First solar tower operating at night


A 260-metre tower, connected to 70,000 mirrors, stands in the area outside Dubai to produce electricity using a solar receiver designed by the Liège company John Cockerill.

A new 260-metre high tower has been built in the Mohammed Bin Rashid Al Maktoum solar park in Dubai. There is nothing special about the architecture of the tower, which is made of concrete and rises like a chimney, but a molten salt solar receiver has been installed at the top. With a diameter of 22 m, a height of 40 m and a mass of approximately 1,500 tonnes, this is a real technological feat for which the Liège company John Cockerill can take credit. 

In practical terms, as Gérald Thomas, Director of solar applications at the Belgian company, explains, "Cold salt from a ground tank is pumped to the heat exchanger at the top of the tower. There, it is heated by the sun's rays and then brought back down to be stored in a salt tank heated to over 560°C with a capacity of 15 hours. From this tank, it is used to generate electricity on demand, via a steam and turbine system.

The Belgian company has already fitted out three other solar towers in China, South Africa and Chile, each on sites that were dry and very sunny deserts. But this tower in Dubai has such a high capacity that it can boast of being the first solar power plant that can even operate at night.

The icing on the cake is that this technology has absolutely no environmental impact. The salts used (NaNO3 and KNO3) run in a closed circuit and could potentially be recycled as fertiliser.