2010 Water Energy Nexus Competition Content Coming Soon.
2009 Water Efficiency Content Below.
Water Efficiency
Context: Why Water Efficiency Matters
Clean water scarcity is perhaps our greatest global humanitarian crisis, and has become an acute economic, political, environmental, and social issue in the U.S. and all over the world. Reducing demand and making use more efficient is the most effective means of addressing the problem.
Clean water demand is rapidly rising, while supply is shrinking:
• Only 1% of the world’s water can be used for human consumption. 70% of the world's surface is covered by water, of which 97.5% is salt water. (1)
• The world's population, currently estimated at 6.6 billion, is growing by about 80 million people each year, which means that demand for freshwater is increasing by 64 billion cubic meters a year. (2)
• Around the world, clean water supply is shrinking due to pollution drainage from aquifers. (3)
Making water use more efficient has major impact beyond ensuring adequate water supply.
• Excessive withdrawals from aquifers alter stream flows, cause saltwater and dirty runoff water to intrude into freshwater aquifers and affect water quality in other ways. (4)
• Water efficiency improves water quality because it reduces water contamination caused by excessive water withdrawals and sewage system failures. (5)
• More efficient water use also decreases the strain on existing supply sources, and reduces the need to build energy-intensive water capture and transport infrastructure. According to the US EPA, letting your faucet run for five minutes uses about as much energy as letting a 60-watt light bulb run for 14 hours. (6)
Defined: Water Efficiency
Water efficiency, generally speaking, means providing the same level of services, but with less water. (Please note that Imagine H2O will use a specific definition of water efficiency for the prize competition which will be defined in the prize rules and eligibility requirements.) Water efficiency gains can come from more intelligent supply or more intelligent use, and results in allowing water users to do the same (or more), with less water. For example, a water efficient washing machine uses less water, but cleans clothes just as well as another washing machine.
Examples of water efficiency innovations are drip irrigation and low-flow showerheads.
Drip irrigation allows to minimize the use of water and fertilizer by allowing water to drip onto the soil through a network of valves, pipes, and emitters.
Low-flow showerheads provide a quality shower with good water pressure while reducing water consumption.
Opportunities: Improving Water Efficiency with Business Solutions
Water efficiency opportunities exist throughout agricultural, commercial, industrial, and residential water use. Worldwide 70% of water use is for agriculture, 22% industrial and 8% residential / municipal.
Agriculture
Agriculture is the primary user of water with 70% of the worldwide consumption. The UN expects a 20% increase in land allocated to farming by 2030, with a further 14% increase in water demand. (7)
80% of irrigation worldwide occurs through flooding methods that are significantly less efficient than sprinkler and drip irrigation methods. By replacing flood irrigation with spray and drip irrigation systems, water requirements in the agriculture sector could be reduced more than 50%. (8)
The market for irrigation systems is estimated to be over $9 Billion (8). Drip irrigation can reduce equipment cost, improve lifetime, and reduce maintenance requirements.
Wireless sensor networks can be applied to reduce water consumption in agriculture. Sensors measure parameters like soil moisture, temperature, humidity, which are transmitted over a low-power wireless network to a controller that defines irrigation schedules minimizing water consumption. An increasing number of wireless sensor networks are being deployed especially in vineyards.
Industrial
Water is used for fabrication, processing, washing, cooling, transporting, and production in industrial facilities such as electric power, nuclear, coal-fired, chemical plants. Semiconductors require very pure water to treat semiconductor wafers during manufacturing, while pharmaceuticals require water for injection, sterile water, and wastewater treatment.
Industrial water treatment is a $95 billion global market (7). In particular, techniques for water reuse and recycling have great potential to improve water efficiency in industrial use. Reused water is reclaimed water that is treated using advanced water treatment techniques, such as filtration, distillation, and reverse osmosis.
Municipal
Municipal use of water includes water flows delivered to residences and businesses through public distribution networks. 30% of home water use is due to flushing toilets and bathing. Implementation of fixtures and other appliances could decrease water use by more than 50%8.
Water efficiency in municipal use can be significantly increased by techniques for water reuse and reprocessing and by an improved water distribution infrastructure.
Current water treatment and distribution systems are largely inefficient. In the U.S. 18% of the total water treated is lost during distribution due to leaking pipes, while in some developing countries water leakage exceeds 50%8.. This situation presents great opportunities for innovative solutions that allow municipalities to operate the distribution infrastructure at lower costs than conventional installation and replacement. Examples are the trenchless pipe laying technology, and pipe rehabilitation technology involving the insertion and inflation of a plastic tube within old pipe. Furthermore, water efficiency can be improved through new approaches to planning and management of the water distribution network. For example, utility companies are moving towards more automated monitoring systems based on wireless water meters.
Monitoring and metering equipment ($4 billion market8) is increasingly used to meter water entering houses and commercial buildings, measure flow through pipes, monitor infrastructure integrity, e.g. using distributed sensors or via robotic inspection, and monitor water quality parameters. Metering can dramatically improve water efficiency by tying pricing to use, spotting leaks, and even demand-response technologies.
Residential equipment ($1 billion market8) includes products that can treat water just before use or as it enters the entire home. This includes for example devices such as pitchers with carbon filters that remove impurities from water or filters attached directly to faucets. Most point-of-entry or under-the-sink water purification devices user reverse osmosis, which generally wastes approximately 90% of incoming water. Improvements in reverse osmosis, or alternatives to it, offer possibilities for increased water efficiency.
Energy
There is a strong connection between water and energy. Technologies for conventional energy generation operate using large amounts of water. For example, large quantities of water are pumped to maintain reservoir pressure underneath depleting oil wells, making the fraction of water extracted as a fraction of well output exceed 90% for many overdriven oilfields. The use of water in the Energy industry is second only to Agriculture.
At the same time, huge amounts of energy are needed for treatment and distribution of water. For example, the energy required for desalination of seawater using reverse osmosis (RO) can account for 40% of the operating costs.
Hence, energy consumption negatively impacts price and availability of water, and vice versa.
First, more efficient water use means conserving energy. There are great opportunities for technologies that will reduce energy use in water treatment. These technologies will involve capturing waste energy throughout the treatment process. Some examples of energy-recovery technologies for water desalination:
• Energy recovery devices. They are quickly becoming essential to desalination operations because allow for significant reduction of energy consumption and waste.
• Microbial fuel cells that feed off wastewater, which have the ability to generate energy from water that was once simply “flushed down the drain.”
• Cogeneration plants co-located with wastewater treatment facilities. Still at development phase in universities and start-ups (see Figure 6.3.1)
Second, there are opportunities in technologies that will reduce water use in energy generation. For example:
• Increase the use of impaired waters for cooling and process requirements (http://www.unm.edu/~cstp/Reports/H2O_Session_5/5-3_WilsonX.pdf)
• Increase geothermal energy production through reinjection of recycled water into the geothermal resources (http://www.prnewswire.com/cgi-bin/stories.pl?ACCT=104&STORY=/www/story/08-15-2007/0004646167&EDATE=)
Landscaping
There are periods of the year, especially in hot, dry climates, when the amount of water used outdoors by a household exceeds the amount used for all other purposes during the rest of the year. Most of this seasonal increase is due to gardening and lawn care: it is estimated that the typical suburban lawn consumes 10,000 gallons above and beyond rainwater each year. Even though many people still do not believe it, it is possible and easy to realize beautiful landscapes that actually save water, prevent pollution, and protect the environment.
Water efficient landscaping requires landscapers to:
- Group plants according to their water needs
- Use native and low-water-use plants
- Limit turf areas to those needed for practical uses
- Use efficient irrigation systems
- Schedule irrigation wisely
- Make sure soil is healthy
- Remember to mulch
- Provide regular maintenance
The problem with common watering practices is that a large portion of the water applied is not absorbed by the plants. It is lost through evaporation, runoff, or being pushed beyond the root zone because it is applied too quickly or in excess of the plants’ needs. The aim of efficient irrigation is to reduce these losses by applying only as much water as is needed to keep your plants healthy.
Drip-type irrigation systems are considered the most efficient of the automated irrigation methods because they deliver water directly to the plants’ roots. Other ways to make irrigation systems more efficient are to install system controllers such as rain sensors that prevent sprinkler systems from turning on during and immediately after rainfall, or soil moisture sensors that activate sprinklers only when soil moisture levels drop below pre-programmed levels. To further reduce your water consumption, consider using alternative sources of irrigation, such as gray water, reclaimed water, and collected rainwater.
The City of Santa Monica, California, was one of the first cities to require the use of xeriscaping (designing the landscape using water-conserving techniques) for all landscapes installed in new commercial and industrial development. Requirements included the use of low water plant materials, 20 percent maximum allowable turf area, low volume methods for irrigation (i.e. auto controllers, moisture sensors, and proper device placement, ongoing maintenance programs, and restricting the use of decorative water fountains and lakes).
1 United Nations: Water for Life, http://www.un.org/waterforlifedecade/factsheet.html
2 UN Report: "Water in a Changing World" http://www.china.org.cn/environment/report_review/2009-03/17/content_17454502.htm
3 De Villiers, Marq. “Water: The Fate of our Most Precious Resource” (p. 14)
4 US EPA: http://www.epa.gov/watersense/water/save/water_quality.htm
5 US EPA: http://www.epa.gov/watersense/water/save/env_benefits.htm
6 US EPA: http://www.epa.gov/watersense/water/save/env_benefits.htm
7 Goldman Sachs, The Essentials of Investing in the Water Sector
8 Lux research, Water Cultivation: The Path to Profit in Meeting Water Needs
RESOURCES
Water Efficiency Articles:
Inc. Magazine: Blue is the New Green
http://www.nanoh2o.com/newsDetail.php5?newsID=52
The Journal for Water Conservation Professionals: In Hard Times, Money for Water
http://www.waterefficiency.net/march-april-2009/in-hard-times.aspx
GreenBiz: The State of Green Business 2009: Water Becomes the New Carbon
http://greenbiz.com/feature/2009/02/03/green-business-2009-water-the-new-carbon
GreenBiz: Water Efficiency is Key to Saving Energy
http://www.greenbiz.com/news/2009/02/27/water-efficiency-key-energy-savings
Good Magazine: How to reduce your water footprint
http://awesome.goodmagazine.com/transparency/web/trans0309walkthisway.html
Water Efficiency Informational Links:
EPA Water Sense Website
http://www.epa.gov/watersense/index.htm
Alliance for Water Efficiency Nonprofit
http://www.allianceforwaterefficiency.org/
WaterEC: Ther International Water Efficiency Conference
http://www.waterec.net/wec.html
PG&E Pacific Energy Center Water Efficiency Showcase:
http://www.pge.com/pec/water/
U.S. Department of Energy: Federal Energy Management Program, Water Efficiency
http://www1.eere.energy.gov/femp/water/
Wikipedia: Water Efficiency
http://en.wikipedia.org/wiki/Water_efficiency
Water Education Foundation
http://www.watereducation.org/
Water Reuse Foundation
http://www.watereuse.org/
Garrison Dam, Up. MO River, ND
Photo Courtesy of Robert Dawson
Follow us
Become a fan
Flickr
LinkedIn