A giant plant using energy from the Sun to power a Moroccan city at night will open next month.
The solar thermal plant at Ouarzazate will harness the Sun's warmth to melt salt, which will hold its heat to power a steam turbine in the evening.
The first phase will generate for three hours after dark; the last stage aims to supply power 20 hours a day.
It is part of Morocco's pledge to get 42% of its electricity from renewables by 2020.
The UN has praised Morocco for the level of its ambition. The UK, a much richer country, is aiming for 30% by the same date.
The Saudi-built Ouarzazate solar thermal plant will be one of the world's biggest when it is complete. The mirrors will cover the same area as the country's capital, Rabat.