Table 1.

Program information and clean cooking adoption rates by case study

Country	Clean fuel promoted	Program Details	Population, stacking/stove use behavior	Primary reasons reported for stacking behavior
				Recurrent Costs	Supply Challenges	Task - based requirements	Other
Ghana	LPG	Government-led program since 2014 to provide LPG access to 50% of Ghana’s population by 2020. Provides a 1-burner LPG stove, 6 kg LPG cylinder, hose, and regulator; participants must pay for the initial filling of gas and for subsequent refills (~5 USD). ~150,000 households received the package as of 2017.	In rural areas almost no sustained use of LPG. 100% of surveyed respondents still used wood as their primary fuel 9 months after LpG distribution; and only 8% still used any LPG 18 months post-distribution.	Recurrent fuel costs	Distance to refill, fuel shortages, lack of spare parts
Peru	LPG	Government-led program since 2012 supplying a voucher subsidizing half the cost of one LPG cylinder per month for eligible households (those matching “living in poverty” criteria). 928,800 active users as of 2017.	In rural areas, among households that used LPG stoves, 95% reported stacking with traditional biomass stoves; approximately 60% of cooking done with LPG and 40% with biomass. Personal PM2.5 exposure was consistently above the WHO interim targets.	Recurrent fuel costs required for exclusive use	Supply chain and logistical barriers to exchange LPG cylinders		Seasonal and taste related preferences
Ecuador	LPG	National, universal LPG subsidy, provided by Ecuadorian government with price fixed at US$1.60/15 kg cylinder since 2001 (with limits on monthly refills in some areas).	In a region where LPG has been heavily subsidized (Carchi district, Ecuador), 93% report LPG is primary fuel, but only 19% use LPG exclusively; 79% of households use wood at least once per week	Costs are still barriers for poorest families	LPG access difficult in some remote locations, leading to time and travel costs	Heating benefit of wood. Woodfuel also useful for energy intensive cooking
	Electric/ induction cooking	The Programs de Eficiencia Energética para la Cocción (PEC) since 2014 includes a consumer credit for an induction stove purchase and 80 kWh of free electricity per month (projected to cover household cooking for a family of five). 670,000 households have participated.	Despite introduction of an induction-cooking program, sustained use of electricity for cooking is almost nonexistent in region studied.	Costs of induction stoves and required cooking pots. Increased electricity costs
Indonesia	LPG	Government-led program, since 2007, to convert 42 million kerosene-using households to LPG. Provides starter package of 3 kg filled cylinder, one-burner stove, rubber hose and regulator. LPG was subsidized. Program has surpassed targets, with 57.2 million free LPG packages distributed as of 2015.	Primary LPG users: Central Jakarta (73%), Yogyakarta (63%), exclusive LPG users: Central Java subdistricts (19.5%) Yogyakarta City (9%). Some stacking with clean fuel (electricity), but 73% of stackers continue to use wood alongside LPG. Quantity of biomass use per month is similar in households with and without LPG.	Fuel cost	Distance required to obtain cylinders	Biomass preferred for larger volume cooking tasks and cooking traditional foods	Local food/taste preferences
Cameroon	LPG	Government LPG Masterplan announced in 2016 to expand LPG use for cooking from < 20% to 58% of all Cameroonian households by 2035. Nascent program but surveys conducted in peri-urban and rural communities near Limbe, Cameroon in 2016-2017	In rural areas, 16% report primary LPG use but only 1% use it exclusively. In peri-urban population, 58% report primary LPG use but only 10% use it exclusively. Thus, 90% of peri-urban and 99% of rural LPG-using households reported stacking LPG with biomass; stackers only obtain about 50% of the LPG per year that would support exclusive use.	Recurrent fuel cost	Travel distance to obtain cylinders and refills	Large amounts of gas needed for slow-cooked staple foods	Safety concerns of LPG
Nigeria	Ethanol	Commercial program to put in place distribution of 2500 CleanCook (ethanol) double burner stoves in a pilot in an urban and peri-urban population around Lagos.	In an urban population, 4-5 months after receiving Clean Cook, 65% reported using it regularly. Of those, approximately 35% reported exclusive use, with the remainder stacking with kerosene. One third also reported cooking with two stoves simultaneously primarily to save time. Fuel canisters were sold at an average rate of 2.3 canisters per household/month. This rate provides approximatively one-third of the estimated amount of fuel that a typical Lagos household requires to meet all their cooking needs.	Initial costs (Willingness To Pay experiment) as well as recurring fuel costs.	Fuel purchase was difficult due to limited retail outlets.	Kerosene used for cooking beans and other slow-cooking fuels because the flame burns hotter and lasted longer than on the CleanCook.	Ethanol fuel canisters become depleted during cooking without warning.
Ethiopia: Refugee camps	Ethanol	Government program in nine refugee camps in collaboration with Gaia Association, a 2-burner Ethanol stove and fuel provided to families for free - 10,500 households have been provided the stoves.	Stacking varied across camps depending on food stuffs. For some, CleanCook stove was well adapted to cooking, others less so.		Intermittent fuel shortages	Stove not well suited to baking traditional injera bread
Ethiopia: Urban program		Low-income urban intervention is a market-driven initiative in partnership with the Former Women Fuelwood Carriers’ Association (FWFCA) which offers a subsidized price for the CleanCook stove. In operation since 2005, with 500 households using the stove (fuel must be purchased at retail rates).	All surveyed respondents stacked, using between 2-5 stoves; 98% report using charcoal; 70% firewood; 6% kerosene, and 50% electricity in addition to ethanol.	Recurring cost of fuel		Stove not well suited to baking traditional injera bread
Rwanda	Biomass pellets	Rwandan for-profit social benefit company, Inyenyeri. Customers sign up to buy 30, 45, or 60 kg of biomass pellets per month. Customers receive 1-3 Mimi Moto gasifier stoves depending on their quantity of pellets. Since 2011 with some changes to program since rollout - 3000 households have adopted the system.	In urban areas, 65% of cooking done with traditional biomass fuels. Exclusive use of the clean technology is extremely rare.	Recurring fuel costs, and need for higher quality cookware	Pellet production by Inyenyeri is currently limited.		Peer perceptions and influence. Additional cooking skill required
China	Biomass pellets	Since 2005, national strategic plans set renewable energy targets for rural household energy programs leading to increased production of densified biomass fuels (pellets and briquettes). While case study focuses on supply-side issues at the factory level; a Sichaun-based cookstove demonstration project evaluated uptake and adoption among 113 households who received the gasifier stoves and pellet fuel at no cost.	In a rural population, 77% of homes continued to regularly use their traditional wood chimney stoves. Daily use of gasifier stove was modest initially (40% of days in month) and declined over time.			Perception that certain local dishes can’t be cooked on the gasifier stove	Many homes already stacked with a different type of clean fuel stove (electric or gas).
East Africa (Kenya, Tanzania, Uganda)	Biogas	African Biogas Partnership Program supported by donor finance and carbon credit mechanisms in three countries, targeting all rural families that own 2 or more stabled cows to support fuel production. Since 2009, local masons installed 27,000 fixed-dome household bio-digesters.	In rural areas, where nearly 93% of households rely primarily on wood or charcoal fuels - after biogas installation 46% report stacking in Kenya, 71% in Tanzania, and 89% in Uganda.		Insufficient gas produced by digester to meet all cooking needs	Woodfuels used to cook traditional staple foods or foods that require long cooking times	Perceptions of taste may also play a role
Cambodia	Biogas	Began in 2006 as joint initiative of the Dutch Development Organization (SNV) and the Cambodian government, and operating as an independent Cambodian initiative since 2015. Program objectives are to create a “self-financing” bio-digester market, with financial sustainability partially achieved through carbon finance. The program installs the Farmer’s Friend bio-digester, from 4 m3 to 12 m3, with estimated gas production 0.8-~4.0 m3/day, with 26,000 bio-digesters installed.	In rural areas, surveys found between 28% and 50% of adopters stacked with wood or charcoal. Measures of wood consumption in control versus intervention households show that biogas adoption reduces wood consumption between 54–78%, but does not eliminate the use of wood fuel.		Insufficient gas produced by biodigester to provide fuel for cooking food for livestock; insufficient size of biogas burners for preparing food for livestock	Animal feed preparation