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countries need to clean up their own energy production acts, while encouraging
developing countries not to follow in their footsteps, but rather to leapfrog to
clean energy technologies directly. Despite three decades of major investments
by less developed nations and multilaterals on electrification projects (often at
huge environmental and social costs), nearly 2 billion
people in developing
regions around the globe still lack electricity. Over 1 billion people are also
without access to safe drinking water. Millions of households rely solely on
kerosene lamps for lighting and disposable batteries for radios. For most of these
people, there is little likelihood of ever receiving electricity from conventional
grid sources. However, there is growing momentum in supplying electricity to
developing regions using solar and wind energy sources. Both
solar and wind
energy technologies offer energy independence and sustainable development by
using indigenous renewable energy resources and by creating long-term local
jobs and industries. The cost of bringing utility power via transmission and
distribution lines to non-electrified villages is great. This is largely due to small
household electrical loads and the fact that many villages are located at great
distances over difficult terrain from the existing grid. Stand-alone solar and wind
energy systems can provide cost-effective, modest levels of power for lighting,
communication, fans,
refrigerators, water pumping, etc. Using a least-cost
model, some governments and national utilities, such as those in Brazil, India,
Central America, South Africa, Mexico and elsewhere, have used PV and wind
systems as an integrated development tool for electrification planning as either
centralized or distributed solutions. Two decades ago,
PV technology was
relatively unknown. The Dominican Republic was one of the early proving
grounds for developing rural PV electrification efforts. The nonprofit group
Enersol Associates began work in 1984, offering technical assistance and
training to Dominican businesses. Nonprofit organizations
also worked to
develop a market for rural PV technology. Enersol began to work closely with
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the Peace Corps using seed funding from the U.S. Agency for International
Development (USAID) to help set up a revolving fund offering rural farmers
low-interest loans to purchase small PV systems. The work of this
nongovernment organization (NGO) later evolved
into private enterprise as
companies such as Soluz formed in the Dominican Republic and Honduras.
Gradually throughout the developing world, small solar companies began to
form as PV module manufacturers began to establish distributor networks to
serve remote, non-electrified areas. The model of
rural off-grid PV systems
(Figure 1.1) has spread globally with over 5 million systems installed. More total
kilowatts of grid-tie PV systems are installed each year; however, numerically
more small, off-gird systems are installed annually. Over time, the focus of PV
projects has changed. Installation of PV systems solely for remote sites has
expanded to include the promotion of rural economic development through PV.
PV provide power for remote water pumping, refrigeration, and water treatment
of community water supplies. Solar distillation can meet individual household
potable water needs from even the most contaminated
and brackish water
sources. For larger load requirements, the combination of PV and wind
technologies with diesel generators and battery storage has proved that hybrid
configurations provide higher system reliability at a more reasonable cost than
with any one technology alone. Solar thermal energy represents the most
competitive but often overlooked solar technology option.
Domestic solar hot
water heating systems typically have cost paybacks from 5 to 7 years— much
better than grid-tied PV systems, where payback may take decades, if ever.
Additionally, large-scale solar thermal concentrating solar power (CSP) plants
have better economies of scale than PV for utility power generation at almost
half the kilowatt-hour cost.