At the time of the World Water Forum that just occurred in Istanbul, Turkey, it is interesting to remind how water and energy are linked.
Hydropower is generating 19% of the electricity worldwide, and as much as 85 % in Brazil and 98% in Norway.
Blue, clean, and no CO2 emission!
On the other hand, providing drinkable water to the population and wastewater treatment are requesting electricity. In the US for example, 3% of the nation electricity is used for water systems : distribution and treatment.
The average amount of energy necessary for production and delivery of drinking water is 0.5kWh par m3. The same amount of energy is requested for wastewater treatment.
This means that from source to discharge, every m3 is spending 1 kWh. Based on the European Union average, 0.4kg of CO2 is then emitted per m3. This is one additional reason to avoid water waste!
But this nothing compared to what is necessary for desalination (getting drinkable water from sea water). The most advanced technology is called “reverse osmosis” and is requesting around 4.5kWh par m3.
In other words, desalination of 1m3 of sea water is producing as much CO2 as the combustion of ¾ litre of gasoline!