Impact of randomly assigned "pay-as-you-go" liquefied petroleum gas prices on energy use for cooking: Experimental pilot evidence from rural Rwanda.

The disease burden related to air pollution from traditional solid-fuel cooking practices in low- and middle-income countries impacts millions of people globally. Although the use of liquefied petroleum gas (LPG) fuel for cooking can meaningfully reduce household air pollution concentrations, major barriers, including affordability and accessibility, have limited widespread adoption. Using a randomized controlled trial, our objective was to evaluate the association between the cost and use of LPG among 23 rural Rwandan households. We provided a 2-burner LPG stove with accessories and incorporated a "pay-as-you-go" (PAYG) LPG service model that included fuel delivery. PAYG services remove the large up-front cost of cylinder refills by integrating "smart meter" technology that allows participants to pay in incremental amounts, as needed. We assigned three randomized discounted prices for LPG to each household at ~4-week intervals over a 12-week period. We modeled the relationship between randomized PAYG LPG price and use (standardized to monthly periods), analyzing effect modification by relative household wealth. A 1000 Rwandan Franc (about 1 USD at the time of the study) increase in LPG price/kg was associated with a 4.1 kg/month decrease in use (95% confidence interval [CI]: -6.7, -1.6; n=69 observations). Wealth modified this association; we observed a 9.7 kg/month reduction (95% CI: -14.8, -4.5) among wealthier households and a 2.5 kg/month reduction (95% CI: -5.3, 0.3) among lower-wealth households (p-interaction=0.01). The difference in price sensitivity was driven by higher LPG use among wealthier households at more heavily discounted prices; from an 80% to 10% discount, wealthy households used 17.5 to 5.3 kg/month and less wealthy households used 6.2 to 3.1 kg/month. Our pilot-level experimental evidence of PAYG LPG in a rural low-resource setting suggests that further exploration of subsidized pricing varied by household wealth is needed to ensure future policy initiatives can achieve targets without exacerbating inequities.

Can the household clean energy transition ameliorate health inequality? Evidence from China.

China is actively encouraging households to replace traditional solid fuels with clean energy. Based on the Chinese Families Panel Survey (CFPS) data, this paper uses propensity scores matching with the difference-in-differences model to examine the impact of clean energy in the household sector on residents' health status, and whether such an energy transition promotes health equity by favoring relatively disadvantaged social groups. The results show that: (1) The use of cleaner cooking fuels can significantly improve residents' health status; (2) The older adult and women have higher health returns from the clean energy transition, demonstrating that, from the perspective of age and gender, the energy transition contributes to the promotion of health equity; (3) The clean energy transition has a lower or insignificant health impact on residents who cannot easily obtain clean energy or replace non-clean energy at an affordable price. Most of these individuals live in low-income, energy-poor, or rural households. Thus, the energy transition exacerbates health inequalities. This paper suggests that to reduce the cost of using clean energy and help address key issues in health inequality, Chinese government efforts should focus on improving the affordability, accessibility, and reliability of clean energy.

How does early-life famine experience influence household energy transition?

The transition of households towards cleaner energy is crucial for achieving sustainable development goals. However, the impacts and associated mechanisms of early-life experiences on household energy transition have not been considered. Based on data from the 2015 Chinese General Social Survey, this study aimed to investigate whether people experiencing China's Great Famine (1959-1961) in their early life promoted household energy transition in adulthood. The varying severity of the Great Famine in different provinces was characterised as a quasi-natural experiment and was used to perform difference-in-differences (DID) estimation analysis for birth cohorts. The results showed that the transitions from firewood, agricultural waste, and animal waste to liquefied petroleum gas and electricity were significant in households with the Great Famine experiences. Specifically, the long-term energy transition effect of the famine was exhibited mostly in those who experienced the famine during childhood (4-11 years old) and adolescence (12-17 years old). Besides, early-life famine experiences led to poor physical health, and more modern forms of energy, such as electricity, were consumed to avoid further deteriorating health. Early-life famine experience also brought psychological trauma to people at that time, which led them to increase Internet use to gain emotional support, and the increased Internet use provided better access to information about the energy transition. Moreover, the household energy transition influenced by early-life famine experience occurred more in female-headed, rural, more educated, and low-income households. Our results illustrated the role of early-life famine experience in household energy transition and provided new insights into developing effective energy policies.

Personal exposure to PM2.5 of indoor and outdoor origin in two neighboring Chinese communities with contrasting household fuel use patterns.

The Chinese government is replacing high-polluting, household coal heating stoves with electricity- and natural gas-powered heaters to improve ambient air quality. The evaluation of the intervention impact on outdoor PM2.5 and personal exposure in community level are in their initial stages. We compared outdoor air pollution and personal exposure in two neighboring communities (~2 km) in northern China with contrasting household fuel use patterns: one where residents primarily used coal for cooking and heating ("coal village") and one where natural gas was the dominant fuel ("gas village"). We collected 24-h outdoor gravimetric PM2.5 samples in each village and concurrently measured 48-h integrated exposures among 71 participants from 41 and 30 households in the coal and gas villages, respectively. PM2.5 samples were analyzed for mass and chemical composition. Daily outdoor PM2.5 concentrations in the coal village (mean ± standard deviation: 109 ± 41 µg/m3) were, on average, 1.3 ± 0.2 times higher than in the gas village (88 ± 38 µg/m3). However, personal PM2.5 exposures were lower in the coal village (116 ± 121 µg/m3 versus 156 ± 106 µg/m3). PM2.5 species that can serve as tracers for residential coal combustion (e.g., S, Se, Zn, Pb, etc.) and dust (Al, Ca, Mg, Fe, Si and Ti) were higher in the coal village, and the proportion of personal PM2.5 of outdoor origin in the coal village was nearly 2 times higher than the gas village. Our results suggest that ambient PM2.5 and its chemical composition can vary at relatively small spatial scales and may reflect community-level differences in the household energy use. However, personal PM2.5 exposures may not mirror between-village differences in outdoor air pollution if only PM2.5 mass is evaluated. Individual chemical composition of PM2.5 exposure can provide important insight in future studies on the effectiveness of source-targeted air quality interventions.

Determinants of Cookstoves and Fuel Choice Among Rural Households in India.

Roughly 2.8 billion people depend on solid fuels for cooking needs, resulting in a tremendous burden of disease from exposure to household air pollution. Despite decades of effort to promote cleaner cooking technologies, displacement of polluting technologies has progressed slowly. This paper describes results of a randomized controlled trial in which eight communities in two regions of rural India were presented with a range of cooking choices including improved solid fuel stoves and clean cooking options like liquefied petroleum gas (LPG) and induction stoves. Using survey data and logistic and multinomial regression, we identify factors associated with two outcomes: (1) pre-intervention ownership of non-solid fuel technologies and (2) household preferences for clean fuels from the range of cooking options offered. The analysis allows us to examine the influence of education, wealth, gender empowerment, stove pricing, and stove exchanges, among other variables. The majority of participants across all communities selected the cleanest options, LPG and induction, irrespective of price, but there is some variation in preferences. Wealth and higher caste stand out as significant predictors of pre-intervention ownership and non-solid fuel cooking options as well as preference for cleaner technologies offered through the intervention. The experimental treatments also influence preferences in some communities. When given the opportunity to exchange, communities in one region are more likely to choose solid fuel stoves (P < 0.05). Giving free stoves had mixed results; households in one region are more likely to select clean options (P < 0.05), but households in the other region prefer solid fuels (P < 0.10).