Water and Energy Rely on Each Other

Water is essential to many activities in the home including washing, cleaning, cooking, drinking and recreation. Industrial processes rely on water for cooling, chemical solvents, cleaning, just to name a few. Forty percent of the worlds’ food is produced from irrigated lands [1]. However, much of this would not be possible without energy; which is a critical input to pump, move, and treat the water required by municipalities, industries and agriculture. Ironically, however, much of this energy would not be available without water to turn turbines, wash inputs, or cool equipment. Thus in many cases use of one resource is inextricably linked to use of the other – hence, the energy-water nexus.

Decades of overuse of energy and water resources, and continued wasteful habits, have led to cumulative environmental degradation that cannot be easily reversed; polluted surface waters, depleted aquifers, loss of biological diversity, and climate change being just a few of the problems to which we have contributed. Through all of this, we have forgotten to take into account that our resources are not limitless.

In many areas, groundwater levels in aquifers that contain fossil water, and do not recharge quickly, have fallen dramatically due to excess withdrawals. Fossil fuel and coal reserves are being relentless mined and in many cases activities must now turn to reserves that previously were deemed either too low in quality or uneconomic to extract. These resources are not renewable. And yet we still over-consume.
Driven by laws of supply and demand, resources continue to be over-extracted and prices continue to rise (figure 1 below). Considering that fossil fuels and coal make up 54% of the secondary energy supply1 the United States [2, 3], a rise in the cost of these will impact the cost of products and services which rely on energy from fossil fuels, including the cost of water. In fact, since 2002 real end-use prices have been increasing mainly due to increases in crude oil prices [3]. Canada is fortunate that the majority of its electricity is produced via hydroelectric generation, however about 20% does come from fossil fuels [4] and thus susceptible to the same price impact.

Climate change throws a wrench into the mix. It is anticipated that as climate changes, water resources will be altered; potentially reducing their quality, quantity, and accessibility [5]. This in turn will require increased energy inputs to purify water of lower quality or pump water from greater depths or distances. Increased energy use will potentially lead to greater greenhouse gas emissions. Additionally, Canada’s hydroelectricity sector could be affected forcing Canada to turn to other energy sources with higher emissions. All of this would ultimately reinforce climate change and create a vicious circle. Thus the imperative to ratchet-down the energy-water nexus and make it more efficient is even more pressing.

http://docs.google.com/viewer?a=v&q=cache:K-73E6qlkF0J:www.policyresearch.gc.ca/doclib/Thirlwell_energy_water_nexus.pdf+water+and+energy&hl=en&gl=ca&pid=bl&srcid=ADGEESgnAyotszTgkVfHM1q7dSlxKSvHDtEgzVCNLG-By0oGbnEIv0XW3AvZv3WO3qWbYKyun_xt_I5-jfOpSz5RgxOMeP0D-FbhvDgtTvYIBTKZqpScuCcuh7wArb1oeH3L58sTH5pS&sig=AHIEtbT-OY9R9CfuVRUPlJYf33fJ1WFv-A