HYDROPOWER is by far the number 1 renewable source of electricity generation.
The theme of this year’s World Water Day, on March 22, is ‘water and energy’, an important subject I feel deserves more attention, and one that readers of this blog will know I often write about.
As I’ve written previously, the complex connections between food, water and energy are unavoidably real and impossible to ignore. Here are ten reasons why:
1. Hydropower (pdf document) is by far the number 1 renewable source of electricity generation in the world, providing about 20% of electricity produced globally (more than 70% is from thermal generation, where water in cooling towers is actually consumed, not just used and then returned unaffected to the rivers). But hydropower is being increasingly challenged due to very high subsidies for less reliable solar and wind power.
2. Very conservative projections (pdf document) indicate that if by 2030, some 5% of road transport will be powered by biofuels, amounting to at least 20% of the water used for agriculture globally.
3. There are, on average, more than 30 grams of salt dissolved in one litre of sea water worldwide. The actual volume of salt in the water defines the amount of energy required to desalinate it for human use.
4. According to the first report of the 2030 Water Resources Group, increase in water use to 2030 will lead to a gap of 40% of withdrawals for human needs no longer covered by sustainable supply. Today, over-pumping of ground water by the world’s farmers already exceeds natural replenishment by more than 4% of total withdrawals.
5. More than 50% of desalination capacity is in the Middle East, largely in Saudi Arabia, where desalination plants meet over two-thirds of the kingdom’s present drinking water needs.
6. Fewer than ten countries hold 60% of the earth’s available freshwater: Brazil, Russia, China, Canada, Indonesia, the United States, India, Columbia, and the Democratic Republic of Congo
7. Globally, commercial energy consumed for delivering water is more than 26 Quads, 7% of total world consumption. (One Quad is the energy equivalent of 36,000,000 tonnes of coal).
8. According to the World Health Organisation, more than 80 million people worldwide suffer C. trachomatis eye infections and 8 million are blinded as a result of the infection which mostly occurs in overcrowded living conditions with limited access to safe water.
9. 99.7% of all the water on earth is not available for human or animal consumption. Of the remaining 0.3%, much is inaccessible due to unreachable locations and depths.
10. According to some studies (pdf document) (Burneya et al. 2009, Sivanappan 1994, Mozo et al. 2006, Belder et al. 2007), drip irrigation has resulted in yield gains of up to 100%, and water savings of 40-80%.