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Making a Better Solar Cooker

Soulskill posted more than 2 years ago | from the making-high-tech-low-tech dept.

Power 167

New submitter jank1887 writes "Back in 2010, the aid organization Climate Healers gave a number of solar-powered cookstoves to rural Indian villages. The stoves were rejected by the communities, mainly because they were useless when they were wanted most: for the evening meal sometimes after the sun goes down, and for breakfast before the sun has risen. Following this, the group issued a challenge to EngineeringForChange. Details of the challenge include the need to provide 1kW of heat at about 200C for two hours in both early morning and late evening, and the users should be able to cook indoors, while sitting. A number of groups, mainly at U.S. and Indian engineering institutions, accepted the challenge, and developed potential solutions. Now, almost a year later, the ten finalist designs have been selected. The actual papers have been posted to the E4C challenge workspace. The goals of most of the designs are to keep the technology simple, although there are a few exceptions, and many include sand-, oil-, and salt-based concentrated thermal storage. Many reports include some level of discussion on the social and economic considerations, barriers to acceptance and sustainability, and how to overcome initial resistance to adoption."

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My Solution (5, Funny)

SJHillman (1966756) | more than 2 years ago | (#39077391)

Solar panel, a bunch of lead-acid batteries and a George Foreman grill and they're good to go.

Re:My Solution (2, Insightful)

emilper (826945) | more than 2 years ago | (#39077413)

yes, and they're ready to go and eat cake

Re:My Solution (4, Interesting)

Asic Eng (193332) | more than 2 years ago | (#39077575)

Try to build it within their cost requirements, present your prototype and compare it with the other designs. If you think you can do better, then help out - you could really make a difference to the lives of many people. I suspect you'll find that your initial idea won't be quite as good as what the other guys came up with, but generally there is always a better solution around somewhere. One more person looking for that can't hurt.

Re:My Solution (2)

Asic Eng (193332) | more than 2 years ago | (#39077659)

To clarify why I think the other guys have better solutions: e.g. the first design doesn't need solar cells (just reflectors) and has no batteries (stores heat instead of electricity). That's a lot more low-tech thus probably better suited for the place where they use it, and likely less expensive.

Re:My Solution (2)

SJHillman (1966756) | more than 2 years ago | (#39078215)

My design's only real advantage is you could whip it together in about 10 minutes using off the shelf components. The batteries would stop charging fully within a year or two of regular use, the Foreman grill is pretty limited in how much you can cook on it and solar cells are damned expensive.

My original jest aside, these designs are pretty cool. I wanted to build a solar oven once, but I live in central and western NY where a solar oven might be useful two or three days out of the year. Now, a wind-rain-and-snow powered oven on the other hand...

Re:My Solution (3, Interesting)

yog (19073) | more than 2 years ago | (#39077783)

Some day, photovoltaic panels will be dirt cheap and will be perfect for these rural villages, but right now they're too expensive even for most Americans.

When I was a teenager, I build a solar stove out of cardboard, plywood, and aluminum foil, based on a design in a book I read. I probably could have made it totally out of cardboard; I wasn't much of an engineer/architect :)

Anyway, the thing worked amazingly well. I demonstrated frying a hamburger (not something you would want to show the Hindu villagers, by the way) and my family was blown away. However, it had three disadvantages. First, it was extremely bright. To stand more or less in front of it to turn the food was a blinding experience.

Second, you needed a black-bottomed pan, which we didn't have, so I painted an aluminum pie pan black on the bottom.

Third, like the article says, it only works in full sunlight. You don't really want to cook the meat and veggies at 3pm, you want to get them started around 5:30 or 6 in most households. It's likely that the villagers are working in the fields or small workshops all day and don't get around to supper until 7pm or later.

At least, it should be quite possible with a reflector cooker to make large pots of rice during the day, which they probably do anyway since it takes relatively long. Solar reflector cookers are perfect for that application because rice mostly wants to simmer at a lower temperature.

Re:My Solution (1)

Anonymous Coward | more than 2 years ago | (#39078845)

an aluminum pie pan?

wait, you eat aluminum pies?

what....how....

Seriously?! (0)

Anonymous Coward | more than 2 years ago | (#39078959)

You really don't know what an aluminum pie pan is?

Your chains must be very thick and heavy.

I'm betting.. (0)

HeLLFiRe1151 (743468) | more than 2 years ago | (#39077409)

they would reject McDonald's hambugers, if they were sent.

Re:I'm betting.. (4, Insightful)

Anonymous Coward | more than 2 years ago | (#39077521)

Damn right too, McDonald's hamburgers are horrible. People living rural lifestyles like this are used to eating real meat instead of processed crap.

Re:I'm betting.. (3, Insightful)

hobarrera (2008506) | more than 2 years ago | (#39077579)

This may sound trollish, but it's quite accurate; people in rural areas will dislike mcdonalds in general, they used to unproccessed meat just like parent said.

Re:I'm betting.. (1)

timeOday (582209) | more than 2 years ago | (#39079037)

Hamburger is pre-chewed meat.

Re:I'm betting.. (0)

Anonymous Coward | more than 2 years ago | (#39077703)

Why? It's not like eating them would violate their tradition of not eating beef.

(Actually, I've had McDonald's hamburger patties cooked on a charcoal grill. They're delicious that way!)

Re:I'm betting.. (2, Interesting)

Anonymous Coward | more than 2 years ago | (#39077759)

Of course. There's a difference between food, and a fuel for humans that's certified safe by the FDA:
http://usnews.msnbc.msn.com/_news/2012/01/31/10282876-mcdonalds-drops-use-of-gooey-ammonia-based-pink-slime-in-hamburger-meat [msn.com]

Re:I'm betting.. (2)

EdIII (1114411) | more than 2 years ago | (#39078187)

Just as a warning to other people, don't click the link.

I stopped eating McDonald's and all that other processed crap years ago, but that article is so shocking I almost blew chunks at the monitor.

I deeply, deeply, deeply regret ever eating anything at McDonald's in my entire life now.

Re:I'm betting.. (1)

HornWumpus (783565) | more than 2 years ago | (#39078335)

If it makes you feel better they used beef (or something like it) until about 95 (well after the last time I ate there). Also be aware Bugger King and Cargill ready made patties still uses the pink slime. Taco Bell would be upgrading their 'beef' by adding pink slime.

Interesting idea... (3, Insightful)

Firethorn (177587) | more than 2 years ago | (#39077419)

I wonder how they thought the original designs would be accepted in the first place - We've long incorporated larger tanks for solar water heating to provide hot water at night. Also, even rural types like their convenience, which means being able to cook inside. BTW, for the Americans - 200C ~ 400F. Considering 80% of my cooking is at 350F, that's sufficient. Reviewing the designs, I am a touch concerned that I don't see thermostats for keeping the temp steady. Not as necessary for meat, but if you're baking bread you need fairly fine control.

Re:Interesting idea... (-1, Troll)

Anonymous Coward | more than 2 years ago | (#39077467)

What I don't understand is why these fagets need to be able to cook sitting down. I don't get to cook sitting down. I don't understand what that shit has to be a part of the fucking design. These developing country fagets can stand up to cook like the rest of us poor suckers.

Re:Interesting idea... (2)

Asic Eng (193332) | more than 2 years ago | (#39077501)

It's not just the inconvenience, it looks like the original designs broke down as well. So the new designs need to be more sturdy, as well. I hope they can get this to work - helping to solve deforestation, reducing cancer risks and eliminating some very hard labor - it really would be a boon for these people.

Re:Interesting idea... (3, Informative)

Phanatic1a (413374) | more than 2 years ago | (#39077511)

Considering 80% of my cooking is at 350F, that's sufficient.

It looks like a number of these designs can't even come close to that:

For night cooking, water passes through the system, becomes steam and enters the kitchen through PVC pipes....
At night, the cook pours water into a spout on the side of the device, the water trickles through channels surrounded by the hot oil, converts to steam and rises to heat a hotplate for cooking...
The device stores excess heat in an insulated chamber filled with salt and can continue to heat water for steam cooking at night...

You can't heat a hotplate to 350F with 212F steam, let alone steam that's cooled off substantially by expanding through PVC pipe to enter your kitchen. People want to cook their food, not just warm it up.

Re:Interesting idea... (3, Informative)

royallthefourth (1564389) | more than 2 years ago | (#39077589)

Steam can certainly be much hotter than 212F; that's just the minimum temperature to get your reservoir boiling.

Re:Interesting idea... (2)

Phanatic1a (413374) | more than 2 years ago | (#39077645)

I didn't say steam can't be much hotter than 212F. The described technologies don't include pressurizing or superheating the steam, so it will be at 212F.

Re:Interesting idea... (-1, Flamebait)

HornWumpus (783565) | more than 2 years ago | (#39077651)

Look up super-heating, think about it for a second, realize you are a moron.

Re:Interesting idea... (1, Informative)

royallthefourth (1564389) | more than 2 years ago | (#39077733)

My comment took into account superheating. This is why I called it the minimum temperature, you barely literate angry teenager.

Re:Interesting idea... (-1, Flamebait)

HornWumpus (783565) | more than 2 years ago | (#39078039)

Now design me a superheater that would be economical and safe to use in a third world kitchen (you blithering moron).

Re:Interesting idea... (2, Insightful)

Beelzebud (1361137) | more than 2 years ago | (#39078111)

Would it kill you to just state your ideas without insults and childish behavior? You might have a point, but no one can get to it through your asshole behavior.

Re:Interesting idea... (-1)

HornWumpus (783565) | more than 2 years ago | (#39078473)

Let me guess, you are from the participation generation? You want a warm fuzzy for adding noise to the discussion? A participation trophy?

Showing up with a snarky comment that shows you don't understand what you are talking about and you expect to be corrected without getting you feelings hurt. Is this your first visit to /.?

I'll type slowly so you can understand: Superheating steam is expensive and dangerous. Adults with a working knowledge of history understand this.

Re:Interesting idea... (0)

Beelzebud (1361137) | more than 2 years ago | (#39078741)

Actually that was my first reply to you. But I can see you can't help but be an asshole, so have at it.

Re:Interesting idea... (0)

Anonymous Coward | more than 2 years ago | (#39077591)

What if they use 350F steam instead?

Re:Interesting idea... (0)

Anonymous Coward | more than 2 years ago | (#39077797)

There was an interesting song about this by the Pointer Sisters. "Steam Heat" - maybe it wasn't by the Pointer Sisters. But it still is a good song.

My, what a tasty snack!

Re:Interesting idea... (1)

PTBarnum (233319) | more than 2 years ago | (#39077643)

Why do you assume the steam is at 212F? That's just a minimum. If the heat sink is at 400F, they could theoretically heat the steam to 400F. I'm not convinced this is a good idea, given the safety risks if there are leaks, but it is possible.

Re:Interesting idea... (1)

Hognoxious (631665) | more than 2 years ago | (#39078223)

Why do you assume the steam is at 212F? That's just a minimum. If the heat sink is at 400F, they could theoretically heat the steam to 400F.

Only if the system is pressurized. You think that's feasible (or even advisable) in this situation?

Re:Interesting idea... (0)

Anonymous Coward | more than 2 years ago | (#39078577)

Only if the system is pressurized. You think that's feasible (or even advisable) in this situation?

You don't need pressure to heat steam up to 200C. Boil some water at 100C, pass the resulting steam over a block of hot metal, and the steam can be heated to whatever the temperature of the metal is.

However, hot steam by itself isn't really what you want. In order to deliver a lot of heat to the cooking surface you want to have the steam condense at 200C, and for that the system does need to be pressurized.

Re:Interesting idea... (1)

timeOday (582209) | more than 2 years ago | (#39078809)

I won't claim to have a good working design for this application, but pressure cooking [motherearthnews.com] is claimed to reduce cooking time by 70% and energy use by 50%, which sounds good when cooking with solar energy in the dark!

Perhaps you could heat up a thermal store in the day, put it into a pressure cooker and add water to efficiently carry the heat from the slug to the food. Apparently pressure cookers can be made quite cheaply [amazon.com] . Hmm, according to the customer reviews on that link pressure cooking is traditional in India, I didn't know that.

Re:Interesting idea... (2)

Tekfactory (937086) | more than 2 years ago | (#39077819)

You know its funny that we regularly cook with 300-400 degree cooking surfaces, but none of our food needs to get much over 170 to be safe to eat. Certain chemical reactions like thickeners won't activate until they reach the boiling point of water, but very little of what we eat needs to go above the temperature of steam.

Everything in your food, pectin, collagen, etc that holds the food together begins to break down around 180 so that things get soft and mushy if left too long.

Maybe these folks need to combine a solar cooker for baseload with rocket stoves that use fuel efficiently and give off very little pollution. The stove could be used to carmelize vegetables, sear meats, toast breads and other applications that require really high heat.

Re:Interesting idea... (0)

Anonymous Coward | more than 2 years ago | (#39078749)

Look up Newton's (yes, that Newton) Law of Cooling (also works for heating), and you'll discover why heating at 212F is not particularly useful for cooking foods to 160F-170F.

Re:Interesting idea... (3, Insightful)

krlynch (158571) | more than 2 years ago | (#39077535)

We've been cooking bread for at least ten thousand years before thermostatic control came along, so I can understand that not being part of the design requirements.

Re:Interesting idea... (2)

Maximum Prophet (716608) | more than 2 years ago | (#39077661)

This is correct.

You can substitute mass for automatic control. As long as it heats up slowly, and cools slowly, manual temperature control is fine. On an outdoor brick/mud oven, you use a damper to control the amount of air that can get to the fire.

Baking bread (4, Interesting)

Firethorn (177587) | more than 2 years ago | (#39077761)

Doh... Of course you're correct, and I'm mostly thinking of my micro-production at home. Of course, back in the day you had the village baker, the average family didn't bake their own bread. What I get for trying to be among the first to post. ;)

I should have stated a concern more for how easy it is to control the temperature of the stove - keeping it reliable is more important than the exact temperature, and many older ovens were large enough that if you wanted hot you used the back of the fire/oven, if you wanted lower temperature you kept it nearer the front.

As for the outdoor brick/mud oven - if it's solar powered you need something to control the damper, and if you're using stored heat you need a way to moderate the heat from extremely sunny/hot days, while still keeping it hot enough on rainy days.

Supplimental heat from a fire, or like in the one case it's 'add water here, get steam there', so if you have some sort of steam limiter, you have temperature control.

Re:Interesting idea... (1)

yog (19073) | more than 2 years ago | (#39077699)

Rural Indian villagers probably would prefer to bake flatbreads (nan, puri, etc.), which can be made in a pan or perhaps a clay cooker. As krlynch points out, these foods were prepared long before modern appliances came about. Making rice seems like a good application for a solar cooker, too. After bringing it to an initial boil, you want the rice to just simmer for a while, perfect for the relatively low temp solar gizmos. And they probably do want to cook rice during the day, late afternoon at best, since it takes so long. Meat and veggies, maybe not so much.

Re:Interesting idea... (1)

Andy Dodd (701) | more than 2 years ago | (#39078225)

If you read the PDF for one of the first symptoms - it was optimized for baking roti, which sounds like a variant of frybread to me based on the description.

Re:Interesting idea... (1)

operagost (62405) | more than 2 years ago | (#39078075)

BTW, for the Americans - 200C ~ 400F.

Or about three times the temperature of my old Pentium 4 CPU. Got it!

That's one cool processor! (0)

Anonymous Coward | more than 2 years ago | (#39078693)

200C =473 K
So your CPU was running at 158K/-115C /-175F?

Temperatures are only proportional if measured from 0K.

Spoiled villagers (-1)

Anonymous Coward | more than 2 years ago | (#39077457)

If these villages can afford to be picky as to when they eat, then they obviously aren't desperate enough for that kind of solar cooker and can afford gas .

Re:Spoiled villagers (5, Insightful)

Anonymous Coward | more than 2 years ago | (#39077531)

If these villages can afford to be picky as to when they eat

Perhaps the problem is they can't afford to be picky when they eat. Ever consider they might need to be working during daylight hours.

Re:Spoiled villagers (-1)

Anonymous Coward | more than 2 years ago | (#39077657)

I thought that's what unemployment was for?

They might be poor, but they have their pride... (5, Interesting)

Firethorn (177587) | more than 2 years ago | (#39077673)

Reading the article, the first contender came with a proposal to give them efficient wood stoves first, to displace the open fires they're currently using. Doesn't imply that they have gas.

Of course, it makes me want to point out that a modern high efficiency wood stove might sufficiently solve the problem to the point that it renders the solar stove unnecessary. Wood is a renewable resource, they apparently have sufficient quantities of it, and from what I remember, ye old wood stoves were ~10x as efficient as open pit fires at heating and cooking, and modern high efficiency ones are ~50% more efficient than the ye old varieties.

So you're lookng at using 1/15th the wood. At which point you have to convince people that using the solar stove is more convienient/valuable than dealing with the much smaller amount of wood the solid fueled stove needs. Well, don't forget cleaning requirements.
Let's see, stove rating areas:

  • Convienence of use
  • Stability of temperature
  • Range ot temperature
  • Maintenance/cleaning requirements
  • Cost of fuel
  • cleanness of fuel
  • availability of fuel
  • endurance of the stove
  • longevity of the stove

The more you get, the better the product.

Good call (1)

sakdoctor (1087155) | more than 2 years ago | (#39078001)

The Philips wood burning stove was way cooler than these looks good on paper solar contraptions. Not that this design would be suitable for these villages, but better wood stoves should have been first on the list.
http://www.research.philips.com/technologies/woodstove.html [philips.com]

I heat my cosy developed-world house using wood, and it's incredibly clean and efficient. And by clean I mean even "a little bit of dust" would be unacceptably dirty. The yearly chimney sweep shows that the combustion itself is very close to complete, and the fuel itself is free. Garden waste to most people.

Re:Good call (0)

Anonymous Coward | more than 2 years ago | (#39078311)

I'd go w/ a woodstove with gasifier....if you cook with the wood gas then you can pipe it where you need it, which means you could run a small (converted) genset or (more likely in the short term) use any excess for lighting.

A pair of empty paint cans and a bit of metal tubing is all it takes to get started. These would be compatible with the existing pit fires and it wouldn't be hard to parallel them for more/less gas. Although that wouldn't be ideal, the pit-fires I mean, it would be a cheap way to start and would get them used to having wood gas available for cooking/etc.

Re:They might be poor, but they have their pride.. (1)

Maximum Prophet (716608) | more than 2 years ago | (#39078369)

a modern high efficiency wood stove might sufficiently solve the problem to the point that it renders the solar stove unnecessary.

Also, a wood stove is a stored solar powered stove. You don't have to burn only wood in it, just woody material. Which comes from growing stuff in sunlight. One of the best converters of Sunlight to burnable biomass is hemp. You can use the fiber to make ropes/clothes/paper, then use the rest as fuel.

Re:They might be poor, but they have their pride.. (0)

Anonymous Coward | more than 2 years ago | (#39078699)

In my experience (around three years with Engineers Without Borders), there are two main reasons a solar cooker would be desirable over a wood oven:

1) Indoor air pollution. A lot of houses in developing countries don't have proper venting for their fires/wood stoves, so the smoke just stays inside and creates a load of health problems. This can be solved either with wood stoves with proper venting or solar cookers that don't give of smoke at all.

2) In some countries (Haiti and parts of Central America, for example), wood is rare and/or moderately expensive. Using solar cookers can free up a significant amount of money that a family can use for other expenses to help them slightly raise their standard of living.

That being said, if wood is plentiful and cheap and stoves are available with sufficient venting, it's better than a poorly vented stove or an open fire. The point of organizations like Engineering 4 Change is to raise standard of living by creating solutions that are simple to use and sustainable in the sense that if something breaks, the community can fix it for a cost that is not prohibitive. Environmentally friendly solutions are certainly preferred, and are often the side effect of having to work with very minimal or costly energy sources, but being green is typically not the biggest concern of the target communities - it's usually something more along the lines of getting enough water or building a bridge above a ravine so the hospital is 10 minutes away instead of an hour away.

Re:They might be poor, but they have their pride.. (2)

tocsy (2489832) | more than 2 years ago | (#39078777)

Dammit, for some reason the computer logged me out when I was posting this so now it's anonymous.

Stop giving the things away... (1, Insightful)

orphiuchus (1146483) | more than 2 years ago | (#39077491)

...and sell them at a loss. That way the villagers will attach some value to the things and actually use them.

Re:Stop giving the things away... (2)

sakdoctor (1087155) | more than 2 years ago | (#39077747)

That isn't what happened, but thanks for sharing your narrow perspective.
The goal of this charity is "to heal the climate crisis though reforestation" ... total hypocrisy of course, given mine and your ecological footprint.

Wahwhua = White affluent hippy with head up ass

Wahwhua: Here is a crappy solar cooker we designed. Use this instead of harvesting firewood.
Villagers: This solar cooker is completely inferior to our existing wood stoves. It's not fit for purpose.
Wahwhua: Ok, here is our new design. You should use this because YOU'RE damaging the planet.

Re:Stop giving the things away... (1)

orphiuchus (1146483) | more than 2 years ago | (#39077905)

You're actually the one missing the point here. Lung disease is one of the leading killers of children and women in the developing world and the primary cause is indoor cooking fires. This is a solution to that problem.

The fact that people who understand that have manipulated Wahwhuas into supporting these measures is just icing on the cake.

Re:Stop giving the things away... (1)

Gordonjcp (186804) | more than 2 years ago | (#39078175)

Lung disease is one of the leading killers of children and women in the developing world and the primary cause is indoor cooking fires

So what they really need is some sort of device, possibly resembling a long metal tube, that can duct the smoke from the cooking stove out of the house.

Shit, I shouldn't have posted that, now I'll never be able to patent it.

Re:Stop giving the things away... (1)

timeOday (582209) | more than 2 years ago | (#39078991)

Come on now, history as already played this out. 19th century London was covered in soot and it was pretty awful.

Re:Stop giving the things away... (1)

sakdoctor (1087155) | more than 2 years ago | (#39078177)

To which the solution is, better wood burning stoves, with a chimney to improve draft, operating temperate and efficiency, while eliminating indoor pollutants.
Even a flue that's not completely air-tight is a start, because the pressure is lower than ambient, and it draws air in along its length.

Re:Stop giving the things away... (1)

oh_my_080980980 (773867) | more than 2 years ago | (#39078789)

Because they can afford that......

Re:Stop giving the things away... (1)

tmosley (996283) | more than 2 years ago | (#39077915)

I'm not sure Western carbon footprint has anything to do with deforestation. We don't get our carbon from rainforests, we get it from under the ground.

You appear to have conflated two separate issues that both happen to fall under the umbrella of "environmentalism". Same situation is where some people don't know the difference between the hole in the ozone layer and global warming.

Re:Stop giving the things away... (1)

timeOday (582209) | more than 2 years ago | (#39078963)

If the stated goal of this charity is "to heal the climate crisis though reforestation," then yes, there is a direct link - we want them to grow forests to soak up all the carbon we're digging up and spewing into the air. (Burning firewood, by contrast, is carbon neutral if harvested at the same rate as the forest re-grows).

But I'm sure providing better health and convenience to the recipients is part of the aim as well.

Cost is extremely important. (1)

Anonymous Coward | more than 2 years ago | (#39077567)

The Sol^R solution [engineeringforchange.org] (pdf [engineeringforchange.org] ) looks very promising, but this passage from the executive summary bothers me:

"In Rajasthan, [India,] the design will cost a total of $502. The cost of the unit is less important than if the unit is successful in replacing wood burning stoves. If implemented, the women of these rural villages will escape the health issues acquired from smoke inhalation while still working during the day."

Cost is extremely important. If they can't afford to build it they'll just stick to what they have. The goal of the project is to get it under $400 for a reason.

Re:Cost is extremely important. (0)

Anonymous Coward | more than 2 years ago | (#39077681)

I don't know how I came up with the $400 amount. However, my point still stands.

Re:Cost is extremely important. (1)

Khashishi (775369) | more than 2 years ago | (#39078147)

Most of the cost of the design ($265.2) is from 13 gallons of olive oil. I cannot understand how they figured that olive oil was the most cost effective thermal fluid. Surely they could use a cheaper oil.

Re:Cost is extremely important. (1)

Anonymous Coward | more than 2 years ago | (#39078405)

In the middle east, the best working fluid would probably be palm oil. It is, literally, around every street corner. It is thick at room temperature, but at working temp, it should be fine.

All you need... (2)

Oswald McWeany (2428506) | more than 2 years ago | (#39077633)

Solar powered cooker?

Grow trees using power of the sun. Sun dries out broken sticks and kindling. Rub stick on piece of wood with bow. When you get a glow- blow on it and light kindling. Cook food over resulting fire. Roast marshmallows- drink beer; get guitar (or sitar) out- everyone starts to sing Eagles songs.

Everyone is happy and goes to bed smelling like campfire smoke. Is there anything better?

Re:All you need... (2)

royallthefourth (1564389) | more than 2 years ago | (#39077667)

Is there anything better?

Yes. Singing anything other than The Eagles [youtube.com] would be better.

Re:All you need... (1)

Asic Eng (193332) | more than 2 years ago | (#39077683)

Oh come on. They have a problem with deforestation. They get sick from the open fires indoors. Carrying that wood through the mountains is hard labor.

Everyone is happy and goes to bed smelling like campfire smoke. Is there anything better?

Yes.

Re:All you need... (1)

Oswald McWeany (2428506) | more than 2 years ago | (#39077847)

Oh come on. They have a problem with deforestation. They get sick from the open fires indoors. Carrying that wood through the mountains is hard labor.

Fine- go ahead and be rational about it.

Re:All you need... (1)

pla (258480) | more than 2 years ago | (#39078243)

They have a problem with deforestation.

Burn dried dung instead of wood.


They get sick from the open fires indoors.

Cook outside (or more usefully, build the stove into a wall with the chimney outside and the cook-surface inside).


Carrying that wood through the mountains is hard labor.

Cry me a river - See #1, or... Just move closer to the damned trees.

Re:All you need... (1)

Beelzebud (1361137) | more than 2 years ago | (#39078333)

*golf clap*

Re:All you need... (1)

Daniel_Staal (609844) | more than 2 years ago | (#39078835)

They have a problem with deforestation.
Burn dried dung instead of wood.

Raising animals is even more costly in terms of plant matter you need to grow. (Admitted, they might have a suitable animal already - but don't assume they all do.)

They get sick from the open fires indoors.

Cook outside (or more usefully, build the stove into a wall with the chimney outside and the cook-surface inside).

They may not have any useful outdoor space. Or there may be other reasons to stay indoors; rain is obvious, malaria and other insect-borne diseases aren't quite as obvious, but are reasonable reasons to stay indoors, among others.

And you are assuming they have a strong-walled structure that can be modified. I wouldn't bet on that. (Cardboard and corrugated steel are common building materials in many developing countries. Slightly better is wood, straw, and mud, which could accommodate such an opening if put in during construction, but not after.) Plus the fact that a chimney costs money and takes up space, both of which are at a premium. (And it needs maintenance, and when the stove is off needs to be sealed from the outside like any door or window, at least.)

Carrying that wood through the mountains is hard labor.

Cry me a river - See #1, or... Just move closer to the damned trees.

Which would be away from their land, and their job. Quite possibly they are living on the edge of a city, working in the city, and getting fuel from a nearby forest. Moving towards the forest decreases their income - even if they can find land to move to. (Upon which they would need to build a new house, and then move all their stuff into it... Moving costs money in and of itself.)

Oh, and with the constant use of wood for fuel, the forest itself is moving - away from them. How often should they move?

Re:All you need... (0)

Anonymous Coward | more than 2 years ago | (#39079225)

So you obviously have nothing of value to offer. Deforestation is a serious problem. Countries like Haiti and Ethiopia face a fundamental and huge obstacle to development due to deforestation on top of everything else. Indians already burn dung and there is still need for improvement. There is only so much dung but sunlight is abundant enough to work.

Re:All you need... (1)

Anonymous Coward | more than 2 years ago | (#39079137)

1. Then maybe they should plant some trees?? The problem is not as much deforestation as stupidity. And yes, I do mean stupidity.

http://www.nobelprize.org/nobel_prizes/peace/laureates/2004/maathai-bio.html [nobelprize.org]

Here's is someone that actually tries to reverse this stupidity of burning everything down and then bitching that there are no trees around. Heck, there are still people that believe beyond a shadow of a doubt that humans cannot plant trees. That it is only "god" that can make trees grow.

2. There is a known solution to indoor fires. That solution is known as a chimney.

Solar stoves are great. But realistically, they are only useful at or near noon hours.

If you want to cook overnight, plant some trees. Not only will they provide you with wood, but they will provide you with *food* and shade. And if you plant enough, they will even change your local climate. Trees, and especially fruit trees, are the most important economic improvement poor people can make in their lives.

Re:All you need... (2)

1u3hr (530656) | more than 2 years ago | (#39077883)

Grow trees using power of the sun. Sun dries out broken sticks and kindling. Rub stick on piece of wood with bow. When you get a glow- blow on it and light kindling. Cook food over resulting fire. Roast marshmallows- drink beer; get guitar (or sitar) out- everyone starts to sing Eagles songs. Everyone is happy and goes to bed smelling like campfire smoke. Is there anything better?

That's what they're doing now. And causing deforestation in the process. It's also pretty labour intensive to walk for hours to the forest, cut and collect wood, carry it back to the village.

ONly problem (1)

arcite (661011) | more than 2 years ago | (#39077957)

Too many people cutting down the trees day after day means....no more trees.

Re:All you need... (0)

Anonymous Coward | more than 2 years ago | (#39078521)

I was thinking ethanol. Before you scoff at that, consider that farmers have been distilling hooch since time immemorial. Ethanol only becomes a net loser when you centralize it and deliver it. Farmers don't need accounting and delivery and all that. They just need to grow more food, fermant and distill some, and feed the mash back to their cattle (it makes good feed). I suspect that if they didn't have subsidized kerosene as the other poster mentioned, they'd be doing this.

What? You can't grow more food? Birth control. What? Immoral? Less moral than starving to death? If that's not the problem, then at some point you're going to exceed carrying capacity and it's going to get messy. The fact that they subsidize kerosene to prevent deforestation tells us they're already getting perilously close to carrying capacity or over. 1+ billion people? Sorry. There just may not be any good solution.

Their heart is in the right place, but.. (5, Interesting)

Powercntrl (458442) | more than 2 years ago | (#39077663)

There are actually government subsidies on kerosene in place in India specifically to prevent deforestation. The kerosene stoves are actually quite safe, efficient, clean burning and relatively inexpensive (by developed nation standards). Now before you start with the "OMG fossil fuels BAD!!!", remember that the grid-connected electric ranges that are so popular here in the USA are running on varying percentages of power derived from nasty, dirty coal - with the added bonus of generation and transmission losses. Since we're talking about a point-of-use fuel, these "third world" kerosene stoves are actually a pretty green solution. Perhaps instead of providing these people with pie-in-the-sky solar stoves that we wouldn't even use ourselves, we should offer good old kerosene stoves and maybe take a closer look at our own wastefulness.

problem with kerosense (2)

arcite (661011) | more than 2 years ago | (#39077997)

Kerosene is actually expensive as the price can fluctuate (even with subsidies the black market ensures price inflation). Kerosene is also responsible for many early deaths and chronic diseases due to inhaling the poisonous fumes, not to mention the fire hazards. A viable solar cooker would not only be more sustainable, but also safer for the users.

Therein lies the crux of the issue (3, Interesting)

Powercntrl (458442) | more than 2 years ago | (#39078155)

The Japanese and the Amish use kerosene appliances quite heavily in their societies. A properly designed kerosene stove will burn just as clean as the LP/natural gas stoves that we seem to be entirely unafraid of, here in the US. Notice the incredibly clean, blue flame this stove [youtube.com] burns with.

What it boils down to is, as you said, a problem of getting the subsidized fuel to the people who need it. It seems like that's the real issue here, not some engineering challenge to show off to some poor villagers how advanced our high tech is (again, never minding the fact many of us use electric stoves that get their power from dirty coal!).

What a fucking (-1)

Anonymous Coward | more than 2 years ago | (#39077741)

waste of time

Re:What a fucking (1)

Beelzebud (1361137) | more than 2 years ago | (#39077821)

You forgot to attribute that quote to who said it. Namely your parents.

Re:What a fucking (2)

Attila Dimedici (1036002) | more than 2 years ago | (#39078427)

No, his parents said "What a waste of fucking time."

My experiment (1)

jones_supa (887896) | more than 2 years ago | (#39077843)

This is just something simple, but some summers ago I made the "Fun-Panel" from the solarcooking.org plans [solarcooking.org] . I was surprised how well it worked, was actually able to fully cook some small stuff. A fun and recommended geeky project.

Why not just propane? (1)

mveloso (325617) | more than 2 years ago | (#39077929)

Why does the stove need to be solar?

For the heat storage solutions, what happens when someone (a child) kicks the stove over by mistake? Burns, disfigurement, death. Great.

Why not just a propane stove with a "turn off if you tip over" design?

Re:Why not just propane? (3, Interesting)

Daniel_Staal (609844) | more than 2 years ago | (#39078217)

Propane is expensive and hard to store and transport. (At least by 'developing country villager' standpoint.) Easiest way to transport it is large metal canisters, of which the canister itself would cost a month's salary, quite often. Of course, the canister is recyclable, so they'd only have to pay that once, but it's still an expensive item. Then they have to carry it back and forth from the refueling station, and pay for the actual fuel.

From the villager's standpoint, that's not much different than using a wood stove; at least the wood will be cheap/free.

Dung fired stoves? (1)

basecastula (2556196) | more than 2 years ago | (#39078677)

Why havent dung fired stoves and indoor pollution been addressed in these comments?

Wrong way (2)

slapout (93640) | more than 2 years ago | (#39078045)

They need a solar powered fridge to keep the food they cooked yesterday from going bad.

Well, they work in Tibet (0)

Anonymous Coward | more than 2 years ago | (#39078213)

I was very surprised when I saw a few--or a few dozen solar heaters in almost every Tibetan village when I went there in October. I have no idea if they get it all the way up took boiling. The main use seems to be to get the kettles hot and then finish on the stove.
As you can see in this picture [google.com] , they also make a great dog bed.

This may be obvious, but... (0)

Anonymous Coward | more than 2 years ago | (#39078415)

What's wrong with a regular-old wood burning stove?

Thanks, Slashdot (5, Informative)

Rob Goodier (1861316) | more than 2 years ago | (#39078563)

I wrote the article for Engineering for Change and I'm so glad to see this discussion on Slashdot. I've been a fan reading the daily email for a while now. It's interesting to see that, in a just a few comment strings, some of you came to the same conclusions about the best ways to introduce new technologies that it has taken maybe decades for people who are educated in development issues to reach. Also, your discussion of better solutions other than solar (efficient wood stoves) and better materials (why olive oil?) is the same kind of thing that the community at Engineering for Change struggles with. Our members find different answers that sometimes conflict, and often a solution depends a lot on the place where you use it. So, a universally perfect cook stove might not exist. Just a few thoughts. Thanks again! Rob

Re:Thanks, Slashdot (1)

Daniel_Staal (609844) | more than 2 years ago | (#39078975)

Some of us have been educated in development issues. ;) A site like this is worldwide, and draws a lot of people. Even if they have no formal education in the subject, a portion of the population will have seen or worked with the issues directly. It wouldn't surprise me if some of the comments are from people currently living in countries where these are targeted, who can drive by the people it is for any time they wish. For myself, I grew up in developing countries in a family who were working directly on some of these very issues. No formal education in the subject - but I've helped build the types of houses these people are living in, and I know what level of resources they are likely to have.

YUO FAIL It (-1)

Anonymous Coward | more than 2 years ago | (#39078759)

All your cookers are belong to us (2)

What Goes Around (710594) | more than 2 years ago | (#39078825)

Sorry. Couldn't resist after seeing the following comment here https://www.engineeringforchange.org/news/2012/02/04/ten_solar_cookers_that_work_at_night.html [engineeringforchange.org]

Re: Ten solar cookers that work at night
Hi I has been worked for a better new solar cooker, These schemes seems applicable,i am interested to see their details, Please send them to my email : mashhoodim2@asme.org thanks

we are talking monsoon country (0)

Anonymous Coward | more than 2 years ago | (#39078855)

It should be a device that is solar assisted as it should work conventionally when the sun don't shine.
Also wood is not so plentiful as you see many bodies float down the river Ganges as they stop the cremating fires when the families depart to save the wood and dump the bodies.

I have a better design (1)

Rix (54095) | more than 2 years ago | (#39078957)

We direct solar power at a large body of water, and collect the precipitation runoff in a basin (natural or otherwise). When needed, we allow the collected water to flow down through turbines to generate electricity, which we distribute and run through a resistor below the cooking surface.

The issues are more then just fuel (4, Insightful)

SmallFurryCreature (593017) | more than 2 years ago | (#39079021)

There are some real idiots on Slashdot who can't think outside the box that is their mothers basement.

Wood burning has some nasty side effects. First off, wood isn't all that efficient for burning, meaning you need a lot of it. Neither can you turn it on/off as you want, meaning you waste a lot of energy. Consider a gas grill to a coal one. The coals needs to first burn up, then glow and finally cool down. The gas grill is hot in an instant and the moment you stop using it, you can turn of the supply of fuel.

The second problem is that wood is not a renawable resource if you use it up to fast. Trees only grow so fast and it is VERY easy to use them up faster then they can regrow. Land is also expensive and often owned by someone. You can't just go around collecting wood from anywhere and the more people there are, the more this is true. Removing trees even if you intend to replace them also causes climate change. Don't believe this? The rain forest causes most of its own rain, trees evaporate a hell of a lot of water but also capture a lot of it again, it is a complex system that can easily turn forest to desert if upset. See the expanding Sahara as an example.

Then there is another issue, collecting wood is a labor intensive task, often falling down to the women. Gathering it means they can't go to school, can't do anything else. It also forces them to go outside their village, in Africa especially this opens them to attack. Not every area in the world is safe to go outside. One of the reasons for putting wells inside villages is pricesly this, to protect the women and stop them to having to spent every waking hour collecting basic resources.

The solar stove is a good idea. There is just one snag. Those making the decisions ain't the ones who would benefit from it. The mentioned problems of cooking outside sunlight hours are trivial to solve by adjusting how you eat. But the ones in charge don't want to do that, the old ways suit them just fine. They can afford to send their women out to collect wood, and if they get attacked, they are just killed to spare the family shame. Never underestimate the evilness of a village elder.

Change will come but it will come slowly, just as it did in our own history. It isn't so long ago we cooked on wood and coal and suffered from it. Research the clean air act of Britain. You would be suprised how recent it is.

Take it slow with this solar cooker, don't get the adults or old people involved at all, show the kids at school. Those girls will one day have to buy their own stove and if they have learned they can cook at least some percentage of their food without having to spend a fortune on fuel, some might just do it when they got the chance.

Similar things happened in our own history, the bicycle was a huge liberator. While the proper women thought they were indecent, lots of young women took them as it allowed them to take jobs far further from home and thus increase the earning capacity of their family. If you get payed by the hour, any hour not spend travelling means more money and the further your range, the more options you have.

These things go faster then you might think but slower then you might wish. The solution for the solar cooker is already known and used. Hot stones. Heat a stone, it retains the heat for long enough to continue cooking after the fire has gone out (sun has gone down). And people adjusted to this. Just takes time for the old to be replaced by the young.

The IEEE had a fascinating article on this (3, Interesting)

sirwired (27582) | more than 2 years ago | (#39079081)

A couple of years ago, the IEEE magazine of the Society for the Social Implications of Science and Technology had a fascinating article about this very topic. (Although it did not involve solar stoves; instead it was about combination stoves/small generators to supply low levels of lighting and communication access to a rural village, in addition to a stove.) I can't remember how the electricity was generated; it was something non-mechanical... As an added bonus the stoves vastly improved the air quality of the dwelling; at least, they would have if they were used.

What they determined was that the style of cookstove used varies by region, and that a design put together by some appliance designer many thousands of miles away is invariably not going to design a stove that is going to get used in some isolated rural village in the boondocks.

It'd asking somebody that's used an oven all their life to start doing all their cooking over an open fire... given the choice, I'm just going to keep doing what I've been doing.

The project also failed to account for distribution and transportation difficulties. A bulky stove weighing a couple of hundred pounds is really hard to transport into a mountain village accessibly only via a one-week journey by donkey.

interference (1)

lkcl (517947) | more than 2 years ago | (#39079269)

i have to question the "wisdom" of interfering with traditional ways
of living, like this. i remember seeing a report somewhere that
said it was disgraceful that people in poor countries didn't have
lights, to which the answer is, "so you want to have people not only become dependent on electricity, but you also want them to stop living in tune with nature, make them deprive themselves of sleep, and place them in front of flickering light sources?"

in other words, they wanted to inflict the exact same kind of pain and suffering that the first world subjects itself to, onto the third world.

in this case, they seek to inflict non-traditional cooking routines and methods onto these people who have lived generations of lives eating at times which make sense in their environment.

_why_??

SImplest solution (0)

Anonymous Coward | more than 2 years ago | (#39079341)

My Solution:
Use solar power aka sunlight to grow wood. Use it as firewood, cook whenever you want. Proven technology.

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