This article is about sustainable energy usen.. For the law of conservation of energy in physics., see Conservation of energy.
Energy conservation are efforts made to reduce the consumption of energy by using less of an energy service. This can be achieved either by using energy more efficiently (using less energy for a constant service) or by reducing the amount of services used (for example, by driving less). Energy conservation is a part of the concept of eco-sufficiency. Energy conservation reduces the need for energy services, and can result in increased environmental quality, national security, personal financial security and higher savings. It is at the top of the sustainable energy hierarchy. It also lowers energy costs by preventing future resource depletion.
Energy can be conserved by reducing wastage and losses, improving efficiency through technological upgradation and improved operation and maintenance.
Some countries employ energy or carbon taxes to motivate energy users to reduce their consumption. Carbon taxes can allow consumption to shift to nuclear power and other alternatives that carry a different set of environmental side effects and limitations. Meanwhile, taxes on all energy consumption stand to reduce energy use across the board, while reducing a broader array of environmental consequences arising from energy production. The State of California employs a tiered energy tax whereby every consumer receives a baseline energy allowance that carries a low tax. As usage increases above that baseline, the tax is increasing drastically. Such programs aim to protect poorer households while creating a larger tax burden for high energy consumers. 7D
One of the primary ways to improve energy conservation in buildings is to use an energy audit. An energy audit is an inspection and analysis of energy use and flows for energy conservation in a building, process or system to reduce the amount of energy input into the system without negatively affecting the output(s). This is normally accomplished by trained professionals and can be part of some of the national programs discussed above. In addition, recent development of smartphone apps enable homeowners to complete relatively sophisticated energy audits themselves.
Building technologies and smart meters can allow energy users, business and residential, to see graphically the impact their energy use can have in their workplace or homes. Advanced real-time energy metering is able to help people save energy by their actions.
In passive solar building design, windows, walls, and floors are made to collect, store, and distribute solar energy in the form of heat in the winter and reject solar heat in the summer. This is called passive solar design or climatic design because, unlike active solar heating systems, it doesn't involve the use of mechanical and electrical devices.
The key to designing a passive solar building is to best take advantage of the local climate. Elements to be considered include window placement and glazing type, thermal insulation, thermal mass, and shading. Passive solar design techniques can be applied most easily to new buildings, but existing buildings can be retrofitted.
In the United States, suburban infrastructure evolved during an age of relatively easy access to fossil fuels, which has led to transportation-dependent systems of living. Zoning reforms that allow greater urban density as well as designs for walking and bicycling can greatly reduce energy consumed for transportation. The use of telecommuting by major corporations is a significant opportunity to conserve energy, as many Americans now work in service jobs that enable them to work from home instead of commuting to work each day.
Consumers are often poorly informed of the savings of energy efficient products. A prominent example of this is the energy savings that can be made by replacing an incandescent light bulb with a more modern alternative. When purchasing light bulbs, many consumers opt for cheap incandescent bulbs, failing to take into account their higher energy costs and lower lifespans when compared to modern compact fluorescent and LED bulbs. Although these energy-efficient alternatives have a higher upfront cost, their long lifespan and low energy use can save consumers a considerable amount of money. The price of LEDs has also been steadily decreasing in the past five years, due to improvement of the semiconductor technology. Many LED bulbs on the market qualify for utility rebates that further reduce the price of purchase to the consumer. Estimates by the U.S. Department of Energy state that widespread adoption of LED lighting over the next 20 years could result in about $265 billion worth of savings in United States energy costs.
The research one must put into conserving energy is often too time consuming and costly for the average consumer, when there are cheaper products and technology available using today's fossil fuels. Some governments and NGOs are attempting to reduce this complexity with ecolabels that make differences in energy efficiency easy to research while shopping.
To provide the kind of information and support people need to invest money, time and effort in energy conservation, it is important to understand and link to people's topical concerns. For instance, some retailers argue that bright lighting stimulates purchasing. However, health studies have demonstrated that headache, stress, blood pressure, fatigue and worker error all generally increase with the common over-illumination present in many workplace and retail settings. It has been shown that natural daylighting increases productivity levels of workers, while reducing energy consumption
In warm climates where air conditioning is used, any household device that gives off heat will result in a larger load on the cooling system. Items such as a stove, dish washer, clothes dryer, hot water and incandescent lighting all add heat to the home. Low power or insulated versions of these devices give off less heat for the air conditioning to remove. The air conditioning system can also improve in efficiency by using a heat sink that is cooler than the standard air heat exchanger such as geothermal or water.
In cold climates heating air and water is a major demand on household energy use. By investing in newer technologies in the home, significant energy reductions are possible. Heat pumps are a more efficient alternative to using electrical resistance heaters for warming air or water. A variety of efficient clothes dryers are available, and the classic clothes line requires no energy, only time. Natural gas condensing boilers and hot air furnaces increase efficiency over standard hot flue models. New construction implementing heat exchangers can capture heat from waste water or exhaust air in bathrooms, laundry and kitchens.
In both warm and cold climate extremes, airtight thermal insulated construction will largely determine the efficiency of a home. Insulation is added to minimize the flow of heat to or from the home, but can be labor-intensive to retrofit to an existing home.
Energy conservation by the countries
Despite the vital role energy efficiency is envisaged to play in cost-effectively cutting energy demand, only a small part of its economic potential is exploited in the Asia. Governments have implemented a range of subsidies such as cash grants, cheap credit, tax exemptions, and co-financing with public-sector funds to encourage a range of energy-efficiency initiatives across several sectors. Governments in the Asia-Pacific region have implemented a range of information provision and labeling programs for buildings, appliances, and the transportation and industrial sectors. Information programs can simply provide data, such as fuel-economy labels, or actively seek to encourage behavioral changes, such as Japan's Cool Biz campaign that encourages setting air conditioners at 28-degrees Celsius and allowing employees to dress casually in the summer.
At the end of 2006, the European Union (EU) pledged to cut its annual consumption of primary energy by 20% by 2020. The 'European Union Energy Efficiency Action Plan' is long-awaited. Directive 2012/27/EU is on energy efficiency.
As part of the EU's SAVE Programme, aimed at promoting energy efficiency and encouraging energy-saving behaviour, the Boiler Efficiency Directive specifies minimum levels of efficiency for boilers fired with liquid or gaseous fuels.
Petroleum Conservation Research Association (PCRA) is an Indian government body created in 1977 and engaged in promoting energy efficiency and conservation in every walk of life. In the recent past PCRA has done mass media campaigns in television, radio & print media. An impact assessment survey by a third party revealed that due to these mega campaigns by PCRA, overall awareness level have gone up leading to saving of fossil fuels worth crores of rupees(Indian currency) besides reducing pollution.
Bureau of Energy Efficiency is an Indian governmental organization created in 2001 responsible for promoting energy efficiency and conservation.
Since the 1973 oil crisis, energy conservation has been an issue in Japan. All oil based fuel is imported, so indigenous sustainable energy is being developed.
The Energy Conservation Center promotes energy efficiency in every aspect of Japan. Public entities are implementing the efficient use of energy for industries and research. It includes projects such as the Top Runner Program. In this project, new appliances are regularly tested on efficiency, and the most efficient ones are made the standard.
In Lebanon and since 2002 The Lebanese Center for Energy Conservation (LCEC) has been promoting the development of efficient and rational uses of energy and the use of renewable energy at the consumer level. It was created as a project financed by the International Environment Facility (GEF) and the Ministry of Energy Water (MEW) under the management of the United Nations Development Programme (UNDP) and gradually established itself as an independent technical national center although it continues to be supported by the United Nations Development Programme (UNDP) as indicated in the Memorandum of Understanding (MoU) signed between MEW and UNDP on 18 June 2007.
Until recently, Nepal has been focusing on the exploitation of its huge water resources to produce hydro power. Demand side management and energy conservation was not in the focus of government action. In 2009, bilateral Development Cooperation between Nepal and the Federal Republic of Germany, has agreed upon the joint implementation of "Nepal Energy Efficiency Programme". The lead executing agencies for the implementation are the Water and Energy Commission Secretariat (WECS). The aim of the programme is the promotion of energy efficiency in policy making, in rural and urban households as well as in the industry. Due to the lack of a government organization that promotes energy efficiency in the country, the Federation of Nepalese Chambers of Commerce and Industry (FNCCI) has established the Energy Efficiency Centre under his roof to promote energy conservation in the private sector. The Energy Efficiency Centre is a non-profit initiative that is offering energy auditing services to the industries. The Centre is also supported by Nepal Energy Efficiency Programme of Deutsche Gesellschaft für Internationale Zusammenarbeit. A study conducted in 2012 found out that Nepalese industries could save 160,000 Megawatt hours of electricity and 8,000 Terajoule of thermal energy (like diesel, furnace oil and coal) every year. These savings are equivalent to annual energy cost cut of up to 6.4 Billion Nepalese Rupees. As a result of Nepal Economic Forum 2014, an economic reform agenda in the priority sectors was declared focusing on energy conservation among others. In the energy reform agenda the government of Nepal gave the commitment to introduce incentive packages in the budget of the fiscal year 2015/16 for industries that practices energy efficiency or use efficient technologies (incl. cogeneration).
In Nigeria, the Lagos State Government is encouraging Lagosians to imbibe an energy conservation culture. The Lagos State Electricity Board (LSEB) is spearheading an initiative tagged "Conserve Energy, Save Money" under the Ministry of Energy and Mineral Resources. The initiative is designed to sensitize Lagosians around the theme of energy conservation by connecting with and influencing their behavior through do-it-yourself tips and exciting interaction with prominent personalities. In September 2013, Governor Babatunde Raji Fashola of Lagos State and rapper Jude 'MI' Abaga (campaign ambassador)() participated in the Governor's first ever Google+ Hangout on the topic of energy conservation.
In addition to the hangout, during the month of October (the official energy conservation month in the state), LSEB hosted experience centers in malls around Lagos State where members of the public were encouraged to calculate their current household energy consumption and discover ways to save money using the 1st-ever consumer-focused energy app in sub-saharan Africa. To get Lagosians started on energy conservation, Solar Lamps and Phillips Energy-saving bulbs were also given out at each experience center. Pictures from the experience centers: (part of Lagos state government energy initiatives)
Sri Lanka currently consumes fossil fuels, hydro power, wind power, solar power and dendro power for their day to day power generation. The Sri Lanka Sustainable Energy Authority is playing a major role regarding energy management and energy conservation. Today, most of the industries are requested to reduce their energy consumption by using renewable energy sources and optimizing their energy usage.
Turkey aims to decrease by at least 20% the amount of energy consumed per GDP of Turkey by the year 2023 (energy intensity).
Main article: Energy conservation in the United States
The United States is currently the second largest single consumer of energy, following China. The U.S. Department of Energy categorizes national energy use in four broad sectors: transportation, residential, commercial, and industrial.
Energy usage in transportation and residential sectors, about half of U.S. energy consumption, is largely controlled by individual consumers. Commercial and industrial energy expenditures are determined by businesses entities and other facility managers. National energy policy has a significant effect on energy usage across all four sectors.
Another aspect of energy conversation is using Leadership in Energy and Environmental Design. (LEED) This program is not mandatory, it is voluntary. This program has many categories, Energy and Atmosphere Prerequisite, applies to energy conservation. This section focuses on energy performance, renewable energy, energy performance, and many more. This program is designed to promote energy efficiency and be a green building, which is part of conservation. As mention above “energy conservation are efforts made to reduce the consumption of energy.”
U.S. Green Building Council (2013). LEED Reference Guide for Building Design and Construction (v4 ed.). U.S. Green Building Council. p. 318-466. ISBN 1932444181. [by tagore sai 123]
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Early humans first made controlled use of an external, nonanimal energy source when they discovered how to use fire. Burning dried plant matter (primarily wood) and animal waste, they employed the energy from this biomass for heating and cooking. The generation of mechanical energy to supplant human or animal power came very much later—only about 2,000 years ago—with the development of simple devices to harness the energy of flowing water and of wind.
The earliest machines were waterwheels, first used for grinding grain. They were subsequently adopted to drive sawmills and pumps, to provide the bellows action for furnaces and forges, to drive tilt hammers or trip-hammers for forging iron, and to provide direct mechanical power for textile mills. Until the development of steam power during the Industrial Revolution at the end of the 18th century, waterwheels were the primary means of mechanical power production, rivaled only occasionally by windmills. Thus, many industrial towns, especially in early America, sprang up at locations where water flow could be assured all year.
The oldest reference to a water mill dates to about 85 bce, appearing in a poem by an early Greek writer celebrating the liberation from toil of the young women who operated the querns (primitive hand mills) for grinding corn. According to the Greek geographer Strabo, King Mithradates VI of Pontus in Asia used a hydraulic machine, presumably a water mill, by about 65 bce.
Early vertical-shaft water mills drove querns where the wheel, containing radial vanes or paddles and rotating in a horizontal plane, could be lowered into the stream. The vertical shaft was connected through a hole in the stationary grindstone to the upper, or rotating, stone. The device spread rapidly from Greece to other parts of the world, because it was easy to build and maintain and could operate in any fast-flowing stream. It was known in China by the 1st century ce, was used throughout Europe by the end of the 3rd century, and had reached Japan by the year 610. Users learned early that performance could be improved with a millrace and a chute that would direct the water to one side of the wheel.
A horizontal-shaft water mill was first described by the Roman architect and engineer Vitruvius about 27 bce. It consisted of an undershot waterwheel in which water enters below the centre of the wheel and is guided by a millrace and chute. The waterwheel was coupled with a right-angle gear drive to a vertical-shaft grinding wheel. This type of mill became popular throughout the Roman Empire, notably in Gaul, after the advent of Christianity led to the freeing of slaves and the resultant need for an alternative source of power. Early large waterwheels, which measured about 1.8 metres (6 feet) in diameter, are estimated to have produced about three horsepower, the largest amount of power produced by any machine of the time. The Roman mills were adopted throughout much of medieval Europe, and waterwheels of increasing size, made almost entirely of wood, were built until the 18th century.
In addition to flowing stream water, ocean tides were used to drive waterwheels. Tidal water was allowed to flow into large millponds, controlled initially through lock-type gates and later through flap valves. Once the tide ebbed, water was let out through sluice gates and directed onto the wheel. Sometimes the tidal flow was assisted by building a dam across the estuary of a small river. Although limited in operation to ebbing tide conditions, tidal mills were widely used by the 12th century. The earliest recorded reference to tidal mills is found in the Domesday Book (1086), which also records more than 5,000 water mills in England south of the Severn and Trent rivers. (Tidal mills also were built along the Atlantic coast in Europe and centuries later on the eastern seaboard of the United States and in Guyana, where they powered sugarcane-crushing mills.)
The first analysis of the performance of waterwheels was published in 1759 by John Smeaton, an English engineer. Smeaton built a test apparatus with a small wheel (its diameter was only 0.61 metre) to measure the effects of water velocity, as well as head and wheel speed. He found that the maximum efficiency (work produced divided by potential energy in the water) he could obtain was 22 percent for an undershot wheel and 63 percent for an overshot wheel (i.e., one in which water enters the wheel above its centre). In 1776 Smeaton became the first to use a cast-iron wheel, and two years later he introduced cast-iron gearing, thereby bringing to an end the all-wood construction that had prevailed since Roman times. Based on his model tests, Smeaton built an undershot wheel for the London Bridge waterworks that measured 4.6 metres wide and that had a diameter of 9.75 metres. The results of Smeaton’s experimental work came to be widely used throughout Europe for designing new wheels.
During the mid-1700s a reaction waterwheel for generating small amounts of power became popular in the rural areas of England. In this type of device, commonly known as a Barker’s mill, water flowed into a rotating vertical tube before being discharged through nozzles at the end of two horizontal arms. These directed the water out tangentially, much in the way that a modern rotary lawn sprinkler does. A rope or belt wound around the vertical tube provided the power takeoff.
Early in the 19th century Jean-Victor Poncelet, a French mathematician and engineer, designed curved paddles for undershot wheels to allow the water to enter smoothly. His design was based on the idea that water would run up the surface of the curved vanes, come to rest at the inner diameter, and then fall away with practically no velocity. This design increased the efficiency of undershot wheels to 65 percent. At about the same time, William Fairbairn, a Scottish engineer, showed that breast wheels (i.e., those in which water enters at the 10- or two-o’clock position) were more efficient than overshot wheels and less vulnerable to flood damage. He used curved buckets and provided a close-fitting masonry wall to keep the water from flowing out sideways. In 1828 Fairbairn introduced ventilated buckets in which gaps at the bottom of each bucket allowed trapped air to escape. Other improvements included a governor to control the sluice gates and spur gearing for the power takeoff.
During the course of the 19th century, waterwheels were slowly supplanted by water turbines. Water turbines were more efficient; design improvements eventually made it possible to regulate the speed of the turbines and to run them fast enough to drive electric generators. This fact notwithstanding, waterwheels gave way slowly, and it was not until the early 20th century that they became largely obsolescent. Yet even today some waterwheels still survive; in the early 1970s there were more than 1,000 grain mills in use in Portugal alone. Equipped with submerged bearings, these modern waterwheels certainly are more sophisticated than their predecessors, though they bear a remarkable likeness to them.
Windmills, like waterwheels, were among the original prime movers that replaced animal muscle as a source of power. They were used for centuries in various parts of the world, converting the energy of the wind into mechanical energy for grinding grain, pumping water, and draining lowland areas.
The first known wind device was described by Hero of Alexandria (c. 1st century ce). It was modeled on a water-driven paddle wheel and was used to drive a piston pump that forced air through a wind organ to produce sound. The earliest known references to wind-driven grain mills, found in Arabic writings of the 9th century, refer to a Persian millwright of 644 ce, although windmills may actually have been used earlier. These mills, erected near what is now the Iran–Afghanistan border, had a vertical shaft with paddlelike sails radiating outward and were located in a building with diametrically opposed openings for the inlet and outlet of the wind. Each mill drove a single set of stones without gearing. The first mills were built with the millstones above the sails, patterned after the early waterwheels from which they were derived. Similar mills were known in China by the 13th century.
Windmills with vertical sails on horizontal shafts reached Europe through contact with the Arabs. Adopting the ideas from contemporary waterwheels, builders began to use fabric-covered, wood-framed sails located above the millstone, instead of a waterwheel below, to drive the grindstone through a set of gears. The whole mill with all its machinery was supported on a fixed post so that it could be rotated and faced into the wind. The millworks were initially covered by a boxlike wooden frame structure and later often by a “round-house,” which also provided storage. A brake wheel on the shaft allowed the mill to be stopped by a rim brake. A heavy lever then had to be raised to release the brake, an early example of a fail-safe device. Mills of this sort first appeared in France in 1180, in areas of Syria under the control of the crusaders in 1190, and in England in 1191. The earliest known illustration is from the Windmill Psalter made in Canterbury, England, in the second half of the 13th century.
The large effort required to turn a post-mill into the wind probably was responsible for the development of the so-called tower mill in France by the early 14th century. Here, the millstone and the gearing were placed in a massive fixed tower, often circular in section and built of stone or brick. Only an upper cap, normally made of wood and bearing the sails on its shaft, had to be rotated. Such improved mills spread rapidly throughout Europe and later became popular with early American settlers.
The Low Countries of Europe, which had no suitable streams for waterpower, saw the greatest development of windmills. Dutchhollow post-mills, invented in the early 15th century, used a two-step gear drive for drainage pumps. An upright shaft that had gears on the top and bottom passed through the hollow post to drive a paddle-wheel-like scoop to raise water. The first wind-driven sawmill, built in 1592 in the Netherlands by Cornelis Cornelisz, was mounted on a raft to permit easy turning into the wind.
At first both post-mills and the caps of tower mills were turned manually into the wind. Later small posts were placed around the mill to allow winching of the mill with a chain. Eventually winches were placed into the caps of tower mills, engaged with geared racks and operated from inside or from the ground by a chain passing over a wheel. Tower mills had their sail-supporting or tail pole normally inclined at between 5° and 15° to the horizontal. This aided the distribution of the huge sail weight on the tail bearing and also provided greater clearance between the sails and the support structure. Windmills became progressively larger, with sails from about 17 to 24 metres in diameter already common in the 16th century. The material of construction, including all gearing, was wood, although eventually brass or gunmetal came into use for the main bearings. Cast-iron drives were first introduced in 1754 by John Smeaton, the aforementioned English engineer. Little is known about the actual power produced by these mills. In all likelihood only from 10 to 15 horsepower was developed at the grinding wheels. A 50-horsepower mill was not built until the 19th century. The maximum efficiency of large Dutch mills is estimated to have been about 20 percent.
In 1745 Edmund Lee of England invented the fantail, a ring of five to eight vanes mounted behind the sails at right angles to them. These were connected by gears to wheels running on a track around the cap of the mill. As the wind changed direction, it struck the sides of the fantail vanes, realigning them and thereby turning the main sails again squarely into the wind. Fabric-on-wood-frame sails were sometimes replaced by all-wood sails with removable sections. Early sails had a constant angle of twist; variable twist sails resembling a modern airplane propeller were developed much later.
A major problem with all windmills was the need to feather the sails or reduce sail area so that if the wind suddenly increased during a storm the sails would not be ripped apart. In 1772 Andrew Meikle, a Scottish millwright, invented the spring sail, a shutter arrangement similar to a venetian blind in which the sails were controlled by a spring. When the wind pressure exceeded a preset amount, the shutters opened to let some of the wind pass through. In 1789 Stephen Hooper of England introduced roller blinds that could all be simultaneously adjusted with a manual chain from the ground while the mill was working. This was improved upon in 1807 by Sir William Cubitt, who combined Meikle’s shutters with Hooper’s remote control by hanging varying weights on the adjustment chain, thus making the control automatic. These so-called patent sails, however, found acceptance only in England and northern Europe.
Even though further improvements were made, especially in speed control, the importance of windmills as a major power producer began to decline after 1784, when the first flour mill in England successfully substituted a steam engine for wind power. Yet, the demise of windmills was slow; at one time in the 19th century there were as many as 900 corn (maize) and industrial windmills in the Zaan district of the Netherlands, the highest concentration known. Windmills persisted throughout the 19th century in newly settled or less-industrialized areas, such as the central and western United States, Canada, Australia, and New Zealand. They also were built by the hundreds in the West Indies to crush sugarcane.
The primary exception to the steady abandonment of windmills was resurgence in their use in rural areas for pumping water from wells. The first wind pump was introduced in the United States by David Hallay in 1854. After another American, Stewart Perry, began constructing wind pumps made of steel and equipped with metal vanes in 1883, this new and simple device spread around the world.
Wind-driven pumps remain important today in many rural parts of the world. They continued to be used in large numbers, even in the United States, well into the 20th century until low-cost electric power became readily available in rural areas. Although rather inefficient, they are rugged and reliable, need little attention, and remain a prime source for pumping small amounts of water wherever electricity is not economically available.Rex WailesFred Landis