Letters

Why solar cookers failed

I am in entire agreement with your excellent article on solar cookers, "Cloudy Days for Solar Cooker" (June 30) by Koshy Cherail.

Three types of solar cookers have been tried out in the past -- the hot box or solar oven; the unpressurised, direct, solar steam cooker without storage and those with a focussing dish mirror. In innovation theory, this is a classic example of "technology push", that is, technical solutions looking for a social application.

"Technology push" innovations might be adopted if they satisfy a real demand, or if a product is being heavily promoted or subsidised. The needs, priorities and demands of users need to be studied before attempting to develop or introduce a technology or system. This is the "demand pull" approach to innovation.

The box type solar cooker suffers from many drawbacks. Many are impractical and demanding too much effort from the cooks, they are not versatile and many traditional dishes couldn't be cooked on them, and, finally, they are not durable enough and their thermal performance is inefficient.

Apart from these deficiencies, the natural and social environment of the beneficiaries of dissemination programmes have not been taken into account sufficiently. The cookers were often distributed in areas where they were not needed, where they could not be used for lack of sunshine or space, where people could not afford them even when the cookers were subsidised or where cooking traditions were inimical with the design of the cookers.

Domestic solar cookers must cater to various social conditions and needs, if they are to be accepted and, because cooking and eating are a private activity, there must be ways of channelling energy from the sun into the kitchen.

A JAGADEESH, Hyderabad,

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I was thinking of writing a short piece on why solar cookers have not taken off, but found that Koshy Cherail has done a better job than what I had in mind.

Solar energy reaches the earth in a very diluted form. It is suitable for warming oneself in winter, for ripening grain, or drying clothes. With some effort, one can get low grade heat from this source at competitive prices, which would be sufficient to heat water or cook food. I thought (although I realised later that I was wrong) that it would be possible to make the cooker cheaper and simpler by sacrificing its efficiency a little. I borrowed a box type cooker from a friend, who had bought it at a 50 per cent discount and kept it in his attic after the novelty of the product had worn off.

My wife refused to have anything to do with the experiment, but that did not deter me. It did not take me long to realise the shortcomings of this project. No sensible person, who has easy access to cooking gas, electricity, kerosene, coal, wood or agricultural wastes will put up with the inconveniences and unreliability of the product. Only those who have to undergo even more inconvenience in gathering fuel by walking for hours would be tempted to use the cooker. But, unfortunately, these are the same people who cannot afford even highly subsidised cookers. Besides, solar cookers cook an insufficient quantity of rice for a rural family of four or five persons.

RAMA, Hyderabad ...

Tired Ozone

The sun that shines so bright
Possesses the killer's unseen right,
Fighting in the atmosphere's war zone
Where lies the tired warrior called OZONE
Whose enemies have become two-fold
Ever since we humans became bold
'Cause we polluted the air, sea and water
Making the ambience dirtier and hotter.

Nature's once strong wall
Now begins to fall
The eyes of the warrior begin to sway
As they look back at us in dismay.
How mercilessly we stabbed him in the back
Making our unseen future so black

Let us lend him a helping hand
And discard all biologically non-degradable brands.
Let him have some breathing space
And stop hitting him in the face.
Ramesh C Kamo, Hassan (Kathmandu) ...

Politicians should read Down To Earth

It's really great to know that you're publishing Down To Earth on a fortnightly basis. But it will fulfil its real objective only if politicians read the magazine. Many countries participated in the Rio conference, but what was the result? Absolutely nothing.

RAMI SHANKAR RAO, Secunderabad ...

Maintain present quality

Congratulations on getting Down To Earth off the ground. The magazine is great and I wish you luck in maintaining the present quality of the product. Your cartoonist is brilliant.

Being a fortnightly magazine, it should be a good forum for exchanging views in short guest editorials and letters from readers. I look forward to my next copy. Keep up the good work.

JEFFREY Y CAMPBELL, New Delhi ...

Educating people

This is my message to Down To Earth: India abounds in natural resources, but this is in sharp contrast to the prevailing widespread poverty. On the other hand, several of our natural resources are being speedily eroded -- a trend that will ultimately prove disastrous for life itself. Education in science and environment should be conducted on a war footing, both in a formal and informal manner and at the grassroots level. This is the only way Indians can be lifted from the quagmire of poverty and ignorance. In this context, a magazine such as yours is welcome.

G S YONZONE, Darjeeling ...

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