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.
- Cost: 150-200 RMB (22-29 USD) + tax + shipping
- Weight: 95kg (209 lbs)
- Long Distance Transportation: 20% breakage in route to the villages
- Collection Area: 1.88 m2
- Reflector: Both tar and silicon glue lose efficacy when exposed to weathering. If mirrors are not placed tightly together, these glues melt and the mirrors fall off within a few weeks to a few months.
- Assembly Time: 20 minutes
- Boil Time/5L water (summer): 10 minutes, sunny day (30 C ambient; 86 F)
- Boil Time/5L water (winter): 2.5 hours, sunny day (-15 C ambient; 5 F)
- Accidents:
- Starts unwanted fires
- Burns through pots
- Cooking: Fast but cooks food unevenly
(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.
- Cost: 420-500 RMB (62-74 USD) + tax + shipping
- Collection Area: 1.62 m2 (0.81 per wing)
- Weight: 70 kg
- Long Distance Transportation: Mylar often tears during transport to villages.
- Reflector: Pasting Mylar leaves many bubbles and insufficiently pasted edges which tear easily during transportation and weathering.
- Assembly Time: 5-10 minutes
- Boil Times: Slightly less than concrete cooker
- Cooking: Fast but cooks food unevenly
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.