SMALL SCALE WIND ENERGY SYSTEMS

 


Published with financial support from The Netherlands Minister for Development Cooperation

"Small Scale Wind Energy Systems" is a quarterly publication of the Regional Energy Resources Information Center (RERIC) - AIT, Bangkok, Thailand and edited by RED Renewable Energy Development v.o.f. It is distributed as a supplementary sheet with the "RERIC News" and by direct mailing. Citation is encouraged on the condition that the source is indicated.


March 1997

 

The Stimulation of Local Development for Windpumps in Asia

This article describes the progress of a project which has succeeded in stimulating windpump activities in China, India, the Philippines and Vietnam. This has been achieved through the formation of associations of the key players within each country to formulate national plans for windpump market development. In addition an international workshop attended by four representatives from each country association promoted collaboration between countries in the Asian region and provided a forum to introduce the associations to a database of windpump publications developed by the project consultants.

Previous articles in RERIC News have described work analysing the market for windpumps (see RERIC News Vol. 17 nos. 3 & 4) and an article by one of the authors described the objectives and methodology of the project being reported here.

This work was supported by the United Kingdom’s Overseas Development Administration. HGa are the project co-ordinators with additional consultancy support from Gamos Ltd and RED.

National Developments

The project started in each country with a workshop attended by representatives of the key organisations in the country. Following this workshop the national associations were formed and developed their terms of reference (TORs) and national strategy plans which were presented at the international workshop.

International workshop

The international workshop was hosted by CSR at Auroville, India in November 1996. Four representatives of each local association participated as well as the consultant team. One session analysed the barriers to the development of the windpump market and the workshop then divided into three groups in order to discuss possible solutions. Each group addressed these problems from the different, but overlapping, perspectives indicated by the figure below.

 

 

Policy & integration

It was suggested that the associations were an effective way to co-ordinate representation of the windpump industry in the formulation and implementation of policy and that:

Markets & users awareness

A major barrier to windpump development is a lack of awareness or mistrust of windpumps which often have poor reputations. To remedy this promotional information needs to be gathered from successful demonstration projects and made available to policy makers and potential users.

Technical, manufacturing & sales

It was agreed that windpumps could be made more reliable and hence attractive to the market by taking the following actions;

Country Initiatives

Proposals from China

The Chinese representatives proposed two major projects:

It is proposed that both projects be funded by a combination of local and foreign funds. Other support activities were proposed to promote windpump technology and develop additional applications.

Proposals from India

The Windpump Network India (WPNI) will be undertaking several activities aimed at developing local and state government initiatives to promote windpump development and to stimulate the uptake of mature technologies;

Proposals from the Philippines

The representatives from the Philippines outlined the development plans of the Wind Energy Association of the Philippines (WEAP) which divide into three components.

Technical

Marketing

Policy

Using it’s position in the government supported Renewable Energy Association of the Philippines (REAP) the association will lobby for an amendment of the Non-Conventional Energy Bill to provide more encouragement for renewables.

Proposals from Vietnam

Technical knowledge of windpumping and its applications in Vietnam is still limited and therefore the first stage of the proposed programme will involve data collection regarding wind resources in Vietnam, technical exchanges on wind machine design and manufacture, and investigation of available technologies which could be suitable for the local conditions.

The second stage will move into demonstrations of appropriate windpumps for various applications. A very good potential market is for low lift pumps to serve shrimp farms and salt pans. Other potential applications include small irrigation schemes for vegetables and cash crops, and domestic water supply. There is also strong interest in small wind generators.

Database Development

A key issue to emerge during the course of the project was the need for appropriate and adequate information to inform and assist the regional networks. A database has been developed which includes information on windpumps and material related to project management, financing, development issues and manufacturing. The CD ROM database includes photos, video clips, manufacturers data, technical papers and related literature. Some key publications are included in the database in their entirety and others are referred to which can then be obtained from either the source or a library. The CD ROM is currently available only to the four local associations but it is hoped to be able to finance wider distribution and continued improvement.

Conclusions

The formation of country associations made up of existing key players appears to be an effective way to stimulate the activities of the windpump sector. The activities of those within the association have previously been carried out in isolation from their fellow association members; the networks which have been stimulated by the association has encouraged a more co-ordinated lobby to policy makers and a more integrated approach to addressing the challenges faced by those working to promote the use of windpumps.

At the international workshop held in India it was widely agreed that an international network would be beneficial. A group comprising of a member from each country association is currently investigating the formation of such an international network.

The country associations can be contacted at the addresses below;

China:

Mr Shen Dechang, The Chinese Academy of Agricultural Mechanisation Sciences, No.1 Beishatan, Dewai, Beijing - 100 083; Tel: +86 010 62017131 / 2522; Fax: +86 010 62017326

India:

Mr Tency Baetens, Centre for Scientific Research & Windpump Network India, Auroshilpam, Auroville - 605 101, Tel: +91 413 62168/62277; Fax: +91 413 62057; E-mail: csr@auroville.org.in

The Philippines:

Mr Alexis Belonio, Wind Energy Association of the Philippines, c/o CPU-ANEC, College of Engineering, Central Philippine University, 5000 Iloilo City, Tel: +63 320 3004; Fax: +63 320 3004

Vietnam:

Mr Trinh Quang Dung, TEC Transviet & Solar Lab, 01 Mac Dinh Chi Street, 01 District Ho Chi Minh City, Tel: +84 8 8295905 / 8258778; Fax: +84 8 8295905

(Dr Daniel Davies & Mr Rod Hacker. HGa Consulting Engineers, Burderop Park, Swindon, SN4 0QD, UK, e-mail: hga@hga.co.uk)

 

Advances in Chinese Wind Generator Technology

The Shandu Animal Husbandry Machinery Factory (SAHMF) in Inner Mongolia, China, is the only factory assigned by the Ministry of Machinery Industry to produce wind generators in series. With twentyone years of experience in product development and production methods, SAHMF's wind generators were the only ones which passed the Ministry's reliability tests. The company now produces three different types of wind energy equipment. The annual production already reaches 10,000 units, or about 65% of the total number of windgenerators produced. Products are not only sold in China but also abroad.

Since 1975, the factory has cooperated with many colleges and institutes for product development. Among them, there are the Institute of Prairie, Chinese Academy of Agricultural Sciences, the Tsinghua University, the Harbin Electronic Engineering College, the Huazhong University of Science and Technology, and others.

Emphasis is on technology improvement. In 1988, a new wind machinery manufacturing technique was acquired from the SVIAB Company in Sweden. At present, thirty different types of wind energy equipment can be produced, ranging in capacity from 50 W to 5 kW. Both wind generators, water lifting windpumps and combined wind-solar cell units are produced. All systems offer good performance at low wind speeds, and the tendency is to further simplify the structures.

Wind generators, however, are our main product. Some of them will be discussed below:

When looking on water-lifting wind machines, SAHMF produces a pull-bar pump and a large flow windpump. These pumps are suitable for areas with high wind resources, to lift water from deep wells, to provide drinking water for men and animals and for irrigation.

The factory is devoted to the development and usage of wind energy as well as to the research and production of wind generators. Regarding the future, the effective usage of wind energy and solar energy will become the subject of mankind, exploring new energy. SAHMF wishes to contribute to the energy problem by making high quality, large-power wind generators, and when possible in cooperation with others.

(Yang Bing, Shandu Animal Husbandry Machinery Factory, Inner Mongolia, China)

 

Indigenous Windpumps in Barangay Utod, Philippines

To our own surprise, locally-made windpumps are being used in Barangay Utod, a rural village in the municipality of Pulupandan, Negros Occidental, in the Philippines. These windpumps were spotted on a mission of our Affiliated Non-Conventional Energy Center of Silliman University, in an effort to monitor existing non-conventional energy systems in our area of coverage (Negros Occidental, Negros Oriental and Siquijor).

The windpumps are made of crude materials. Four rotor blades made of used, corrugated galvanized iron sheet, are attached to wooden spars which form a cross. The mounting frame and the pump rod are made of bamboo. The pump cylinder, at the same time serving as the pump riser, is made of a PVC pipe. One end of the shaft is fastened to the rotor, whereas the other end moves the crank mechanism driving the pump rod.

It should be noticed that the windpump has no tail vane. However, the system does not need such a mechanism because the salt making activity is recurring from January to April, when the prevailing wind is the Northeast Monsoon. The rotor plane is therefore permanently positioned perpendicular to the direction of the prevailing wind.

The production of salt from sea water is a major economic activity in Utod. The use of windpumps eliminates the burden of drawing sea water, thus saving human energy which can be used for productive purposes. This development is a good example of the people's ingenuity to create their own technology in harnessing free energy from nature, to facilitate their lives.

(Mario J. Manginsay, Affiliated Non-Conventional Energy Center, Silliman University, 6200 Dumaguete City, Philippines, Fax: +63(35)225 2900)

 

Wind-Electric Power for Communities in Mauritania

The use of renewable energy technologies for small-scale electric power generation is just beginning in Mauritania. Within the framework of a US$ 40 million programme for pumping in West Africa, the EU Fund for Development is financing the installation of PV pumps in several areas of the country. However, in areas with reasonably satisfactory wind resources (monthly mean wind speed above 4 m/s), wind turbines can provide a more economical method for decentralized electricity generation. Mauritania is one of the windiest countries in West Africa. The sketchy wind data available reveal average wind speeds ranging from 4 to over 8 m/s over much of the country, which would make small wind generation systems more economical over their lifecycle than small engine generators and PV, its only practical competitors.

The UNDP/GEF Project Alizés Electrique

The Alizes Wind-Electric project was designed to build on the Alizes water pumping project between the Mauritanian Government (Ministry of Water and Energy, Division of Energy) and the French NGO GRET. This aimed at establishing village-based water supply using wind-mechanical water pumping units. By requiring (and achieving) financial and social participation by the villagers, the programme has been able to provide clean water on a reliable and continuous basis in the 100 villages that are now served. The new wind-electric project makes direct use of the resources and infrastructure established by GRET, the local private sector, the villages and the Government.

Project Background

Mauritania is a West African country bounded to the north by West Sahara and Algeria, to the east and south-east by Mali, to the south by Senegal, and to the West by the Atlantic Ocean. The land area is slightly over one million sq. km in area, but with only two million inhabitants. Two thirds of the land is desert; the southern region is Sahelian. Only in the flood plain of the Senegal river, the border with Senegal, there is abundant water and rich soil suitable for intensive cultivation. Ten percent of the population lives in the desert, the majority lives on just fifteen percent of the land, primarily in the Sahelian, coastal and Senegal river regions. The subsector of concern in the present project includes the unelectrified population in both the rural areas and the approximately 1 million people in the peripheral zone around the capital, Nouakchott.

Because the rural population density in very low, provision to the villages of basic services such as water pumping, health care, and lighting is difficult and expensive. Even in the more densely populated southern region, villages have only a few hundred inhabitants. A village like Keur-Macene with more than 1,000 inhabitants is considered large. Few villages have any access to electricity.

The lack of electric power in most parts of the country is a major obstacle to improvement in these areas. Electricity is a key input to address these issues (although obviously not the only input necessary). The specific applications of electric power in the rural area include: household lighting, radio and television; water pumping (including deep pumping beyond 30 meters); water treatment; surface pumping for irrigation; battery charging; refrigeration; miscellaneous (electric fencing and other needs); community needs such as health stations, schools, mosques, shops, workshop and public lighting.

Implementation

In the first month of 1996 the Dutch supplier LMW installed 14 wind turbines with capacities of 1,000-2,500 Watt rated power. These turbines are mainly used for charging 12 V/50 Ah batteries. These batteries will be used in private houses with one or two 8-10 Watt tube light and sometimes a black/white TV set per household. The families in the villages pay 200 MU (=1.5 US$) monthly and 200 MU per charging. One family will need about 3-4 chargings a month. The batteries are equiped with a charge 5controller to protect the battery against overcharging and discharging. The battery and controller are put in a wooden box. The controller and the tube light are locally produced.

LMW has several years of experience in Mauritania in wind electric power supply. In 1992, it supplied three wind turbines LMW1003 to GRET through the French company EED in Lille. These turbines have been installed in the southwestern part of the country. One of them has been installed in Tighent and is used for battery charging. The batteries serve a small grid which supplies the small shops in the village. When there is sufficient power, private users' batteries can be charged as well. Tighent is a large village with e.g. a school and a hospital. The output of the wind turbine is too small to supply energy for the whole village.

The second LMW1003 has been installed in a village near Rosso. It is only used for battery charging. An operator takes care of the system and payment from the inhabitants. A refrigerator has been removed because it consumed too much power.

The third wind turbine is used for pumping water in a village named Keur Macene, along the river Senegal. The water is pumped from the river and stored in a tank for 24 hours to precipitate. From the first tank the water is pumped into a second storage tank and will be further processed to clean it for use as drinking water. A storage tank on a hill is 400 m away from the wind turbine. A local network is created in the village. These three wind turbines show the benefits from wind energy: economically by electric light in shops; socially by lighting and TV in households; health by clean water.

Local cooperation

For the execution of the new project, LMW started collaboration with two local companies, one for local production of towers, installation and after-sales service and one for the supply and installation of the electrical works.

During the execution of the project LMW will give training and technology transfer for the installation service and for local production of the towers, tail, frame and tail vane. In the second phase of the project, which started at the end of 1996, another 85 wind-electric turbines will be delivered, but an important part of the system will be produced by local enterprises. LMW however, will supply the materials for the production.

(Johan Kuikman, The Netherlands, Fax: +31(50)534 0104)

 


June 1997

 

EDITORIAL

In March 1996, "Small Scale Wind Energy Systema" made a restart after an absence of one year. As we then wrote, the idea is to provide a platform for people working in this field to communicate with eachother. The newsletter is published with financial support from the Netherlands Minister for Development Cooperation (DGIS). The current contract with the Minister coveres eight quarterly issues from March 1996 till December 1997.

Before considering a possible prolongation, as the editors we would like to sound your interest in this newsletter. Our main question is: do you consider the topics covered by "Small Scale Wind Energy Systems" of use for you, and would you appreciate receiving it in the future? Please send us your response by email, fax or mail. We also welcome any comments and suggestions to improve this news service in the future.

Up to now response from the South has been rather poor. As it seems, the concept we chose to "provide a platform" has not been the most appropriate. We are pondering about altering the concept in the future, but need a better insight in the reader's profile to do so. Any comments in this sense would be very useful.

In the December 1997 issue, we will report you about our findings and inform you about the future for "SSWES" in 1998 and beyond.

Jan de Jongh and Remi Rijs, editors

 

Cambodia - a clean wind

Cambodia is ranked as one of the poorest countries on earth. After many years of destructive civil war the country is trying to stabilise its agriculture after the UN sponsored elections of 1992. Rural development is a priority, and water supplies feature at the top of priorities. In a typical Khmer village one or two old open wells are the only source of water. UNICEF and Oxfam work hard to develop public handpumps.

In an unusually successful move, a consortium of agencies, Christian Outreach, World Concern, Danish Santel Mission, together have been working on using ground water for micro irrigation using windpumps. The windpump element fits in a sequence of development. The village controls a revolving credit fund, and the agencies empower the people to decide their own priorities and actions. New protected open wells are generally the first action of the village. When these have been in use for a while, their thoughts turn to handpumps for more accessible water. When about 10 families have handpumps, they begin to use surplus water and spillage for gardening. The gardening turns to micro irrigation of high value crops. As more people wanted handpumps for vegetables, the Treadle pump from Bangladesh found an enthusiastic market. More than 3000 have been installed in the last three years.

As the village grows in prosperity, their thoughts turn to how they can get more water - and then the choice becomes diesel-mechanical pumps or windpumps. The agencies showed the villagers a video of windpumps in Thailand, and one village was willing to try one demonstration unit. A modified CWD 2740 was applied and has been used to grow about half a hectare of vegetables. Given the problems of fast running pumps, the system has been changed to a higher solidity rotor to give it reliability and a high availability. Initially bearings from Vietnam gave problems through their very low quality. However the manufacturer took the initiative to change the design to incorporate larger bearings that were still low quality but were capable of running for 10 years. The CWD 2740 design was used with a treadle pump to encourage the farmers to see the windpump as a natural extension of their pumping experience. The link between the treadle and the windpump mechanism is made detachable so that in the event of low winds the farmer can supplement the wind water with foot pumping. Two other units are in production by the local manufacture, and the scene looks set for a slow but steady demand for windpumps.

(Simon J. Batchelor, Gamos Ltd, 152 Cumberland Road, Reading RG1 3JY, United Kingdom, Fax: (01189) 351374, Email: simon@gamos.demon.co.uk)

 

China - new research, new applications

Elsewhere in this newsletter, the ODA sponsored network of windpumping has been mentioned. In China this has resulted in several new initiatives. It was agreed at the China workshop that there was little need for new designs, but rather a persistence in the application of existing designs. As a result, two proposals have been developed.

Desalination of over 6,000 hectares is planned in a multiphase project. The TFS5, a commercial windpump system built in China will be used to rehabilitate the land. The proposal is at an early stage and international funding is actively being sought to match the Government funding. HGa and Gamos Ltd have made some technical assistance available to the City Authorities. Irrigation from the seepage of the new city reservoir in Chaungzhou is another practical application of windpumps that is being considered. IT Power Ltd are the collaborators on this proposal and have agreed to allow the Chinese to build one of their new windpumps as soon as the latest version has been tested.

Having said that research was put on the back burner, the workshop did identify very low head applications as needing more research. The TFS5 windpump developed in China and manufactured in Tianjin works with an archimedes screw pump. This limits the system's application to less than 3 m heads. There was a stated need for a system that would work in the 2 m to 6 m range. The Chinese Academy of Agricultural Mechanisation Sciences (CAAMS) has responded by submitting and gaining approval for basic research in windpump systems using centrifugal pumps. They have core funding from the State Government but would welcome an international funding partner.

Interested parties should contact either Gamos Ltd or HGa:

Gamos Ltd, 152 Cumberland Road, Reading, RG1 3JY, United Kingdom, Fax: (01189)351374, Email: simon@gamos.demon.co.uk;

HGa Ltd Consulting Engineers, Burderop Park, Swindon SN4 OQD, United Kingdom, Fax: (01793) 81502

(Simon Batchelor, Gamos Ltd, UK)

 

Colombia picks up Rope Windpump Technology

The March '96 issue of this newsletter reported on an international seminar about "New Developments in Windpumps" held in Bogota, Colombia. The event was attended by representatives of seven Latin-American countries and focused on the "below ground level" problems ecncountered in windpumps and the dissemination of recent developments regarding "3S" - Smoothing, Starting, and Sealing. Part of the seminar was a presentation of several participants about developments in their respective countries. Nicaragua's representative Luis Roman, aroused interest because of the different solution to "3S" problems he proposed.

Mr. Roman, who is responsible for the windpump production workshop AMEC in Managua, presented the developments in Nicaragua around the "bomba de mecate". This is a rope and washer handpump improved in Nicaragua and claimed to be the "most intelligent" handpump until now. It is suitable for wells from 1 m to 80 m deep and is cheaper to produce and easier to maintain than other handpumps. The more than 10,000 pumps installed in Nicaragua over the past 8 years prove it.

The "aerobomba de mecate" developed in Nicaragua is a combination of this rope pump with a lightweight, low-cost windmill. The safety and orientation system of these windpumps is based on the Dutch CWD designs. About ninety units have been installed in the last few years in Nicaragua and most of the owners prove able to maintain the windpump after some initial technical assistance. The concept of the rope pump (which has a rotating shaft) connected to a wind rotor avoids most of the traditional "3S" problems:

After the seminar, an agreement was made with AMEC to introduce the rope windpump in Colombia. A two-step "transfer-of-technology" workshop was devised which would be held in Cali and included two visits (of two weeks each) of AMEC's technical expert to Colombia. During the first phase, components were brought to Colombia and a rope windpump was assembled under supervision of AMEC people from Nicaragua. This unit was installed near Cali and monitored during about 4 months. During the second visit, several changes were put through (mainly to adapt components to locally available materials) and a second windpump was constructed and installed. Jigs were made to enable future manufacturing of the rotor, head and tail in small series. Both visits included an on-the-job training for the APROTEC technicians on design, production and installation.

The retail price for the 3 m windpump in Colombia is about US$ 900,- (including a 13 m tower), which is a slightly higher than in Nicaragua. Costs and maintenance appear so attractive that several windpumps were ordered shortly thereafter; it is expected that demands will grow in the future. One may conclude that -with relatively little effort- a successful transfer of this technology was established.

(Jesús Gómez, APROTEC, Calle 15b norte #AN51, Cali, Columbia, Fax: +57(2)667 0082, Email: mavillad@mafalda.univalle.edu.co)

 

Prospects in Senegal

The first serious attempts to assess available wind resources in Senegal were performed by CERER (Study Center for Research on Renewable Energy) in the years 1970-1975. Later on, ASECNA (Agency for Air Navigation Security) deployed activities between 1981 and 1992. As a result, two areas were identified with particularly favorable wind conditions.

The first area lies between Dakar-Thies and St. Louis-Dagana and shows an annual mean wind speed between 5-6 m/s at 10 m height. This area probably has the best wind conditions in Senegal. As a second area with less wind potential, the coastal region between Dakar and Gambia was identified.

Former attempts in the country to harness wind resources all have failed to a larger or lesser extent. In fact, Senegal has a history of more than twenty years of wind energy projects, a few of which are worthwhile mentioning:

It is obvious that the wind energy projects implemented up to now, have not been too successful. The main reasons for the lack of success are:

Despite the unsuccessful experiences in the past, current government policies include the promotion of wind energy. The Spanish company Desarrollos Eólicos has plans for a 10 or 15 MW grid-connected wind farm. The pre-investment studies are undergoing: potential sites have been determined and the economy of such a project is being assessed.

Currently, there is little activity regarding small wind power. Nevertheless, the need for rural electricity and water supply remains unaltered and windpower still establishes a possible alternative to diesel and PV. Hopefully, future wind projects will benefit from the experiences learned in the past.

(Zaccaria Koïta, Service Energies Renouvables - SENELEC, BP 93 Dakar, Senegal)

 

Third Wind Energy Training Course in the Philippines

Within the framework of a programme to improve institutional infrastructure and manufacturers' capabilities, a three week course on windpumping will be held at Iloilo City, the Philippines, next October. The course is organized by the Central Philippines University ANEC (Affiliated Nonconventional Energy Center) under auspices of the Government of the Philippines (DOE-NCED). Co-sponsor of the course is the Dutch Minister of Cooperation (DGIS) through the Royal Netherlands Embassy at Manila.

The course will be directed by Mr. Jan de Jongh of Dutch consultant RED vof and include the construction of a small, modern windpump. During the first part of the course, typical design weaknesses and structure failures will be discussed by Sri Lanka ITDG's Mr. Sunith Fernando. The practical activities will be deployed at the Jober Light Industries workshop at Cabatuan on the Iloilo island.

The training course is primarily of interest for manufacturers, implementors and university people working on renewable energy development.

The event is the third course organized by the ANECs and RED vof. Former events took place in May and November 1995 and covered implementation aspects and a general introduction to windpump design. Windpumping is currently the main and most developed application of wind energy in the country, but it is the intention to extend the programme to small wind electric power in the nearby future.

Information can be obtained from:

Mr. Reuben Quejas, DOE-NCED, PNOC Complex, Merritt Rd., Fort Bonifacio, Makati, Metro Manila, Philippines, Tel: +63(2)844 1021, Fax: +63(2)818 8614, EMail: ncedoe@doe.gov.ph)

 

CESADE Encouraged to Continue Small Windcharger Development

The Nicaraguan organization Centro de Estudios y Acción para el Desarrollo (CESADE) has recently completed an assessment of their indigenous small wind battery charger. The technology of this wind generator is based on the rope-and-washer windpump which is progressively penetrating the local market. The energy output of the system was required to be equivalent to and possibly slightly better than a 50 Wp solar home system (SHS).

CESADE's was challenged by the lack of alternatives to boost the development of electricity services in the Nicaraguan coutryside. The organization typically assists small and medium size farmers to increase productivity and improve quality of life. The accent is on sustainable development, particularly important since the Nicaraguan agriculture is suffering from severe erosion. CESADE' working area is mainly the dry tropics of Central Nicaragua and the Pacific Coast and its activities include improvement of agricultural methods, genetic improvement of crops and cattle, and a general information service to the communities.

Perhaps the mayor difficulty encountered by this sector is the lack of capital for investment. Therefore, CESADE locally develops low-cost technology which is then produced and sold commercially. If necessary, CESADE provides short term credits to facilitate the commercialization of equipment to the farmers. The rope-and-washer windpump "aerobomba de mecate" as produced by the Managua based AMEC workshop illustrates this strategy. The organization receives financial support from several European ONGs.

A minimum level of access to electricity is considered to contribute to quality of life in the countryside. In fact, many farmers in CESADE's target group use car batteries to power a radio and television and sometimes electric lighting. Batteries are charged at a local automotive workshop against payment of between 30 and 60 Cordobas (US$ 3,- to US$ 5,-) and sometimes quite a distance has to be bridged. As Nicaragua has fairly good renewable energy resources, a small wind or PV system for domestic power supply would be the solution. Yet, the cost of imported equipment is prohibitive for this sector, moreover as it does not have access to commercial bank loans. A commercial 50 Wp V system costs between US$ 500,- and US$ 600,- (without battery) and the smallest available windchargers imported from the US are even more expensive.

CESADE has recognized that a locally-made product might be developed to substitute the out-of-reach import equipment. Triggered by their positive experiences with the rope-and-washer windpump, a small battery charger was developed which has been tested at the AMEC workshop in Managua since December 1996. Between February and June 1997, the concept has further been improved and tested with technical assistance from abroad. The first design was two-bladed with a rotor diameter of 2 meter, a tower height of 7 m, and included a belt transmission. A second design included a three-bladed rotor, but the rotor head and hinged side vane safety system were basically copied from the -larger- rope windpump. Both rotors are slow-runners with steel plate rotor blades fixed to a welded tube spar construction. It proved not feasible to construct a fast running rotor using this technique.

Under field tests the energy output proved very satisfactory (approx. 0.3 kWh per day) and supplied power to a household of a 12" B&W television, and three light bulbs of 40 W each. During the test period, the owner quickly learned to balance his power demand to the supply of wind power. In fact, some dedicated demand side management may be required to compensate for the absence of a sophisticated load controller. The generator used in both models was a 110 V DC electric motor bought in the US which provided about 65 W maximally at 12 V. The transmission was needed to obtain the required generator speed of 3,000 - 5,000 rpm.

Initially, the emphasis is on effectiveness and sustainability rather than high energy conversion efficiency. The investigation of technical reliability is ongoing and focuses on the transmission and the electric generator, which in fact are the only new components added to the original rope windpump design. Bearing in mind CESADE's philosophy of sustainability -which has proven quite successful for the rope windpump business- a certain degree of simple user maintenance is acceptable. The lifetime of the transmission belt has proved beyond expectation and replacement once or twice a year is considered acceptable. The electric generator is the most expensive component and should have a lifetime of more than three years. It is uncertain if the applied DC motors will last that long and therefore a more suitable but cheap generator type is seeked for.

CESADE recognizes there is ample room for technical improvement, but foresees a large potential market inside and outside the country. The targeted retail price of about US$ 300,- without battery is easily achieved and might even be lowered with some product engineering. This price is considered as sufficiently low to enable commercialization of domestic power supply without external subsidies. The units would be sold with short term credits of one year maximally. The cost of energy assuming a 5 years' lifetime and US$ 20,- maintenance cost annually would be about US$/kWh 1,-, which is substantially lower than solar (based on a long term, commercial loan scheme).

Additional information can be obtained from:

Henk Holtslag & Enock Matute, Centro de Estudios y Acción para el Desarrollo (CESADE), Apartado Postal JN 4317, Managua, Nicaragua, Fax: +505-266 9270, EMail: cesade@nicarao.apc.org

 


September 1997

 

EDITORIAL

In this issue, we have news from priests in Zimbabwe and Guyana. Everwhere on Earth, "bringing water to the thirsty" is a rewarding labor, and windpumping is often the most viable way. Also on windpumping, we have news from Poldaw in the UK.

As the editors, we tried to stress the importance of joining the scattered efforts to develop small scale wind energy. Activities in small wind energy technology -renewables in general- as currently deployed are rather insignificant considering the huge potential market for rural electrification. The access to and the exchange of information may be a first step to concerted action. Enjoy!

Jan de Jongh and Remi Rijs, editors

 

Small Wind Power and Concerted Action

In the industrialized world there are quite a number of windmill manufacturers who have gone through decades of product designing, testing, modifying, and finally, commercializing. In the US, windpump development goes back to the 1850’s, while wind electricity had conquered its place in the countryside by the mid-thirtees. Since then, the focus of wind energy application has certainly changed, but the experiences have not gone lost. Regions comparable to the Great Plains are found all over the world, with a similar economic and agricultural profile -and with good wind resources. In all these regions, wind power was and still is a valid option.

Wherever on Earth, people require water and energy for the same reason as once on the Great Plains. To build up a prolific agriculture and to achieve a comfortable standard of living. To have food, education, health care, communication, safety. Money, prime materials and technical skills are a basic condition for an autonomous development towards acquiring these standards. On the Great Plains, as in Argentina, Australia, South Africa, this condition was fulfilled.

In the developing countries this condition is not met. However, the demand for electricity is evident, if not to improve quality of life and productivity, at least to hook up with modern life. It is obvious that local people try to do something about it. In virtually every country there is at least one group of engineers, technicians, and especially researchers from universities active in renewables.

What people build are water turbines, solar dryers, and windmills. These have been used by mankind since the Bronze Age and often local examples exist. People do not build PV, since there is no tradition and there is nothing to copy about it. While the working principle of windmills and water wheels is transparent, photovoltaics is a mistery, performing its action in silence.

Yet, the lack of success of local windmill designs is striking. Why? Because of limited capacity and money, limited knowledge and lack of suitable materials. And if a reasonable product might come out, it is too expensive for the market.

But how many people in the industrialized countries have managed to build a windmill that lasted for more than a year? Having modern machinery, materials, and a fair amount of money at their disposal? Very few. Even an engineer in aeronautics has to learn the basics before he should even think about trying it. An engineer in a developing country, so much more restricted in his possibilities, is not likely to make it.

It is questionable whether local groups should put their effort into exploring the basics of renewable energies. As part of a learning process, perhaps. But to establish a competitive production of reliable equipment, probably not. It makes not much sense to re-invent the wheel, especially not where skilled and knowledged people are scarce. Worldwide, very few people are involved in the development of small wind energy. Therefore, substantial progress may only be expected through concerted action.

Access to information is a first prerequisite for the efficient allocation of human efforts. Once people know where to focus on, they may start seeking money, materials, and technical assistance.

Only by having access to information, they may know what to look for and where. Information and the exchange of experiences will be of interest to all parties. The market for rural electrification can never be addressed by manufacturers of the current size. It is a market that demands for high volumes, low profits, and products adapted to the local situation. Only combined effort may bring this.

(Remi Rijs - editor)

 

Windpump Production at the Driefontein Mission in Zimbabwe

This summer, Brother Walter Schurtemberger of the Swiss catholic Bethlehem Missionary Society paid us a visit at Eindhoven University. He works and lives at the Driefontein Mission, Mwuva, Zimbabwe, where he runs a Metal Work Training. The Mission has a population of about 2,000 people, including 50 foreigners. It has its own food production, two hospitals with 270 and 150 beds, and various schools and training centers. The Metal Work Training counts about 25 trainees with an intake of 12 yearly. The training takes three years, during which period the trainees are lodged at the Mission.

His first contacts with the former CWD at Eindhoven date back to 1987. As a result, the school started producing the CWD 2740 windpump, initially with some assistance from a CWD consultant. The school now produces one or two units yearly, which are sold to farmers in the area. The income yield flows back to the school which is basically self-supporting. Every five year he is allowed to leave the Mission and go to Europe for some months. On July 22, we listened to his experiences:

"In 1987 we were looking for a new project for the trainees at our school. During their career they not only learn basic technical skills, but also produce agricultural equipment which is sold to clients in the surroundings of the Mission. This has proven advantageous as they learn to understand and build relatively complex structures and get a grasp of working in a commercial environment. The income generated is needed to cover the operating costs of the workshop and to pay the salaries of the instructors. Our institution is private and does not receive any support from the State. For the larger investments, for example a piece of machinery, we relay on support from our home base in Switzerland."

"Our trainees are very much wanted by the industries in Zimbabwe. In the region, it is quite uncommon to find a craftsman which combines good technical skills with a feeling for how to run a business. The basis for these qualities are the discipline and responsibility they learn at the Mission. All trainees have a small garden where they grow their own food. They also have to do the washing and cleaning. At the beginning they feel uncomfortable as this work is traditionally done by women, but later they enjoy being able to survive on their own."

"We have never had any serious accident in the workshop and this is because they feel responsible for each other’s safety. Contrary to the State schools, we cannot afford much of protective cloths. Instead, we teach our trainees to work safely, keep the workfloor tidy and operate the machines only if they are sure that everything is under control."

"A unique thing is that all trainees leave with a full set of tools made by themselves, as they will need in their professional life. It is the very essential part of their skill training and gives them full confidence and courage for the future as in a country like Zimbabwe tools may be scarce to find. We also give them insight in how things work, not only the equipment but also production processes, marketing, and even building sites. For the same reason, we prefer the old Swiss workshop machinery rather than more modern equipment, as one can see how they work and learn how to repair and maintain them."

"Regarding the windpumps, we are in the first place a Mission school and not a factory. Altogether we built and installed eleven CWD 2740 windpumps since our start in 1987. There is a strong demand for water lifting devices in the region and windpumping is probably the cheapest option. A promotion campaign to raise the farmers’ interest in windpumps would be very useful. But this takes a lot of time and effort and we don’t have the capacity for it. We would also like to advise farmers with respect to water supply and usage and act as a kind of consultant. Therefore we should update our knowledge and also have more manpower. And in the workshop, what we really need is some method of quality control. Some input by a foreign consultant would be very helpful to us, like we had in the eighties when a Dutch consultant assisted us to build and install the windpump."

"The main applications for windpumps in the region are cattle watering, domestic and garden use and sometimes irrigation. We have two models CWD 2740, one for 6 meter pumping depth and one for 20 meter depth. The first model costs about ZWD 19,000,- (US$ 1,650,-) and the latter one about ZWD 26,000,- (US$ 2,250,-). Both windpumps are meant for users with a lower to medium income.

There are also commercial windpumps for a pumping head of 80 meter and larger volumes. In Zimbabwe we have the Southern Cross windpump imported from South Africa, and the Stewards & Lloyds, which is produced in Harare. The Southern Cross costs about ZWD 50,000,- (US$ 4,300,-) and a smaller size windpump about ZWD 28,000,- (US$ 2,400,-). These windpumps are bought by large farmers and communities."

"It is getting more difficult to keep things running. In the past, workshops in the villages were able to maintain the classical windpumps but now when something goes wrong people just abandon them. The windmills have become too complex for them and it is difficult to get the spare parts. The transport services in the country have deteriorated very much. We used to have a small railway station in the neighborhood where the train stopped and dropped the materials we ordered from the city. Now we have to go to Harare to buy iron for our workshop."

"Even I can feel, that in Africa not only the weather is drying up but also the people. Therefore when I am on leave in Europe, I spend as much time as I can in studying, observing and collecting information for our library, wherever I go."

(Information: Brother Walter Schurtemberger, Driefontein Mission, Post Bag 7001, Mvuma, Zimbabwe)

 

Poldaw Windpump News

-Applications, Commercialisation, New Developments-

The Poldaw windpump design in a 3.5 metre rotor diameter version has been in service since early 1993, and in commercial production since November 1994. This brief note gives an update on commercial growth since then, and also discusses various applications beyond the usual ones of pumping water from wells and boreholes. The progress on development of a 5 metre model and other future plans are also discussed.

There are currently licensed manufacturers in 6 countries, these being Zimbabwe, United Kingdom, Pakistan, India, Ghana and Nigeria. Negotiations are taking place with potential manufacturers in several other countries. In general, the terms of the manufacturing licence give the manufacturer exclusive sales rights for the whole of the country. All manufacture is done within the country and in general no materials have to be imported.

Two of the licensees are forgings links with sub-manufacturers, though these have not yet been finalised. The sub-manufacturers are permitted to make some components, e.g. the tower structure, and purchase the rest of the machine from the main licensee. This type of arrangement is encouraged as it improves the geographical coverage of each licensee, while maintaining control over quality of the critical parts of the machine. This arrangement is enabling the licensee in Pakistan to export windpumps into neighbouring Afghanistan, without adversely affecting the resources available to serve the Pakistan market.

Links are being forged between the various licensees, to their mutual advantage. For example, the piston pumps are only available in a limited range of sizes in some countries, so sales of these components between licensees are occurring. Also there are plans for other related products, such as handpumps, to be traded between windpump manufacturers.

Sales in each country have been initially slow, but in most cases there has been encouraging growth as the reputation spreads. Typical quantities sold have been 10 to 20 in the first year of production. Sales in the UK have been surprisingly good, as without any promotion at all, 6 machines have been installed in the last year. Since the UK is generally well supplied with electricity, it was never envisaged that there would be substantial sales there, but currently there are serious enquiries for substantial numbers of windpumps.

There have been no significant reliability problems with the windmills, though there have been a few problems with the down-well equipment. The manufacturers are very confident that the design is fundamentally robust and will stand up to many years of use with little attention.

Most applications in developing countries so far have been extracting water from boreholes and shallow wells, for supplying drinking water to people or livestock. Customers have included farmers, schools, clinics, community projects etcetera. Some applications have been for small scale irrigation, in particular drip irrigation schemes.

In the UK, some other applications have emerged, which are slightly unusual. In some cases air pumps have been fitted instead of water pumps, and the pressurized air has been used to aerate compost, or to aerate liquid effluents. This is a true wind pump - using wind to pump wind!

Another application with great sales potential is the extraction of leachate liquors from landfill sites (rubbish tips). In these cases, windpumps are not only cheaper than electric or diesel pump installations, but also safer, as there is no risk of the windpump igniting the methane gas often present at such sites.

A recent enquiry has been for circulating water through reed bed foul water treatment plants. Here the maximum water flow requirement is usually in the winter, when there is plenty of wind available. A special low head high volume pump is being designed for this type of application.

A 5 metre rotor version of the Poldaw has now been fully designed, and a pre-production trial model will be built in India later in 1997. This machine is capable of pumping from 140 metres depth, 50% more than for the 3.5 metre version.

Future plans include the development of a low cost robust hand pump unit, and also an ultra low cost small windpump of about 2 to 2.5 metre rotor diameter, which would be sufficiently lightweight and simple to be installed by the purchaser.

(Sandy Polak, Poldaw Designs, Neale Consulting Engineers Ltd, 43 Downing Street, Farnham GU9 7PH, United Kingdom, fax: +44(1252)737 106, email: ncel@msn.com)

 

Bringing Water to the Thirsty

In March 1993 I was approached by Vanda Radzik, of the Red Tread Women's Press, Georgetown, Guyana, who published my book, "Journal of a Flying Priest", to coordinate a water sanitation development project in five villages within my 10,000 square mile parish. Vanda being based in Georgetown needed, so she said, a 'local' coordinator for the project, and she was willing to pay PND65 a month to the obliging person. The general idea was that she would look after the education side of the project, and I would supervise the erection of five windmills, and the digging of wells, and the building of water towers, and the plumbing, and the transportation and the local workforce, and the village self-help cooperation etc. plus, the construction of 10 VIP latrines -not superloos but "Ventilated Improved" for the schools.

The five chosen villages were Annai, 5 hours drive from my home between the months of October and May but only accessible by helicopter at other times; Nappi, an hour and a half away, which already had a 20 foot diameter hole, 50 foot deep which had yet to reach any water; Moco Moco, 45 minutes drive where the local 30 foot borehole had been condemned because someone had buried a corpse a little too close to the site; Kumu, just half an hour away which already had a good borehole with aquifer (water) at 25 feet; and Rupunau, seven hours drive away and the least accessible. Vanda gaily said there would be tons of money available, and we had from March to September in which to complete the project.

Plenty of unkept promises ensued, like "the windmills and pumps are still en route from Beatrice, Nebraska, the home of Dempster Windmills Inc." So, in April, rather than doing nothing we started digging holes at two other sites, Surama, Kwaterman, and at Moco Moco and Rupunau. We had been ousted, superseded, and pre-empted at Annai by the World Bank project who would be supplying a rather superior solar-powered pump, and had been asked to choose a nearby village as the recipient of the poorer cousin, a windmill. When we did get going things did not go well; the rains started early in May and lasted until the end of September, and still the windmills and water pumps had not arrived. There was no helicopter available, nor even budgeted for! All the holes we dug filled up with rainwater, the one at Rupunau collapsed, the soil being very sandy. So, undaunted, we turned our minds to constructing VIP latrines. The simple improvement in the ventilation was a 6 inch diameter 10 foot long PVC pipe, painted black, sited at the back of he toilet. The idea was to attract heat from the sun because of the black paint, and then the hot air is supposed to rise inside the pipe and suck out the gaseous odours, usually associated with pit latrines -I do hope you are not having dinner while reading this article! -the top of the pipe is loosely meshed with mosquito netting to discourage birds of the air from landing on the same and pecking the pipe with holes. The end result is a odourless, (relatively) flyless sojourn in the VIP 'morning lounge', especially if the seat is covered prior to and post -wonderful invention.

As you might have guessed, a few months in 1993 were not enough to finish our projects. To save paper I will cut this story short: by March 1996 the project status was, all VIP latrines completed and operational, all windmills installed except for the one at Rupunau, all water tanks and towers completed, all educational programmes completed, four extra pumps installed. At Nappi we claim to have erected the biggest windmill in Guyana, 40 foot tall, 14 foot fan and 560 lbs of gearing at the top. One man pulled up the gearing using a double wheel block and tackle. Having gained the admiration of the locals there followed a chalk-talk in the village lecture hall on the principles of lifting gear.

Strange what one is called to do as a Jesuit priest in Guyana. Helping to bring water to the thirsty is just one of the tasks we do in addition to our more spiritual duties.

(Tony Metcalfe SJ, Guyana, adopted from: Jesuits & Friends, 11 Edge Hill, London SW19 4 LR, United Kingdom, Fax: +44(181)946 2292, Email: 100105.1436@compuserve.com)

 


December 1997

 

EDITORIAL

Two years have past since we took over editing this newsletter from Dick Veldkamp and Frank Goezinne. We have had financial support by the Minister of Development Cooperation from The Netherlands during this period, which has come to an end with this last issue. As we announced in June, we would like to continue gathering "small wind news" from the field and asked for reactions.

We got some, but not too many. Yet, the few reactions we got were very heartwarming and convinced us once again that "Small Scale Wind Energy Systems" indeed fills a gap. People in Zimbabwe and Albania for instance, wrote that in fact our tiny newsletter was their only connection with the outside world -so please don’t cut it! While here in Europe, we heard more than once that "small wind" needs ongoing promotion to show that it is a valid technology for water pumping and electricity supply. Still, donor and development organizations are opting for solar power alone, discarding wind power simply because they don’t know it.

Small wind energy has a future, because it is cost-effective, reliable and sustainable. Provided the right context is there -just as needed by any other technology. Small wind has an extra asset: it can be adopted by local technicians and transformed into an indigenous product; perhaps not a necessary asset everywhere, but certainly it is in the remote areas. Communication and the exchange of experiences are key words to facilitate this process. Especially, since the "family" of people who believe in small wind power, is so small and dispersed.

There is still a lot to do. Water lifting machines are never universal and this is particularly true for windpumps, as they have to cope with two local resources: water and wind. The technology of windpumps is not old and established, as might be concluded from their success in the American Mid-West. Windpumping is new and complex, since it must always be embedded in the social, economical and technological context of a developing country. This is a serious task. And since developing countries are usually poor, a little help from abroad will always be welcome.

For the moment, "Small Scale Wind Energy Systems" will be suspended. We are pondering about a new formula to continue in the near future, perhaps integrated in two windpumping networks that have emerged during the last years: in Southeast Asia and in Latin America. The establishment of these networks is in fact quite some progress! So for now, let’s say "see you later" instead of "goodbye", and don’t forget: keep writing!

Jan de Jongh and Remi Rijs, editors

 

Improvement of Windpumps in Auroville

In 1994-95 the Center of Scientific Research in Auroville, India, carried out a research project "Field Testing and Monitoring of Load Matching Devices for Water Pumping". The project focused on field trials using various load-matching devices on a AV55 test windpump, to compare the reliability and costs of the technically most promising devices. The results of this project were very promising and reported previously in this letter [Paul Smulders, Increasing the Water Output of Windpumps, SSWES June 1996].

With the matching valve and spring device, an increase of 50% was gained compared to the windpump without any gadgets. This increase in output was mainly gained in low and medium wind, the lower cut-in windspeed resulting in many more pumping hours. Obviously the main advantage for the user is a more regular daily output. In addition, the higher number of pumping hours and increased overall output suggests that the blade area of the rotor could be reduced (compared to the original AV55 windpump), thus saving cost.

Modified Rotor Design

To verify whether a smaller rotor would give satisfatory results on the AV55 windpump in combination with a load-matching device, the original rotor was changed from 44% to 33% solidity as follows: rotor diameter 5.6 m (unchanged); swept area 19.3 m2 (unchanged); blade number 16 (was: 24); blade dimensions 150 x 30 cm2 (was: 150 x 34 cm2); effective blade area 8.16 m2 (was: 10.8 m2). The blade angle was slightly increased to keep the running speed low. During the tests with the matching valve, a 4.5 kg counterweight was attached to one of the blade tips, to balance the weight of the pumprods.

Reliability Tests

The spring device was tested in the Test-Bed Windmill for one and a half year. Simultaneously, other spring devices were mounted on other AV55 windmills in the Auroville area, in Gaia (4 yr.), Anasuya (4 yr.), Djaima (3 ½ yr.), Samriddhi (2 ½ yr.), and Pitchandikulam (2 yr.). None of them exhibited any problems: not a single spring broke. The Teflon bush in the additional rod guides and the lower rod connection, which was replaced by a spherical roller bearing, proved to perform well.

The matching valve ran for 1 year on the test windpump without any problems, while several matching valves were installed on AV55 windpumps in the field. Three more AV55 windpumps were equipped with matching valves about a year ago, and are all working fine.

In Vikas, the pump was checked after it had been operating with a matching valve for 2 years, equivalent to approx. 10 million pump cycles. The pump was removed to change the worn-out pump washers, giving the opportunity to examine the valve. The polypropylene float looked good with no noticeable wear or deformation. The brass valve seat was worn and needed refacing, but the wear was similar to that of a piston valve seat of conventional design. However, it would be advisable to use a more resistant material for the valve seat, possibly stainless steel or a suitable plastic material.

Output Performance

The increase in output for both devices may be illustrated by the figure below, indicating the water discharge as a function of the wind speed for the spring valve (Figure 1) and matching valve (Figure 2). To measure the output an average of 500 readings (every 10 min.) was taken.

Figure 1: ---: conventional drive, stroke 140 mm; - - -: spring device, stroke 180 mm; . . .: spring device, stroke 228 mm, small rotor.

It is observed that very high overall efficiency (Cph) values are found for the matching valve in low wind speeds. This result has been carefully examined but no mistakes could be found.

Figure 1: ---: conventional drive, stroke 140 mm; - - -: matching valve, stroke 228 mm; . . .: matching valve, stroke 228 mm, small rotor + counterweight.

A possible explanation could be the effect of turbulence and the high energy pattern factor (about 3) at low wind speeds, together with the high inertia of the windpump system. The standard procedure based on 10-minute average values, would overestimate the performance at the corresponding windspeed, which effect would be most notable at low windspeeds. Particularly in the case of a windpump equipped with a matching valve and a counterweight, the inertia effect may be an even bigger factor.

Conclusions

One may conclude that neither of both devices needed any additional maintenance or showed mechanical problems. The counterweight fitted to the rotor during the matching valve tests has so far not caused any trouble, provided that the rotor shaft and bearing assembly are sufficiently strong. The effect of balancing the pump rod weight is most pronounced at low wind speeds (below 10km/h).

The smaller rotor solidity has resulted in a significant loss of output, which is not justified by the 2% reduction of production cost. The designer will therefore return to the original rotor design with a solidity of 44%.

The gain in water output obtained with little extra cost involved, makes the implementation or retrofitting of both load-matching devices very interesting. The use of a counterweight in the rotor further reduces the cut-in windspeed and improves the overall performance in low winds.

Some people may ask why bother, as the available power below -say- 7 km/h is so small? However, it exactly means that in periods of low wind, a family will just have that little bit of water to cook and take a shower, and to water the plants around the house.

(extracted from "Improvement of Windpumps, Long-term Observations of Successfully Tested Loadmatching Devices", Robert Trunz, October 1997, CSR Center for Scientific Research, Auroshilpam, Auroville - 605 101, India, Fax: +91-413-62057)

 

Windcharger Developments in the Philippines

Jover Light Industries (JLI) in Cabatuan has now started the development of a small windcharger as a complement to its existing wind pump production. The small JB 1.25 wind generator is reported to deliver up to 4 A of charging current at higher wind speeds (12 V); and about 1 A at lower wind speeds. The design is based upon the Virya 1.25 windmill as developed by Kragten Design in The Netherlands. The permanent-magnet generator is made from an AC electric motor using a newly built anchor and 4 neodynium magnets imported from The Netherlands.

The small single test model built until now is mounted on top of Hector Jover’s house and has survived lasts year’s big typhoon -which hit the coast with wind speeds of upto 180 km/hr.

Only the two-bladed rotor pressed from one piece of sheet metal, developed a fatigue crack at the blade hub, and a blade was torn off. The failure was attributed to the heavy gyroscopic forces caused by the fast yaw movements in high winds. A second rotor was made of thinner sheet material (0.8 mm) to make it more flexible, and has been running fine until now.

The system includes an electronic overload protection diverting excess load to a heat sink. The availability of the neodynium magnets is the main problem, as they need to be imported from other countries. Altogether, the expected retail price of the complete windcharger will be in the order of US$ 300,-, which is considerably lower than for a 50 Wp solar home system. JLI has already had various requests for a small windcharger from people living in the mountains where wind conditions are fairly good.

(Hector Jover - JLI, 104-A, Divina Gracia St., La Paz, Iloilo City 5000, Iloilo, Philippines, Fax: +63-33-335 1017)

 

Regional Dissemination of Rope Windpump Technology

After several years of production and improvement, it is now planned to start spreading the Nicaraguan rope windpump technology to the Latin American region. To this purpose, a project has been formulated by the Nicaraguan organization CESADE, who has advocated the technology for many years.

The rope windpump technology will be evaluated prior to its dissemination. By doing so, CESADE hopes to see its own expectations be confirmed by an external, independent organization. Several wind energy experts from Latin America will be involved in the project, a.o. from Colombia and Costa Rica, as well as from Nicaragua itself. The results of the evaluation will be presented at two workshops: a national one for a broad public in Nicaragua, and a regional one, specifically for (potential) manufacturers and organizations from Latin America involved in wind energy. Possibly some grants are available for a number of participants.

The idea is to benefit as much as possible from the momentum gained during the workshops and to start the actual transfer-of-technology shortly thereafter. It is planned to have at least four units produced in -possibly- four different countries by the end of the year. The Royal Embassy of The Netherlands in Managua (DGIS) has been approached for funding and a decision is due for the second half of January. If approval is obtained, both workshops will be held at the beginning of May 1998.

Windpump manufacturers or experts from Latin America with interest to participate in the workshops, are invited to write to CESADE or -alternatively- may contact the editors.

(CESADE: Mr. Enock Matute, Apartado Postal JN 4317, Managua, Nicaragua, Fax: 00-505-266 9270)

 

From the field…

Brother Schurtemberger’s Christmas Greetings included some reflections on the interview we had with him last Summer. "In the near future," he states, "because of El Niño or other circumstances, we will have plenty of wind but no more water to pump with our windmills… and perhaps one day, in fifty or a hundred years time, people will start planting trees to get their rainforest back and ban any transport of exotic wood to Europe."

"But," he concludes from his remote home at the Driefontein Mission in Zimbabwe, "it’s very encouraging to see that technology is being transferred in our own field, even though it comes slowly. In fact, one should make use of experiences worldwide: do not try to re-invent the wheel."

 

The Chinese Wind Machinery Industry

China counts no less than ten manufacturers of small wind generators and windpumps, of which the Shangdu Livestock Machinery Work is the most renowned. The company accounts for about half of the annual wind generator production of 20,000 units in China, which makes it, by output and number of installed machines, the leading company in the world.

The Shangdu enterprise was founded in 1958 and started production of wind generators in 1974. It offers 3 series of products and 28 different types, which are sold not only in China but also exported to 22 countries, such as Indonesia, Sweden, Mongolia, Malaysia, Germany and Thailand. In 1996, 500 small wind generators (100 and 300 W) were exported to Indonesia at one time. The products are considered mature in technology and have a steady quality. Among them the 100 and 300 W windmills are most welcomed by local users. Both are upwind models equipped with glass fiber rotor blades, a permanent-magnet generator and a side vane safety mechanism.

Larger Systems

The trend in small wind electricity generation is shifting towards higher capacities. In the past, peasants and herdsmen bought wind generators with 50 to 100 W power output. With the rise of living standards, a refrigerator, color TV and washing machine came in sight, increasing the demand for electric power. Especially, the capacity of wind generators for export is more than 300 W.

In the past, wind generators were bought for stand-alone family use but now they are more and more integrated into networks for several families or a village. Multi-energy sources can compensate each other. As the supply of wind energy is discontinuous, diesel or photo-voltaic electricity can be used for replenishment, giving rise to "wind-PV", "wind-diesel", and "wind-PV-diesel" combinations.

The utilization range has enlarged step by step. In the past, wind generators were mainly used by farmers and herdsmen for lighting and TV, but now also by frontier stations, road maintenance squads, microwave stations, meteorological observatories, island fishermen, navigation lamps on rivers and seas, etcetera.

Foreign Cooperation

In recent years, some Chinese factories have started to cooperate with foreign companies and import technology. The Inner Mongolia Shangdu Livestock Machinery Works, for instance, cooperates with the Swedish SWIAB company for the production of the 750 W wind generator; the Inner Mongolia Power-Machine Factory has imported advanced French technology and developed a series of seven wind generator models, of which the 5 and 10 kW types can already be made in China. Now, the technological performance, reliability and product quality of small wind generator sets have made great progress, and our products are now being exported to 22 countries.

(Shen Dechang - CAAMS, No. 1 Beishatan Dewai, Beijing, China, Fax: +86(010)6487 7326)

 

On the Outlook…

Mr. Shi Pengfei from the Ministry of Electric Power informed us that Chinese manufacturers are looking for international contacts and potential customers. Those readers who are interested in receiving product information on small Chinese wind generators and windpumps, can write or send a fax to one of the following addresses:

Mr. Shi Pengfei, Director New Energy Division, Ministry of Electric Power,Hydropower Planning General Institute, Liupukang, Beijing 100011, P.R. China, Phone: +86(10)641 1177, Fax: +86(10)6401 4093

Mr. Yang Shuhua, General Manager, Qingdao Natural Energy Mechatronics Company, 22 Siliu Nan Road, Qingdao, Shandong 266042, P.R. China, Phone: +86(532)485 1122 ext. 305, Fax: +86(532)485 7541

 


 

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