Posts by Catlin Powers
Himalayan Sun Delivers Austrian Cakes to Rural China
Published August 05, 2009 @ 11:40AM PT
An Austrian baker teamed up with One Earth Designs this week to test two internationally manufactured solar cookers, the CooKit and the HotPot, in a small agricultural village on the Himalayan plateau (2700 meters (9000 ft) in elevation).
The Qualitative Results:
The Austrian baker, Michaela Borghese, was able to make one delectable cake (on the HotPot), some bread (on the CooKit), vegetables (on the HotPot) and Austrian potato dumplings (on the HotPot).
The CooKit attracted many admirers, including the village goats who found its cardboard frame quite appetizing.
The Quantitative Results:
Simultaneous water boiling tests were performed to compare these two solar cookers. Each cooker was used to boil 1L of water. In the case of the HotPot, the standard black bottomed, clear glass topped pot was used. In the case of the CooKit, an un-blackened stainless steel pot with a diameter of 10 inches and a height of 7.5 inches was employed contained within a plastic oven bag.
The boiling point at the test elevation and barometric pressure was 91.6°C, the ambient temperature ranged from 18°C to 24.15°C during the tests, and the average solar irradiance was 865 W/m2.
The HotPot was able to boil 1L of water in 1 hour and 39 minutes (see graph below). The dip in the curve occurred when the pot was opened to add dumplings.
If we assume a 1m2 effective reflector area and negligible conduction losses, the efficiency of the HotPot reflector is 7.16%.
E = (Qw - Ql)/(Ac)*(Ia)
The CooKit was not able to boil the 1L of water. Its water temperature peaked at 79.6°C after 3 hours and 19 minutes.
We previously tested the HotPot and the CooKit in both nomadic and agricultural regions (2500-4500 m.a.s.l (8,200 ft - 14,800 ft)) during winter clear sky conditions. Bellow 5°C ambient temperature, neither was able to boil water. Windy conditions also greatly reduced their efficiency.
Putting the Data in Context:
The performance of the HotPot and CooKit during summer and winter tests suggest that neither is well-suited for use in regions where fast, high temperature cooking is preferred. Although the HotPot was able to cook a wide range of foods under summer clear-sky conditions, none of these foods are eaten in W. China where stir-frying and boiling tea or soup water are the primary cooking techniques. The HotPot's 1.5 hour boiling time for 1L of water is considered too long by local women who are able to boil 5L of water in 5-20 minutes on their stoves and existing solar cookers (see "Nomadic Entrepreneurs: A New Generation Fueled by the Sun" for more info on current W. China solar cookers). The CooKit's inability to boil water even under the best summer conditions suggests that it is similarly ill-suited to this region.
On a positive note, the temperatures achieved by the HotPot and CooKit under Himalayan conditions suggests their wide applicability in regions where stewed foods are popular. Indeed, there already exists much evidence of their success in such regions.
About the Instruments:
During these tests, temperature was measured using Maxim iButton Thermochrons. Water temperatures were measured using DS1922T iButtons (Range:0 to 125 C) encased in DS9107 waterproof capsules. Ambient temperatures were measured using DS1922L iButtons (Range: -40 to 85 C). We’ve been using these for a while and have compared them against a variety of thermocouples with excellent performance results. We highly recommend them.
Solar irradiance was measured using a MicroCircuit Labs DSL-1 Solar Data Logger (this cost $160 but, if you don’t need a logger, MicroCircuit Labs also sells a build-it-yourself irradiance meter for only $24.95). So far, the performance has been quite good but we haven’t been using it for long so we may have more to say later.
One Earth Designs (OED) was founded in 2007 by Catlin Powers and Scot Frank (OED website; OED facebook page; Twitter @OneEarthDesigns). Catlin will post on Mondays and Wednesdays. You can also find her on Twitter @catlinpowers.
Threatened Habitats Threaten Humans
Published August 03, 2009 @ 03:35AM PT
Marmots once dug their homes in deep holes across the Himalayan plateau, helping turn over the soil and creating the grassland's most important water reservoirs. Now, they are being hunted for their skins. Piles of rocks speckle the mountainsides where marmots scratched futilely against the solid rock in an attempt to escape their hunters. The grassland moisture is drying up. The plains are becoming desert.
Yesterday, I wrote that rats ("grass rats" in Chinese) had infected humans here in Qinghai with the black plague. That translation was incorrect. The vector species were marmots. Currently, it is believed that the disease took two routes of transmission: (1) street dogs eating a dead marmot and infecting goats who later died from the plague and infected the man who buried them and (2) fleas transmitted from marmots to humans during poaching activities.
China has long been known as the breeding ground for the worlds' most dangerous and widespread diseases. Each year, the US designs its flu vaccines based on new strains found in China. Why?
One possible answer is that China has a high population of animals and humans living in close proximity to one another, often with minimal infrastructure to restrict cross-transmission of diseases.
The Chinese government and NGOs have pumped a lot of resources into improving rural infrastructure. They have installed running water projects, built clinics, manufactured solar cookers, and distributed thousands of improved stoves. Despite these admirable efforts, W. China's rates of death and illness due to water and airborne diseases remain some of the highest in the world (with unofficial numbers likely to be much much greater due to the shear difficulty of getting health care out to China's rural masses).
Perhaps the solution does not lie in infrastructure development alone. China needs doctors to staff its clinics and public health professionals to design preventative medicine programs. It needs engineers and locals to work together to design pollution management systems which break the cycle of disease transmission and it needs scientists who can help prevent the ecosystem imbalances which have been associated with so many disease outbreaks including historical cases of the pneumonic and bubonic plagues.
Humans worldwide need to reconsider the basic way that we interact with our environment, reduce our environmental pollution, and create healthy living spaces for ourselves as well as the animals and plants upon which we depend.
One Earth Designs (OED) was founded in 2007 by Catlin Powers and Scot Frank ( OED website; OED blog; OED facebook page; Twitter @OneEarthDesigns). Catlin will post on Mondays and Wednesdays. You can also find her on Twitter @CatlinPowers.
Unusual Rains Bring Black Plague to W. China
Published August 02, 2009 @ 07:31AM PT
Qinghai, China - Unusually heavy rains drive rats and mice indoors. One dead and 11 hospitalized with Pneumonic Plague (bacterial infection by Yersinia pestis carried by rats; an advanced form of the bubonic plague which killed millions in Europe in the 1300s). Yushu and Golok prefectures are under quarantine.
The news is spreading through the villages by word of mouth. Villagers accross Qinghai are self-quarantining themselves (where official quarantines are not already in place). I just returned to the city areas. Other OED members and affilates are still in affected prefectures.
One Earth Designs (OED) was founded in 2007 by Catlin Powers and Scot Frank ( OED website; OED blog; OED facebook page; Twitter @OneEarthDesigns). Catlin will post on Mondays and Wednesdays. You can also find her on Twitter @CatlinPowers.
Nomads Who Capture the Sun
Published July 30, 2009 @ 11:43AM PT
Some say that solar cookers and solar panels pull the sun down from the sky and that this can cause evil in the world. Others say that humans should use the sun, as plants do, to live and grow without polluting the sky gods’ kingdom with black smoke.
The SolSource 3-in-1 was born from this second desire. It harnesses the suns’ energy for cooking, heating, and electricity generation without pulling it from the sky.
The initial concept for the SolSource solar cooker platform was born out of a memory relayed by a Ladakhi nomad.
“The colors of our land are changing. The land was once a vast expanse of green grasses dotted with black tents. Now it is a desert of yellow and white.
When I was a child, we would move our black yak tents from place to place and only leave a small pile of white ashes on the ground where we had been. Now, my children think it is better to live in a white synthetic tent and leave the ground covered with yellow plastic. They think that everything from the outside is better than what we make even when it doesn’t work as well…like the synthetic tents that let in all the cold air and have to be replaced every two years.”
The Himalayan terrain is one of the harshest on Earth and its inhabitants have displayed incredible ingenuity in adapting to that environment, sheltered by their woven yak-hair tents which last for 20 years and whose fibers swell to keep out the rain.
The design of the SolSource Cooker through close collaboration among villagers, students, and development workers, is an attempt to continue a traditional line of local innovation. It merges design principles of traditional nomadic tents with those of synthetic high-altitude hiking tents to produce a light-weight, portable, and weather hardy solar concentrator that enables the maximum range of cooking styles including stir-frying.
Field tests have yielded 28% efficiency compared to 20% efficiency of butterfly cookers tested simultaneously. The most recent iteration of the SolSource solar cooker reduced its weight to 6 kg. Although staking down the bamboo legs gives the device excellent stability against the wind, many villagers thought that it was too light and were worried that it would not last long under windy conditions. We plan to revert to several elements of our previous prototype design which bring the weight of the device to 8 kg.
The other element that we changed during our recent tests was the design of our thermoelectric component. The feedback was that the previous prototype which was slightly less efficient but which allowed people to boil water while also generating electricity was highly preferred by villagers.
We have partnered with four communities to begin local manufacture and income generation of the SolSource 3-in-1 over the next year.
>Pictures are coming soon when I have a good internet connection...
One Earth Designs (OED) was founded in 2007 by Catlin Powers and Scot Frank ( OED website; OED blog; OED facebook page; Twitter @OneEarthDesigns). Catlin will post on Mondays and Wednesdays. You can also find her on Twitter @CatlinPowers.
Nomadic Entrepreneurs: A New Generation Fueled By the Sun
Published July 16, 2009 @ 07:36AM PT
As a child, she tended yaks and goats on the mountainsides of rural Qinghai, China but things have changed since then. She still considers herself a nomad. Now, however, she is a nomad of business and it is solar panels and solar cookers she tends.
Dorma (卓玛) rose in the business world by migrating from trade to trade and from city to city; wherever opportunity presented itself. She is one of the few women of her ethnicity to run her own non-restaurant business.
One Earth Designs recently visited Dorma’s factory with local university students to negotiate solar technology prices. Seventy watt solar panels cost 2,000 RMB (293 USD) and 8 watt solar panels cost 400 RMB (58 USD).
As for solar cookers, China has a handful of standard designs that you can read about here. Dorma sells the two most popular designs:
(1) Concrete Butterfly Solar Cooker:
Butterfly solar cookers are asymmetric parabolas. In this solar cooker, the asymmetric parabolic dish is made from concrete. Small mirrors (usually 1”x 1”) are then pasted on the surface of the concrete parabola using tar or silicon adhesive. The base of the cooker is a circular concrete slab.
(2) Cast Iron Butterfly Solar Cooker
This is also an asymmetric parabolic solar cooker. The dish is made from two cast iron wings that unscrew for separate transportation. Mylar is pasted on the surface to boost specular reflectivity. Standard paper glue is used as the adhesive. The base is designed like a wheelbarrow in order to increase portability.
Although Dorma sells these cookers, she does not manufacture them. We went to visit solar cooker factories in Gansu, Sichuan, and Qinghai in order to compare prices and profit margins. Here, we report these values for the concrete solar cooker (only the government manufactures metal cookers as the unsubsidized cost of purchasing them is prohibitively expensive for most households).
The total price of manufacturing a concrete solar cooker averaged 84 RMB (12 USD). Profit margins for the factory owner ranged from 36 to 116 RMB (5-17 USD).
Many factory workers had recently relocated to urban centers from the countryside. Workers laying mirrors were able to make 6 cookers per day, thus earning 36 RMB (5 USD). If they work 7 days per week every day of the year they can make slightly more than 2/3rds China’s average urban income. The workers we spoke with had bandages covering cuts on their fingers from the edges of the glass mirrors.
Workers laying concrete were able to make 13-15 cookers per day, thus earning 39-45 RMB (6-7 USD). If they work every day of the year, they earn a few hundred RMB short of China’s average urban income.
One Earth Designs is inspired by Dorma’s success and saddened by the low wages and poor working conditions faced by rural peoples relocating to urban areas (those few able to find city jobs). We are working with local development organizations, universities, and communities to nurture a new generation of nomadic entrepreneurs skilled at merging traditional design practices and materials with modern needs and urban capacities.
Stay tuned for an introduction to our novel solar cooker design, the SolSource 3-in-1, and its potential as a local income generator.
One Earth Designs (OED) was founded in 2007 by Catlin Powers and Scot Frank ( OED website; OED blog; OED facebook page; Twitter@OneEarthDesigns). Catlin will post on Mondays and Wednesdays. You can also find her on Twitter @CatlinPowers.
Sustainable Change: Local and Holistic Grass-roots Development
Published July 14, 2009 @ 08:17AM PT
Good Technology vs. Good Implementation: Recently, a paper was written which greatly offended our friends and partners in China. The paper described local grassroots efforts as being less effective than those made by One Earth Designs and other foreign-led groups because locals ‘lacked the technical ability to create sustainable infrastructure’. This is an opinion that we have heard voiced by many international development workers. BUT creating sustainable change requires much more than just good technology.
My favorite example is a set of greenhouses that one foreign aid organization built here in Qinghai. The organization didn’t tell the villagers how to use them so, instead of growing crops, the villagers stored their motorcycles inside so that the motors would start more easily in the winter.
Without an understanding of the social, economic, political, cultural, and environmental contexts of a region; without both listening to constituents and teaching about new ideas; without follow-through and continuity; and without scalability, development projects (no matter their technical excellence) are doomed to failure.
Informed Impact & Local Students’ Efforts: Unlike foreign-based organizations, local groups have a much deeper understanding of and greater ability to meet these conditions.
In western China, they have done so. Thousands of rural communities have accessed tap water, adopted cleaner cooking technologies, revised farming practices, and built schools with libraries through student and community led grass-roots efforts. A few examples are Shamo Thar’s Development Program at Qinghai Normal University, Pentok, The Bridge Fund (TBF), the Jinpa Trust, the Friendship Charity Association, the Normgo Education Association, and the Snowland Service Group.
Communities and grass-roots development groups have built a wealth of sustainable social and physical infrastructure by implementing their own solutions and reaching out to others (whether neighboring communities or aid organizations) for any additional resources they need along the way.
In fact, it is only when local groups need project funding, technical capacity building, or confidence to act based on local knowledge (even when others might put them down for doing so) that foreign-led groups are any use at all. One Earth Designs aims to build confidence and technical capacity in the arenas of science and engineering, but our impact is by no means comparable to that achieved by the teachers, students, and communities who really run the show.
Foreign Students’ Efforts: The offending paper was written by a student ‘changemaker' visiting Qinghai for just one month. While the author cannot be blamed for misunderstanding the dynamics of local development efforts, s/he should be held accountable for acting upon misconceptions. The same holds true for all student changemakers.
Social entrepreneurship and sustainable development are popular terms among US students. But, although the US university community offers many resources to help students become changemakers (in their own communities or abroad), few turn talk into action. Many of those who do take action fail to understand the communities they work with or to ensure project continuity beyond the 1-3 months of their involvement.
Even worse, I have often heard students lying to the communities with which they are working. I once heard an Engineers Without Borders (EWB) regional staff member counsel local chapters to ‘tell communities that [they] will return regardless of whether or not [they] actually will’ because it ‘fosters a sense of trust’. [NOTE: This does not reflect on EWB as a whole. I have personally witnessed many good outcomes of work done by EWB members]
Students who really want to make change can start out with three steps. First, they can learn from the mistakes and successes of other students doing development projects. Skill-building conferences such as the Global Engagement Summit (GES) at Northwestern University, the International Development Design Summit (IDDS) hosted by MIT, and Clinton Global Initiative University's (CGIU’s) annual student conference are just a few of the great opportunities in this vein. Second, students should spend time travelling and living in the region where they hope to make positive impact. Third, students should learn how they can best help directly from their partner communities.
Sensitivity & Academic Integrity Abroad: Lastly, please make every effort not to jeopardize the lives or work of your community partners.
As changemakers, your actions have the potential to create great positive impact in the world. The positive nature of this impact, however, hinges on your intentions. If your intentions are sincere, they will lead you to respect and connect deeply with those around you. By doing so, you will naturally find a way to do good things in the world.
One Earth Designs (OED) was founded in 2007 by Catlin Powers and Scot Frank ( OED website; OED blog; OED facebook page; Twitter@OneEarthDesigns). Catlin will post on Mondays and Wednesdays. You can also find her on Twitter @CatlinPowers.
Apologies
Published July 14, 2009 @ 07:29AM PT
Sincere apologies for the long silence. A combination of regional unrest, waterborne illness, and electrical failures (blown out resistors) prevented posts this past week. There are many interesting stories to tell including an offensively placed garbage can meant to protect someone from the rain and a nighttime police visitation. I cannot write about these here, so I will move on to other important topics.
...no pictures in posts to come
...can no longer access twitter
