Water and energy are both interlinked and very interdependent. They both have direct and indirect impacts because the energy production being pursued determines the amount of water required to produce the energy.
Freshwater and energy are vital for human existence, well-being and sustainable socio-economic development. More than 1.3 billion people still lack access to electricity, especially rural areas where 2.6 billion people use biomass for cooking leading to major health issues.
The countries with the most rapid economic growth face the greatest risk of water and energy risks.
Approximately 90% of global power generation is water intensive.
Thermal power plants are responsible for roughly 80% of the global electricity production. Power plant cooling is responsible for 43% of total freshwater withdrawals in Europe and nearly 50% in the United States.
Growing demand for limited water supplies places increasing pressure on water intensive energy producers to seek alternative approaches, especially in areas where energy is competing with other major water users (agriculture, manufacturing, drinking water and sanitation services for cities) and where water uses may be restricted to maintain healthy ecosystems.
In the context of thermal power generation , there is an increasing potential for serious conflict between power, other water users and environmental considerations.
Trade-offs can sometimes be reduced by technological advances, but these advances may carry trade-offs of their own. From a water perspective, solar photovoltaic and wind are clearly the most sustainable sources for power generation.
Support for the development of renewable energy, which remains far below that for fossil fuels, will need to increase dramatically before it makes a significant change in the global energy mix, and by association, in water demand.
Use of geothermal energy for power generation is underdeveloped and its potential is greatly under appreciated. It is climate independent, produces minimal or near-zero greenhouse gas emissions, does not consume water, and its availability is infinite at human time scales.
Agriculture is currently the largest user of water at the global level, accounting for some 70% of total withdrawals.
The food production and supply chain accounts for about one-third of total global energy consumption. The demand for agricultural feed stocks for bio fuels is the largest source of new demand for agricultural production in decades, and was a driving factor behind the 2007–2008 spike in world commodity prices.
As bio fuels also require water for their processing stages, the water requirements of bio fuels produced from irrigated crops can be much larger than for fossil fuels.
Energy subsidies allowing farmers to pump aquifers at unsustainable rates of extraction have led to the depletion of groundwater reserves.
Applying energy efficiency measures at the farm and at all subsequent stages along the agri-food chain can bring direct savings, through technological and behavioural changes, or indirect savings, through co-benefits derived from the adoption of argo-ecological farming practices.
Knowledge-based precision irrigation can provide flexible, reliable and efficient water application, which can be complemented by deficit irrigation and waste water reuse.
Many rapidly growing cities in developing countries already face problems related to water and energy and have limited capacity to respond.
As energy cost is usually the greatest expenditure for water and waste water utilities, audits to identify and reduce water and energy losses and enhance efficiency can result in substantial energy and financial savings.
The future water and energy consumption of a new or an expanding city can be reduced during the early stages of urban planning through the development of compact settlements and investment in systems for integrated urban water management.
Such systems and practices include the conservation of water
sources, the use of multiple water sources – including rainwater harvesting, storm water management and waste water reuse – and the treatment of water to the quality needed for its use rather than treating all water to a potable standard.
The chemically bound energy in waste water can be used for domestic cooking and heating, as fuel for vehicles and power plants, or for operating the treatment plant itself. This bio-gas replaces fossil fuels, reduces the amount of sludge to be disposed of and achieves financial savings for the plant.
The availability of adequate quantities of water, of sufficient quality, depends on healthy ecosystems and can be considered an ecosystem service. The maintenance of environmental flows enables this and other ecosystem services that are fundamental to sustainable economic growth and human well-being.
Ecosystem services are being compromised worldwide, and energy production is one of the drivers of this process.
Natural or green infrastructure can complement, augment or replace the services provided by traditional engineered infrastructure, creating additional benefits in terms of cost-effectiveness, risk management and sustainable development overall.
Source: United Nations
Joshua D. Mosshart Bio
Cleantech Grants
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