The water-energy “nexus” – the intricate connection and special relationship between water and energy – has long been at the heart of humanity’s efforts to harness and manage energy for its own uses.
The importance of this nexus was already evident in 1939, when the Belgian city of Liège hosted a Specialised Expo under the theme “Water Management”, celebrating the completion of the Albert Canal.
The Expo included engaging conferences and scenic displays in Palais 34 of the “Heavy Industry”, providing visitors with comprehensive explanations about electricity production. This pavilion illustrated how water is an active agent that is converted into electricity using turbines in hydropower plants, or a secondary agent used to condense steam and cool combustion engines in thermoelectric stations.
The French pavilion revealed a country dedicated to promoting energy efficiency and maximising its supply of “houille blanche” (white coal), by showcasing its highly developed hydroelectric plants, which represented 55% of the country’s total electricity production in 1938.
Visitors to the Expo also received practical information about how hydropower was supplied to isolated cities over long distances, using high-voltage lines. Water was extracted from rivers using dams and subterranean pipes; and converted to electricity in hydropower plants, which facilitated electricity distribution and access. Fascinating dioramas illustrated the spectacular results of this process in Algeria, Syria, Lebanon and Morocco, where electricity was made accessible to distant villages following the construction of reservoir-dams and hydropower plants.
Expo 1939 Liège established the link between water and electricity production, and also demonstrated the importance of water when using electricity in various industries. Visitors were informed, for example, of the electrolysis process, where water is decomposed into oxygen and hydrogen by passing an electric current through it to produce clean hydrogen gas. This process was first limited to electroplating, but the Expo showcased the growing need for electrolytic processes in the metallurgy and chemical industries, where water was used as a refrigerant that efficiently managed the extremely high temperatures up to 3,000 degrees, produced during electro thermal and electrochemical fabrications.
Through hydropower, tidal power, and heat pumps, but also as a key component in thermal energy generation and biomass production, water plays an essential role and is at the heart of considerations concerning Future Energy. Expo 1939 demonstrated water’s potential in energy production, which remains just as relevant today. The nexus is strengthened by pressing questions about the energy required to fulfil humankind’s growing demand for water and the treatment of wastewater. At Expo 2017 Astana, participants will continue to explore the water-energy nexus, showcasing new ways that water can contribute to energy, and vice versa.