- Efficient energy use
:"Energy efficiency" redirects here. For energy efficiency as a ratio in physics, see
Energy conversion efficiency."Efficient energy use, sometimes simply called energy efficiency, is using less energy to provide the same level of energy service. An example would be insulating a home to use less heating and cooling energy to achieve the same temperature. Another example would be installing fluorescent lightsand/or skylights instead of incandescent lights to attain the same level of illumination. Efficient energy use is achieved primarily by means of a more efficient technology or process rather than by changes in individual behaviour. [Diesendorf, Mark (2007). " Greenhouse Solutions with Sustainable Energy", UNSW Press, p. 86.] Energy efficient buildings, industrial processes and transportation could reduce the world's energy needs in 2050 by one third, and be crucial in controlling global emissions of greenhouse gases, according to the International Energy Agency. [ [http://www.scidev.net/News/index.cfm?fuseaction=readNews&itemid=2929&language=1 Invest in clean technology says IEA report] ]
Energy efficiency and
renewable energyare said to be the “twin pillars” of sustainable energy policy. [ [http://aceee.org/store/proddetail.cfm?CFID=2957330&CFTOKEN=50269931&ItemID=432&CategoryID=7 The Twin Pillars of Sustainable Energy: Synergies between Energy Efficiency and Renewable Energy Technology and Policy] ]
Making homes, vehicles, and businesses more energy efficient is seen as a largely untapped solution to addressing
global warming, energy security, and fossil fuel depletion. Many of these ideas have been discussed for years, since the 1973 oil crisisbrought energy issues to the forefront. In the late 1970s, physicist Amory Lovinspopularized the notion of a "soft path" on energy, with a strong focus on energy efficiency. Among other things, Lovins popularized the notion of negawatts-- the idea of meeting energy needs by increasing efficiency instead of increasing energy production.
Energy efficiency has proved to be a cost-effective strategy for building economies without necessarily growing
energy consumption, as environmental business strategist Joel Makowerhas noted. For example, the state of Californiabegan implementing energy-efficiency measures in the mid-1970s, including building code and appliance standards with strict efficiency requirements. During the following years, California's energy consumption has remained approximately flat on a per capita basis while national U.S. consumption doubled. As part of its strategy, California implemented a three-step plan for new energy resources that puts energy efficiency first, renewable electricity supplies second, and new fossil-fired power plants last.
Still, efficiency often has taken a secondary position to new power generation as a solution to
global warmingin creating national energy policy. Some companies also have been reluctant to engage in efficiency measures, despite the often favorable returns on investments that can result. Lovins' Rocky Mountain Institutepoints out that in industrial settings, "there are abundant opportunities to save 70% to 90% of the energy and cost for lighting, fan, and pump systems; 50% for electric motors; and 60% in areas such as heating, cooling, office equipment, and appliances." In general, up to 75% of the electricity used in the U.S. today could be saved with efficiency measures that cost less than the electricity itself.
Other studies have emphasized this. A report published in 2006 by the McKinsey Global Institute, asserted that "there are sufficient economically viable opportunities for energy-productivity improvements that could keep global energy-demand growth at less than 1 percent per annum" -- less than half of the 2.2 percent average growth anticipated through 2020 in a business-as-usual scenario. Energy productivity -- which measures the output and quality of goods and services per unit of energy input -- can come from either reducing the amount of energy required to produce something, or from increasing the quantity or quality of goods and services from the same amount of energy.
Vienna Climate Change Talks 2007Report, under the auspices of the United Nations Framework Convention on Climate Change(UNFCCC), clearly shows "that energy efficiency can achieve real emission reductions at low cost" [ [http://unfccc.int/files/press/news_room/press_releases_and_advisories/application/pdf/20070831_vienna_closing_press_release.pdf Microsoft Word - 20070831_vienna_closing_press_release.doc ] ]
The average American household consumes about 10,000 kwh of electricity every year. Each kwh that is used equals two pounds of carbon dioxide let into the atmosphere. [ [http://www.usagreen.org/homeEnergy.html] ]
Energy efficient appliances
Modern energy-efficient appliances, such as
refrigerators, freezers, ovens, stoves, dishwashers, and clothes washers and dryers, use significantly less energy than older appliances. Current energy efficient refrigerators, for example, use 40 percent less energy than conventional models did in 2001. Modern power management systems also reduce energy usage by idle appliances by turning them off or putting them into a low-energy mode after a certain time. Many countries identify energy-efficient appliances using an Energy Starlabel. [http://www.eesi.org/publications/Fact%20Sheets/EC_Fact_Sheets/EE_Buildings.pdf Energy-Efficient Buildings: Using whole building design to reduce energy consumption in homes and offices] ]
Energy efficient building design
A building’s location and surroundings play a key role in regulating its temperature and illumination. For example, trees, landscaping, and hills can provide shade and block wind. In cooler climates, designing buildings with an east-west orientation to increase the number of south-facing windows minimizes energy use, by maximizing
passive solar heating. Tight building design, including energy-efficient windows, well-sealed doors, and additional thermal insulation of walls, basement slabs, and foundations can reduce heat loss by 25 to 50 percent.
Dark roofs may become up to 70°F hotter than the most reflective white surfaces, and they transmit some of this additional heat inside the building. US Studies have shown that lightly colored roofs use 40 percent less energy for cooling than buildings with darker roofs. White roof systems save more energy in sunnier climates. Advanced electronic heating and cooling systems can moderate energy consumption and improve the comfort of people in the building.
Proper placement of windows and skylights and use of architectural features that reflect light into a building, can reduce the need for artificial lighting.
Compact fluorescent lightsuse two-thirds less energy and last 6 to 10 times longer than incandescent light bulbs. Newer florescent lights produce a natural light, and in most applications they are cost effective, despite their higher initial cost. Increased use of natural and task lighting have been shown to increase productivity in schools and offices.
Energy efficiency for industry
In industry, when electricity is generated, the heat which is produced as a by-product can be captured and used for process steam, heating or other industrial purposes. Conventional electricity generation is about 30 percent efficient, whereas combined heat and power (also called cogeneration) converts up to 90 percent of the fuel into usable energy. [http://www.eesi.org/publications/Fact%20Sheets/EC_Fact_Sheets/EE_Industry.pdf Industrial Energy Efficiency: Using new technologies to reduce energy use in industry and manufacturing] ]
Advanced boilers and furnaces can operate at higher temperatures while burning less fuel. These technologies are more efficient and produce fewer pollutants.
Over 45 percent of the fuel used by US manufacturers is burnt to make steam. The typical industrial facility can reduce this energy usage 20 percent (according to the
US Department of Energy) byinsulating steam and condensate return lines, stopping steam leakage, and maintaining steam traps. Electric motorsusually run on a constant flow of energy, but an adjustable speed drive can vary the motor’s energy output to match the load. This achieves energy savings ranging from 3 to 60 percent, depending on how the motor is used. Motor coils made of superconductingmaterials can also reduce energy losses.
Many industries use
compressed airfor sand blasting, painting, or other tools. According to the US Department of Energy, optimizing compressed air systems by installing variable speed drives, along with preventive maintenance to detect and fix air leaks, can improve energy efficiency 20 to 50 percent.
Energy efficient vehicles
aerodynamicsto minimize drag can increase vehicle fuel efficiency.
vehicle weightcan significantly also improve fuel economy.
More advanced tires, with decreased tire to road friction and rolling resistance, can save gasoline. Fuel economy can be improved over three percent by keeping tires inflated to the correct pressure. Replacing a clogged air filter can improve a cars fuel consumption by as much as 10 percent. [http://www.eesi.org/publications/Fact%20Sheets/EC_Fact_Sheets/EE_Autos.pdf Automotive Efficiency: Using technology to reduce energy use in passenger vehicles and light trucks] ]
Fuel efficient vehicles may reach twice the fuel efficiency of the average automobile. Cutting-edge designs, such as the diesel Mercedes-Benz Bionicconcept vehicle have achieved a fuel efficiency as high as mpg|84, four times the current conventional automotive average.. Also alternative propulsion vehicles that do not use or use less fossil fuels can use energy in a efficient way.
Energy conservationis broader than energy efficiency in that it encompasses using less energy to achieve a lesser energy service, for example through behavioural change, as well as encompassing energy efficiency. Examples of conservation without efficiency improvements would be heating a room less in winter, driving less, or working in a less brightly lit room. As with other definitions, the boundary between efficient energy use and energy conservation can be fuzzy, but both are important in environmental and economic terms. This is especially the case when actions are directed at the saving of fossil fuels. [Diesendorf, Mark (2007). "Greenhouse Solutions with Sustainable Energy", UNSW Press, p. 87.]
Energy efficiency and
renewable energyare said to be the “twin pillars” of a sustainable energy policy. Both strategies must be developed concurrently in order to stabilize and reduce carbon dioxide emissions in our lifetimes. Efficient energy use is essential to slowing the energy demand growth so that rising clean energysupplies can make deep cuts in fossil fuel use. If energy use grows too rapidly, renewable energy development will chase a receding target. Likewise, unless clean energy supplies come online rapidly, slowing demand growth will only begin to reduce total carbon emissions; a reduction in the carbon content of energy sources is also needed. A sustainable energy economy thus requires major commitments to both efficiency and renewables. [ [http://aceee.org/store/proddetail.cfm?CFID=2957330&CFTOKEN=50269931&ItemID=432&CategoryID=7 The Twin Pillars of Sustainable Energy: Synergies between Energy Efficiency and Renewable Energy Technology and Policy] (American Council for an Energy-Efficient Economy)]
If the demand for energy services remains constant, improving energy efficiency will reduce energy consumption and carbon emissions. However, many efficiency improvements do not reduce energy consumption by the amount predicted by simple engineering models. This is because they make energy services cheaper, and so consumption of those services increase. For example, since fuel efficient vehicles make travel cheaper, consumers may choose to drive further and/or faster, thereby offsetting some of the potential energy savings. This is an example of the direct "rebound effect". [http://www.ukerc.ac.uk/Downloads/PDF/07/0710ReboundEffect/0710ReboundEffectReport.pdf The Rebound Effect: an assessment of the evidence for economy-wide energy savings from improved energy efficiency] pp. v-vi.]
Estimates of the size of the rebound effect range from roughly 5% to 40%.Harvard reference | Surname=Greening| Given=Lorna| Title=Energy efficiency and consumption—the rebound effect—a survey.| coauthors = David L. Greene,Carmen Difiglio| Journal=Energy Policy | Volume=28 | Year=2000 | Page=389-401 ] [cite web|url = http://repositories.cdlib.org/ucei/policy/EPE-014 | title = The Effect of Improved Fuel Economy on Vehicle Miles Traveled: Estimating the Rebound Effect Using U.S. State Data, 1966-2001 | authors = Kenneth A. Small and Kurt Van Dender | Date = September 21, 2005 | publisher= University of California Energy Institute: Policy & Economics | accessdate=2007-11-23] [cite web |url=http://www.ncseonline.org/nle/crsreports/energy/eng-80.cfm?&CFID=11262148&CFTOKEN=7028302 | title = Energy Efficiency and the Rebound Effect: Does Increasing Efficiency Decrease Demand? | accessdate=2007-11-21] Rebound effects are smaller in mature markets where demand is saturated. The rebound effect is likely to be less than 30% at the household level and may be closer to 10% for transport. A rebound effect of 30% implies that improvements in energy efficiency should achieve 70% of the reduction in energy consumption projected using engineering models.
Since more efficient (and hence cheaper) energy will also lead to faster economic growth, there are suspicions that improvements in energy efficiency may eventually lead to even faster resource use. This was postulated by economists in the 1980's and remains a controversial hypothesis. Ecological economists have suggested that any cost savings from efficiency gains be taxed away by the government in order to avoid this outcome. [Wackernagel, Mathis and William Rees, 1997, "Perpetual and structural barriers to investing in natural capital: economics from an ecological footprint perspective." "Ecological Economics", Vol.20 No.3 p3-24.]
Alliance to Save Energy
Banning of incandescent lightbulbs
Energy efficiency in British housing
Energy saving lamp
Performance per watt
High temperature insulation wool
Hybrid vehicleand plug-in hybrid vehicle
International Partnership for Energy Efficiency Cooperation
National Electrical Manufacturers Association
National Energy Action
One watt initiative
*Plug-in Hybrid Electric Vehicle
Organizations promoting energy efficiency
International Electrotechnical Commission
International Energy Agency(e.g. One watt initiative)
* [http://energyefficiency.org/eecentre/eecentre.nsf/3a68131a3269325f852569b80053e603/ce56aaf9489e4d5e852569b800734fd5?OpenDocument The Canadian Energy Efficiency Alliance]
Energy Star, from EPA
Climate savers computing initiative
Rocky Mountain Institute
* [http://www.aps.org/energyefficiencyreport/index.cfm APS Energy Efficiency Report on Viable Technology and R&D]
* [http://michaelbluejay.com/electricity Saving Electricity]
* [http://www.renewableenergyaccess.com/rea/news/reinsider/story?id=49238 Energy Efficiency in the Power Grid]
* [http://www.earth-policy.org/Updates/2007/Update66.htm Ban the bulb: Worldwide Shift from Incandescents to Compact Fluorescents Could Close 270 Coal-Fired Power Plants]
* [http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32006L0032:EN:HTML Directive 2006/32/EC of the European Parliament and of the Council of 5 April 2006 on energy end-use efficiency and energy services and repealing Council Directive 93/76/EEC] .
* [http://www.renewableenergyaccess.com/rea/news/story?id=49541 ASHRAE, DOE Partner to Promote Energy Efficiency and Renewable Energy]
* [http://www.energyefficient-power.com/EN/Energy/ A layman's introduction to energy efficiency]
* [http://www.cappershaw.com/content/view/16/32/ Conserving electrical energy in the home]
* [http://www.spartansaving.com Methods of Energy Conservation]
* [http://www.stinkfight.com/2007/10/21/saving-money-by-going-green/ Article on reading your power meter, and explaining how much money you save with newer appliances vs. old ones]
* [http://www.cleanedge.com/views/ Conservation and Efficiency Are Key to Our Energy Future]
* [http://ines-ur.ru/ Institute of Energy Saving - Russia, Ekaterinburg]
* [http://www.wupperinst.org/en/projects/topics_online/energy_efficiency/ Wuppertal Institute for Climate, Environment and Energy - Energy Efficiency] [http://www.batchelor-electrical.co.uk/news/energyefficientf.html Creating Energy Efficient Offices - Electrical Contractor Fit-out Article]
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