Previous research efforts have focused on developing prospective life cycle inventory databases that build upon projections from integrated assessment models but were limited to attributional... Show morePrevious research efforts have focused on developing prospective life cycle inventory databases that build upon projections from integrated assessment models but were limited to attributional system models. A novel approach is required to construct consequential LCI databases that can be applied consistently on a large scale. To this end, the heuristic approach from Bo Weidema was selected as a basis for this study. This approach has been validated with historical data and was adapted in this study to identify the marginal suppliers in a prospective context. The different steps within the approach were analyzed, and alternative techniques for each step within the heuristic method were proposed. The techniques were tested on the future electricity sector using projections from two integrated assessment models (IMAGE and REMIND). Results show the sensitivity of results on the modelling technique selected in each step. The most sensitive step is the selection of the time interval, with even small changes resulting in a noticeable difference. In addition, the results also showed a substantial difference between the projections of the two models. The relevance and goals of the alternative techniques for each step were discussed to guide users in forming the heuristic method for their study. Show less
Concentrated solar power (CSP) can be a flexible renewable resource on electric grids. Here we assess the direct and upstream socio-economic and environmental impacts of the projected deployment of... Show moreConcentrated solar power (CSP) can be a flexible renewable resource on electric grids. Here we assess the direct and upstream socio-economic and environmental impacts of the projected deployment of CSP in China and Europe, using Input-Output Analysis. We first quantify the CSP experience curve, finding a learning rate of similar to 16%, and combine this with future projections for installed capacity from China's National Development and Reform Commission and the International Energy Agency. We find employment intensities of 4.2 and 2.3 person-year/GWh in China and Europe, respectively (higher than PV and wind). The carbon emission intensity of CSP is currently higher than alternatives but this gap may narrow through learning. Carbon intensities are estimated at 129.7 and 99.8 gCO2eq/kWh in 2020 (in China and Europe, respectively) and could drop to 40.4 and 31.1 gCO2eq/kWh by 2050 given the projected expansion. We discuss the importance of including both environ -mental and socio-economic dimensions when assessing the impact of energy technologies and provide context for the role of CSP in the energy transition. Show less
Offshore wind energy (OWE) is a cornerstone of future clean energy development. Yet, research into global OWE material demand has generally been limited to few materials and/or low technological... Show moreOffshore wind energy (OWE) is a cornerstone of future clean energy development. Yet, research into global OWE material demand has generally been limited to few materials and/or low technological resolution. In this study, we assess the primary raw material demand and secondary material supply of global OWE. It includes a wide assortment of materials, including bulk materials, rare earth elements, key metals, and other materials for manufacturing offshore wind turbines and foundations. Our OWE development scenarios consider important drivers such as growing wind turbine size, introducing new technologies, moving further to deep waters, and wind turbine lifetime extension. We show that the exploitation of OWE will require large quantities of raw materials from 2020 to 2040: 129-235 million tonnes (Mt) of steel, 8.2-14.6 Mt of iron, 3.8-25.9 Mt of concrete, 0.5-1.0 Mt of copper and 0.3-0.5 Mt of aluminium. Substantial amounts of rare earth elements will be required towards 2040, with up to 16, 13, 31 and 20 fold expansions in the current Neodymium (Nd), Dysprosium (Dy), Praseodymium (Pr) and Terbium (Tb) demand, respectively. Closed-loop recycling of end-of-life wind turbines could supply a maximum 3% and 12% of total material demand for OWE from 2020 to 2030, and 2030 to 2040, respectively. Moreover, a potential lifetime extension of wind turbines from 20 to 25 years would help to reduce material requirements by 7-10%. This study provides a basis for better understanding future OWE material requirements and, therefore, for optimizing future OWE developments in the ongoing energy transition. Show less
Liang, Y.; Kleijn, E.G.M.; Tukker, A.; Voet, E. van der 2022
Deployment of clean energy technologies will require a considerable amount of materials. The surge in demand for metals related to emerging energy technologies may hinder the energy transition. In... Show moreDeployment of clean energy technologies will require a considerable amount of materials. The surge in demand for metals related to emerging energy technologies may hinder the energy transition. In this study we provide a comprehensive overview and analysis of existing work in this field, a solid quantitative baseline for material requirements of different energy technologies and quantitative information that can be used to generate learning curves for the material requirements of different energy technologies. We conducted a quantitative review of the material requirements of low-carbon energy technologies in 132 scientific publications, and provided a comparative analysis of detailed data including material intensity and lifetime data. Besides providing a large amount of structured quantitative data, the results of our work indicate that: (1) research on the demand for low carbon technology related metals has received much attention since the 2010s; (2) around 80% of the publications focus on the global level while national level studies are underrepresented; (3) science-based future scenarios are the main means of estimating total future material requirements; (4) most studies foresee material constraints of large-scale implementation of low-carbon technologies and the secure and responsible supply of these materials is still the subject of discussion; (5) changes in metal intensity caused by technological development and material requirements for non-critical components are important though often overlooked. Show less
Zhang, C.; Hu, M.; Laclau, B.; Garnesson, T.; Yang, X.; Tukker, A. 2021
Buildings have become a major concern because of their high energy use and carbon emissions. Thus, a material-efficient prefabricated concrete element (PCE) system was developed to incorporate... Show moreBuildings have become a major concern because of their high energy use and carbon emissions. Thus, a material-efficient prefabricated concrete element (PCE) system was developed to incorporate construction and demolition waste as feedstock for residential building energy renovation by over-cladding the walls of old buildings. By conducting life cycle assessment and life cycle costing using the payback approach, this study aims to explore the life cycle performance of energy conservation, carbon mitigation, and cost reduction of the PCE system in three European member states: Spain, the Netherlands, and Sweden. The results show that the energy payback periods for Spain, the Netherlands, and Sweden were 20.45 years, 17.60 years, 19.95 years, respectively, and the carbon payback periods were 23.33 years, 16.78 years, and 8.58 years, respectively. However, the financial payback periods were less likely to be achieved within the building lifetime, revealing that only the Swedish case achieved a payback period within 100 years (83.59 years). Thus, circularity solutions were considered to shorten the PCE payback periods. Using secondary materials in PCE fabrication only slightly reduced the payback period. However, reusing the PCE considerably reduced the energy and carbon payback periods to less than 6 years and 11 years, respectively in all three cases. Regarding cost, reusing the PCE shortened the Swedish payback period to 29.30 years, while the Dutch and Spanish cases achieved investment payback at 42.97 years and 85.68 years, respectively. The results can be extrapolated to support the design of sustainable building elements for energy renovation in Europe. Show less
Xu, B.; Zhang, J.; Egusquiza, M.; Chen, D.; Li, F.; Behrens, P.A.; Egusquiza, E. 2021
Decision-making on the optimum transition pathway to an energy economy that meets agreed carbon reduction goals in the European Union (EU) by 2050 is challenging, because of the size of the... Show moreDecision-making on the optimum transition pathway to an energy economy that meets agreed carbon reduction goals in the European Union (EU) by 2050 is challenging, because of the size of the infrastructural legacy, technological uncertainties, affordability and assumptions on future energy demand. This task is even more complicated in transportation because of additional issues, such as minimum travel range at acceptable impact on payload and ensuring hazzle-free long-distance driving in case of regionally varying fuel economies. Biofuels were the first viable option for a large-scale partly renewable fuel economy. E10 and B7 fuels have been successfully and remarkably smoothly introduced, owing to the fact that these are liquid and can be used in conventional combustion engines with little impact on full-tank travel range. In contrast, the decision-making process on biofuels in the EU has been particularly turbulent, with an initially favourable assessment changing into controversial. Here the compatibility between the fuel economies of member states and avoidance of disruptive social effects are considered as essential pre-requisite of a viable transition pathway. Rebalancing three different aspects of the social dimension of sustainability is used to demonstrate that a succession of infrastructures based on liquid fuels, with biofuels as an interlock towards an economy that includes methanol-based eFuel, has the potential to bring continuity, reduce dependence on anticipated technological advances and improve cost management. Awareness of this underexposed prospect of biofuel may positively affect the assessment on its role in a low-carbon fuel economy, potentially influencing the current decision-making process on biofuels. Show less
Wang J., Dias Rodrigues J.F., Hu M.M., Behrens P.A., Tukker A. 2019
The emissions of the Chinese industrial sector alone comprise 24.1% of global emissions (7.8 GtCyr 1 in 2015). This makes Chinese industrial emissions of unique national and international relevance... Show moreThe emissions of the Chinese industrial sector alone comprise 24.1% of global emissions (7.8 GtCyr 1 in 2015). This makes Chinese industrial emissions of unique national and international relevance in climate policy. This study reports a literature survey that quantitatively describes the evolution of these emissions from 2000 to 2050 in the context of policy goals. The survey reveals that: (1) The major historical factor contributing to the decrease in industrial CO2 emissions has been the reduction in energy intensities. However, that decrease has been more than compensated for by increases in industrial activity. (2) An ensemble of projections shows that China's industrial emissions will likely peak in 2030, in alignment with China's commitment to the Paris Agreement. The timing of the peak varies across industrial sub-sectors, with ferrous metals and non-metallic products sectors peaking first, and the electricity sector later. (3) The assumptions underlying optimistic scenarios broadly match the drivers of recent decreases in historical emissions (energy intensity, industrial structure and energy mix). Furthermore, these factors feature prominently in China's policy portfolio to both develop and decarbonize the Chinese industrial sector. The industrial carbon intensity targets of 2020 and 2025 are close to the median predictions in the medium scenarios from studies. Show less
Wang, J.; Dias Rodrigues, J.F.; Hu, M.; Behrens, P.A.; Tukker, A. 2019
The emissions of the Chinese industrial sector alone comprise 24.1% of global emissions (7.8 GtCyr−1 in 2015). This makes Chinese industrial emissions of unique national and international relevance... Show moreThe emissions of the Chinese industrial sector alone comprise 24.1% of global emissions (7.8 GtCyr−1 in 2015). This makes Chinese industrial emissions of unique national and international relevance in climate policy. This study reports a literature survey that quantitatively describes the evolution of these emissions from 2000 to 2050 in the context of policy goals. The survey reveals that: (1) The major historical factor contributing to the decrease in industrial CO2 emissions has been the reduction in energy intensities. However, that decrease has been more than compensated for by increases in industrial activity. (2) An ensemble of projections shows that China's industrial emissions will likely peak in 2030, in alignment with China's commitment to the Paris Agreement. The timing of the peak varies across industrial sub-sectors, with ferrous metals and non-metallic products sectors peaking first, and the electricity sector later. (3) The assumptions underlying optimistic scenarios broadly match the drivers of recent decreases in historical emissions (energy intensity, industrial structure and energy mix). Furthermore, these factors feature prominently in China's policy portfolio to both develop and decarbonize the Chinese industrial sector. The industrial carbon intensity targets of 2020 and 2025 are close to the median predictions in the medium scenarios from studies. Show less
Understanding the water use of power production is an important step to both a sustainable energy transition and an improved understanding of water conservation measures. However, there are large... Show moreUnderstanding the water use of power production is an important step to both a sustainable energy transition and an improved understanding of water conservation measures. However, there are large differences across the literature that currently present barriers to decision making. Here, the compiled inventory of the blue water use of power production from existing studies allowed to uncover the characteristics of water use and to investigate current uncertainties. The results show that photovoltaics, wind power, and run-of-the-river hydropower consume relatively little water, whereas reservoir hydropower and woody and herbaceous biomass can have an extremely large water footprint. The water consumption of power production can differ greatly across countries due to different geographic conditions. Only a few studies provided the values for the influencing factors of water use, such as the capacity factor. Values that are reported came mainly from assumptions and other literature rather than direct measurement. Omitting a life cycle stage may lead to significant underestimations. Water scarcity is attracting more attention, but the few existing results are not useable for a regional comparison due to data gaps and inconsistent measurements. In the future, a clear and detailed definition of the water footprint and system boundary of power production is essential to improving comparisons and energy systems modelling. Show less
This article provides a review of the latest status and policy framework for wind energy in Africa. In addition, it takes a close look at Kenya, which is one of the most successful African... Show moreThis article provides a review of the latest status and policy framework for wind energy in Africa. In addition, it takes a close look at Kenya, which is one of the most successful African countries in terms of attracting renewable energy (RE) investments, including the largest wind farm on the continent. Globally, wind energy development needs strong government policy. Following numerous bilateral and multilateral efforts, by 2016, the majority of African countries had defined RE supporting policies, with nearly half also having defined their wind energy targets. However, the review of such policies on the continent as a whole, as well as a closer examination of the situation in Kenya, indicate that established supportive policies and fiscal incentives remain important for the development of wind energy on the African continent but are not the decisive factors. It also suggests that international private participation in energy generation and renewable/wind energy expansion in Africa is critical and expected to increase. Consequently, it may be challenging to ensure that African countries capitalise on their inherent advantage in terms of clean energy during their energy transition processes. Show less
