Inefficiency Plagues the ‘Energy-Water Nexus’

The intent of the House hearing was to solicit expert testimony on the state of the energy-water nexus and measures that can be taken to improve the relationship. Congress has made gestures to address the issue. For example, a bill introduced by Rep. Eddie Bernice Johnson (D-TX), who chairs the Committee on Science, Space, and Technology, would direct the Department of Energy (DOE) to incorporate the consideration of water use and treatment into all its relevant research, development, and demonstration programs and additional coordination functions to ensure that this issue is given adequate attention and resources moving forward. The DOE would also need to take specific steps to research and advance energy-efficient technologies for water distribution, treatment, and collection systems.

Why a Disconnect?

Given the strong interdependence of energy and water, why do the two seem to operate under separate regimes to the advantage of neither?

Several explanations were offered by Kate Zerrenner, the senior manager of the Environmental Defense Fund’s Energy-Water Initiatives, who gave the most comprehensive picture of the energy-water nexus at the hearing. According to Zerrenner, the most fundamental problem may be the absence of a common language. Even something as ostensibly simple as measurement can be an obstacle. “Electricity is measured in megawatt-hours (MWh) or megawatts (MW), and water is measured in gallons or acre-feet, neither of which is meaningful to the other sector,” said Zerrenner. She also described several of the broader discrepancies.

• Policy development, technological advancements, and investment opportunities for energy and water are largely independent rather than coordinated. Even municipalities that own and operate their water and electric utilities often have planning and management systems that operate as though under separate authorities.
• Energy and water policies at both the federal and state levels are outdated. For example, they were developed to support traditional central thermal power plants, which are both highly water- and energy-intensive processes.
• Policy and regulatory barriers inhibit cross-sector coordination. The power sector operates under national reliability standards (top-down), while water is much more localized (bottom-up). Each sector has its own regulatory framework and oversight agencies at the state and federal levels, as well as workforce training structures that are not aligned with each other.
• Water planners typically assume they have the energy they need, and energy planners assume they have the water they need. A mismatch in planning objectives by different actors can prevent the beneficial siting and combining of technologies.
• To a large extent, the energy sector is market-based and run by private, often big companies acting on regional, national, or global markets. Energy efficiency is a driving force for development. Energy is priced on the market, and there is a high awareness about energy prices among customers.
• The water sector, on the other hand, is dominated by small public utilities acting on regulated markets at the local municipal level. Water is largely characterized by inefficient use or overuse, and incentives for technical advancements are insufficient. There is low customer awareness of water prices, and marginal cost pricing or cost-recovery pricing is common. The price of water is set based on principles that include affordability and accessibility, and the price does not typically reflect the supply technique or treatment process. The existing water price also does not capture region-specific water conditions or relative water scarcity. As a result, the cost of water can be a small share of overall energy production cost, even for water-intensive users.
• Private companies acting under market forces often dictate the location of energy infrastructure whereas water infrastructures are often located using more public interest criteria.

The Next Steps

Different approaches and new technologies are available both to cut down water use by utilities and improve energy efficiency by water systems. For example, one witness pointed out that some utilities are acquiring treated sewage water for cooling; the witness added that the prospects for this approach may be limited because municipalities are charging for this water. Desalination technologies, as well as the use of corrosion resistant materials in thermoelectric plants, are also available and can expand the use of seawater for cooling. A witness said the DOE is pursuing a national research effort intended to lower the cost and energy requirements of desalination and treatment of nontraditional water sources.

Another long-term approach suggested by Zerrenner is to build water grids similar to electric power grids. This transition would begin with the wider installation of smart water meters.

“While smart meters are increasingly deployed in electrical grids, monitoring of water infrastructure lags significantly,” testified Zerrenner. “Networks of remote, automated leak detection could help in prioritizing repairs to aging water infrastructure, with concomitant energy savings, particularly in locales with high embedded energy costs of water, such as Southern California and the Southwest.”

Zerrenner says the resulting data would also enable better cost-benefit water planning, identify anomalies in the system, prioritize and inform policies and implementation efforts, identify conservation potential for customers, and provide a mechanism for customer feedback about the rate of consumption and impact of that consumption.

Again, smart water meters would be only one part of the grid approach. “Although discussions about meters are plentiful, integrative, strategic, and macro-level discussions of smart water grids are lacking in academic and other literatures,” Zerrenner adds.

Testimony from the House hearing is available here.

SOURCE TO THE COMPLETE ARTICLE ABOUT THIS HEAING ON THE WATE ENERGY NEXUS

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Taxonomy

• Energy Reduction
• Water-Energy Nexus
• Energy-Water Nexus