Technology

In Swaziland, saving a "virtual forest" with an efficient new stove design

MATSAPHA, SWAZILAND — Setting out to design a new fuel efficient wood-burning stove for developing countries, Crispin Pemberton-Pigott started by imagining a “virtual forest.”

He knew that conservationists often speak of “virtual power plants” when they promote various measures to conserve electricity. And so he began by imagining how many trees might be saved if one could invent an inexpensive and yet truly efficient wood-burning cooker.

“In a way, the Vesto stove began as a flight of fancy, to see if I could bring to market an innovative stove that ignored the nay-sayers who said a commercially viable, highly efficient stove cannot be made cheaply,” said Mr. Pemberton-Pigott, head of New Dawn Engineering here, an appropriate technology design and manufacturing company that serves southern Africa.

“If it worked, we could save a very large number of people the effort of cutting down trees, and at the same time avoid the need to plant a lot of new trees for fuel,” said Mr. Pemberton-Pigott. “So the idea of creating a virtual forest emerged.”

Mr. Pemberton-Pigott's “flight of fancy” has paid off. The stove burns just one-quarter of the wood needed to cook on an open fire, and it is virtually smokeless. New Dawn has sold more than 1,000 of the new stoves since its invention in early 2002.

Moreover, the stove was honored in September 2004 by the Design Institute of South Africa (DISA), taking the top Chairman's Special Award, which called it “an outstanding piece of design which is of the highest international standard.”

“The relatively low retail price brings the Vesto stove within reach of people at the lower end of the economic scale,” the Award citation reads. Judging criteria included innovation, cost/value relationship, performance, safety and ergonomics, environmental impact, appearance, and ease of installation and maintenance.

“That is the highest such design award that we know of in Africa,” said Mr. Pemberton-Pigott. The stove also won recently in the Houseware category at an annual event held by the South African Bureau of Standards. And in November, the Stainless Steel Development Association gave the product a Merit Award for the innovative use of stainless steel.

The three new awards cement the reputations of Pemberton-Pigott and his New Dawn Engineering as among the most innovative and creative of appropriate technology companies in the world.

Founded by Mr. Pemberton-Pigott and his wife Margaret in 1984, New Dawn makes a wide range of simple but highly efficient machines for use at the village level in Africa and other developing regions. In addition to the Vesto and other stoves, these machines include hand-operated oil presses and rock crushers, fence makers, and various brick and roof tile makers.

“We believe that labor-intensive equipment and virtuous social and economic development can be catalysts not only for third world countries, but for illustrating a better future for mankind,” said Mr. Pemberton-Pigott. “In this day, actions must exceed words.”

Mr. Pemberton-Pigott, who moved from Canada to Africa 28 years ago, cites his practice of the Bahá'í Faith as the inspiration behind New Dawn's efforts to design and manufacture economical machines for Africa 's villages.

“The Bahá'í writings speak of the importance of initiating ‘measures which would universally enrich the masses of the people,'” said Mr. Pemberton-Pigott. “They say there can be ‘no undertaking greater than this.'”

How it works

The portable Vesto stove burns wood and dung more efficiently and with fewer emissions than conventional stoves. Dung, especially, is a notoriously low-yield and smoky fuel but is used in some regions of Africa, such as Ethiopia, where no other fuel is available.

The key to this efficiency, said Mr. Pemberton-Pigott, is a design that pre-heats incoming air while using that air to insulate the fire and prevent heat loss.

“This increases the efficiency of burning low quality fuel, like dung, by up to six fold,” said Mr. Pemberton-Pigott.

The Vesto has three types of secondary air inlets, allowing it to function as both a charcoal-producing gasifier and a charcoal burning, wood burning, or dung burning stove.

Another feature of the Vesto design is that it can be manufactured relatively simply. “Its production does not require complex and expensive tooling or high capital expenditure,” said Mr. Pemberton-Pigott. “Many innovative stoves are so elaborate that they are almost impossible to make in a simple environment. In designing this stove, we sought both simplicity and extreme efficiency.”

Based on a modified 25-liter paint can, the stove sells for about US$29.00. If sales increase, and more units are produced, that price will drop further, said Mr. Pemberton-Pigott.

In addition to burning fuel more efficiently — a considerable benefit in a region where forests are becoming increasingly difficult to sustain — the stove also offers innovative safety measures.

“Stoves are a major source of health problems for women and children,” says Pemberton-Pigott. “The Vesto addresses these by being safe to use — not very hot on the outside.”

Unlike a paraffin stove, the Vesto contains its fire in a gas-insulated tin, which not only makes it cooler to the touch but confines the fire if the stove is knocked over.

In addition, the fact that the Vesto burns virtually any biomass fuel means that households can move away from the use of expensive charcoal.

“African cities use huge amounts of charcoal, produced at despairingly low conversion rates from virgin forests,” said Mr. Pemberton-Pigott. “No one has ever converted a large urban population from charcoal back to wood.

“Doing so would also save large tracts of forest because the wood is so much more efficient in terms of the total heat in the fuel and the total amount of cooking done by it compared with charcoal.

“To achieve this, it would be necessary to have a stove that burned charcoal well and wood very well,” said Mr. Pemberton-Pigott. “People might buy it as a fast-lighting charcoal stove, but then sooner or later they would run out of charcoal and try burning wood.”

“They would immediately realize that the lower cost wood was a good or even better fuel than the charcoal had been,” said Mr. Pemberton-Pigott.

The Moya Center for Orphans and Vulnerable Children in Swaziland recently received a donation of four Vesto stoves for its child-headed households.

“All of these children had been using firewood and an open fire to cook their food,” said Jane Cox, director of the Moya Center. “And their ‘kitchens' are a smoke trap and particularly unhealthy.

“I have been back to these households [since they got stoves] and they speak with one voice,” said Ms. Cox. “They use a fraction of the firewood they had been using, with the amazing result of water boiling within 10 minutes and no smoke visible. The children's faces light up as they speak of the Vesto stove.”

For more information, visit http://www.newdawnengineering.com/

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