The Moroccan city of Ouarzazate is used to big productions. On the edge of the Sahara desert and the centre of the north African country’s “Ouallywood” film industry it has played host to big-budget location shots in Lawrence of Arabia, The Mummy, The Living Daylights and even Game of Thrones.
Now the trading city, nicknamed the “door of the desert”, is the centre for another blockbuster – a complex of four linked solar mega-plants that, alongside hydro and wind, will help provide nearly half of Morocco’s electricity from renewables by 2020 with, it is hoped, some spare to export to Europe. The project is a key plank in Morocco’s ambitions to use its untapped deserts to become a global solar superpower.
When the full complex is complete, it will be the largest concentrated solar power (CSP) plant in the world, and the first phase, called Noor 1, will go live next month. The mirror technology it uses is less widespread and more expensive than the photovoltaic panels that are now familiar on roofs the world over, but it will have the advantage of being able to continue producing power even after the sun goes down.
The potential for solar power from the desert has been known for decades. In the days after the Chernobyl nuclear accident in 1986 the German particle physicist Gerhard Knies, calculated that the world’s deserts receive enough energy in a few hours to provide for humanity’s power needs for a whole year. The challenge though, has been capturing that energy and transporting it to the population centres where it is required.
As engineers put the finishing touches to Noor 1, its 500,000 crescent-shaped solar mirrors glitter across the desert skyline. The 800 rows follow the sun as it tracks across the heavens, whirring quietly every few minutes as their shadows slip further east.
When they are finished, the four plants at Ouarzazate will occupy a space as big as Morocco’s capital city, Rabat, and generate 580MW of electricity, enough to power a million homes. Noor 1 itself has a generating capacity of 160MW.
Morocco’s environment minister, Hakima el-Haite, believes that solar energy could have the same impact on the region this century that oil production had in the last. But the $9bn (£6bn) project to make her country’s deserts boom was triggered by more immediate concerns, she said.
“We are not an oil producer. We import 94% of our energy as fossil fuels from abroad and that has big consequences for our state budget,” el-Haite told the Guardian. “We also used to subsidise fossil fuels which have a heavy cost, so when we heard about the potential of solar energy, we thought; why not?”
Solar energy will make up a third of Morocco’s renewable energy supply by 2020, with wind and hydro taking the same share each.
“We are very proud of this project,” el-Haite said. “I think it is the most important solar plant in the world.”
Each parabolic mirror is 12 metres high and focussed on a steel pipeline carrying a ‘heat transfer solution’ (HTF) that is warmed to 393C as it snakes along the trough before coiling into a heat engine. There, it is mixed with water to create steam that turns energy-generating turbines.
The HTF is made up of a synthetic thermal oil solution that is pumped towards a heat tank containing molten sands that can store heat energy for three hours, allowing the plant to power homes into the night. The mirrors are spaced in tier formations, to minimise damage from sand blown up by desert winds.