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This study builds a bridge between the advancements from prospective life cycle assessments (pLCAs) and dynamic life cycle assessments (dLCAs) to improve the evaluation of circular economy (CE) strategies for long-lived products such as energy technologies. Based on a literature review of recent developments from pLCA and dLCA, an extended LCA methodology is proposed that provides guidance in the consideration and integration of technological and market dynamics across all major LCA steps of a dLCA, whose flows and impacts extend over a long period of time. This ensures a more accurate assessment of the impacts on global warming over time by explicitly incorporating temporal differentiation into goals and scopes, life cycle inventories, and interpretations. The methodology was applied to compare two CE measures for wind turbines: full repowering, including material recycling, and partial repowering. The analysis revealed that full repowering is the environmentally preferable option from the perspective of global warming potential, as the higher electricity output offsets the emissions associated with decommissioning and new construction. The findings were robust under various assumptions on future technological advancements, the underlying decarbonization scenario aligned with the Paris Agreement, and the application of discounting of future emissions. Ultimately, this work provides a practical yet adaptable approach for integrating future-oriented LCA methods into decision-making for more sustainable infrastructure and machinery.

The aim of this study is to look into the current information surrounding decommissioning and life extension strategies in the offshore wind sector and critically assess them to make informed decisions upon completion of the initial design life in offshore wind farms. This was done through a two-pronged approach by looking into the technical aspects through comprehensive discussions with industrial specialists in the field and also looking into similar but more mature industries such as the Offshore Oil and Gas sector. For the financial side of the assessment, a financial model was constructed to help portray a possible outcome to extend the life for a current offshore wind farm, using the existing data. By employing a techno-economic approach for critical assessment of life extension strategies, this study demonstrates the advantages and disadvantages of each strategy and looks to inform the offshore wind industry the best course of action for current wind farms, depending on their size and age.

Decarbonizing the world economy, before the most damaging effects of climate change become irreversible, requires substantially increasing renewable energy generation in the near future. However, this may be challenging in mature wind energy markets, where many advantageous wind locations are already engaged by older wind farms, potentially generating suboptimal wind harvesting. This research developed a novel method to systematically analyze diverse factors to determine the level of maturity of wind markets and evaluate the adequacy of wind farm repowering at regional and individual levels. The approach was applied to wind markets in the United States (U.S.), in which several states were identified as having diverse levels of maturity. Results obtained from case studies in Texas indicated a consequential number of wind farms that have reached their twenty-year end-of-life term and earlier obsolescence levels. The proposed approach aided in determining wind farms that may benefit from total or partial repowering. The method indicated that total repowering of selected installations would significantly increase overall wind energy generation, considering that these older installations have access to some of the best wind speeds, infrastructure and areas to grow. The proposed method can be applied to different world wind markets.

For over two decades, the construction of wind turbines in Germany has been supported by guaranteed feed-in tariffs determined by the Renewable Energy Sources Act (EEG), the primary goal of which is climate protection, in addition to reducing the country’s dependence on the import of (finitely available) fossil fuels. After China and the United States, Germany ranks third worldwide in the production of wind energy. The number of onshore wind turbines in Germany has risen to approximately 30,000 plants, of which approximately 10,000 wind turbines will fall out of the guaranteed EEG funding window in the next one to two years. There are basically two alternatives for these wind turbines: either continuing operations, with the sale of electricity at relatively low and fluctuating electricity stock prices, or repowering, which opens access to the fixed feed-in tariffs for another 20 years. However, repowering has the disadvantages that an approval process must be carried out and the investor must participate in a tender. There is no guarantee for the granting of a building permit; economically feasible operations also depend on the fact that one can win a contract without the submitted price being set too low. This area of tension is illustrated by a wind farm in Mecklenburg-Western Pomerania and analysed economically. The investment in new, more efficient, and larger wind turbines currently promises a high return. The profitability of the investment in wind turbines is determined using the net present value (NPV) method. In addition, a risk analysis is carried out using stochastic simulation. As a result, the feed-in tariff contributes to over 95% of the variance in the net present value (NPV).

Out of 2 TWe of coal power plant capacity in operation globally today, more than half is less than 14 years old. Climate policy related to limiting CO2-emissions makes the longer-term operation of these plants untenable. In this study, we assess the spectrum of available options for the future of both equipment and jobs in the coal power sector by assessing the full scope of “retrofit decarbonization” options. Retrofit decarbonization is an umbrella term that includes adding carbon capture, fuel conversion, and the replacement of coal boilers with new low-carbon energy sources, in each case re-using as much of the existing equipment as economically practicable while reducing or eliminating emissions. This article explores this idea using the Polish coal power fleet as a case study. Retrofit decarbonization in Poland was shown to be most attractive using high-temperature small modular nuclear reactors (SMRs) to replace coal boilers, which can lower upfront capital costs by ~28–35% and levelized cost of electricity by 9–28% compared to a greenfield installation. If retrofit decarbonization is implemented globally by the late 2020s, up to 200 billion tons of otherwise-committed CO2-emissions could be avoided.

Indonesia is intensively building solar energy, which divided into three types, namely rooftop, solar farm, and floating solar with a target-installed capacity of 37.15 GW. A lot of land area is required for the development of solar energy for the next 20-25 years. The average land area required for 1 PV module is approximately 2 m 2 , so it is predicted that the new land area needed will be difficult to obtain in the future. Repowering is a solution to deal with these potential problems, repowering is an interesting new business in Europe when we have to face power plants that have entered the end-of-life. The study aims to analyze if repowering is implemented, we can reduce the Levelized Cost of Electricity. A plant with a capacity of 1.4 MWp will be used as the basis for the simulation. Using a monitoring system to see energy production, temperature, irradiance, and performance ratio is used as the methodology for collecting data. After that, it will analyze from a technical and economic point of view. The result shows that energy production increased by 24% or by 10,645,786 kWh and the Levelized Cost of Electricity decreased by 0.02 USD/kWh with an IRR of 5.67% and a payback period of 14.5 years. This study finds that repowering can reduce electricity tariffs and increase energy production.

Repowering the Brazilian hydroelectric park is a way to expand the use of energy from hydro sources, even in a scenario where the options to build new projects are increasingly restricted. Several technical and economic aspects must be considered when evaluating the feasibility to carry out a repowering process, where indicators are considered to choose the best option. The repowering suggests the addition of assured energy, however, electromechanical equipment improvement may occur simultaneously with automation systems. Sizing is generally precise for a hydropower plant and there is no need for repowering so that the project can increase its useful life, consequently, rehabilitation is recommended. This paper shows a methodology to evaluate intervention alternatives in a project, as well as a rehabilitation case study for the Marimbondo Hydroelectric Power Plant

Offshore wind turbines are normally designed for a nominal service life of 20 to 25 years; however, with a significant number of units approaching the second half of their service life, the discussion on selecting the most appropriate end-of-life scenario becomes ever more relevant. Scenarios to be investigated mainly include decommissioning, repowering, or service life extension, while such decisions depend on a number of criteria which should be taken into account and should ultimately inform a techno-economic and risk assessment. This paper performs an initial comparative assessment between two of these scenarios, repowering and decommissioning, through a purpose developed techno-economic analysis model which calculates relevant key performance indicators. The economic model of risk aversion is further adopted to calculate the certainty equivalent of LCoE (levelized cost of energy) based on each of the examined end-of-life scenarios and a stochastic expansion of the deterministic model. An application to a typical, hypothetical offshore wind farm qualifies the full repowering scenario as the prevailing option, under the assumptions considered, with a lower amount of risk premium (1.136 £/MWh) and certainty equivalent (69.821 £/MWh) in comparison to other scenarios, reducing LCoE by nearly 35% compared to partial decommissioning and 36.5% compared to full decommissioning.

India’s ambitious net-zero climate goals include plans for a four-fold increase in current levels of wind energy generation by 2030. Many existing wind farms in India occupy sites with the best wind resources nationally but use older, smaller turbines that achieve lower capacity factors compared to modern turbine designs. A strategy of replacing existing wind turbines with state-of-the-art models (termed repowering) could boost capacity factors and ensure maximal use of available wind resources. However, a nationwide assessment of the potential wind generation increases resulting from repowering is currently lacking for India. Here, we present the first validated synthetic wind generation dataset for India based on reanalysis data and show that full repowering of the existing fleet of wind turbines could boost capacity factors by 82% nationwide (from 0.19 to 0.35). Our assessment of attainable capacity factors under full repowering exceeds equivalent estimates within the National Electricity Plan of India and national decarbonisation pathways compiled by the Intergovernmental Panel on Climate Change (IPCC), suggesting less total installed capacity is required to achieve specific generation outcomes than previously estimated. Ongoing technological progress, leading to increased turbine dimensions, will drive capacity factors beyond the levels estimated here, which could further add to the generation benefits of repowering. Yet, despite the higher average output from a repowered fleet of wind generators, substantial variability in generation across timescales persists, highlighting the increasing need for power system flexibility within a decarbonised energy system.

This paper presents a robust repowering approach to the structural response of tubular steel wind turbine towers enhanced by internal stiffening rings. First, a structural response simulation model was validated by comparison with the existing experimental data. This was then followed with a mesh density sensitivity analysis to obtain the optimum element size. When the outdated wind turbine system needs to be upgraded, the wall thickness, the mid-section width-to-thickness ratio and the spacing of the stiffening rings of wind turbine tower were considered as the critical design variables for repowering. The efficiency repowering range of these design variables of wind turbine towers of various heights between 50 and 250 m can be provided through the numerical analysis. Finally, the results of efficiency repowering range of design variables can be used to propose a new optimum design of the wind turbine system when repowering a wind farm.