| by Harry
Hutchinson, Executive Editor |
The
idea seemed to offer something for everyone involved. Volunteer work and
charitable money would put photoelectric systems into communities that
power lines don't reach. With a bank of batteries to store the energy,
residents would be able to share the electricity.
Engineers in various disciplines and their students would get valuable
hands-on experience working together to design and build the solar-electric
installations. The job would involve them in cross-disciplinary collaboration
to design electrical and mechanical systems, and to work out the logistics
for making everything come together.
Then for the first time, several villages off the grid in El Salvador
would be able to reap the benefits of electricity and perhaps would begin
to prosper. Several isolated communitieswhere light at night came
from burning kerosene or wood, where radios, if there were any at all,
ran on batteriesmight inch a little closer to the modern experience.
As they expected to do, the engineers and their students learned a great
deal as they tested and refined the systems they built. But they learned
something unexpected, too: that putting technology into the hands of the
needy doesn't automatically lift them out of poverty. Now, to get more
out of the technology they can deliver, the team members are rethinking
the cultural and social implications of their work.
 |
| Lighting an icon: The church at
El Alto was damaged during El Salvador's long civil war, but the tower,
now lighted at night, survived unharmed. |
The idea began at the University of Central America, where Cesar Villalta,
who became team leader for the project, is a professor of electrical engineering.
"The main challenge was to design a photovoltaic system capable of providing
energy to the whole community in the most efficient way possible, technically
as well as economically," Villalta said. "The idea was to assemble a multidisciplinary
group in which every member takes care of the specific area he or she
is good at."
Working with Villalta were other professors from UCA. Ismael Sanchez,
a mechanical engineer who heads the Energy Sciences Department, handled
logistics. Carlos Rivas, a mechanical engineer, and José Carlos Hasbun,
a civil engineer with a specialty in structures, took charge of mechanical
design. They enlisted students in various roles along the way.
El Salvador lies in Central America. In the north-south split between
the have and have-not countries, it clearly falls in the south. According
to the World Bank, gross national income per capita is $2,200, compared
with an average of a little more than $2,900 for all of Latin America
and the Caribbean.
In the developed world, per capita income is closer to $26,000. It is
estimated that more than 40 percent of the 6.5 million people in El Salvador
live below the poverty line; that is, they make so little that they cannot
buy all the necessities of life.
There could be no question that the people to be served by the photoelectric
systems qualified for aid.
Backed by funds from Europe, the team finished three rural installations
in the two and a half years between late 1999 and the middle of 2002.
The first was at Higueral, about a two-hour drive from the campus in San
Salvador; the second at Izotalío, a trip of three hours, and the
third at El Alto, about an hour and a half away. "In distance they are
not far," Carlos Rivas said, "but the roads to get there are in pretty
bad shape and the vehicle has to go slow." Getting to Izotalío requires
four-wheel drive, or a hike.
The original hope was that the towns could use the electricity to develop
the modest beginnings of an eco-tourism trade.
"The landscape that surrounds the communities is really beautiful," Rivas
explained, "and we know that many people from the city like camping, hiking,
and outdoor activities. We thought that the communities could become a
domestic tourist attraction. With electricity, people could have blenders
and maybe small refrigerators to store food and offer something to the
tourists. This did not happen, and we don't see the day it could happen."
The residents were trained to maintain and operate their electrical systems,
but they had no practical model to follow for running a business. Nor
are there resources available to advertise the towns as rural destinations.
What's more, the communities are not well prepared to receive guests.
In some cases, livestock wanders freely among the houses, and sanitary
facilities are meager.
"Making technology accessible to people is not enough," Rivas said. "We
have to make sure that they are able to use it successfully for improving
their lives."
Technical vs. Social
All the installations are at elevations where for a couple of months of
the year the winds can be severe. The support structure has to be strong
enough to stand up to those winds and also must be adjustable to follow
the sun at different seasons. The structure must rotate, and the panels
have to be tilted at different angles at various times of the year.
To get the most exposure to sunlight, the panels have to tilt 30 degrees
from the horizontal facing south in November, December, and January. By
May and then again in August, the panels work best if they are horizontal.
In June and July, they should incline 10 degrees off the horizontal facing
north.
The need to reorient the array from time to time presented problems no
one could foresee. According to Rivas, the team trained the townspeople
to handle the panels, but often in practice, no one steps up to make the
periodic adjustments.
He believes one reason may be that the systems are community property,
and not the province of individuals. "We told them that the community
owned the system, not anybody in particular," he said. As a result,
no one feels a personal responsibility for adjusting the panels.
"We now think that it is better to select some members of the community,
form a sort of enterprise, and allow them to charge the other members
of the community a reasonable fee for keeping the system running,"
Rivas said. "We think that they have to have the authority to penalize
anybody who does not want to follow the rules and that they deserve to
get paid for all their trouble. Of course, we don't want anybody
to exploit a resource to the detriment of others, but as sad as it might
sound, we do not believe anymore in good intentions and solidarity to
keep these projects running."
Rivas also suggests another possible reason for people's reluctance
to maintain the systems: a fear of meddling with something no one really
understands. Although they were trained in the basics of caring for the
hardware, the residents of the towns have no idea how the panels generate
electricity, and so are leaving them alone.
All the installations use polycrystalline silicon solar panels. Some use
panels made by Atersa and others by Isofoton, both of which are based
in Spain. An array of a dozen lead-acid batteries stores electricity generated
during the day. According to Rivas, the systems are designed so that if
the sky were overcast for seven days, there will be enough electricity
stored in the batteries to satisfy the design load.
The first installation, at El Higueral, cost $20,000 and was funded by
Bruder und Schwester in Notthat is, Brother and Sister in Needin
Austria. The array of panels can generate 5 kilowatt-hours a day for a
community of about 125 people. The power serves 25 family homes and a
house used for community gatherings.
The design, developed largely by Hasbun, has four legs, with freedom to
rotate. The two rear legs are telescopic, made of one pipe that slides
inside another, to allow for changing the tilt of the panels.
Proving the Design
One of the jobs assigned to the students was to validate the design.
"We used these projects as opportunities to teach our students the use
of engineering software in a real-life design," Rivas said. "They simulated
practically every structure. They created a model in AutoCAD, and then
they used that model to simulate stresses and deformation using Algor.
Basically, the stresses were caused by the weight of the panels and the
wind, so we simulated that effect. Simulating the structures and watching
them 'behave' in a simulated scenario, and then watching them installed
in real life and working as expected is for us, and for our students,
a very valuable learning experience." AutoCAD is a product of Autodesk
in San Rafael, Calif. Algor, the developer of analysis software, is based
in Pittsburgh, Pa.
The team could not wait for the windy months to measure the wind speed,
and used estimates instead, based on what residents had to say. "They
told us that in some months the winds were capable of taking the roofs
off the houses and that walking was difficult," Rivas said, "so as a design
feature, we assumed that the winds could be as strong as 70 kilometers
per hour, just to be on the safe side. Right now (almost four years later
and being there during the installation and on some windy days), we estimate
that the maximum wind speed could be around 40 kilometers per hour."
The second system, located at Izotalío, differed from the first one
in a couple of different ways.
Villalta suggested that the four legs be replaced by a single post. It
would look better and also reduce the footprint of the structure.
With the new single-post structure, swivel proved to be no problem, although
adjusting the tilt of the panels required some effort.
 |
 |
| High tech on high ground: beginning
from top, the long view from Izotalío to the nearest highway;
sunset, and battery time, at El Alto; mounting panels on the four-legged
supports at Higuera; an installation on the later single-post supports
at El Alto. |
 |
 |
The tilting mechanism used plates attached at the top of the support
post and to the back of the panel platform. Someone could align different
holes in the plates at different seasons to adjust the inclination of
the solar panels. The plates were secured by a pin.
Before it went into the field, students put the new design through computer
analysis, as well, by using Algor software at the university.
During the Izotalío project, the team added a logic module called
LOGO, from Siemens. It would prevent the batteries from over-discharging.
Rivas said the controller also works as a timer to program the use of
energy according to the annual availability of solar radiation. The region
has rainy seasons each year.
The 80 residents of Izotalío received a system that can generate
3.5 kWh a day. It cost $18,000, provided by Bultzapen, an organization
in San Juan, Spain, whose mission is to promote development in the countries
of the South.
The third installation, at El Alto, was the largest, able to generate
7 kWh in a day. It cost $30,000, and was funded by another Spanish organization,
Solidaridad Internacional in Bilbao. The group supports development projects
in Latin America, Africa, and the Middle East.
El Alto is a community of about 115. Besides 23 homes, the community school
and the church were electrified.
The church has special significance, Rivas said. During El Salvador's
long civil war, that region of the country was held by the guerrillas
and became a battleground. The people left their homes to get out of harm's
way.
The church took hits during air raids by government forces, and part of
it has since been rebuilt. However, when the fighting ended and the people
returned, they found the steeple untouched and standing in the rubble
of war. The structure has become a symbol of hope.
Rivas and the team are still working on the mechanical design. They have
come up with a new adjustment mechanism that is easier to operate than
the plate-and-pin system. This version uses a cable that attaches to hooks
at various elevations on the support post to adjust the incline. A winch
takes up slack in the cable.
The team has put an installation using the cable-and-winch system on top
of UCA's architecture building, where it supplements electricity from
the grid and can power emergency lights during an outage.
The next big changes in design may come in the approach to cultural rather
than engineering issues.
"The main challenge was to design a photovoltaic system capable of providing
energy to the whole community in the most efficient way possible," Villalta
said, "Personally, I'm happy with the results, and I think that these
projects show what UCA can do with its human and material resources."
At the same time, what was meant to enhance the life of a community became
a source of social friction.
| What
was meant to enhance life became a source of social friction. |
Part of the distribution plan was that every house would have a fuse
box so no one could draw too much energy from the batteries. If someone
exceeded the current allowed, the fuse would burn out. Replacement would
require a trip to a local leader, and an admission that someone had accidentally
or intentionally taken more than an equal share of the community's electricity
supply.
According to Rivas, some people did start overtaxing their household systems.
Instead of going through the steps of replacing their burnt fuses, a few
homeowners ran wires around the boxes. Even in cases where village leaders
knew someone was cheating, they were reluctant to take corrective steps
because they did not want trouble with neighbors.
Even the presence of the engineering team upset local order. The engineers
used global positioning system devices to calculate the distances they
would have to wire. They downloaded information from laptop computers.
The people watching them work lived in a town with no electricity. Understandably,
the outsiders from the university became celebrities.
"We were some guys that came there with weird gadgets they probably had
never seen before, and were doing things they could not understand," Rivas
said. "Because we were different, and maybe because we could do things
they did not understand, some people tried to become closer to us to get
the admiration of other members of the community."
When it became clear that people were associating with the engineers to
enhance social status, Rivas and the others tried to make a point of speaking
to everyone, even visiting different homes in the evening. Even so, the
rise in status among those who worked with the engineers to build the
installations and in other capacities created tension in relations with
traditional community leaders.
"We learned that putting technology in the hands of our people is not
enough to make them develop," Rivas said. "As engineers, we were too excited
about the systems, and did not anticipate how the community would react
and use it. For future projects, we have to make sure to include sociology
and anthropology people. We limited ourselves to solving the technical
issues, assuming that once those issues were solved everything would work
automatically, but it turned out that the cultural issue is as important
as the technology."
Assessing the Gains
Although the net effect of electrifying the three villages has generally
fallen short of the engineers' expectations, there have been gains in
the quality of life. In El Alto, there is a small refrigerator that keeps
some foods longer. The people sell chilled beverages to visitors from
time to time, although not on the scale originally envisioned.
According to Rivas, the people are exposed to less smoke from burning
wood for light, and spend less money on kerosene and batteries. They can
conduct nighttime activities in churches or schools. There is enough power
in town now to operate a small television set.
A major advance is summed up in a story that took place in Izotalío.
Rivas has a photo that was taken in the village showing where the nearest
paved road is. You can't see the highway, only the white rock where the
roadbed was carved out of a distant mountain slope. To go to townthat
is, to San Salvadorpeople from Izotalío have to hike miles
through the forest, down their mountain, across the valley, and partway
up the other side, to reach the highway where they can catch the bus.
That's the way to the nearest hospital.
Rivas said that, when a man from the village suffered an accident and
had to be taken to the hospital, his neighbors laid him in a hammock,
and tied the hammock to a sapling trunk. That way, two people, one at
each end of the trunk, could carry him through the forest to the highway,
where they would flag down a vehicle or take the bus. They were doing
what others before them had done in emergencies.
But this time there was a difference. The electrical system made it possible
for the village to have a phone for the first time, a single cell phone
shared by the community. When the party reached the highway with the injured
man, this time there would be no wait for a bus, no attempt to stop a
random motorist. This time, perhaps for the first time in their experience,
an ambulance was already there, waiting for them.
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