A Bright Alternative: Austro-Indian Solar Cooking Initiatives

bridges vol. 25, April 2010 / Feature Article

By Simone Pötscher

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For centuries, humankind has worshipped the sun, but today we also harness it for energy. In India, the transition from worshipping Surya to also using its power for cooking was brought along by the technical expertise of Austrian physicist Wolfgang Scheffler, when he introduced his improved parabolic concentrator solar cooking concept to Deepak and Shirin Gadhia in 1994. Together with this Indian (solar) power couple, an amazing success story began, showing how technology transfer paired with hard work on the ground can improve the lives of many in rural India. A project that started by providing single solar cookers more than a decade ago led to the 2009 opening of the world's largest solar steam cooking system at the Shirdi Sai Baba Shrine, Maharashtra, where this environmentally friendly technology now cooks food for up to 50,000 people per day.

The dangers associated with daily meal preparation

Smoke and sooth development caused by cooking with fire wood.

Women cooking on mud stoves fueled by burning wood, dung, or crop residue, is common among three-quarters of the population in India, and some 2 billion people around the world, mainly in developing countries. According to the World Health Organization, 400,000 of India's population dies prematurely every year due to effects of biomass fuel used in households. Exposure to smoke and poisonous fumes from burning biomass in poorly ventilated homes is a major cause of cardiovascular and respiratory diseases in women and children. In addition to its devastating effects on health, using traditional cookstoves for meal preparation also has a negative impact on the environment: In India, one major contributor to deforestation is the use of brush, branches, and trees for firewood. "We are currently using about three kilos of wood per person every day, which is a major problem," states Deepak Gadhia, founder of Gadhia Solar Energy Systems Pvt. Ltd., one of the leading manufacturers of solar systems in India.

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Enters solar cooking - a "bright" alternative

Solar cooking could be part of the solution for India: With 250-300 sunny days per year, this natural resource is plentiful and - unlike fuel - is available for everyone at no cost. Solar cookers could eliminate exposure to harmful smoke; and dangerous and time-consuming gathering of biomass would no longer be necessary.

The Indian government, along with non-governmental institutions, has recognized the potential for using the sun as an energy source and, for the past 50 years, has been at the forefront of promoting solar cookstove programs. The Ministry of New and Renewable Energy (MNRE) established the "Solar Energy Centre" in 1982 with the aim of promoting and developing solar energy technologies. Subsidies on e.g., solar cookers vary, depending on the program or type of cooker, but typically range up to 50 percent. "Government support is very important. Poor people cannot afford solar cookers, so subsidies help make this technology available to everyone who wants it," explains Deepak Gadhia.

Common Solar Cooker Designs
Parabolic Cooker: The sun's rays are captured in a reflector, which focuses them at a point under a pot. The effect is like a stove top burner or a campfire. Temperatures can reach above 400 degrees Fahrenheit, hot enough to fry food.
Box Cooker: The sun's rays are received in an insulated black box with a transparent lid, which lets in the sun's rays. Inside the box, this sunshine turns to heat, which is trapped in the box. The effect is similar to the oven in your kitchen. Temperatures can reach around 300 degrees Fahrenheit.
Panel Cooker: A combination of the two systems, which is portable and less expensive. Temperatures can reach around 250 degrees Fahrenheit.

Source: Solar Household Energy, Inc. (14 April 2010)

Through support of local and international government programs, non-governmental organizations, and charitable organizations, hundreds of solar cooking designs and variations thereof have been tested and further developed. Nevertheless, "there is still room for new and improved options," states Wolfgang Scheffler, an inventor of solar cooking devices. Solar cookers have had to overcome cultural, geographic, and climatic obstacles. For example, cooking with solar devices while directly exposed to the sun represents a problem for middle-class women who culturally avoid sun exposure.  Affordability of solar options hinders spread of the technology in low-income areas. Also, the necessity for extended cooking periods when using a solar cooking device, or lack of sun availability during evening times when most Indian families are used to consuming their meals, reduced the acceptance of early solar devices.

While there are also valid concerns about the durability and lack of availability for maintenance of solar cookers, cultural barriers presented the largest hurdle according to Shirin Gadhia, president of the non-governmental organization Eco-Center ICNEER and wife of Deepak Gadhia. She recalls an experience while coaching women on how to best cook dishes using solar cookers: "Once the food started heating up, women were looking under the pot to see where the fire is. They thought it's magic when they didn't see any."

Solving problems - bringing sun into kitchens

Making Tea with 2,7 m2 Scheffler Reflector at barefoot college in Rajastan.

Scheffler recognized almost 30 years ago that only a "hands-on" approach and involvement of end users of solar cooking devices could really make a difference. So he experimented with solar cooker designs, always keeping local conditions such as infrastructure, climate, and above all, user behavior and sociocultural circumstances in mind.

Scheffler's very first concept for an improved parabolic cooker is - in adapted versions - still the product people refer to when using the term "Scheffler cooker" today. With the Scheffler cooker, sun rays concentrated by a primary reflector are directed to a focal area that may lie in the kitchen. This area can be a secondary reflector targeted at bottom of the cooking pot, or, alternatively, bundled sun rays could hit the cook pot directly, providing heat required for cooking (see picture for details).

Scheffler cooker for community kitchens (click image to enlarge).

Besides channeling the sun directly to a fixed focus in the kitchen, eliminating the need for the cook to be exposed to the sun, the uniqueness of the Scheffler concentrator lies in the flexible form of the elliptically shaped parabolic reflector. "The mirrored surface of the parabolic dish can bend so it has a different shape every day of the year. It almost flexes like rubber," Scheffler sums up the mechanics in a few words. A photovoltaic motor or mechanical clockwork fabricated from bicycle parts is responsible for aligning the reflector with movements of the sun throughout the day for most efficient capture of the sun. In addition, the angle of the curved reflector is adjusted to the seasons by tilting the device.

Scheffler reflectors are designed to be very cost-efficient and are manufactured locally with mild steel and mirrored glass, materials available in India. In simple workshops, Scheffler teaches construction, assembly, and maintenance of solar reflectors to local people, thus making users independent of out-of-community support. Through years of further developing the technology and design, the surface area of Scheffler reflectors has grown from 8m2, to ~10m2, and up to 16m2. Compared to other solar cooking devices predominantly used to cook for single households, Scheffler thinks big: His designs are capable of supporting solar cooking for entire communities. An 8m2 reflector, for example, produces an average of 2.6 kW - enough cooking power to feed 50 people. The 16m2 model generates around 5 kW, and can produce enough heat to cook for 80 to 100 persons.

Meeting between Deepak Gadhia and Wolfgang Scheffler.

"Wolfgang is the ‘Ghandi' of Europe. He has no income from his invention and acts on the firm belief that goodness will prevail. He does it to change perspectives and lives," said Deepak Gadhia on Scheffler's decision not to patent his technology, thus making it available to those most in need. An estimated 1,000 Scheffler cookers are in use in India today. "Most of them are used for community cooking, for example in schools. In the future, a bigger focus is being put on industrial use," states Scheffler.

Going commercial - bringing steam into kitchens

Scheffler and Gadhia Solar Energy Systems Pvt. Ltd., who, on the manufacturing end, have commercial use of Scheffler solar concentrators in mind, introduced solar steam cookers that implement Scheffler's technology for cooking for thousands of people in schools, hotels, hospitals, army bases, and industrial canteens* . "On such large scales, limiting harmful emissions into the atmosphere, and reducing fuel required does have a significant positive impact on the environment," explains Scheffler.

Solar Steam System cooking for 18,000 people in Abu Road, Rajastan.

Solar steam systems consist of multiple large Scheffler reflectors installed on terraces or roofs of a building in need of solar energy, with the apparatus' solar receivers directed at mild steel pipes half-filled with water.  Sun rays reflected onto the surface heat the water in the pipes - temperatures reaching up to 500 degrees Celsius at the focus area - thus creating steam that is directed straight to the kitchen with no need for electricity. Boiler systems retaining heat, and backup systems, are installed for times without sunshine.

Motivated in part by government incentives, Indian businesses have also caught on to the notion of going solar. As a result, "India is going forward. We are proud of the largest concentration of solar cookers in the world," says Deepak Gadhia. Currently, the world's single largest solar cooking system is installed at the Shirdi Sai Baba Shrine in Western India. By going solar, the spiritual center feeds up to 50,000 Hindu and Muslim pilgrims per day, while decreasing its carbon footprint, as well as operating costs, by annually saving up to 1,000 tons of liquid petroleum.

World's Largest Solar Cooking System
Location: Shirdi, Maharashtra
Meals prepared: 40,000 - 50,000 / day
Manufacturing time: 10 months
Solar Dishes: 73 dishes at 16m2 each
Steam produced: 3,500 kg / 7,716 lbs / day
Gas saved: 100,000 kg / 220,462 lbs  / year
Monetary savings: ~30,000 USD / year
System Costs: ~279,000 USD
Government subsidies: ~122,800 USD
Maintenance Costs: ~20,000 USD / year
Steam generated by Scheffler reflectors has been industrially used in food, dairy, pharmaceutical, chemical, textile, paper, and other industries. Specific applications, such as desalination of seawater or using heat in order to cool air, as is done at the 160-bed hospital of Muni Seva Ashram in Goraj, improve the quality of life for the Indian population. Other uses save lives by  improving hygienic conditions at home and in public health-care institutions: Heat produced by solar cookers pasteurizes water, disinfects household dishes, and sanitizes medical instruments.

Despite all those projects, the team around Scheffler and Deepak and Shirin Gadhia is not running out of steam, either literally or figuratively: Scheffler reflectors have also been tested recently for delivering energy used in solar crematoriums and for a solar power plant. When asked about his priorities for advancing solar cooking in India in upcoming years, Scheffler stresses: "We put a strong focus on training more companies on manufacturing solar cookers, so the production can meet the demand."

North-South Cooperation: Austrian schools support solar cooking in India

Awareness of the potential of solar cooking has not only been created in India: In May 2000, during a solar conference organized by local NGOs Intersol and Plage in Salzburg, Austria, a school project was launched. Eventually, more than 20 Austrian schools with pupils aged 10 through 18 participated in the first project "2x50 Solar Cookers for India." The goal of the north-south cooperation is not only to provide India with alternative energy sources, but also to teach Austrian students about India - the country, the people, and the customs. Many subjects such as home economics, geography, physics, history, and biology are involved in preparing the students for the task at hand. "It has been a long journey," states teacher Elisabeth Fuchs on the involvement of her secondary school. "Students are spreading the excitement among each other. They have managed to keep the efforts going for almost 10 years now."

Austrian students collecting money solar cooking at local markets.

Austrian students are cooking local as well as Indian dishes on their self-assembled Solar Cookers, selling them at nearby farmers' markets and at parent-teacher conferences for donations. Through their efforts, students in Upper Austria and Salzburg have raised enough funds in the first year for 50 solar cookers** , a number that was matched by local county governments. "We see this cooperation as a bridge that connects two cultures, from children to children, and country to country. It's like with pen friends when children learn about a country and culture," said Peter Machart, an Austrian secondary school teacher who was one of the initiators of the cooperation. Since its early beginnings, Austrian school projects have managed to raise about €25,000, sending almost 300 solar cookers to Indian villages.

With the help of Shirin Gadhia's local NGO, Eco Center ICNEER, cookers funded via Austrian school initiatives are provided to the Barli Development Institute for Rural Women, a training center for underprivileged girls and women in Indore, Madhya Pradesh. Multiple weeklong courses related to solar cooking have become standard, and guidance is available for months thereafter.

Shirin Gadhia training local girls on solar cooking.

Creating awareness through education is one of the key success factors of the program. During their training at Barli Institute, Indian girls and women practice assembly and maintenance, learn cooking traditional dishes on solar cookers, and are briefed in how to use their newly acquired skills to produce goods to be sold at markets as means to generate income. Once a girl is dedicated to bringing a solar cooker back to her village, micro-credits are made available to her to help fund the device. Shirin Gadhia explains: "Over time, the girl can pay back the money with the earnings she has from selling food. It can only work this way, because also in India there is no value put on things we receive for free." When Shirin Gadhia educates women on solar cooking, she follows her personal mantra that, when "educating a boy, you educate an individual. When educating a girl, you educate a community." The successful results of the efforts speak for themselves: 90% of distributed cookers are still utilized, and have not been diverted from their intended use.

Deepak Gadhia is aware of the many challenges that still lie ahead. He also knows that the combined efforts of Austrian school children and their teachers, Austrian and Indian NGOs, an Austrian scientist, and many local Indian women all working for one common goal - to provide solar cookers to those who can not afford them and to make India a healthier place to live - are still only the tip of the iceberg. But he firmly believes in the future success of their project. The past 20 years confirm his belief that: "There is no shortcut to success. India is a big country but only a slow gradual process can be successful. And it will." And with the help of Surya, that success is beyond the shadow of a doubt.


This article is based on interviews conducted by the author, Simone Pötscher, with Elisabeth Fuchs, Deepak Gadhia, Shirin Gadhia, Peter Machart, and Wolfgang Scheffler. Simone Pötscher has been senior program manager at the Office of Science & Technology since July 2006.

References & Sources:

* Another key player in establishing large-scale solar cooking systems in India is Golo Pilz, affiliated with Brahma Kumaris World Spiritual University.

The solar cooker model "SK14," a domestic solar cooker designed by Dieter Seifert, is funded by Austrian school projects.

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