the leading source of patents across all four types of listed stoves. And India is the leading source of scientific articles for 3 of the 4 stove technologies, likely driven by research from universities and non-profit foundations, which are less likely to patent and commercialize research findings.

**Patent and Publication Counts for Indoor Cooking Stoves, to 2010**

||China|India|South<br>Africa|Japan|US|Germany|France|UK|Korea|Total|
|---|---|---|---|---|---|---|---|---|---|---|
|_Patents from 1960s to 2010_<br>_:_|||||||||||
|solar stoves|483|0|0|69|56|8|12|8|2|665|
|biomass stoves|273|2|<br>0|5|16|3|0|0|0|307|
|LPG stoves|304|1|<br>0|10|8|0|0|1|5|358|
|Kerosene / butane stoves|143|0|<br>1|112|21|2|4|2|18|313|
|_Publications 1990-2010_<br>_:_|||||||||||
|solar stoves|7|86|12|6|17|9|4|7|0|215|
|biomass stoves|40|61|3|7|101|8|7|17|4|319|
|LPG stoves|1|26|<br>2|2|18|2|0|2|2|68|
|Kerosene / butane stoves|3|50|<br>2|3|41|4|0|4|1|132|

**_Aakash Ganga (‘river from sky’), Rajasthan, India_** : modernizing an ancient rainwater harvesting system to collect safe drinking water is a low-cost adaptation to arid regions, which has won the 2010 Lemelson-MIT award for sustainability. It spurred additional innovations and thereby generated a range of efficiency and more inclusive growth co-benefits:

-automating the traditional surveying system with satellite imaging shortens design time, minimizes earthwork and reduces material costs

-a numbering plan for reservoirs facilitates co-investments

-induced demand for stretchable roofs has spurred more innovation

-accounting transparency has spurred policy debate on broader inequities in water affordability.

**_Novel uses of rice husks, one of India’s most common waste products_** : Husk Power Systems (HPS), winner of the 2011 Ashden Awards for sustainable energy, has adapted and converted an existing biomass gasification using diesel technology into a single fuel rice husk gasifier for rural electrification; households stop using dim kerosene lamps when they get HPS electricity, saving on kerosene (with associated reductions in CO2 emissions) and facilitating evening studying/learning and other productive activities. Tata Consulting Services US$24 _Swach_ ( ̳clean‘ in Hindi) water filter targeted at rural households with no electricity or running water, using ash from rice milling to filter out bacteria, is another example.

**_Solar irrigation with electric vehicles in Bangladesh_** : use of lithium-ion batteries (second-hand, recycled from electric cars) that are powered by solar panels allow mobile shallow-tube irrigation systems to meet rural farmer irrigation needs in Bangladesh and other countries that face limited electricity supply and make heavy use of groundwater.

Source: Popp (2011) on cooking stoves (using a combination of keyword and patent classification searches on the Delphion on-line patent database, and using a keyword search of abstracts and titles in the Web of Knowledge database); web searches and interviews for others.

Besides BoP innovation, the adaptation of existing technologies to local conditions is a growing area of green innovation in developing countries. Box 2 provides some recent examples of technology adaptations by innovative developing country companies that solve limitations of resources, labor and infrastructure. They create important co-benefits including more sustainable company cultures.

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