3.3.4.2 Reducing Standby Power Losses in Appliances and Equipment
Improving the energy efficiency of appliances and equipment can result in reduced
energy consumption in the range of 10 to 70%, with the most typical savings
in the 30% to 40% range (Acosta Moreno et al., 1996; Turiel et al., 1997). Implementation
of advanced technologies in refrigerator/freezers, clothes washers, clothes
dryers, electric water heaters, and residential lighting in the US is estimated
to save 3.35EJ/yr by 2010, reducing energy use of these appliances by nearly
50% from the base case (Turiel et al., 1997).
A number of residential appliances and electronic devices, such as televisions,
audio equipment, telephone answering machines, refrigerators, dishwashers, and
ranges consume electricity while in a standby or off mode (Meier et al., 1992;
Herring, 1996; Meier and Huber, 1997; Molinder, 1997; Sanchez, 1997). These
standby power losses are estimated to consume 12% of Japanese residential electricity,
5% of US residential electricity, and slightly less in European countries (Nakagami
et al., 1997; Meier et al., 1998). Metering studies have shown that such standby
losses can be reduced to one watt in most of these mass-produced goods (Meier
et al., 1998). The costs of key low-loss technologies, such as more efficient
switch-mode power supplies and smarter batteries, are low (Nadel et al., 1998)
and a recent study found that if all US appliances were replaced by units meeting
the 1-watt target, aggregate standby losses would fall at least 70%, saving
the USA over US$2 billion annually (Meier et al., 1998).
3.3.4.3 Photovoltaic Systems for Buildings
Photovoltaic systems are being increasingly used in rural off-grid locations,
especially in developing countries, to provide electricity to areas not yet
connected to the power infrastructure or to offset fossil fuel generated electricity.
These systems are most commonly used to provide electricity for lighting, but
are also used for water pumping, refrigeration, evaporative cooling, ventilation
fans, air conditioning, and powering various electronic devices. In 1995, more
than 200,000 homes worldwide depended on photovoltaic systems for all of their
electricity needs (US DOE, 1999a). Between 1986 and 1998, global PV sales grew
from 37MW to 150MW (US DOE, 1999b). Rural electrification programmes have been
established in many developing countries. In Brazil, more than 1000 small stand-alone
systems that provide power for lighting, TVs, and radios were recently installed
in homes and schools, while two hybrid (PV-wind-battery) power systems were
installed in the Amazon Basin to reduce the use of diesel generators that supply
power to more than 300 villages in that area (Taylor, 1997). Similar projects
have been initiated in South Africa (Arent, 1998), Egypt (Taylor and Abulfotuh,
1997), India (Stone and Ullal, 1997; US DOE, 1999b), Mexico (Secretaria de Energia,
1997), China, Indonesia, Nepal, Sri Lanka, Vietnam, Uganda, Solomon Islands,
and Tanzania (Williams, 1996). Recent developments promoting increased adoption
of photovoltaic systems include the South African Solar Rural Electrification
Project (Shell International, 1999), the US Million Solar Roofs Initiative (US
DOE, 1999a), the effort to install 5000MW on residences in Japan by 2010 (Advisory
Committee for Energy, 1998), and net metering, which allows the electric meters
of customers with renewable energy generating facilities to be reversed when
the generators are producing energy in excess of residential requirements (US
DOE, 1999b).
3.3.4.4 Distributed Power Generation for Buildings
Distributed power generation relies on small power generation or storage systems
located near or at the building site. Several small scale (below 500kW), dispersed
power-generating technologies are advancing quite rapidly. These technologies
include both renewable and fossil fuel powered alternatives, such as photovoltaics
and microturbines. Moving power generation closer to electrical end-uses results
in reduced system electrical losses, the potential for combined heat and power
applications (especially for building cooling), and opportunities to better
co-ordinate generation and end-use, which can together more than compensate
for the lower conversion efficiency and result in overall energy systems that
are both less expensive and emit less carbon dioxide than the familiar central
power generating station. The likelihood of customer sites becoming net generators
will be determined by the configuration of the building and/or site, the opportunities
for on-site use of cogenerated heat, the availability and relative cost of fuels,
and utility interconnection, environmental, building code, and other regulatory
restrictions (NRECA, 2000).
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