Lithium is a highly interesting metal, in part due to the increasing interest in lithium-ion batteries. Several recent studies have used different methods to estimate whether the lithium production can meet an increasing demand, especially from the transport sector, where lithiumion batteries are the most likely technology for electric cars. The reserve and resource estimates of lithium vary greatly between different studies and the question whether the annual production rates of lithium can meet a growing demand is seldom adequately explained. This study presents a review and compilation of recent estimates of quantities of lithium available for exploitation and discusses the uncertainty and differences between these estimates. Also, mathematical curve fitting models are used to estimate possible future annual production rates. This estimation of possible production rates are compared to a potential increased demand of lithium if the International Energy Agency's Blue Map Scenarios are fulfilled regarding electrification of the car fleet. We find that the availability of lithium could in fact be a problem for fulfilling this scenario if lithium-ion batteries are to be used. This indicates that other battery technologies might have to be implemented for enabling an electrification of road transports. Highlights:• Review of reserves, resources and key properties of 112 lithium deposits • Discussions of widely diverging results from recent lithium supply estimates • Forecasting future lithium production by resource-constrained models • Exploring implications for future deployment of electric cars

PostprintThis is the accepted version of a paper published in Resources, Conservation and Recycling. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination.Citation for the original published paper (version of record):Walan, P., Davidsson, S., Johansson, S., Höök, M. (2014) Phosphate rock production and depletion: Regional disaggregated modeling and global implications.Resources, Conservation and Recycling, 93(0) AbstractNumerous recent studies discuss phosphate rock extraction, and some even propose that a peak in production could be reached in coming decades. This would have great consequences as phosphate rock based fertilizers are irreplaceable in modern agriculture. Studies suggesting an impending peak commonly use curve fitting models where mathematical functions are fitted to historical world production data, while studies using other methods reach completely different results. Also, a sudden increase in global reserve estimates is commonly used to dismiss these warnings, and has somewhat altered the debate. The recent multiplication of estimated reserves is mostly based on an increase of the Moroccan reserve estimate, leading to Morocco currently making up most of the global reserves. This study models global phosphate rock production using a disaggregated curve fitting model based on the production in individual major producing countries, providing a somewhat different view than most studies, and show that the global trade of phosphate rock could be completely dependent on Morocco in the future. There are several different factors that can potentially limit global production and these factors should be considered for the individual producing countries. Society's total dependence on phosphate rock should be further investigated despite claims of large resource occurrences.Highlights:  Phosphate rock production is modelled using curve fitting models.  Global production is disaggregated into major producing countries.  Phosphorous exports will rely heavily on Morocco in the future.  Potential bottlenecks should be further analysed for separate regions.

Two of the most fundamental concepts in the current debate about future oil supply are oilfield decline rates and depletion rates . These concepts are related, but not identical. This paper clarifies the definitions of these concepts, summarizes the underlying theory and empirically estimates decline and depletion rates for different categories of oilfield. A database of 880 post-peak fields is analysed to determine typical depletion levels, depletion rates and decline rates. This demonstrates that the size of oilfields has a significant influence on decline and depletion rates, with generally high values for small fields and comparatively low values for larger fields. These empirical findings have important implications for oil supply forecasting.

Purpose Several life cycle assessments (LCA) of wind energy published in recent years are reviewed to identify methodological differences and underlying assumptions. MethodsA full comparative analysis of 12 studies were undertaken (10 peer-reviewed papers, 1 conference paper, 1 industry report) regarding six fundamental factors (methods used, energy use accounting, quantification of energy production, energy performance and primary energy, natural resources, and recycling). Each factor is discussed in detail to highlight strengths and shortcomings of various approaches. ResultsSeveral potential issues are found concerning the way LCA methods are used for assessing energy performance and environmental impact of wind energy, as well as dealing with natural resource use and depletion. The potential to evaluate natural resource use and depletion impacts from wind energy appears to be poorly exploited or elaborated on in the reviewed studies. Estimations of energy performance and environmental impacts are critically analyzed and found to differ significantly. Conclusions and recommendationsA continued discussion and development of LCA methodology for wind energy and other energy resources are encouraged. Efforts should be made to standardize methods and calculations. Inconsistent use of terminology and concepts among the analyzed studies are found and should be remedied. Different methods are generally used and the results are presented in diverse ways, making it difficult to compare studies with each other, but also with other renewable energy sources.

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A thorough review of twelve recent studies of production costs from different power generating technologies was conducted and a wide range in cost estimates was found. The reviewed studies show differences in their methodologies and assumptions, making the stated cost figures not directly comparable and unsuitable to be generalized to represent the costs for entire technologies. Moreover, current levelized costs of electricity methodologies focus only on the producer's costs, while additional costs viewed from a consumer perspective and on external costs with impact on society should be included if these results are to be used for planning. Although this type of electricity production cost assessments can be useful, the habit of generalizing electricity production cost figures for entire technologies is problematic. Cost escalations tend to occur rapidly with time, the impact of economies of scale is significant, costs are in many cases site-specific, and country-specific circumstances affect production costs. Assumptions on the cost-influencing factors such as discount rates, fuel prices and heat credits fluctuate considerably and have a significant impact on production cost results. Electricity production costs assessments similar to the studies reviewed in this work disregard many important cost factors, making them inadequate for decision and policy making, and should only be used to provide rough ballpark estimates with respect to a given system boundary. Caution when using electricity production cost estimates are recommended, and further studies investigating cost under different circumstances, both for producers and society as a whole are called for. Also, policy makers should be aware of the potentially widely different results coming from electricity production cost estimates under different assumptions.

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The energy supply of China is completely dominated by coal, making future coal production projections for China important. Recent forecasts suggests that Chinese coal production might reach a peak in 2010-2039 with widely different maximum production levels. Estimated ultimately recoverable resources (URR) significantly influence the projections. However, widely different URR-values were used and due to poor understanding of the Chinese coal classification. To mitigate these shortcomings, a comprehensive investigation of this system and analysis of historical evaluation of resources and reporting issues are performed. A more plausible URR is then derived, indicating that many analysts underestimate volumes available for exploitation. Projections based on the updated URR using a modified curve-fitting model indicate that Chinese coal production could peak as early as 2024 at a maximum annual production of 4.1 Gt. By considering other potential constraints, it can be concluded peak coal in China appears inevitable and immediate. This event can be expected to have significant impact on the Chinese economy, energy strategies and greenhouse gas (GHG) emissions reduction strategies.