Water, energy and mitigation

Climate change will affect availability and use of both water and energy. Since these resources are linked, with energy needed to supply water and water used in generating energy, the effect of climate on energy and water use will be complex .

Boosting water and energy use efficency through investment in relavant technologies and infrastructure are critical pathways to achieving the Millennium Development Goals and reducing carbon emissions. Technology, innovation, a sense of shared responsibility and political will are factors that bring real solutions as we strive to keep pace with increasing needs from a growing population.

Core messages

Click here for IWAs core messages on the Water and Energy Nexus

Water and Energy Facts:

+ Global primary energy demand is projected to increase by just over 50% between now and 2030.

+ Freshwater withdrawals are predicted to increase by 50% by 2025 in developing countries, and 18% in developed countries.

Energy consumption, efficiencies and compensation need to be considered in ordered approach, namely:

1. Use Less

2. Produce less emissions (through clean technologies or through improved efficiency)

3. Offset or compensate emission

1. Use less - Energy & Water Efficiency

- Domestic:

• Use washing machines and dishwashers more efficiently: A few simple actions can cut your energy and water use -washing clothes at 30 degrees saves energy, and today's detergents wash just as well at low temperatures; run washing machines and dishwashers with full loads, as a half load uses more than half the energy and water of a full load; switching off and unplugging appliances at the wall when not in use will save the energy used by lights and displays cleaning filters regularly keeps appliances running efficiently.
  
  
• Flush less water down the toilet: Toilet flushing accounts for about a third of household water usage. You probably flush away as much water in a day as you drink in a whole month. There are easy ways to reduce this: install a water displacement device (or 'hippo') in the cistern of a higher flush toilet – these reduce the amount of water used for each flush, typically by one or two litres when buying a new toilet, choose a water-saving, low-flush or dual-flush version fit a variable flushing device to existing higher flush toilets - this will give you a choice of flush volumes to help save water throw cotton wool, sanitary products and other waste in the bin, not the toilet.
  
  
• Save water in the garden: A garden hose can use more water in an hour than a family of four uses in a day. Some simple ways of saving water in the garden include: using a watering can rather than a hose – this will make a huge difference to the amount of water you use in your garden; buying a water butt to collect rain water - you’ll save mains water and the energy used to treat it.
  
  
• Make use of greywater and rainwater: Any water that has been used in the home, except water from toilets, is called greywater. Shower, bath and washbasin water can be re-used in the garden. Guidelines for doing this include: only watering non-edible plants with greywater; making sure it is cool before you use it; avoiding pouring it straight on to foliage. You can also collect rainwater. The simplest method of doing this is using a water butt.

- Industry:

Industries like oil refineries, semiconductors manufactures, and facilities that process fruits, vegetables and meat require large amounts of water to provide us valuable social goods like gasoline, computers and food. Industry uses water for landscaping, cooling, and laundry, in kitchens and restrooms, and for over all processing needs, like fabricating, diluting, incorporating water into a product, and/or for sanitation needs within the facility.

According to EPA, by implementing a water efficiency program, industrial facilities can cut operating costs in a variety of ways. Saving water also means cutting costs for electric power, gas, chemicals and wastewater disposal. In addition, efficient water use can have major environmental, public health and economic benefits by helping to improve water quality, maintain aquatic ecosystems and protect drinking water resources.
EPA offers this list of measures as a starting point for industrial facilities interested in improving water efficiency.

+ General management practices Make a corporate commitment to water efficiency

• Designate a water efficiency coordinator.
• Develop a mission statement and a plan.
• Educate and involve employees in water efficiency efforts.
• Inform your chemical suppliers or service contractors (cooling tower, laundry, dishwasher, landscaping) that water efficiency is a priority.

+ Equipment changes: High-efficiency plumbing fixtures, appliances and other equipment yield substantial savings on water, sewer and energy bills:

• Install high-efficiency toilets, or retrofit water-saving devices on existing ones.
• Install aerators on faucets and showerheads.
• Install high-pressure, low-volume nozzles on spray washers.
• Install in-line strainers on all spray headers; inspect nozzles regularly for clogging.
• Replace high-volume hoses with high-pressure, low-volume cleaning systems.
• As equipment wears out, replace with water-saving models.
• Equip hoses with spring-loaded shutoff nozzles.

+ Operating and maintenance procedures: A small investment in these areas can yield big savings

• Detect and repair all leaks.
• Identify discharges that may be re-used, and implement re-use practices. Some discharges with potential for re-use are: final rinses from tank cleaning, keg washers, fermenters; bottle and can soak and rinse water; cooler flush water, filter backwash pasteurizer and sterilizer water; final rinses in wash cycles; boiler makeup; refrigeration equipment defrost; equipment cleaning; floor and gutter wash;
• Use fogging nozzles to cool products.
• Adjust overflows from recirculation systems by controlling the rate at which make-up water is added: install float-controlled valve on the make-up line, close filling line during operation, provide surge tanks for each system to avoid overflow.
• Turn off all flows during shutdowns. Use solenoid valves to stop the flow of water when production stops.
• Adjust flow in sprays and other lines to meet minimum requirements.

- Agriculture:

Efficent irrigation schmes can be used to save water, e.g., by reducing losses due to evaporation and run-off through drip irrigation.

- Utilities effuency programmes:

Significant water and energy efficiency gains can be achieved by minimizing water losses in water supply systems, due to not only wasting the water itself, but also the energy used to pump and distribute it. Energy can be recovered in water and wastewater transport and treatment system - heat, cooling and energy production. New cooling systems can be designed in power plants to have an optional trade-off between water and energy requirements and impacts (e.g., parallel condensing systems that combine wet and dry cooling systems (source -World Business Council for Sustainable Development)

2. Transfer to less greenhouse gas

Significant technical progress relevant to greenhouse gas emissions reduction has been made since 1995 and has been faster than anticipated. Advances are taking place in a wide range of technologies at different stages of development, e.g., the market introduction of wind turbines, the rapid elimination of industrial by-product gases such as N2O from adipic acid production and perfluorocarbons from aluminium production, efficient hybrid engine cars, the advancement of fuel cell technology, and the demonstration of underground carbon dioxide storage. Technological options for emissions reduction include improved efficiency of end use devices and energy conversion technologies, shift to low-carbon and renewable biomass fuels, zero-emissions technologies, improved energy management, reduction of industrial by-product and process gas emissions, and carbon removal and storage.

- At least up to 2020, energy supply and conversion will remain dominated by relatively cheap and abundant fossil fuels. Natural gas, where transmission is economically feasible, will play an important role in emission reduction together with conversion efficiency improvement, and greater use of combined cycle and/or co-generation plants.

- Low-carbon energy supply systems can make an important contribution through biomass from forestry and agricultural by-products, municipal and industrial waste to energy, dedicated biomass plantations, where suitable land and water are available, landfill methane, wind energy and hydropower, and through the use and lifetime extension of nuclear power plants. After 2010, emissions from fossil and/or biomass-fueled power plants could be reduced substantially through pre- or post-combustion carbon removal and storage. Environmental, safety, reliability and proliferation concerns may constrain the use of some of these technologies .

- In agriculture, methane and nitrous oxide emissions can be reduced, such as those from livestock enteric fermentation, rice paddies, nitrogen fertilizer use and animal wastes.

- Depending on application, emissions of fluorinated gases can be minimized through process changes, improved recovery, recycling and containment, or avoided through the use of alternative compounds and technologies.

- Renewable energy: Renewable energy use can be encouraged for water treatment processes, as well as wastewater plants.

3. Compensate

Although there have many projects and action plans been implemented at global, regional and national levels, significant effects of climate change will still occur. Examples include changes in sea level, precipitation patterns, geological features such as permafrost, and harm to sensitive ecosystems such as coral reefs.

In order to avoid difficult valuation issues, problems of proving causation, and long time lags, damages would be based on the cost of climate change adaptation, such as the expenses of preventing damage to or restoring infrastructure and ecosystem services.

Survey

A global energy-water-risk survey is going to be launched in late 2010, more information will be posted here shortly.