Energy conservation in the United States
Encyclopedia
The United States is currently the second largest single consumer of energy. 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 domestic 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.
s used for personal or freight transportation. Of the energy used in this sector, approximately 65% is consumed by gasoline
-powered vehicles, primarily personally owned. Diesel-powered transport (trains, merchant ships, heavy trucks, etc.) consumes about 20%, and air traffic consumes most of the remaining 15%.
The two oil supply crisis
of the 1970s spurred the creation, in 1975, of the federal Corporate Average Fuel Economy
(CAFE) program, which required auto manufacturers to meet progressively higher fleet fuel economy targets. The next decade saw dramatic improvements in fuel economy, mostly the result of reductions in vehicle size and weight which originated in the late 1970s, along with the transition to front wheel drive. These gains eroded somewhat after 1990 due to the growing popularity of sport utility vehicle
s, pickup truck
s and minivan
s, which fall under the more lenient "light truck" CAFE standard.
In addition to the CAFE program, the U.S. government has tried to encourage better vehicle efficiency through tax policy. Since 2002, taxpayers have been eligible for income tax credits for gas/electric hybrid vehicles. A "gas-guzzler
" tax has been assessed on manufacturers since 1978 for cars with exceptionally poor fuel economy. While this tax remains in effect, it currently generates very little revenue as overall fuel economy has improved.
Another focus in gasoline conservation is reducing the number of miles driven. An estimated 40% of American automobile use is associated with daily commuting
. Many urban areas offer subsidized
public transportation to reduce commuting traffic, and encourage carpool
ing by providing designated high-occupancy vehicle lane
s and lower tolls for cars with multiple riders. In recent years telecommuting
has also become a viable alternative to commuting for some jobs, but in 2003 only 3.5% of workers were telecommuters. Ironically, hundreds of thousands of American and European workers have been replaced by workers in Asia
who telecommute from thousands of miles away.
Fuel economy-maximizing behaviors
also help reduce fuel consumption. Among the most effective are moderate (as opposed to aggressive) driving, driving at lower speeds, using cruise control, and turning off a vehicle's engine at stops rather than idling. A vehicle's gas mileage decreases rapidly highway speeds, normally above 55 miles per hour (though the exact number varies by vehicle). This is because aerodynamic forces
are proportionally related to the square of an object's speed (when the speed is doubled, drag
quadruples). According to the U.S. Department of Energy (DOE), as a rule of thumb, each 5 mi/h you drive over 60 mi/h is similar to paying an additional $0.30 per gallon for gas. The exact speed at which a vehicle achieves its highest efficiency varies based on the vehicle's drag coefficient
, frontal area, surrounding air speed, and the efficiency and gearing of a vehicle's drive train and transmission.
The efficiency of furnace
s and air conditioners has increased steadily since the energy crises of the 1970s. The 1987 National Appliance Energy Conservation Act
authorized the Department of Energy to set minimum efficiency standards for space conditioning equipment and other appliances each year, based on what is "technologically feasible and economically justified". Beyond these minimum standards, the Environmental Protection Agency
(EPA) awards the Energy Star
designation to appliances that exceed industry efficiency averages by an EPA-specified percentage.
Despite technological improvements, many American lifestyle changes have put higher demands on heating and cooling resources. The average size of homes built in the United States has increased significantly, from 1500 sq ft (139.4 m²) in 1970 to 2300 sq ft (213.7 m²) in 2005. The single-person household has become more common, as has central air conditioning: 23% of households had central air conditioning in 1978, that figure rose to 55% by 2001.
As furnace efficiency gets higher, there is limited room for improvement—efficiencies above 85% are now common. However, improving the building envelope
through better or more insulation
, advanced windows, etc., can allow larger improvements. The passive house
approach produces superinsulated
buildings that approach zero net energy consumption. Improving the building envelope can also be cheaper than replacing a furnace or air conditioner.
Even lower cost improvements include weatherization
, which is frequently subsidized by utilities or state/federal tax credits, as are programmable thermostat
s. Consumers have also been urged to adopt a wider indoor temperature range (e.g. 65 °F (18.3 °C) in the winter, 80 °F (26.7 °C) in the summer).
One underutilized, but potentially very powerful means to reduce household energy consumption is to provide real-time feedback to homeowners so they can effectively alter their energy using behavior. Recently, low cost energy feedback displays
, such as The Energy Detective or wattson, have become available. A study of a similar device deployed in 500 Ontario homes by Hydro One showed an average 6.5% drop in total electricity use when compared with a similarly sized control group.
Standby power
used by consumer electronics and appliances while they are turned off accounts for an estimated 5 to 10% of household electricity consumption, adding an estimated $3 billion to annual energy costs in the USA. "In the average home, 75% of the electricity used to power home electronics is consumed while the products are turned off."
Energy usage in some homes may vary widely from these averages. For example, milder regions such as the southern U.S. and Pacific coast of the USA need far less energy for space conditioning than New York City or Chicago. On the other hand, air conditioning energy use can be quite high in hot-arid regions (Southwest) and hot-humid zones (Southeast) In milder climates such as San Diego, lighting energy may easily consume up to 40% of total energy. Certain appliances such as a waterbed, hot tub, or pre-1990 refrigerator use significant amounts of electricity. However, recent trends in home entertainment equipment can make a large difference in household energy use. For instance a 50" LCD television (average on-time= 6 hours a day) may draw 300 Watts less than a similarly sized plasma system. In most residences no single appliance dominates, and any conservation efforts must be directed to numerous areas in order to achieve substantial energy savings. However, Ground, Air and Water Source Heat Pump
systems, solar heating systems and evaporative coolers are among the more energy efficient, environmentally clean, and cost-effective space conditioning and domestic hot water systems available (Environmental Protection Agency), and can achieve reductions in energy consumptions of up to 69%.
Smart ways to construct homes such that minimal resources are used to cooling and heating the house in summer and winter respectively can significantly reduce energy costs.
can reduce lighting energy by approximately fifty percent in many commercial buildings.
Commercial buildings can greatly increase energy efficiency by thoughtful design, with today's building stock being very poor examples of the potential of systematic (not expensive) energy efficient design (Steffy, 1997). Commercial buildings often have professional management, allowing centralized control and coordination of energy conservation efforts. As a result, fluorescent lighting (about four times as efficient as incandescent) is the standard for most commercial space, although it may produce certain adverse health effects. Potential health concerns can be mitigated by using newer fixtures with electronic ballasts rather than older magenetic ballasts. As most buildings have consistent hours of operation, programmed thermostats and lighting controls are common. However, too many companies believe that merely having a computer controlled Building automation
system guarantees energy efficiency. As an example one large company in Northern California boasted that it was confident its state of the art system had optimized space heating. A more careful analysis by Lumina Technologies showed the system had been given programming instructions to maintain constant 24 hour temperatures in the entire building complex. This instruction caused the injection of nighttime heat into vacant buildings when the daytime summer temperatures would often exceed 90 °F (32.2 °C). This mis-programming was costing the company over $130,000 per year in wasted energy (Lumina Technologies, 1997). Many corporations and governments also require the Energy Star rating for any new equipment purchased for their buildings.
Solar heat loading through standard window designs usually leads to high demand for air conditioning in summer months. An example of building design overcoming this excessive heat loading is the Dakin Building
in Brisbane, California
, where fenestration was designed to achieve an angle with respect to sun incidence to allow maximum reflection of solar heat; this design also assisted in reducing interior over-illumination
to enhance worker efficiency and comfort.
Recent advances include use of occupancy sensors to turn off lights when spaces are unoccupied, and photosensors to dim or turn off electric lighting when natural light is available. In air conditioning systems, overall equipment efficiencies have increased as energy codes and consumer information have begun to emphasise year round performance rather than just efficiency ratings at maximum output. Controllers that automatically vary the speeds of fans, pumps, and compressors have radically improved part-load performance of those devices. For space or water heating, electric heat pumps consume roughly half the energy required by electric resistance heaters. Natural gas heating efficiencies have improved through use of condensing furnaces and boilers, in which the water vapor in the flue gas is cooled to liquid form before it is discharged, allowing the heat of condensation to be used. In buildings where high levels of outside air are required, heat exchangers can capture heat from the exhaust air to preheat incoming supply air.
A company in Florida tackled the issue of both energy-conservation and enhancing its workplace environment by implementing a conveyor system that is 40-60% quieter than traditional systems, emitting a noise level of only 55-50 decibels, equivalent to a soft-rock radio station. Lighting was addressed by not only programming the lighting console so that isolated lights could be switched on and off in designated areas of the warehouse, but also by enhancing natural lighting through the use of skylights and a high-gloss floor.
Increasing costs have forced energy-intensive industries to make substantial efficiency improvements in the past 30 years. For example, the energy used to produce steel and paper products has been cut 40% in that time frame, while petroleum/aluminum refining and cement production have reduced their usage by about 25%. These reductions are largely the result of recycling waste material and the use of cogeneration
equipment for electricity and heating.
Another example for efficiency improvements is the use of products made of High temperature insulation wool
(HTIW) which enables predominantly industrial users to operate thermal treatment plants at temperatures between 800 and 1400°C. In these high-temperature applications, the consumption of primary energy and the associated CO2 emissions can be reduced by up to 50% compared with old fashioned industrial installations. The application of products made of High temperature insulation Wool is becoming increasingly important against the background of the currently dramatic rising cost of energy.
U.S. agriculture has doubled farm energy efficiency
in the last 25 years.
The energy required for delivery and treatment of fresh water often constitutes a significant percentage of a region's electricity and natural gas usage (an estimated 20% of California's total energy use is water-related). In light of this, some local governments have worked toward a more integrated approach to energy and water conservation
efforts.
To conserve energy, some industries have begun using solar panels to heat their water
.
Unlike the other sectors, total energy use in the industrial sector has declined in the last decade. While this is partly due to conservation efforts, its is also a reflection of the growing trend for U.S. companies to move manufacturing operations overseas.
included incentives which provide a tax credit of 30% of the cost of the new item with a $500 aggregate limit; the program was initially set to expire at the end of 2007 but was extended to 2010 and the aggregate limit increased to $1,500 by the Energy Improvement and Extension Act of 2008 and the The American Recovery and Reinvestment Act of 2009, when it will expire.
The states and local areas (e.g., cities or counties) have various initiatives, and the U.S. Department of Energy funded a database known as DSIRE which provides information on these initiatives. The state of Maryland has set a target of reducing its electricity usage by 15% from 2008 to 2015.
By Executive Order 13514, U.S. President Barack Obama
mandated that by 2015, 15% of existing Federal buildings conform to new energy efficiency standards and 100% of all new Federal buildings be Zero-Net-Energy
by 2030.
Transportation
The transportation sector includes all vehicleVehicle
A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....
s used for personal or freight transportation. Of the energy used in this sector, approximately 65% is consumed by gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
-powered vehicles, primarily personally owned. Diesel-powered transport (trains, merchant ships, heavy trucks, etc.) consumes about 20%, and air traffic consumes most of the remaining 15%.
The two oil supply crisis
1973 oil crisis
The 1973 oil crisis started in October 1973, when the members of Organization of Arab Petroleum Exporting Countries or the OAPEC proclaimed an oil embargo. This was "in response to the U.S. decision to re-supply the Israeli military" during the Yom Kippur war. It lasted until March 1974. With the...
of the 1970s spurred the creation, in 1975, of the federal Corporate Average Fuel Economy
Corporate Average Fuel Economy
The Corporate Average Fuel Economy are regulations in the United States, first enacted by the U.S. Congress in 1975, and intended to improve the average fuel economy of cars and light trucks sold in the US in the wake of the 1973 Arab Oil Embargo...
(CAFE) program, which required auto manufacturers to meet progressively higher fleet fuel economy targets. The next decade saw dramatic improvements in fuel economy, mostly the result of reductions in vehicle size and weight which originated in the late 1970s, along with the transition to front wheel drive. These gains eroded somewhat after 1990 due to the growing popularity of sport utility vehicle
Sport utility vehicle
A sport utility vehicle is a generic marketing term for a vehicle similar to a station wagon, but built on a light-truck chassis. It is usually equipped with four-wheel drive for on- or off-road ability, and with some pretension or ability to be used as an off-road vehicle. Not all four-wheel...
s, pickup truck
Pickup truck
A pickup truck is a light motor vehicle with an open-top rear cargo area .-Definition:...
s and minivan
Minivan
Minivan is a type of van designed for personal use. Minivans are typically either two-box or one box designs for maximum interior volume – and are taller than a sedan, hatchback, or a station wagon....
s, which fall under the more lenient "light truck" CAFE standard.
In addition to the CAFE program, the U.S. government has tried to encourage better vehicle efficiency through tax policy. Since 2002, taxpayers have been eligible for income tax credits for gas/electric hybrid vehicles. A "gas-guzzler
Gas-guzzler
Gas-guzzler commonly refers to a vehicle that consumes fuel inefficiently.The term originally came into use in the US when congress established Gas Guzzler Tax provisions in the Energy Tax Act of 1978 to discourage the production and purchase of fuel-inefficient vehicles...
" tax has been assessed on manufacturers since 1978 for cars with exceptionally poor fuel economy. While this tax remains in effect, it currently generates very little revenue as overall fuel economy has improved.
Another focus in gasoline conservation is reducing the number of miles driven. An estimated 40% of American automobile use is associated with daily commuting
Commuting
Commuting is regular travel between one's place of residence and place of work or full time study. It sometimes refers to any regular or often repeated traveling between locations when not work related.- History :...
. Many urban areas offer subsidized
Subsidy
A subsidy is an assistance paid to a business or economic sector. Most subsidies are made by the government to producers or distributors in an industry to prevent the decline of that industry or an increase in the prices of its products or simply to encourage it to hire more labor A subsidy (also...
public transportation to reduce commuting traffic, and encourage carpool
Carpool
Carpooling , is the sharing of car journeys so that more than one person travels in a car....
ing by providing designated high-occupancy vehicle lane
High-occupancy vehicle lane
In transportation engineering and transportation planning, a high-occupancy vehicle lane is a lane reserved for vehicles with a driver and one or more passengers...
s and lower tolls for cars with multiple riders. In recent years telecommuting
Telecommuting
Telecommuting or telework is a work arrangement in which employees enjoy flexibility in working location and hours. In other words, the daily commute to a central place of work is replaced by telecommunication links...
has also become a viable alternative to commuting for some jobs, but in 2003 only 3.5% of workers were telecommuters. Ironically, hundreds of thousands of American and European workers have been replaced by workers in Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
who telecommute from thousands of miles away.
Fuel economy-maximizing behaviors
Fuel economy-maximizing behaviors
Fuel economy-maximizing behaviors describe techniques that drivers can use to optimize their automobile fuel economy. The energy in fuel consumed in driving is lost in many ways, including engine inefficiency, aerodynamic drag, rolling friction, and kinetic energy lost to braking...
also help reduce fuel consumption. Among the most effective are moderate (as opposed to aggressive) driving, driving at lower speeds, using cruise control, and turning off a vehicle's engine at stops rather than idling. A vehicle's gas mileage decreases rapidly highway speeds, normally above 55 miles per hour (though the exact number varies by vehicle). This is because aerodynamic forces
Automotive aerodynamics
Automotive aerodynamics is the study of the aerodynamics of road vehicles. The main concerns of automotive aerodynamics are reducing drag , reducing wind noise, minimizing noise emission, and preventing undesired lift forces and other causes of aerodynamic instability at high speeds...
are proportionally related to the square of an object's speed (when the speed is doubled, drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...
quadruples). According to the U.S. Department of Energy (DOE), as a rule of thumb, each 5 mi/h you drive over 60 mi/h is similar to paying an additional $0.30 per gallon for gas. The exact speed at which a vehicle achieves its highest efficiency varies based on the vehicle's drag coefficient
Drag coefficient
In fluid dynamics, the drag coefficient is a dimensionless quantity that is used to quantify the drag or resistance of an object in a fluid environment such as air or water. It is used in the drag equation, where a lower drag coefficient indicates the object will have less aerodynamic or...
, frontal area, surrounding air speed, and the efficiency and gearing of a vehicle's drive train and transmission.
Residential sector
The residential sector refers to all private residences, including single-family homes, apartments, manufactured homes and dormitories. Energy use in this sector varies significantly across the country, due to regional climate differences and different regulation. On average, about half of the energy used in U.S. homes is expended on space conditioning (i.e. heating and cooling).The efficiency of furnace
Furnace
A furnace is a device used for heating. The name derives from Latin fornax, oven.In American English and Canadian English, the term furnace on its own is generally used to describe household heating systems based on a central furnace , and sometimes as a synonym for kiln, a device used in the...
s and air conditioners has increased steadily since the energy crises of the 1970s. The 1987 National Appliance Energy Conservation Act
National Appliance Energy Conservation Act
The National Appliance Energy Conservation Act is a 1975 piece of legislation by the United States Congress which regulates energy consumption of specific household appliances in the United States. Though minimum Energy Efficiency Standards were first established by the United States Congress in...
authorized the Department of Energy to set minimum efficiency standards for space conditioning equipment and other appliances each year, based on what is "technologically feasible and economically justified". Beyond these minimum standards, the Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
(EPA) awards the Energy Star
Energy Star
Energy Star is an international standard for energy efficient consumer products originated in the United States of America. It was first created as a United States government program during the early 1990s, but Australia, Canada, Japan, New Zealand, Taiwan and the European Union have also adopted...
designation to appliances that exceed industry efficiency averages by an EPA-specified percentage.
Despite technological improvements, many American lifestyle changes have put higher demands on heating and cooling resources. The average size of homes built in the United States has increased significantly, from 1500 sq ft (139.4 m²) in 1970 to 2300 sq ft (213.7 m²) in 2005. The single-person household has become more common, as has central air conditioning: 23% of households had central air conditioning in 1978, that figure rose to 55% by 2001.
As furnace efficiency gets higher, there is limited room for improvement—efficiencies above 85% are now common. However, improving the building envelope
Building envelope
The building envelope is the physical separator between the interior and the exterior environments of a building. Another emerging term is "Building Enclosure". It serves as the outer shell to help maintain the indoor environment and facilitate its climate control...
through better or more insulation
Building insulation
building insulation refers broadly to any object in a building used as insulation for any purpose. While the majority of insulation in buildings is for thermal purposes, the term also applies to acoustic insulation, fire insulation, and impact insulation...
, advanced windows, etc., can allow larger improvements. The passive house
Passive house
The term passive house refers to the rigorous, voluntary, Passivhaus standard for energy efficiency in a building, reducing its ecological footprint. It results in ultra-low energy buildings that require little energy for space heating or cooling. A similar standard, MINERGIE-P, is used in...
approach produces superinsulated
Superinsulation
Superinsulation is an approach to building design, construction, and retrofitting that dramatically reduces heat loss by using much higher levels of insulation and airtightness than normal...
buildings that approach zero net energy consumption. Improving the building envelope can also be cheaper than replacing a furnace or air conditioner.
Even lower cost improvements include weatherization
Weatherization
Weatherization or weatherproofing is the practice of protecting a building and its interior from the elements, particularly from sunlight, precipitation, and wind, and of modifying a building to reduce energy consumption and optimize energy efficiency.Weatherization is distinct from building...
, which is frequently subsidized by utilities or state/federal tax credits, as are programmable thermostat
Thermostat
A thermostat is the component of a control system which regulates the temperature of a system so that the system's temperature is maintained near a desired setpoint temperature. The thermostat does this by switching heating or cooling devices on or off, or regulating the flow of a heat transfer...
s. Consumers have also been urged to adopt a wider indoor temperature range (e.g. 65 °F (18.3 °C) in the winter, 80 °F (26.7 °C) in the summer).
One underutilized, but potentially very powerful means to reduce household energy consumption is to provide real-time feedback to homeowners so they can effectively alter their energy using behavior. Recently, low cost energy feedback displays
Home energy monitor
A home energy monitor provides prompt, convenient feedback on electrical or other energy use. Devices may also display cost of energy used, and estimates of greenhouse gas emissions...
, such as The Energy Detective or wattson, have become available. A study of a similar device deployed in 500 Ontario homes by Hydro One showed an average 6.5% drop in total electricity use when compared with a similarly sized control group.
Standby power
Standby power
Standby power, also called vampire power, vampire draw, phantom load, or leaking electricity , refers to the electric power consumed by electronic and electrical appliances while they are switched off Standby power, also called vampire power, vampire draw, phantom load, or leaking electricity...
used by consumer electronics and appliances while they are turned off accounts for an estimated 5 to 10% of household electricity consumption, adding an estimated $3 billion to annual energy costs in the USA. "In the average home, 75% of the electricity used to power home electronics is consumed while the products are turned off."
Home energy consumption averages
- Home heating systems, 30.7%
- Water heating, 13.5%
- Home cooling systems, 11.5%
- Lighting, 10.3%
- Refrigerators and freezers, 8.2%
- Home electronics, 7.2%
- Clothing and dish washers, 5.6% (includes clothes dryers, does not include hot water)
- Cooking, 4.7%
- Computers, 0.9%
- Other, 4.1% (includes small electrics, heating elements, motors, pool and hot tub heaters, outdoor grills, and natural gas outdoor lighting)
- Non end-user energy expenditure, 3.3%
Energy usage in some homes may vary widely from these averages. For example, milder regions such as the southern U.S. and Pacific coast of the USA need far less energy for space conditioning than New York City or Chicago. On the other hand, air conditioning energy use can be quite high in hot-arid regions (Southwest) and hot-humid zones (Southeast) In milder climates such as San Diego, lighting energy may easily consume up to 40% of total energy. Certain appliances such as a waterbed, hot tub, or pre-1990 refrigerator use significant amounts of electricity. However, recent trends in home entertainment equipment can make a large difference in household energy use. For instance a 50" LCD television (average on-time= 6 hours a day) may draw 300 Watts less than a similarly sized plasma system. In most residences no single appliance dominates, and any conservation efforts must be directed to numerous areas in order to achieve substantial energy savings. However, Ground, Air and Water Source Heat Pump
Heat pump
A heat pump is a machine or device that effectively "moves" thermal energy from one location called the "source," which is at a lower temperature, to another location called the "sink" or "heat sink", which is at a higher temperature. An air conditioner is a particular type of heat pump, but the...
systems, solar heating systems and evaporative coolers are among the more energy efficient, environmentally clean, and cost-effective space conditioning and domestic hot water systems available (Environmental Protection Agency), and can achieve reductions in energy consumptions of up to 69%.
Best building practices
Current best practices in building design, construction and retrofitting result in homes that are profoundly more energy conserving than average new homes. This includes insulation and energy-efficient windows and lighting.Smart ways to construct homes such that minimal resources are used to cooling and heating the house in summer and winter respectively can significantly reduce energy costs.
Commercial sector
The commercial sector consists of retail stores, offices (business and government), restaurants, schools and other workplaces. Energy in this sector has the same basic end uses as the residential sector, in slightly different proportions. Space conditioning is again the single biggest consumption area, but it represents only about 30% of the energy use of commercial buildings. Lighting, at 25%, plays a much larger role than it does in the residential sector. Lighting is also generally the most wasteful component of commercial use. A number of case studies indicate that more efficient lighting and elimination of over-illuminationOver-illumination
Over-illumination is the presence of lighting intensity beyond that required for a specified activity. Over-illumination was commonly ignored between 1950 and 1995, especially in office and retail environments; only since then has the interior design community begun to reconsider this practice.The...
can reduce lighting energy by approximately fifty percent in many commercial buildings.
Commercial buildings can greatly increase energy efficiency by thoughtful design, with today's building stock being very poor examples of the potential of systematic (not expensive) energy efficient design (Steffy, 1997). Commercial buildings often have professional management, allowing centralized control and coordination of energy conservation efforts. As a result, fluorescent lighting (about four times as efficient as incandescent) is the standard for most commercial space, although it may produce certain adverse health effects. Potential health concerns can be mitigated by using newer fixtures with electronic ballasts rather than older magenetic ballasts. As most buildings have consistent hours of operation, programmed thermostats and lighting controls are common. However, too many companies believe that merely having a computer controlled Building automation
Building automation
Building automation describes the functionality provided by the control system of a building. A building automation system is an example of a distributed control system...
system guarantees energy efficiency. As an example one large company in Northern California boasted that it was confident its state of the art system had optimized space heating. A more careful analysis by Lumina Technologies showed the system had been given programming instructions to maintain constant 24 hour temperatures in the entire building complex. This instruction caused the injection of nighttime heat into vacant buildings when the daytime summer temperatures would often exceed 90 °F (32.2 °C). This mis-programming was costing the company over $130,000 per year in wasted energy (Lumina Technologies, 1997). Many corporations and governments also require the Energy Star rating for any new equipment purchased for their buildings.
Solar heat loading through standard window designs usually leads to high demand for air conditioning in summer months. An example of building design overcoming this excessive heat loading is the Dakin Building
Dakin Building
The Dakin Building is an architectural award-winning class A office building on the San Francisco Bay in Brisbane, California. Serving as a corporate headquarters building for several companies of national prominence, it was built from the profits of the Garfield character whose licensed products...
in Brisbane, California
Brisbane, California
Brisbane is a small city located in the northern part of San Mateo County, California on the lower slopes of San Bruno Mountain. It is on the northeastern edge of South San Francisco, next to the San Francisco Bay and near the San Francisco International Airport.The population was 4,282 as of...
, where fenestration was designed to achieve an angle with respect to sun incidence to allow maximum reflection of solar heat; this design also assisted in reducing interior over-illumination
Over-illumination
Over-illumination is the presence of lighting intensity beyond that required for a specified activity. Over-illumination was commonly ignored between 1950 and 1995, especially in office and retail environments; only since then has the interior design community begun to reconsider this practice.The...
to enhance worker efficiency and comfort.
Recent advances include use of occupancy sensors to turn off lights when spaces are unoccupied, and photosensors to dim or turn off electric lighting when natural light is available. In air conditioning systems, overall equipment efficiencies have increased as energy codes and consumer information have begun to emphasise year round performance rather than just efficiency ratings at maximum output. Controllers that automatically vary the speeds of fans, pumps, and compressors have radically improved part-load performance of those devices. For space or water heating, electric heat pumps consume roughly half the energy required by electric resistance heaters. Natural gas heating efficiencies have improved through use of condensing furnaces and boilers, in which the water vapor in the flue gas is cooled to liquid form before it is discharged, allowing the heat of condensation to be used. In buildings where high levels of outside air are required, heat exchangers can capture heat from the exhaust air to preheat incoming supply air.
A company in Florida tackled the issue of both energy-conservation and enhancing its workplace environment by implementing a conveyor system that is 40-60% quieter than traditional systems, emitting a noise level of only 55-50 decibels, equivalent to a soft-rock radio station. Lighting was addressed by not only programming the lighting console so that isolated lights could be switched on and off in designated areas of the warehouse, but also by enhancing natural lighting through the use of skylights and a high-gloss floor.
Industrial sector
The industrial sector represents all production and processing of goods, including manufacturing, construction, farming, water management and mining.Increasing costs have forced energy-intensive industries to make substantial efficiency improvements in the past 30 years. For example, the energy used to produce steel and paper products has been cut 40% in that time frame, while petroleum/aluminum refining and cement production have reduced their usage by about 25%. These reductions are largely the result of recycling waste material and the use of cogeneration
Cogeneration
Cogeneration is the use of a heat engine or a power station to simultaneously generate both electricity and useful heat....
equipment for electricity and heating.
Another example for efficiency improvements is the use of products made of High temperature insulation wool
High temperature insulation wool
In the 1950s, the term “Refractory Ceramic Fibre” was coined for the aluminium silicate fibres developed at this time.On account of their chemical purity and resistance to high temperatures as well as on the basis of their use in other applications, this definition was made to differentiate...
(HTIW) which enables predominantly industrial users to operate thermal treatment plants at temperatures between 800 and 1400°C. In these high-temperature applications, the consumption of primary energy and the associated CO2 emissions can be reduced by up to 50% compared with old fashioned industrial installations. The application of products made of High temperature insulation Wool is becoming increasingly important against the background of the currently dramatic rising cost of energy.
U.S. agriculture has doubled farm energy efficiency
Electrical energy efficiency on United States farms
Electrical energy efficiency on United States farms covers the use of electricity on farms and the methods and incentives for improving the efficiency of that use.U.S...
in the last 25 years.
The energy required for delivery and treatment of fresh water often constitutes a significant percentage of a region's electricity and natural gas usage (an estimated 20% of California's total energy use is water-related). In light of this, some local governments have worked toward a more integrated approach to energy and water conservation
Water conservation
Water conservation refers to reducing the usage of water and recycling of waste water for different purposes such as cleaning, manufacturing, and agricultural irrigation.- Water conservation :Water conservation can be defined as:...
efforts.
To conserve energy, some industries have begun using solar panels to heat their water
Solar hot water
Solar water heating or solar hot water systems comprise several innovations and many mature renewable energy technologies that have been well established for many years...
.
Unlike the other sectors, total energy use in the industrial sector has declined in the last decade. While this is partly due to conservation efforts, its is also a reflection of the growing trend for U.S. companies to move manufacturing operations overseas.
Government incentives and initiatives
The Energy Policy Act of 2005Energy Policy Act of 2005
The Energy Policy Act of 2005 is a bill passed by the United States Congress on July 29, 2005, and signed into law by President George W. Bush on August 8, 2005, at Sandia National Laboratories in Albuquerque, New Mexico...
included incentives which provide a tax credit of 30% of the cost of the new item with a $500 aggregate limit; the program was initially set to expire at the end of 2007 but was extended to 2010 and the aggregate limit increased to $1,500 by the Energy Improvement and Extension Act of 2008 and the The American Recovery and Reinvestment Act of 2009, when it will expire.
The states and local areas (e.g., cities or counties) have various initiatives, and the U.S. Department of Energy funded a database known as DSIRE which provides information on these initiatives. The state of Maryland has set a target of reducing its electricity usage by 15% from 2008 to 2015.
By Executive Order 13514, U.S. President Barack Obama
Barack Obama
Barack Hussein Obama II is the 44th and current President of the United States. He is the first African American to hold the office. Obama previously served as a United States Senator from Illinois, from January 2005 until he resigned following his victory in the 2008 presidential election.Born in...
mandated that by 2015, 15% of existing Federal buildings conform to new energy efficiency standards and 100% of all new Federal buildings be Zero-Net-Energy
Zero-Net-Energy USA Federal Buildings
A Zero-Net-Energy Building is an official designation in the United States for a building whose construction and operation creates zero net emissions of greenhouse gases, as specified in President Obama's Executive Order 13514 of October 5, 2009....
by 2030.
See also
- EarthshipEarthshipAn earthship is a type of passive solar house made of natural and recycled materials. Designed and marketed by Earthship Biotecture of Taos, New Mexico, the homes are primarily constructed to work as autonomous buildings and are generally made of earth-filled tires, using thermal mass...
- Energy and the environment
- Environment of the United StatesEnvironment of the United StatesThe environment of the United States comprises diverse biotas, climates, and geologies. Environmental regulations and the environmental movement have emerged to respond to the various threats to the environment.-Animals:...
- Passive housePassive houseThe term passive house refers to the rigorous, voluntary, Passivhaus standard for energy efficiency in a building, reducing its ecological footprint. It results in ultra-low energy buildings that require little energy for space heating or cooling. A similar standard, MINERGIE-P, is used in...
- Portland Energy ConservationPortland Energy ConservationPECI is an American company based in Portland, Oregon that provides energy conservation services for organizations ranging from retail stores to utilities, as they shift their thinking toward energy efficiency measures to help meet increased energy demand...
- SuperinsulationSuperinsulationSuperinsulation is an approach to building design, construction, and retrofitting that dramatically reduces heat loss by using much higher levels of insulation and airtightness than normal...
- Self-sufficient homes
- Zero energy buildingZero energy buildingA zero-energy building, also known as a zero net energy building, Net-Zero Energy Building , or Net Zero Building, is a popular term to describe a building with zero net energy consumption and zero carbon emissions annually. Zero energy buildings can be independent from the energy grid supply...
- Zero-Net-Energy USA Federal BuildingsZero-Net-Energy USA Federal BuildingsA Zero-Net-Energy Building is an official designation in the United States for a building whose construction and operation creates zero net emissions of greenhouse gases, as specified in President Obama's Executive Order 13514 of October 5, 2009....
External links
- US Department of Energy - resources for industry
- Energy usage by state, by fuel and per capita, 2007
- American Council for an Energy-Efficient Economy