Cross-posted from the blog of the U.S. Green Building Council, Northern California Chapter
The President’s inauguration speech sparked renewed dialogue about the need for a comprehensive energy plan to address climate change. Recent decreases in lake levels in Texas is causing the city of Wichita Falls to look for new ways to stabilize their water supplies. Frequently missing from both of these discussions is the inherent relationship between water and energy. This relationship should be capitalized on when crafting programs and policies aimed at solving these tough issues at the national and municipal level.
Energy is needed to transport, treat, heat, cool, and recycle water and, conversely, water is needed in energy extraction, production, and processing. As a result, saving water saves energy and saving energy saves water. This overlap between energy and water has come to be known as the “energy-water nexus.” Recognizing and taking advantage of the energy-water nexus is beneficial to both the energy and water communities because when they coordinate they can simultaneously reduce consumption of these two resources through accounting for those embedded savings.
Saving electricity at the end-use (customer) level saves water because it avoids additional baseload electricity generation and water required for that generation process. The U.S. Geological Survey estimates thermoelectric-power withdrawals account for 49 percent of total water use and 53 percent of fresh surface-water withdrawals; an average of 23 gallons of water used per kilowatt-hour. This is a large amount of water saving potential that could be captured simply through increased energy efficiency.
In addition, reducing the use of all fossil fuels also saves water needed for resource extraction, production, processing, etc. The recent increase in hydraulic fracturing (“fracking”) to access natural gas has brought a significant amount of attention to the impacts natural gas extraction has on water. Fracking uses large volumes of pressurized water to create fractures in the rock layer and releases the natural gas. Furthermore, some observers are also worried about underground water pollution from gas leaks during fracking. Despite these concerns, little attention has been given to the fact that if we utilize natural gas and electricity generated by natural gas more efficiently we not only reduce energy consumption and extend the life of our domestic natural gas resources, but we also save significant amounts of water and potential pollution of water sources.
Saving water at the end-use (customer) level and throughout the distribution system can save energy because it reduces the energy needed for water withdrawal, transportation, and treatment. Water supply and wastewater treatment are often provided by municipal governments and the energy required for these services is one of the largest energy expenditures for a local government, according to the Environmental Protection Agency. Increasing water efficiency can greatly reduce operating costs for local governments. Without proper water-energy nexus planning in government and in the private sector, embedded savings can go unnoticed or uncalculated and the full benefits of efficiency are underestimated.
Energy and water utilities have worked together to implement efficiency measures that save both energy and water (e.g., efficient clothes washers and better cooling towers), but experience has been limited. In addition to expanded cooperation between the water and energy sectors, utilities can undertake numerous other activities to promote demand-side reductions at the residential and commercial level, such as offering education and outreach programs, combined energy and water audits, energy and water efficiency kits, and rebate and installation programs. However, in order to reach greater, more sustained dual savings, utilities, policymakers, and the private sector should focus on creating programs that implant the energy-water nexus into their operation and planning.
Programs that work collaboratively to reduce energy and water often involve partnerships among government, utilities, and companies. These collaborations can be challenging, but they are ultimately mutually beneficial and can result in enhanced outreach capabilities and customer contacts, increased staff, and financial resources, and a greater body of knowledge to draw from.
ACEEE and Alliance for Water Efficiency (AWE) recently released a report, titled Tackling the Nexus: Exemplary Programs that Save Both Energy and Water, detailing some of the exemplary programs that save both energy and water. The successful programs profiled in the report, and also in the ACEEE online Water-Energy Directory, help highlight the value of the energy-water nexus and designing innovative energy-water efficiency programs.
Rachel Young will be presenting at the 10th Annual Water Conservation Showcase, March 19, 2013 at the Pacific Energy Center. The event is free to attend, and you can register and learn more at http://www.usgbc-ncc.org/water2013.