• Energy Research

Citizen-driven approaches are promising to overcome the challenges in the energy transition of geographical islands. However, the economic profitability of related activities must be ensured to achieve the intrinsic and sustainable uptake of related solutions in an island’s communities. Here, we investigate the long-term (2020–2054) economic profitability of solar-based prosumption on islands belonging to the European Union (EU), soft-linking energy system modelling and actor-related cash-flow analysis. This combination considerably extends common assessments of the profitability of renewable energy technology and long-term projections of island energy systems. We base our case study on the French overseas territory of Mayotte, discussing household affordability and the socio-economic impact of prosumerism. These topics are relevant to transferability on non-EU islands. The profitability of investments in PV depends on (i) the size of the PV system, with larger systems (>9 kWp) profiting from lower specific investment costs compared to smaller systems; (ii) the time of investment, with more profitable investments to be expected in early periods; (iii) the level of decarbonization of the entire energy sector, with an ongoing decarbonization reducing the compensation or energy-saving possibilities; and (iv) the market behavior, with the practice of feeding in all electricity produced rather than self-consuming energy offering a higher expected return on investment under current feed-in-tariff (FiT) compensation schemes. We introduce various policy measures to improve solar rooftop PV profitability and discuss their trade-offs and effectiveness. While indirect subsidies via FiT are generally effective in improving PV profitability, they undermine efforts to incentivize decentralized self-consumption. From the perspective of harmonizing efforts in the energy transition of African and European islands, we recommend a careful evaluation of the trade-offs in relevant regulations required for the economic incentivization of prosumers to achieve compatibility with the principles of a citizen-driven and just energy transition. Particular attention must be paid to context-specific socio-economic characteristics, including low access to financial resources and non-financial access barriers, including legal status.

As on many other European islands, the energy system of Mayotte suffers from low reliability of supply, low share of renewable energies, and high costs of supply. Residential Demand Response (DR) schemes can significantly increase the flexibility of the inherent weak power grid, increasing the potential for renewable energy integration. Given that active involvement of the population is required to unlock the potential of DR, pre-assessing the population’s preferences in DR is vital to tailor favorable schemes and assure long-term uptake of the solution. As a fundamental study, this paper assesses the population’s preferences on direct load control (DLC), electricity tariffs, major motivation, and remuneration goods by processing findings from a survey of 146 residents on Mayotte. Advanced k-means cluster analysis, multinomial logistic regression, one-way analysis of variance, and Chi-square tests were applied to the survey responses to identify socio-demographic influencers. The results indicate four distinct groups of people concerning their interest in DR schemes, with increasing age being a significant predictor for higher interest. Interest in DLC varies with the device/appliance controlled and socio-demographic characteristics. The preferred tariffs correspond to the results of previous literature. Financial incentives play a subordinate role in the main motivation for participation compared to social and environmental attractions as well as non-monetary remuneration goods, supporting the impression of a high sense of community and suitability of islands as laboratories for energy innovations. Follow-up studies must reflect on the ability/willingness to pay as well as the current state of awareness and knowledge of electricity supply to validate speculations on underlying reasons for DR preferences and flag constraints for the DR scheme implementation.

As part of the United Nations’ (UN) Sustainable Development Goal 7 (SDG7), SDG target 7.1 recognizes universal electrification and the provision of clean cooking fuel as two fundamental challenges for global society. Faltering progress toward SDG target 7.1 calls for innovative technologies to stimulate advancements. Hydrogen has been proposed as a versatile energy carrier to be applied in both pillars of SDG target 7.1: electrification and clean cooking. This paper conducts a semi-systematic literature review to provide the status quo of research on the application of hydrogen in the rationale of SDG 7.1, covering the technical integration pathways, as well as the key economic, environmental, and social aspects of its use. We identify decisive factors for the future development of hydrogen use in the rationale of SDG target 7.1 and, by complementing our analysis with insights from the related literature, propose future avenues of research. The literature on electrification proposes that hydrogen can serve as a backup power supply in rural off-grid communities. While common electrification efforts aim to supply appliances that use lower amounts of electricity, a hydrogen-based power supply can satisfy appliances with higher power demands including electric cook stoves, while simultaneously supporting clean cooking efforts. Alternatively, with the exclusive aim of stimulating clean cooking, hydrogen is proposed to be used as a clean cooking fuel via direct combustion in distribution and utilization infrastructures analogous to Liquid Petroleum Gas (LPG). While expected economic and technical developments are seen as likely to render hydrogen technologies economically competitive with conventional fossil fuels in the future, the potential of renewably produced hydrogen usage to reduce climate-change impacts and point-of-use emissions is already evident today. Social benefits are likely when meeting essential safety standards, as a hydrogen-based power supply offers service on a high tier that might overachieve SDG 7.1 ambitions, while hydrogen cooking via combustion fits into the existing social habits of LPG users. However, the literature lacks clear evidence on the social impact of hydrogen usage. Impact assessments of demonstration projects are required to fill this research gap.

Journal of cleaner production 306, 127191 (2021). doi:10.1016/j.jclepro.2021.127191 Published by Elsevier Science, Amsterdam [u.a.]

Mini-grids are expected to be the least cost option to electrify more than half a billion people living predominantly in isolated communities in sub-Saharan Africa. Providing a high reliability of power supply to satisfy paying customers is vital for the challenging business case of mini-grid owners. Therefore, renewable-based mini-grids of the third generation commonly include either diesel generators or battery storage for backup power supply. Power-to-hydrogen-to-power (P2H2P) is a promising alternative to overcome technical, financial, and social shortcomings of diesel generators and batteries. Previous research highlights the challenging economic competitiveness of P2H2P in specific case studies only. Here, we conduct a model-based techno-economic analysis on an archetypal representative mini-grid to compare the economic performance of P2H2P against the diesel generator and battery storage. We identify key parameters decisive for the competitiveness of P2H2P via sensitivity analysis. Under today's conditions, P2H2P is financially viable in 100 % decarbonized mini-grid systems. Ongoing trends of increased fuel price and P2H2P technology improvements must continue to achieve economic advantages of P2H2P over the diesel generator. However, P2H2P is competitive in locations in which the diesel price is higher than 2.6 USD/l or when P2H2P investment costs drop by >50 %, which is expected beyond 2040. Sensitivity analysis shows that increasing P2H2P system efficiency can substantially benefit the economic performance. Seasonal variations on the African continent are insufficient to create exploitable advantages of P2H2P against the short-term storage of batteries. The results suggest especially larger future PV mini-grids to combine battery storage and P2H2P rather than including common diesel generators or only including batteries when trends towards cheaper and more efficient technologies continue and diesel prices increase. Future work should investigate economic effects of the unique multi-usability of hydrogen on the mini-grid system, such as the usage as clean cooking fuel.

To close the gap of 500 million people living without access to electricity in rural Sub-Saharan Africa strategies of countries facing forced action rely on minigrid deployment. While recent studies on fuel cells in such energy systems are limited to technical and economic considerations, this paper performs a multi-criteria decision analysis to investigate their holistic fit into the economic, technical, environmental, and social system, comparing results against established power generation technologies.Findings from scenarios which shed light on 1. strategically important criteria according to academic expert opinions captured in a survey, 2. criteria decisive for actual market penetration of technologies and 3. future parameter and criteria in alliance with sustainable development, indicate the fuel cell to be highly suitable for rural power generation in minigrids. While large-scale centralized water electrolysis could improve the low economic performance – still major disadvantage – of stand-alone fuel cells, the authors see relevant future work to be made in the definition of economic niches and use-cases for decentralized hydrogen production, as reliability of supply and synergies to other end-uses are promising.

Hydrogen has recently been proposed as a versatile energy carrier to contribute to archiving universal access to clean cooking. In hard-to-reach rural settings, decentralized produced hydrogen may be utilized (i) as a clean fuel via direct combustion in pure gaseous form or blended with Liquid Petroleum Gas (LPG), or (ii) via power-to-hydrogen-to-power (P2H2P) to serve electric cooking (e-cooking) appliances. Here, we present the first techno-economic evaluation of hydrogen-based cooking solutions. We apply mathematical optimization via energy system modeling to assess the minimal cost configuration of each respective energy system on technical and economic measures under present and future parameters. We further compare the potential costs of cooking for the end user with the costs of cooking with traditional fuels. Today, P2H2P-based e-cooking and production of hydrogen for utilization via combustion integrated into the electricity supply system have almost equal energy system costs to simultaneously satisfy the cooking and electricity needs of the isolated rural Kenyan village studied. P2H2P-based e-cooking might become advantageous in the near future when improving the energy efficiency of e-cooking appliances. The economic efficiency of producing hydrogen for utilization by end users via combustion benefits from integrating the water electrolysis into the electricity supply system. More efficient and cheaper hydrogen technologies expected by 2050 may improve the economic performance of integrated hydrogen production and utilization via combustion to be competitive with P2H2P-based e-cooking. The monthly costs of cooking per household may be lower than the traditional use of firewood and charcoal even today when applying the current life-line tariff for the electricity consumed or utilizing hydrogen via combustion. Driven by likely future technological improvements and the expected increase in traditional and fossil fuel prices, any hydrogen-based cooking pathway may be cheaper for end users than using charcoal and firewood by 2030, and LPG by 2040. The results suggest that providing clean cooking in rural villages could economically and environmentally benefit from utilizing hydrogen. However, facing the complexity of clean cooking projects, we emphasize the importance of embedding the results of our techno-economic analysis in holistic energy delivery models. We propose useful starting points for future aspects to be investigated in the discussion section, including business and financing models.