Printer Friendly

Best intentions: the tools of improvement don't always fit the hand in need.

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 communities--where light at night came from burning kerosene or wood, where radios, if there were any at all, ran on batteries--might 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.

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 Jose 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 Izotalio, 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 Izotalio 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 Not--that is, Brother and Sister in Need--in 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 Izotalio, 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.

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 Izotalio 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 Izotalio 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.

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 Izotalio. 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 town--that is, to San Salvador--people from Izotalio 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.
COPYRIGHT 2005 American Society of Mechanical Engineers
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2005 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:using photoelectric systems to provide electricity
Author:Hutchinson, Harry
Publication:Mechanical Engineering-CIME
Geographic Code:1USA
Date:Feb 1, 2005
Previous Article:Cheaper watches: research looks at wireless networks to lower the cost of monitoring plant machinery.
Next Article:Managing across cultures: how do you design food-processing equipment if you know next to nothing about the culture in which it will be used?

Terms of use | Privacy policy | Copyright © 2021 Farlex, Inc. | Feedback | For webmasters