• Energy Research
• 2021-2025close
• 11. Sustainability close
• University of Oxford close

Green ammonia is gaining momentum as a globally significant technology for deep decarbonisation. In this thesis, several models are developed across chemical, techno-economic, and energy system modelling disciplines to explore the future role of green ammonia. First, standalone models of production (i.e., power-to-ammonia) and re-electrification (i.e., ammonia-to-power) are developed and compared to competing technologies. Second, these models are integrated into a planning and dispatch energy system model (ESM) of India to 2050. The ESM has several novel additions including the sector coupling of hydrogen and ammonia, multiple years of granular weather data, and learning-curve-based technology cost forecasts. India is chosen as an ideal case study given its globally unmatched demand growth in all three relevant sectors: electricity, green hydrogen, and green ammonia. The projected electricity demands for green hydrogen and ammonia production account for 25% of the total Indian electricity demand in 2050, underscoring the transformational potential that green hydrogen and ammonia sector coupling can have on the Indian energy system. The results of the state-of-the-art ESM highlight synergistic effects of hydrogen and ammonia sector coupling with the power system. The least-cost system employs seasonal green ammonia production paired with up to 40 million tonnes (i.e., 200 TWh) of ammonia storage, as well as some re-electrification via gas turbines. Sector coupling reduces system curtailment, addresses challenges of long-duration storage, and improves system resilience to interannual weather variations. While India is a crucial case study from a global decarbonisation perspective, the methodology and findings are generally applicable, and it is the aim of this work to motivate and accelerate the wider research community into considering the potential impacts of green ammonia sector coupling on electricity grid design. Finally, this work highlights strategic technology development direction for ammonia producers and gas turbine manufacturers, as well as implications for policymakers.

Interdisciplinary energy research that focuses on the upcoming energy transition is growing at pace and scale given the goal of the Paris Agreement to limit global warming to 1.5 °C. As a consequence, integrated interventions are needed to support the energy transition. However, gaps in the energy literature remain on how to manage uncertainties inherent in energy transition. Based on a review that showcases some of the shortcomings in the current literature, this paper introduces a novel framework to provide a structure on how to engage with uncertainty called targeted and tangential effects. Relevant case studies in residential energy and energy justice as well as household retrofits and health are used to demonstrate how the targeted and tangential framework can be used. The targeted and tangential effect concept provides an innovative framework for energy researchers and practitioners to use to proactively recognize and identify uncertainty in the energy transition. Benefits and shortcomings of this framework are presented. Areas of future research are identified, including relevance for policy.

Abstract Background Estimates indicate that household air pollution caused by solid fuel burning accounted for about 1.03 million premature mortalities in China in 2016. In the country’s rural areas, more than half the population still relies on biomass fuels and coals for cooking and heating. Understanding the health impact of indoor air pollution and socioeconomic indicators is essential for the country to improve its developmental targets. We aimed to describe demographic and socioeconomic characteristics associated with solid fuel users in a rural area in China. We also estimated the risk of cardiovascular disease and all-cause mortality in association with solid fuel use and described the relationship between solid fuel use, socioeconomic status and mortality. We also measured the risk of long-term use, and the effect of ameliorative action, on mortality caused by cardiovascular disease and other causes. Methods We used the China Kadoorie Biobank (CKB) site in Pengzhou, Sichuan, China. We followed a cohort of 55 687 people over 2004–13. We calculated the mean and standard deviation among subgroups classified by fuel use types: gas, coal, wood and electricity (central heating additionally for heating). We tested the mediation effect using the stepwise method and Sobel test. We used Cox proportional models to estimate the risk of incidences of cardiovascular disease and mortality with survival days as the time scale, adjusted for age, gender, socioeconomic status, physical measurements, lifestyle, stove ventilation and fuel type used for other purposes. The survival days were defined as the follow-up days from the baseline survey till the date of death or 31 December 2013 if right-censored. We also calculated the absolute mortality rate difference (ARD) between the exposure group and the reference group. Results The study population had an average age of 51.0, and 61.9% of the individuals were female; 64.8% participants (n = 35 543) cooked regularly and 25.4% participants (n = 13 921) needed winter heating. With clean fuel users as the reference group, participant households that used solid fuel for cooking or heating both had a higher risk of all-cause mortality: hazard ratio (HR) for: cooking, 1.11 [95% confidence interval (CI) 1.02, 1.26]; heating, 1.34 (95% CI 1.16, 1.54). Solid fuel used for winter heating was associated with a higher risk of mortality caused by cerebrovascular disease: HR 1.64 (95% CI 1.12, 2.40); stroke: HR 1.70 (95% CI 1.13, 2.56); and cardiovascular disease: HR 1.49 (95% CI 1.10, 2.02). Low income and poor education level had a significant correlation with solid fuel used for cooking: odds ratio (OR) for income: 2.27 (95% CI 2.14, 2.41); education: 2.34 (95% CI 2.18, 2.53); and for heating: income: 2.69 (95% CI 2.46, 2.97); education: 2.05 (95% CI 1.88, 2.26), which may be potential mediators bridging the effects of socioeconomic status factors on cardiovascular disease and all-cause mortality. Solid fuel used for cooking and heating accounted for 42.4% and 81.1% of the effect of poor education and 55.2% and 76.0% of the effect of low income on all-cause mortality, respectively. The risk of all-cause mortality could be ameliorated by stopping regularly cooking and heating using solid fuel or switching from solid fuel to clean fuels: HR for cooking: 0.90 (95% CI 0.84, 0.96); heating: 0.76 (95% CI 0.64, 0.92). Conclusions Our study reinforces the evidence of an association between solid fuel use and risk of cardiovascular disease and all-cause mortality. We also assessed the effect of socioeconomic status as the potential mediator on mortality. As solid fuel use was a major contributor in the effect of socioeconomic status on cardiovascular disease and all-cause mortality, policies to improve access to clean fuels could reduce morbidity and mortality related to poor education and low income.

AbstractIn this paper, we introduce and test a framework to qualitatively assess the environmental impact of climate adaptation innovations with the ambition to facilitate the implementation of these adaptations. The framework was designed to enable continuous environmentally conscious benchmarking based on three environmental performance indicators: sustainable design, environmental impact and ecological impact. It was pilot tested by uninvolved experts and key-persons for two large-scale nature-based flood adaptation innovations in the Netherlands and discussed with environmental assessment professionals. Our findings indicate how the inclusion of our framework helps to identify important knowledge gaps regarding environmental co-benefits and trade-offs, and can be beneficial to both those developing the innovation and the local authorities charged with assessing the suitability of innovations. We conclude by noting how the incorporation of environmental impact assessment from the design stage of adaptations could supplement existing environmental assessment regulations pre-empting concerns rather than reacting to them.

Abstract Biofuels have been promoted as a renewable energy option in many countries, but have also faced extensive scrutiny over their sustainability. Food security is perhaps the most debated sustainability impact of biofuels, especially in regions such as Sub-Saharan Africa that experience high rates of malnutrition and have been a major destination for biofuel-related investments. This study assesses the local food security impacts of engagement in biofuel crop production using a consistent protocol between multiple crops and sites. We use standardized metrics of food security related to dietary diversity and perceptions of hunger, and focus on feedstock smallholders and plantation workers in four operational projects: a large-scale jatropha plantation (Mozambique), a smallholder-based jatropha project (Malawi) and two hybrid sugarcane projects (Malawi, Eswatini). Collectively these reflect the main feedstocks, modes of production and land use transitions related to biofuel projects in Sub-Sahara Africa. Inverse Probability Weighting analysis indicates that involvement in sugarcane production improved household food security for plantation workers and feedstock smallholders. Conversely, involvement in jatropha production does not have a statistically significant positive effect on household food security for both workers and smallholders. Regression models indicate that the factors driving food security indicator levels vary between study sites. Wealth indicators influence food security indicators in several sites, but the absolute level of income plays a smaller role, while income stability/regularity, access to credit and stable markets for selling sugarcane be important drivers as indicated by the strong effect of proxy variables on indicators.

This paper models the retrofitting of traditional rural dwellings in Uganda by introducing passive cooling and daylighting measures. With climate change, outdoor temperatures in parts of the Global South will become unbearable. Communities will be forced to spend more time indoors and thus require further cooling and daytime lighting for thermal and visual comfort. Passive measures can address this while also attenuating energy consumption and diversifying energy use. For the first time, these measures are combined and modelled for those purposes in a rural developing country context where there is limited access to electricity. Using SketchUp and EnergyPlus™, we simulate 15 scenarios of passive cooling and daylighting measures for two baseline scenarios: electrified mud hut and semi-permanent dwelling. Those are also feasible scenarios for similar greenfield unelectrified architectures. The results from the simulated scenarios on electrified dwellings include energy savings, and from these, payback periods are calculated. Two cost-effective scenarios are identified. For mud huts, combining shading (through vegetation) with a centralised fibre optic solar concentrator enables an annual reduction of 31 % of energy consumption. For semi-permanent dwellings, painting rooftops white combined with the integration of solar water light bulbs reduces energy consumption by 47 %. In terms of payback periods for the selected scenarios, the former is four years and nine months, while the latter is two months.

Planned adaptations are commonly adopted by governments considering large-scale socio-economic and political interventions, while local communities innovate their adaptive responses using locally available resources â also known as autonomous adaptation. Congruence between planned and autonomous adaptation is needed to develop a concerted and effective effort to minimize the negative impacts of context-specific vulnerability. This paper offers a systematic framework for building congruence between planned and autonomous adaptation using a six-step approach to guide their integration while maintaining an environment for future autonomous innovations. We applied this framework to previously conducted case studies in Spain, Bangladesh and Canada, revealing key lessons for using autonomous adaptation as leverage points for sustainable climate adaptation. © 2021 The authors would like to acknowledge funding from the Canadian Social Sciences and Humanities Research Council Funding 201989 (Rahman PI). The authors would also like to thank Professor Kate Sherren, School for Resource and Environmental Studies, Dalhousie University, Halifax, Canada for her comments on the earlier draft of the paper.

Smallholders, who cultivate ±30% of the global palm oil land, are critical to the realization of a sustainable palm oil sector. However, particularly independent smallholders, untied to mills, lag behind in yields and experience challenges to market their produce. Sustainability certification, such as by the Roundtable on Sustainable Palm Oil (RSPO), is proposed as a way to improve smallholder livelihoods, while protecting the environment. However, independent smallholders experience barriers to obtain certification. Through interviews with 18 RSPO certified independent smallholder groups in Indonesia and 9 certification facilitators, this study examines how pre-certification conditions regarding smallholders’ socio-economic backgrounds, legality, group organization, planation management practices, and local supply chain conditions impact prospects for RSPO certification, and how groups who successfully achieved certification have dealt with challenges during the certification process. We found that the majority (77%) of RSPO certified independent smallholders in Indonesia consists of ‘former scheme’ smallholders. These smallholders often have clear land legality and are organized in groups prior to certification, which increases their eligibility for RSPO certification. However, due to upfront and recurrent costs for certification, as well as complexities in meeting RSPO standards, access to certification is strongly dependent on external facilitators. To up-scale certification for independent oil palm smallholders, and include more non-scheme smallholders, certification projects should involve more local actors including local governments and certified smallholder groups. In addition, certification should focus on core social and environmental concerns for smallholders, while being flexible with regards to the forms of proof needed to fulfil legality requirements.