I recently read a new report entitled “The Water-Energy Nexus: Adding Water to the Energy Agenda,” by Diana Glassman, Michele Wucker, Tanushree Isaacman, and Corinne Champilou (New York: World Policy Institute and EBG Capital, March 2011.). As it noted, “…as new energy policies are emerging– is the time to consider water. Energy decisions are a series of complex tradeoff decisions between water, national security, cost, and carbon. Furthermore, energy is inextricably linked with agriculture (biofuels consume more than one third of the US corn crop) and forests (increased demand for energy crops may drive conversion of forests into agricultural land). As a result, policy makers and leaders across all sectors of society also must consider national security, cost, and carbon consequences of energy’s impact on agriculture and forests.” Here is the executive summary:
The competition between water and energy needs represents a critical business, security, and environmental issue, but has not yet received the attention that it merits. Energy production consumes significant amounts of water; providing water, in turn, consumes energy. In a world where water scarcity is a major and growing challenge, meeting future energy needs depends on water availability –and meeting water needs depends on wise energy policy decisions.
Competition for water among municipalities, farmers, industrial and power suppliers is already evident in a range of locations, particularly in the Southwest United States but also around the world. As water tables decline, the Organization for Economic Cooperation and Development estimates that 2.8 billion people—nearly half of the world’s population– live in areas of high water stress, rising to 3.9 billion by 2030 if present trends continue. As cities grow, municipal water demands will increase. As populations rise and increase their consumption of meat, agricultural competition for water will intensify.
In the United States, generating energy consumes 20% of the water not used by agriculture. Rising demand for energy—both conventional and alternative– has the potential to significantly increase water consumption. As energy producers and consumers seek to reduce carbon emissions, water consumption frequently rises because many cleaner forms of conventional and alternative energy are potentially more water-intensive. Both traditional and renewable energy production are evolving toward potentially more water-intensive technologies, which risks adding to demands on water resources. New energy technologies are being developed to reduce water consumption. However, they are generally expensive, can reduce energy efficiency, and will need time before they can be commercially available at scale.
Now—as new energy policies are emerging– is the window of opportunity to add water to the agenda.
Nations around the world are evaluating their energy options and developing policies that apply appropriate financial carrots and sticks to various technologies to encourage sustainable energy production, including cost, carbon, and security considerations. Water needs to be part of this debate, particularly how communities will manage the trade-offs between water and energy at the local, national, and cross-border levels. These decisions will impact businesses, investors, security, environment, justice, development, and sustainability. Policy makers, business leaders, investors, non-organizations, and the public at large need sound, non-partisan information to make the right choices. However, information about the water-energy nexus is often fragmented, weak and incomplete, difficult to compare, and filled with jargon. Inaccuracies in media reports are common because of gaps in understanding of the dynamics of the interaction between water and energy. Muddling the debate further, proponents on all sides of energy debates sometimes selectively choose (or even mischaracterize) data to their advantage.
To enhance the quality of discussion and decision-making on the water-energy nexus, this policy paper provides the context needed to evaluate key tradeoffs. We present a comprehensive, user- friendly guide to the most credible available data about water consumption per unit of energy produced across a spectrum of traditional and alternative energy technologies. We identify data holes and important issues that merit further attention. We also have created a glossary to help non-experts decipher energy jargon.
Based on existing data, the most startling finding is that (with some notable exceptions) both traditional and existing alternative energy technologies are evolving toward higher water consumption per unit of energy produced.
Both emerging petroleum and alternative transportation fuels consume more water than conventional petroleum-based fuels:
• Petroleum from the Canadian oil sands extracted via surface mining techniques can consume 20 times more water than conventional oil drilling. As a specific example of an underlying data weakness, this figure excludes the increasingly important steam-assisted gravity drainage technique (SAGD) method. We encourage future researchers to fill this hole.
• Irrigated first-generation soy- and corn-based biofuels can consume thousands of times more water than traditional oil drilling, primarily through irrigation. More research is needed to evaluate second and third generation biofuels.
The picture on electricity generation is mixed:
• Among conventional power plants, gas-fired plants consume the least amount of water per unit of energy produced. Coal- and oil-fired plants consume roughly twice as much water as gas-fired plants. Nuclear consumes approximately three times as much. The nuclear figure may seem surprisingly low in light of the public debate around nuclear water; this reflects frequent confusion between water withdrawal (which tends to be much higher) and water consumption. More research is needed on contemplated future projects including modular nuclear energy.
• One of the “cleaner” coal technologies, the integrated gasification combined cycle process, reduces a coal plant’s water consumption by half, while also reducing carbon emissions and other pollutants. However, contemplated carbon capture technologies could increase a coal plant’s water consumption by 30%-100%
• Wind and solar photovoltaic electricity consume minimal water and are the most water- efficient forms of conventional or alternative electricity production.
• The installed base of the solar thermal form of electricity generation (as opposed to photovoltaic) consumes twice as much water as coal and five times as much as gas-fired power plants.
• Natural gas produced by a technique called hydraulic fracturing is a game-changer that could alter the entire energy mix of transportation fuels and electricity generation. The main water issue here involves pollution, which is beyond the scope of this paper; however, additional research is needed on consumption, particularly in order to reflect substantial changes in the technology and its application to oil. Current data indicate that natural gas produced by hydraulic fracturing consumes seven times more water than conventional gas extraction but roughly the same amount of water as conventional oil drilling.
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