Simply speaking, energy efficiency refers to getting the
same (or similar) benefits from an energy device for a reduced amount of energy
consumption by it. For example, a
13-Watt compact fluorescent (CFL) bulb produces a comparable amount of light
output (lumens) as a 60-Watt incandescent bulb. Thus, the CFL bulb is 78 percent more energy efficient from an
energy consumption consideration. Therefore,
the CFL is an energy efficient device.
For market acceptability of an energy efficient device, the life cycle
cost benefits of such a device need to be considered. Life cycle cost calculations factor in the initial costs and life
spans of the two bulb types as well as the cost of electricity. Such calculations show that the higher
life span of the CFL well offsets the higher initial cost of the CFL, typically
resulting in cost savings of about 60 to 70 percent for the CFL over the useful life
of the CFL. Therefore, the CFL is an
economical, energy-efficient device.
There are many definitions of Energy Efficiency put forth by
various organizations. Some of these
definitions are provided below.
Energy Efficiency refers to programs that are aimed at reducing the energy used by
specific end-use devices and systems, typically without affecting the
services ... www.pplweb.com/glossary.htm
Energy efficiency refers to products or systems designed to use
less energy for the same or higher performance than regular products or
systems. Energy-efficient buildings are designed to use less energy than
traditional buildings; see green buildings for details. ... www.mtpc.org/cleanenergy/energy/glossaryefficiency.htm
Refers to products or systems using less energy to do the same or
better job than conventional products or systems. Energy efficiency saves
energy, saves money on utility bills, and helps protect the environment by
reducing the demand for electricity. ... www.epa.gov/greenpower/whatis/glossary.htm
Refers to technologies and measures that reduce the amount of electricity and/or
fuel required to do the same work, such as powering homes, offices and
industries. www.nrdc.org/reference/glossary/e.asp
Energy efficiency can be defined in slightly
different ways, and includes using less energy (kWh) to achieve the same
benefits (e.g. internal temperature, industrial output etc), or using the
same or a lesser amount of energy (kWh) but achieving more benefits (e.g.
a warmer home, higher output). . www.reeep.org/media/downloadable_documents/9/0/SERN%20Glossary.doc
Conversion ratio of output and input energy of energy production
technologies and end-use appliances. The lower the efficiency, the more
energy is lost. www.rwedp.org/d_units.html
Energy efficiency is one way of reducing greenhouse gas emissions.
By cutting down on the energy our society needs to grow and develop, we
can reduce the amount of greenhouse gas emissions. ... www.travelsmart.gov.au/teachers/teachers7.html
The ratio between the consumption of energy and a given quantity;
usually refers to the amount of primary or final energy consumed per unit
of gross domestic or national product. www.lineadecreditoambiental.org/html/glossary.html
This is about making the best or most efficient use of energy in
order to achieve a given output of goods or services, and of comfort and
convenience. This does not necessitate the use of less energy, in which
respect it differs from the concept of energy conservation. www.london.gov.uk/mayor/strategies/sds/further-alts/docs/glossary.rtf
the measure of the amount of energy which any technology can
convert to useful work; technology with a higher energy efficiency will
require less energy to do the same amount of work. www.wefixhvac.com/glossary.htm
The construction of buildings and their arrangement on sites so
that the resources involved are minimized. A result of energy efficiency , there should be a reduction
in both demand for resources and damage to the environment due to energy
generation. online.gateshead.gov.uk/udp/local_plan/written/cpt28.htm
In physics and engineering, including mechanical and electrical
engineering, energy efficiency is a dimensionless number, with a value
between 0 and 1 or, when multiplied by 100, is given as a percentage. ... en.wikipedia.org/wiki/Energy efficiency
Using less energy/electricity to perform the same function. Programs designed to use energy more efficiently:
doing the same with less. ... www.neo.ne.gov/statshtml/glossarye.htm
Making homes, vehicles, and businesses more energy efficient is seen as a
largely untapped solution to addressing global
warming and energy security. Many of these ideas have been
discussed for years, since the 1973
oil crisis brought energy issues to the forefront. In the late 1970s,
physicist Amory Lovins popularized 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 Makower has noted. For example, the state of California
began 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
warming in 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 Institute points 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.