Domestic Rooftop Solar Electricity- Is it Such a Good Idea?
John ED Barker, PhD
Adjunct Professor, School of Sustainability
Part 1- Elsewhere
Several years ago, I visited the island of Amantani in Lake Titcaca, Peru. My partner, Diane and I had just walked the exhilarating Inca Trail with a small tour group and a “family stay” on Amantani was the next goal in our five-week tour across South America.
Amantani is a two-hour boat trip from the Peruvian lake port of Puno. It is concisely described in Wikipedia:
Amantaní is an island on the Peruvian side of Lake Titicaca. According to a 1988 census, it has a population of 3,663 Quechua speakers divided among about 800 families. The island is circular and about 9.28 km² in size. It has two mountain peaks, Pachatata (Father Earth) and Pachamama (Mother Earth), with ancient Inca and Tiwanaku ruins on top of both. The hillsides, are terraced mostly worked by hand and planted with wheat, quinoa, potatoes, and other vegetables. Livestock, including alpacas, also graze the slopes……
Similar to the Taquileños, the inhabitants of Amantaní are also known for their textiles, as well as their ceramics. Most of the inhabitants live in houses of adobe. There is a small health clinic and school on Amantaní, and, while there are no hotels, some families offer meals and overnight lodging to tourists. In return, guests are expected to bring food (such as rice or sugar) as a gift. The island has no cars and is powered for only a few hours a day by a generator.
As I stepped from the boat, bearing the recommended gifts of food, I was greatly surprised- not having noticed the last line in the Wikipedia summary before. Alongside the pebble-decorated concrete footpath that passes for a main street in the town were streetlights similar to those along the streets of Sydney, Perth or Beijing. To the top of the wooden pole was bolted an arch of steel terminating in an alien-like lamp-head. Wires spanned from pole to pole to the end of the street where two similar poles supported a large transformer between them- again similar to those found in any suburban street that hasn’t put all its power cabling underground. A web of wires spread out from the transformer to the nearby houses. Nothing unusual, perhaps, but it looked distinctly odd, juxtaposed with the simple adobe houses, on the roofs of which were small panels of solar cells- about the size of the ones commonly seen on emergency phones on our freeways- about 50 watts by my estimate. I wondered- were these isolated peasants actually early adopters combining mains electricity and solar electricity in a feed-in tariff program? The reality turned out to be more grim than this- and more illuminating of the broader issues facing solar electricity everywhere.
Our host family lived in a typical, small, two-storey iron-roofed adobe dwelling with a courtyard, across which swung a 240-volt mains electric line. But separate from this wire, exposed insulated wires ran along the wall outside our upstairs bedroom, through the top of the low door to a crudely-fixed switch next to a light fitting on the wall. The fitting contained an 11-watt “energy saving” fluorescent globe. Half-a-metre below the 12-volt switch was another switch which must have had a conduit hidden in the wall, leading to a naked 240-volt light globe in the middle of the ceiling. From outside, it was apparent that the host’s bedroom had a similar lighting arrangement. The wires also ran to the ground-floor kitchen.
The next morning we saw the kitchen/dining room, which had a similar “energy saver” globe and a similar higher voltage globe in the middle of the ceiling. The 240-volt incandescent globe was obviously not in use as it was completely covered with that dark brown tar that accumulates on surfaces near open fires in small rooms. In the corner of the kitchen was such a fireplace- just a partly bricked-in space with an open top and an aperture for poking in small pieces of wood. The host’s twenty-one-year-old daughter prepared a breakfast of tea, corn soup, beans and a thin corn bread- all prepared in a pot and fry pan on the stove as smoke swirled around the room, adding an incremental layer of tar to the defunct light globe. Later she told us that she was the youngest of four sisters- the older three had left the island to work in Puno. Her education had been truncated so that she could be the housekeeper. Her mother and father were both fifty-five, she told us- but mother looked a lot older. Undoubtedly the ravages of hard work and years of inhaling tarry smoke in the kitchen were taking their toll- as they have with millions of poor people in Africa, Asia and Central and South America.
I was particularly sensitized to this issue as we arrived in Peru directly from Beijing, where I had presented a paper at the World Solar Congress on my development of a very low-cost solar oven[i]. The World Health Organisation, I had read, estimated that two million people- mainly women and young children- die each year from respiratory ailments caused by continual cooking in conditions like this. The mother was undoubtedly somewhere in the “long tail” of countless millions of women whose health had been affected and lives undoubtedly shortened by poorly ventilated open kitchen wood- burning stoves.
Perhaps paradoxically, the firewood and the power poles came from stands of eucalyptus trees dotted around the island. These trees grow better there than in their native Australia- fertile soils and a lack of natural predators is the usual explanation. The indigenous trees would have been cut down many years ago- perhaps even centuries ago. The soil moisture and fertility-depleting characteristics of eucalypts is well known in South America. It seems that they have bought into a Faustian bargain- the price of their fire is their soil.
That night the townspeople hosted us at a dance-party in their town hall, where the women in our tour-group wore local dress and our men wore ponchos and Indian hats. We were all shown how to perform one of the local dances and much local beer was consumed under the dingy lighting- the town hall had a PV system three times the size of the domestic systems- enough for about half a dozen energy-saver globes for a few hours with the storage batteries.
As we left the island, I quizzed our guide as to what was happening with the electrical systems on the island. According to him, until the mid ‘nineties, the island essentially had no power- except for a few small gen-sets used for public purposes. The households relied on candles and kerosene lamps- much the same as we had in countryside Western Australia in the ‘fifties. Then a politician came along and promised electricity for all in return for their votes. The newly-elected politician was true to his word and a 240-volt diesel generator system, street lighting and house lighting was duly installed. The system was designed to run for about three hours each evening. However, it wasn’t long before there were technical difficulties and with fuel price rises, the islanders felt that the system wasn’t worth it. A couple of years later some of the islanders were able to purchase their own small stand-alone solar electric systems, he said.
I was able to complete this story later with an article I found via Google by Dr Manfred Horn of the Centre for Renewable Energy at the National Engineering University (CER-UNI) in Lima[ii]. The paper had been presented at the 2003 ISES World Solar Congress- that year’s version of the conference that I had just attended in Beijing. According to Dr Horn, the 250 Kw, 240-volt diesel generator system had been installed in 1997 as part of the Peruvian Rural Electrification Scheme. It was to serve 600 families, who would pay $3 per month per family. His paper confirmed that technical problems and rising fuel prices led to it being abandoned. However, in 1999 the islanders were able to participate in a solar electric scheme that Horn had first presented to the Peruvian Ministry for Energy and Mines in 1996. This scheme had started on the island of Taquile with a grant of $100,000 he had been able to obtain from the Ministry. The basic system, as described above, was a 50-watt PV module, three 11-watt energy-saver globes, a 12-volt, 100 a-h battery and associated electrics, including a battery charger for radios and other small appliances. Rather than being a gift, the householders had to pay off most of their $850 systems with five tranches of $150 over three years. All of the initial 100 households paid back the money, enabling a rolling fund to be established, which was later used for the people on the island of Amantani. The $150 was less than the money that they were accustomed to spending on candles and kerosene and radio batteries. These systems provided on average about one-fifth of a kwh (unit) a day- enough to power the three globes for about six hours. At this rate the battery has about four to five days’ storage. It wasn’t the luxury of our Australian average household of about 20 units each day- about 100 times the rate of the adobe households of Amantani.
On our return to shore, we proceeded by bus across the Altiplano– the 3,500 metre-high sedimentary basin the size of Tibet that straddles the Andes between the coastal deserts and the inland jungles. High tension electricity poles followed the road and frequently branched off to the clusters of adobe hovels and occasional brick mansions, all courtesy of the Peruvian Rural Electrification Scheme.
Since our return to Australia, I have often thought about electricity supplies that I have seen- from Bali to Beijing to Bolivia- they are in a mess. The “Bird’s Nest” stadium in Beijing could have been a metaphor for the tangled wires that festoon their power poles- the same muddles are seen throughout India, Asia and South America- where the demand for electricity has outstripped the community planning capabilities. Pollution is everywhere. Chinese lungs are filled with the grey smoke from coal-fired power stations and the lungs of a billion women and young children on four continents are filled with the brown tar of unventilated wood-fired stoves. Electrical bird’s nests atop Australian eucalypt poles and tar from Australian eucalypts in the peasants’ lungs. Have we anything else to contribute?
Dr Horn’s “early adopter” demonstrations on Amantani seemed to be bearing fruit. I found the following announcement in an online newsletter for members and supporters of the Alliance for Rural Electrification (ARE):
Ministry in Peru earmarks $200 million to develop renewables in rural communities
Peru’s Ministry of Mines and Energy has completed a 10-year rural electrification master plan based exclusively on renewable energies.
The goal is to reach communities that will not be linked to the national electric grid even within the next 10 years. The strategy seeks to provide 261,520 households with access to solar-based electricity systems and 18,498 households with power generated by new mini and micro hydropower plants.
Putting the plan into action will require an estimated investment of US$218 million through 2020, according to a statement the ministry issued last month. About US$178 million will be set aside for installing solar photovoltaic panels and the balance for building mini and micro HPPs. The program, scheduled to start next year, is to be financed from the Peruvian state budget, user contributions and foreign credit. [iii]
[i] Barker, John ED, The “Solar Nest”-A Very Low Cost Solar Cooker, Proceedings of ISES World Congress 2007 (Vol. I – Vol. V), D. Goswami & Yuen Zhao, eds, Springer 2009 (Available from the Author)
[ii] Horn, Manfred J., Solar Photovoltaics forSustainable Rural Electrification in Developing Countries; The Experience in Peru, “Invited talk” at ISES Solar World Congress 2003 June 14-19, 2003, Göteborg, Sweden (available online at: fc.uni.edu.pe/mhorn/ISES%202003%20(rural%20PV%20electrification)%20.pdf) (Dr Mann’s address: Centro de Energías Renovables, Universidad Nacional de Ingeniería, P.O. Box: 31-139, Lima, Perú, Telefax * 511 – 4810824, email@example.com)