Renewable and Sustainable Energy Transition最新文献

This paper investigates the obstacles to Distributive Generation (DG) uptake in Pakistan, finding inertia and resistance from incumbent actors as key and understanding this as a problem of misaligned institutional logics. Focusing particularly on bank finance and drawing lightly on a neo-institutional framework of types of logic and mechanism – we highlight misalignment of regulative, cognitive, and normative aspects of the institutionalized system, driven in particular by difficulties in acquiring finance, and lack of sufficient incentives for the distribution companies to facilitate DG. This in turn leads to: (i) the continuance of user preferences for fossil-fuel back-up energy systems that compensate for daily power outages; (ii) under-facilitation of DG by the incumbent distribution companies; (iii) restricted lending behavior; (iv) and, overall, limited planning, coordination, and collaboration between the actors in the system. While focused on Pakistan, the attributes that the country shares with several others in the region allow for some generalization of the findings.

Cogeneration has higher efficiency than separate heat and power generation. Since both are generated in a single process, it is necessary to allocate the emissions to by-products for comparing their environmental performance. Numerous methods exist resulting in very different allocations. There is no consensus regarding the method choice. The main objective of this article is the development and implementation of an evaluation scheme allowing the choice of an appropriate method for specific applications. This scheme consists of nine criteria in the categories “Applicability”, “Environmental relevance”, and “Systematic approach” allowing a rating. The Finnish method performs best for a standard use case resulting in emission factors of 322 g CO₂ / kWh_el and 192 g CO₂ / kWh_th. Both are associated with less emissions per unit then the electricity and district heating mix of Germany in 2020 that were 375 g CO₂ / kWh_el and 270 g CO₂ / kWh_th. Therefore, cogeneration electricity and heat could contribute to climate protection in the short- to mid-term. The implementation of two sensitivity analyses shows that the location and country-specific emission factors can have a great influence on the results and the contribution to climate protection. Depending on use case and individual importance of certain criteria the Energy, the Exergy or the Greenhouse Gas method can be preferable. Each scored with one point less than the Finnish method. In contrast to existing publications, this study supports decision-makers in transparently selecting an appropriate allocation method when assessing the products of cogeneration by considering different criteria.

While fossil fuel prices soar during the 2022 global energy crisis, the European Union activates all available fossil-fuel levers and Greece still plans to use natural gas as a transition fuel for delignitisation, with strong concerns over potential exacerbation of energy poverty and hurdles to progress in climate action. This study assesses the trajectory of the Greek electricity mix and its reliance on natural gas under the current policy framework on the one hand, and an ambitious scenario aiming for complete decarbonisation by 2035 on the other. We model these scenarios using an energy system modelling framework, comprising LEAP and OSeMOSYS model implementations for Greece, and use a stakeholder-informed fuzzy cognitive mapping exercise to uncover transition uncertainties. While power generation from natural gas is projected to increase by almost 50% until 2030 under existing policies, the proposed decarbonisation scenario has the potential to achieve complete independence from Russian gas by 2026 while also leading to a cleaner and considerably cheaper power sector. This ‘higher climate ambition’ scenario is found feasible and more robust in case high fossil fuel prices persist post-2022, even if bottlenecks stressed by stakeholders such as community acceptance or technological constraints emerge and potentially constrain the expansion of certain renewable energy technologies. Apart from the added value of stakeholder input in modelling science, as reflected in the impact of barriers Greek stakeholders critically highlighted, our results emphasise that a diversified energy-supply mix alongside bold energy efficiency strategies are key to rapid and feasible decarbonisation in the country.

To better support informed decision-making around renewable heating strategies on local scale, a new methodology was developed for simulating integrated heating scenarios. This paper proposes, describes and demonstrates the modeling methodology with a focus on a variety of KPIs, allowing a more inclusive evaluation of technical options, systems and scenarios. Key KPIs include system costs, CO₂ emissions, mitigation costs and end-user costs and investments. Key function of the model is an in-depth cost analysis by a breakdown of costs among types of measures (home equipment, insulation, local equipment and infrastructure), cost components (investments, O&M, taxes, subsidies) and stakeholders (system, government, owner-occupiers, renters, real estate owners, grid operators and local entrepreneurs). The methodology was applied to a fictive Dutch neighbourhood according to the urban and building typology provided in the paper. The results of six scenarios show large variety in costs among scenarios with significantly higher costs than the reference scenario in all scenarios, with scenario ‘hybrid’ and ‘efficiency’ presenting the best potential of becoming cost-competitive with the reference scenario in 2030. The method is suitable for evaluating a wide diversity of settings and contexts.

Consumption of solid fuels (such as biomass, dung, and coal) causes household air pollution, which reportedly is responsible for over 3.5 million premature deaths worldwide. Therefore, over the last couple of years, national governments, and organization as well as international organizations are promoting energy transition from these solid fuels to clean and modern fuels in households. This paper aims to provide comprehensive review of the conceptualization and the drivers of the household energy transition to clean fuels. A systematic literature review approach was identified and used to systematically identify, select, evaluate, and synthesize the relevant published and gray literature appropriate to answer the research question of the study. It is found that the majority (78.4%) of studies conceptualized household energy transition as a switch/shift from one energy fuel to another, while few studies conceptualized energy transition as a change in energy conversion technologies (11.8%) and change in energy use patterns (9.8%). Furthermore, this study found that majority of the studies identified socioeconomic and market/economic factors as key determinants of household energy transition with few studies reported environmental factors, behavioral and government/structural factors as drivers for household energy transition.

Climate change mitigation entails different meanings for developed and developing countries. As a major emitting, high-income, developing economy that is largely dependant on hydrocarbons, Russia currently sits in the middle of the two groups, needing not only to drastically reduce emissions but also to ensure necessary economic growth to finance decarbonisation. This study explores two mitigation scenarios, one reflecting a cautious and the other a more ambitious decarbonisation pathway for Russia. These scenarios are co-created with a group of 135 national stakeholders, who inform the underlying assumptions based on their perceptions, expectations, and reservations: the more conservative scenario reflects the average of all input, while the ambitious scenario represents the optimistic end of the stakeholder input range. The two scenarios are modelled in CONTO, an input-output system of interconnected macro-structural calculations at the national level, to analyse the interplay between Russia's economy and decarbonisation progress, shedding light on the implications of mitigation for socioeconomic development. We find that, even for a country as dependant on hydrocarbons and under the most ambitious pathway that is still within experts’ realistic reach, Russia can achieve drastic reduction in absolute emissions and reach net-zero closely after 2050, while also achieving positive economic development in the long run. We highlight the need to prioritise a diverse set of mitigation options currently available and relevant to the Russian context, including energy efficiency and intensity improvements, electrification, and nuclear power, as well as to exploit the large potential lying within the Russian ecosystem's carbon sinks.

The Inflation Reduction Act sets the stage for substantial greenhouse gas emissions reduction in the United States. However, analyses show that on its own, the IRA is insufficient to meet the nation's stated climate goals. We use an energy system optimization model to understand how the U.S. can build on the IRA to meet climate goals. We model two carbon taxes and a suite of efficiency, fuel, and technology standards, including a clean electricity standard (CES), electrification standards for commercial and residential buildings, a zero-emission vehicle (ZEV) standard, and a clean fuel standard for industry. We compare these three policy scenarios to the U.S.’s stated climate goals (Nationally Determined Contribution). The two carbon taxes and the suite of standards achieve the GHG emissions goals outlined in the Paris Agreement, but no scenario reaches net-zero GHG emissions by 2050. Notably, we find that the average GHG abatement cost under the modeled standards is comparable to a carbon tax set at ∼$200/ton, and both policies achieve similar emissions reductions. Temoa's cost-minimization structure results in the carbon tax always reducing emissions more cheaply than a set of standards; but the similarity in cost emphasizes the near-optimal second-best nature of well-designed standards.” The marginal cost of GHG emissions reduction in each scenario is less than 2% of total system costs. While the modeling results indicate that meeting climate targets may still be possible, they demonstrate that doing so will require rapid and sustained deployment of zero-emission technologies across the energy system.

Decarbonising the power sector requires feasible strategies for the rapid phase-out of fossil fuels and the expansion of low-carbon sources. This study assesses the feasibility of plausible decarbonisation scenarios for the power sector in the Republic of Korea through 2050 and 2060. Our power plant stock accounting model results show that achieving zero emissions from the power sector by the mid-century requires either an ambitious expansion of renewables backed by gas-fired generation equipped with carbon capture and storage or a significant increase of nuclear power. The first strategy implies replicating and maintaining for decades the maximum growth rates of solar power achieved in leading countries and becoming an early and ambitious adopter of the carbon capture and storage technology. The alternative expansion of nuclear power has historical precedents in Korea and other countries but may not be acceptable in the current political and regulatory environment. Hence, our analysis shows that the potential hurdles for decarbonisation in the power sector in Korea are formidable but manageable and should be overcome over the coming years, which gives hope to other similar countries.

Variable power outputs are one of the largest challenges facing the widespread adoption of renewable energy systems. The inherent variability of solar resources makes it challenging to integrate large amounts of solar energy into the electric grid. However, the weather factors that influence solar production are often local in nature. In this study, eleven solar photovoltaic systems with publicly available historical data were identified for analysis. The systems are located within a circle with a diameter of approximately 130 km. The historical power output data for each system were acquired, and quality control measures were applied. A comparison is made between the variability of the time-varying power output from individual systems compared to the variability of the aggregated output of the eleven systems combined. Next, the effect of increasing the geographical spread of the aggregated systems is investigated. This is done by comparing the variability of the aggregated time-varying power output from closely-spaced systems against the variability of the aggregated time-varying power output from systems spread out over a large geographical area. Next, the correlations between the outputs from each of the individual systems are explored. The data show that the correlation decreases by approximately 0.1 for each 80 km of separation distance. Finally, the historical solar output data is used to define the “expected output”, and the deviation from this expected output is compared for individual systems and various sets of aggregated systems. The four aggregated systems located far apart are 31% more likely to have a combined output that is close to their expected output, defined as having a normalized power output deviation less than or equal to 0.2 kW/kW. Furthermore, the four aggregated systems located far apart are 54% less likely to have a combined output that is significantly different from their expected output, defined as having a normalized power output deviation greater than or equal to 0.4 kW/kW.

Modeling tools and technologies that will allow reaching decarbonization goals in the most cost-effective way are imperative for the transition to a climate-friendly energy system. This includes models which are able to optimize the design of energy systems with a large number of spatially distributed energy generation sources coupled with adequate short, medium, and long duration storage technologies. Solar photovoltaic and wind energy are likely to become the backbone in a future greenhouse gas neutral energy system and will require low-cost, geographically independent storage technologies in order to balance their intermittent availability. As an alternative to lithium-ion batteries and hydrogen systems, thermal energy storage coupled with a power block (e.g., Carnot batteries, pumped thermal storage, etc.) could be a promising option. Therefore, the current study aims to investigate the influence of renewable generation profiles coupled with alternate storage options (i.e., Li-ion and hydrogen cavern) on the installed capacity of electric-to-thermal-to-electric systems using a 100% renewable electricity system in Germany as a case study. The analyses reveal that Carnot batteries complement established and near-future storage technologies, as they could fill the gap between daily storage such as batteries and seasonal storage such as hydrogen salt caverns. Furthermore, Carnot Batteries could offer multiple options for heat integration further increasing their potential.