hydrocarbons has ebbed and flowed along with public interest in climate change and with the price of oil — itself governed by a complex supply-demand function of geopolitics, technology and industrial need.
In renewables, as with fossil fuels, the concentration of resources is not, in the most part, close to the point of consumption. Wind farms can only be built where there is wind, solar plants where there is sunshine and hydropower where there are rivers. Storage and transmission of solar, in particular, is difficult. By their nature, solar plants only have access to their energy source for limited hours each day. Commonly used photovoltaic cells generate only when the Sun is up.
Two trends are starting to offer an answer. The first is the rise of concentrated solar power. The technology involves focusing sunlight using mirrors, either to heat water directly to generate steam, or to heat another substance, typically molten salts. Solar energy can be stored as heat, and, if the losses from the salts are limited, can generate steam to turn a turbine even after sunset. This, says Till -Stenzel, the local head of the TuNur project, allows the plant to harvest energy during the daytime for release in the hours of darkness. The second is high-voltage direct current transmission (HVDC), which allows energy to be sent over thousands of kilometres without significant losses, improving the efficiency, and hence the economics, of solar generation.
Yet the economics of building and running projects of this type have never seemed to add up for governments and private-sector investors. This has long deeply irritated the grandfather of the desert grid movement, Gerhard Knies, a particle physicist who "retired" in 2001 to advocate full-time for a transition towards large-scale renewables. Knies founded the Trans-Mediterranean Renewable Energy Cooperation, or TREC, in 2003, bringing together experts from Europe, the Middle East and North Africa to build support for initiatives linking the African desert to northern Europe. It was this consortium that morphed, in 2009, into the Desertec Foundation. "Economists are the gravediggers of mankind," Knies says, sipping tea and eating dry toast in the Desertec Foundation’s offices on Hamburg’s Ferdinandstrasse. "They would tell us to buy a car without brakes if it is cheaper."
Knies’ argument is that the prevailing economic assessments of cost, price, supply and demand are based on short-term assumptions that lack any understanding of the catastrophic risks inherent in ignoring the effects of climate change — or of continuing with nuclear power.
His thinking was shaped by the meltdown at Chernobyl in 1986, which set him off on a 25-year -journey towards Desertec.
"If you make one simple mistake [with a nuclear core], the whole problem could not be stopped," he says. "The risk potential is confined in the reactor, this huge amount of energy that can be freed, and that can become destructive. This is what I called the vulnerability of industrial civilisation… Accidents happen, or you can cause accidents. The technical confinement may be achieved, but the social confinement never can be."
It was this that convinced the physicist to consider a post-nuclear, post-fossil-fuel world. Today, he speaks with an idealism that has gone out of fashion among advocates of renewable energy. Global civilisation, he argues, depends on its ability to manage its energy needs. The consumption and generation of energy is, he says, a part of mankind’s evolution but, to date, it has been achieved by borrowing resources from future generations. Wars, he said, will still be fought over energy resources as fossil fuels dwindle. Inequality of energy and prosperity — which are linked — continue to cause conflict and insecurity. Fixing the energy supply in the long term is not just about climate change, or economics — it is about the perpetuation of civilisation. "Deserts… receive enough energy from the Sun in six hours than we use for the whole Earth in a year," he says.
The mission thus far has been a lonely one, but his thesis has been granted two major boosts in the past three years. First, in 2009, a group of major multinational companies, including energy giants RWE and E.ON, industrial conglomerate ABB and the reinsurer Munich Re, endorsed the concept, signing up to the Desertec Industrial Initiative (DII), a private industrial consortium whose objective is to create a market for renewable energy from the world’s deserts.
The second, far less positive, was a tragic reminder of Knies’ early predictions. The Fukushima disaster in Japan last year brought a minute-by-minute drama to the world’s TV screens, as crews struggled to contain a nuclear core. The word "meltdown" circulated on news channels, and politicians and citizens began to fret over the proximity of reactors to urban populations.
Germany reacted most decisively. Chancellor Angela Merkel announced within weeks that the country’s eight oldest reactors would go offline and stay offline, and the remaining nine would be shut down by 2022. Nuclear power accounted for around 23 per cent of German energy use at the time of the announcement. That will need replacing. Some will come from burning gas, a decision that will stretch European commitment to carbon-emissions-reduction goals, and deepen Germany’s dependence on an unpredictable Russia for its energy needs. The rest, Desertec hopes, will come from renewables. There are few visions that offer the scale and scope of the Mediterranean mega-grid.
The idea is gathering momentum. In debt-laden Greece, the environment ministry has proposed the construction of a
multiple gigawatt solar plant, using the power it produces to pay back its creditors in northern Europe. The plan, called Project Helios, remains just a proposal.
Japan, too, which before Fukushima sourced around 30 per cent of its energy from nuclear, has begun to back renewables as an alternative — and to its overwhelming reliance on imported coal, oil and gas. And Gobitec, a South Korean initiative, has proposed a solar super-grid in the Mongolian Gobi desert — something that Desertec too has suggested.
"I think that the Fukushima disaster could be the final nail in the coffin for nuclear energy," Kevin Sara, Nur Energie’s CEO says. "Public demonstrations against nuclear power are gaining momentum in Japan, not losing it." Sara came to renewables after a career in banking and venture capital with Salomon Brothers and Nomura, cofounding the Cleantech Investment Fund Hazel Capital in 2007. He is convinced that, ultimately, solar and wind will replace nuclear.
For the time being, the numbers are working against him. In July, the Organisation for Economic Cooperation and Development reported that, driven by demand from China, India and South Korea, the rate of expansion of nuclear power in Asia has barely slowed since the Japanese tsunami. Sara, however, thinks that the safety requirements will make alternatives economically attractive. "Because of the extra layers of safety that will be required for post-Fukushima new nuclear build, we don’t think that nuclear can be competitive commercially. Baseload solar with storage, combined with high capacity-factor off-shore wind, will be cheaper and will -eventually be able to completely displace nuclear," he says.
Germany, he notes, has remained committed to its promise to completely replace its existing nuclear infrastructure. "This is the goal of the German government, and we believe that Germany will be a key market for our project," he says. "In Germany, anti-nuclear sentiment is strong and deep, and the government views the shift to sustainable renewables as a major long-term -economic growth opportunity for German industry."
Inconveniently, the Desertec concept’s most fervent critic wasone of Germany’s most respected advocates for renewable energy. Hermann Scheer was key to the decision to implement feed-in tariffs at the turn of the millennium, kick-starting the rapid increase in the following years. Scheer, who died in October 2010, repeatedly stated that the project’s economics made little sense. He insisted that the idea that large-scale, "baseload" generation, such as that proposed by Desertec, would be expensive and unnecessary.
The economics of renewables, he said in a succession of interviews, favours decentralised, smaller-scale generation that can be turned on and off on demand. Furthermore, he said, the rapidly falling cost of photovoltaic cells and offshore wind production would mean that, by the time the North African plants came online, they would be too expensive in comparison. This, of course, was before Fukushima. But the criticism has stuck.
"This is true," the Desertec Foundation’s director Thiemo Gropp says. "That’s true for the biggest part of the energy production. I have to explain that in every talk I do. You can say that we can do it with only [decentralised] wind and PV. In principle this is true. But in Germany, what do we do with our fridge overnight if the wind is not blowing?"
Desertec does not develop projects itself, operating instead as an advocacy and advisory group. The DII has created a framework for a reference project in Morocco, and has endorsed others, such as TuNur in Tunisia. But its job hasn’t been made any easier by misrepresentations that it is seeking more than $500 billion (£323 billion) to build a single, massive power plant. Hundreds of projects will be needed to create the capacity and redundancy needed to be a viable alternative to gas or nuclear. "When we have crossed the threshold of the first project, and people realise it works, and that this is only a complementary aspect of a whole solution, and we have a lot of local solutions and decentralised solutions, then there will probably be more momentum," Gropp says.
The other persistent criticism may be harder to counter — that the project will exploit poorer countries for the benefit of richer ones. "One has to tap energy where it is found, and solar energy, you have lots of it in the Sahara region. If the initiative takes into consideration the requirements of the local people, then I don’t see any problem," Daniel Egbe, the Cameroonian scientist and chair of the African Network for Solar Energy says. "If it’s just something to make money… that’s where at the beginning we had some doubts about the initiative. We were saying that it’s a typical, neo-colonialist approach, coming to exploit the resources from Africa and taking it to Europe."
True, solar radiation is often greatest in areas of significant under-development. While from an economic perspective that may decrease the costs of land and labour, it heightens the kind of social tensions — or, in Knies’ words, "social containment" — that could threaten the future of the projects. Egbe says that he has had reassurances from the foundation and its partners that there will be energy-sharing and other initiatives helping to include local economies. But he remains sceptical.


Nur Energie is sensitive to the problem. Tunisia, which underwent dramatic change during the Arab Spring, is wrestling with unemployment: more than 50,000 people graduate annually to fill less than the 25,000 jobs the Tunisian government estimates require a graduate-level education. In desert areas, such as Rjim Maatoug, the sight of young men idling by the roadside is a common one.
Scaravaggi hopes that the construction and operation of the Rjim Maatoug plant will employ thousands, and that the overhead transmission cables can be manufactured in Tunisia, helping to seed an industrial base in the country. Even so, there is a sense that it is an afterthought — the Italian prides himself on not being an ideological supporter of renewables, but a practical one.
The head of the local operation is more bullish. "Tunisia already has a developed industrial tissue and many well-educated workers, which provides a great base to develop our project and build a new industrial sector in solar," Stenzel says. "Our aim is to show that solar projects are both technologically feasible and economically viable and that Tunisia can benefit from the investment as well as the local
integration of the technology. This will also be the base to use more solar in Tunisia itself, where peak demand is during the summer,
just when solar is at maximum production."
In Hamburg, Gropp is becoming used to balancing the ideological rhetoric with the commercial. Both have to be remembered if
the timescales — the economic opportunity left by Germany’s nuclear shutdown and the threat of climate change — are to be met.
"In order to move fast, it has to be a business," he says. "I think creating business cases, as is being tried in the Industrial Initiative, is critical, in addition to awareness in society and politics and academia. But finally, it comes down to the self-regulatory capacity of a
species growing from seven to ten billion."