World Water Day has been observed on 22 March since 1993 when the United Nations General Assembly declared 22 March as “World Day for Water”.
Water and energy are closely interlinked and interdependent. Energy generation and transmission requires utilization of water resources, particularly for hydroelectric, nuclear, and thermal energy sources. Conversely, about 8% of the global energy generation is used for pumping, treating and transporting water to various consumers.
In 2014, the UN System – working closely with its Member States and other relevant stakeholders – is collectively bringing its attention to the water-energy nexus, particularly addressing inequities, especially for the ‘bottom billion’ who live in slums and impoverished rural areas and survive without access to safe drinking water, adequate sanitation, sufficient food and energy services. It also aims to facilitate the development of policies and crosscutting frameworks that bridge ministries and sectors, leading the way to energy security and sustainable water use in a green economy. Particular attention will be paid to identifying best practices that can make a water- and energy-efficient ‘Green Industry’ a reality.
Hydroelectricity is the largest renewable source for power generation and its share in total electricity generation is expected to remain around 16% through 2035.
Hydropower and water use
Most of the water used for hydropower generation is returned to the river though some evaporates and there are important impacts on timing and quality of streamflows.
Industrial water use
Roughly 75% of all industrial water withdrawals are used for energy production.
For developing countries alone $103 billion per year are required to finance water, sanitation and wastewater treatment through 2015.
Energy for water
Energy is required for two components of water provision: pumping and treatment (before and after use).
Waterborne transit is one of the most energy efficient. Inland towing barges are more than 3 times more energy efficient than road trucks and 40% more efficient than rail.
Biogas produced from sewage
In Stockholm, public buses, waste collection trucks and taxis run on biogas produced from sewage treatment plants.
Access to water and sanitation
In 2011, 768 million people did not use an improved source of drinking-water and 2.5 billion people did not use improved sanitation.
Access to electricity
More than 1.3 billion people still lack access to electricity, and roughly 2.6 billion use solid fuels (mainly biomass) for cooking.
Wind power is the most sustainable source of renewable energy, mainly because of its low greenhouse gas emissions and water consumption.
Pollution by fossil fuels
Approximately 15–18 billion m3 of freshwater resources are contaminated by fossil fuel production every year.
Biodiesel and water
China’s target to produce 12 million metric tonnes of biodiesel by 2020 requires an amount of water approximately equivalent to the annual discharge of the Yellow River.
Biofuels and food prices
Geothermal electricity potential
The installed worldwide geothermal electricity capacity could be increased from the current 10 GW to 70 GW with present technology, and to 140 GW with enhanced technology.
Courtesy : Wikipedia and http://www.unwater.org/