Environmental impacts of high penetration renewable energy scenarios for Europe

The prospect of irreversible environmental alterations and an increasingly volatile climate pressurises societies to reduce greenhouse gas emissions, thereby mitigating climate change impacts. As global electricity demand continues to grow, particularly if considering a future with increased electrification of heat and transport sectors, the imperative to decarbonise our electricity supply becomes more urgent. This letter implements outputs of a detailed power system optimisation model into a prospective life cycle analysis framework in order to present a life cycle analysis of 44 electricity scenarios for Europe in 2050, including analyses of systems based largely on low-carbon fossil energy options (natural gas, and coal with carbon capture and storage (CCS)) as well as systems with high shares of variable renewable energy (VRE) (wind and solar). VRE curtailments and impacts caused by extra energy storage and transmission capabilities necessary in systems based on VRE are taken into account. The results show that systems based largely on VRE perform much better regarding climate change and other impact categories than the investigated systems based on fossil fuels. The climate change impacts from Europe for the year 2050 in a scenario using primarily natural gas are 1400 Tg CO2-eq while in a scenario using mostly coal with CCS the impacts are 480 TgCO2-eq. Systems based on renewables with an even mix of wind and solar capacity generate impacts of 120–140 TgCO2-eq. Impacts arising as a result of wind and solar variability do not significantly compromise the climate benefits of utilising these energy resources. VRE systems require more infrastructure leading to much larger mineral resource depletion impacts than fossil fuel systems, and greater land occupation impacts than systems based on natural gas. Emissions and resource requirements from wind power are smaller than from solar power

Contribution of forest wood products to negative emissions : historical comparative analysis from 1960 to 2015 in Norway, Sweden and Finland

Background: Forests and forest products can significantly contribute to climate change mitigation by stabilizing and even potentially decreasing the concentration of carbon dioxide (CO2) in the atmosphere. Harvested wood products (HWP) represent a common widespread and cost-efficient opportunity for negative emissions. After harvest, a significant fraction of the wood remains stored in HWPs for a period that can vary from some months to many decades, whereas atmospheric carbon (C) is immediately sequestered by vegetation re-growth. This temporal mismatch between oxidation of HWPs and C uptake by vegetation generates a net sink that lasts over time. The role of temporary carbon storage in forest products has been analysed and debated in the scientific literature, but detailed bottomup studies mapping the fate of harvested materials and quantifying the associated emission profiles at national scales are rare. In this work, we quantify the net CO2 emissions and the temporary carbon storage in forest products in Norway, Sweden and Finland for the period 1960-2015, and investigate their correlation. We use a Chi square probability distribution to model the oxidation rate of C over time in HWPs, taking into consideration specific half-lives of each category of products. We model the forest regrowth and estimate the time-distributed C removal. We also integrate the specific HWP flows with an emission inventory database to quantify the associated life-cycle emissions of fossil CO2, CH4 and N2O. Results: We find that assuming an instantaneous oxidation of HWPs would overestimate emissions of about 1.18 billion t CO2 (cumulative values for the three countries over the period 1960-2015).We also find that about 40 years after 1960, the starting year of our analysis, are sufficient to detect signs of negative emissions. The total amount of net CO2 emissions achieved in 2015 are about -3.8 million t CO2, -27.9 t CO2 and -43.6 t CO2 in Norway, Sweden, and Finland, respectively. Conclusion: We argue for a more explicit accounting of the actual emission rates from HWPs in carbon balance studies and climate impact analysis of forestry systems and products, and a more transparent inclusion of the potential of HWP as negative emissions in perspective studies and scenarios. Simply assuming that all harvested carbon is instantaneously oxidized can lead to large biases and ultimately overlook the benefits of negative emissions of HWPs.Peer reviewe

Correcting remaining truncations in hybrid life cycle assessment database compilation

Hybrid life cycle assessment (HLCA) strives to combine process‐based life cycle assessment (PLCA) and environmentally extended input–output (EEIO) analysis to bridge gaps of both methodologies. The recent development of HLCA databases constitutes a major step forward in achieving complete system coverage. Nevertheless, current applications of HLCA still suffer from issues related to incompleteness of the inventory and data gaps: (1) hybridization without endogenizing the capital inputs of the EEIO database leads to underestimations, (2) the unreliability of price data hinders the application of streamlined HLCA for processes in some sectors, and (3) the sparse coverage of pollutants in multiregional EEIO databases limits the application of HLCA to a handful of impact categories. This paper aims at offering a methodology for tackling these issues in a streamlined manner and visualizing their effects on impact scores across an entire PLCA database and multiple impact categories. Data reconciliation algorithms are demonstrated on the PLCA database ecoinvent3.5 and the multiregional EEIO database EXIOBASE3. Instead of performing hybridization solely with annual product requirements, this hybridization approach incorporates endogenized capital requirements, demonstrates a novel hybridization methodology to bypass issues of price unavailability, estimates new pollutants to EXIOBASE3 environmental extensions, and thus yields improved inventories characterized in terms of 13 impact categories from the IMPACT World+ methodology. The effect of hybridization on the impact score of each process of ecoinvent3.5 varied from a few percentages to three‐fold increases, depending on the impact category and the process studied, displaying in which cases hybridization should be prioritized. This article met the requirements for a Gold—Gold JIE data openness badge described at http://jie.click/badges

Enabling low-carbon development in poor countries

The challenges associated with achieving sustainable development goals and stabilizing the world’s climate cannot be solved without significant efforts by developing and newly-emerging countries. With respect to climate change mitigation, the main challenge for developing countries lies in avoiding future emissions and lock-ins into emission-intensive technologies, rather than reducing today’s emissions. While first best policy instruments like carbon prices could prevent increasing carbonization, those policies are often rejected by developing countries out of a concern for negative repercussions on development and long-term growth. In addition, policy environments in developing countries impose particular challenges for regulatory policy aiming to incentivize climate change mitigation and sustainable development. This chapter first discusses how climate policy could potentially interact with sustainable development and economic growth. It focuses, in particular, on the role of industrial sector development. The chapter then continues by discussing how effective policy could be designed, specifically taking developing country circumstances into account

Environmental co-benefits and adverse side-effects of alternative power sector decarbonization strategies

A rapid and deep decarbonization of power supply worldwide is required to limit global warming to well below 2 °C. Beyond greenhouse gas emissions, the power sector is also responsible for numerous other environmental impacts. Here we combine scenarios from integrated assessment models with a forward-looking life-cycle assessment to explore how alternative technology choices in power sector decarbonization pathways compare in terms of non-climate environmental impacts at the system level. While all decarbonization pathways yield major environmental co-benefits, we find that the scale of co-benefits as well as profiles of adverse side-effects depend strongly on technology choice. Mitigation scenarios focusing on wind and solar power are more effective in reducing human health impacts compared to those with low renewable energy, while inducing a more pronounced shift away from fossil and toward mineral resource depletion. Conversely, non-climate ecosystem damages are highly uncertain but tend to increase, chiefly due to land requirements for bioenergy

Understanding the Environmental Implications of Energy Transitions. A Case Study for Wind Power

A fundamental change in the ways in which we provide energy to run our economies, an energy transition, is needed to mitigate climate change. Wind power is an important part of future global energy supply in most energy scenarios. This thesis aims to contribute to a better understanding of the environmental implications of energy transitions, primarily by examining the case of wind power. This involves new investigations of both potential negative impacts of wind power and the positive role of the technology in emission reduction, as well as a critical review of past research. Three papers on wind power are presented: a comprehensive literature review of life cycle assessments (LCA) of wind power, a scenario-based LCA of large-scale adoption of wind power, and an LCA of an offshore wind farm. A hybrid LCA methodology is employed in the scenario-based LCA and LCA of an offshore wind farm. Another paper is presented which is not concerned with wind power in particular, but takes the form of an evaluation of limitations of climate change mitigation literature. It helps to achieve the aim stated above by bringing together knowledge of indirect effects of mitigation measures, and by elucidating how these effects may influence the viability of proposed mitigation strategies. The literature review aims to take stock of insights from past research, with a particular view to identifying remaining challenges. A survey of results indicates 0.063 (±0.061) and 0.055 (±0.037) kWh energy used and 20 (±14) and 16 (±10) CO2e emitted per kWh electricity for onshore and offshore cases. Evidence suggests strong positive effects of scale in the lower end of the turbine size spectrum, but is inconclusive for the megawatt range. LCAs tend to assume higher capacity factors than current real-world averages. Limitations of existing research are discussed; this includes poorly understood toxicity and resource depletion impacts, cut-off errors and seemingly inconsistent modelling of recycling benefits in analyses, lack of detailed considerations of installation and use phases, and lack of future-oriented assessments. The scenario-based LCA is an initial attempt to integrate global energy scenario analysis and LCA in order to assess the economy-wide environmental costs and benefits of wind power. The study estimates aggregated global emissions caused by wind power toward 2050, following the International Energy Agency’s BLUE scenarios. It takes into account replacement at end-of-life and changing electricity mix in manufacturing, and distinguishes emissions occurring prior to, during and after the useful life of wind turbines. Results indicate emissions of 2.3 (3.5) gigatonnes CO2e from wind power in 2007-50 in a scenario with 12% (22%) share of wind in electricity supply in 2050. A second key element of the analysis is that life cycle inventories for fossil fuel-based electricity are used to evaluate emissions savings from wind power; the evaluation is performed on the assumption that additional wind electricity, compared with a baseline, displaces fossil fuel electricity. Results suggest that emissions savings grossly exceed emissions caused by wind power, and thus confirm emission benefits of wind power. Uncertainty and limitations in scope of analysis need to be borne in mind when interpreting results. The LCA of an offshore wind farm places special emphasis on marine vessel activities and supply of spare parts. The proposed Havsul I wind farm, Norway is used as a model. Total carbon footprint is estimated to 34 grams CO2e per kWh. Results indicate greater contributions from vessels and spare parts than has previously been thought: Offshore activities during installation and use phases contribute 25-35% to totals for several impact categories (e.g., climate change, acidification) and 43% for photochemical oxidant formation. Supply of spare parts causes 7% of climate impacts and 13% of freshwater ecotoxicity. Assembling evidence from different research fields, the discussion paper identifies important simplifying assumptions in current climate change mitigation assessments. An argument is presented that because simplifying assumptions represent a systematic neglect of indirect, countervailing effects of greenhouse gas-mitigating measures, they lead to overly optimistic assessments, which then become a basis for unrealistic technology optimism in climate policy. For the thesis as a whole, the most significant contribution may be the contribution to moving beyond a single-minded concentration on static, unit-based assessments in wind power LCA research; another main contribution is the use of a hybrid LCA methodology to assess the environmental impacts of large-scale adoption of wind power and an offshore wind farm. By means of LCA studies of wind power and a wider evaluation study of indirect effects of climate change mitigation measures, the thesis illustrates the significance of taking a holistic view in evaluating the environmental implications of energy technologies and transitions

Direct and Indirect Energy Consumption of Households in Beijing

China's economy has grown at remarkable rates in the last three decades, bringing about big improvements in people's quality of life. On the downside, the increased economic activity has contributed to serious environmental problems, many of which are related to the country's energy system. Focusing particularly on Beijing, this study aims at illuminating how income growth and lifestyle changes relate to energy use in the society. An extended input-output analysis is applied to estimate the direct and indirect household energy consumption (HEC) of Beijing households at different levels of development in the year 2005. Using observations of how HEC varies across income groups in 2005 as a basis, projections of HEC towards 2015 are made. According to the results, the total HEC in Beijing amounts to 42% of the total direct energy use occurring in all sectors within Beijing's geographical boundaries. Hence, a significant portion of the energy use in the society can be linked with consumer activities. For urban residents, indirect influences on energy use are found to be more than three times greater than the direct influences. Mainly due to growing incomes, total HEC in urban Beijing will grow substantially in the period 2005-2015, even with overall efficiency improvements corresponding to the central government's targets. The results indicate that the share of transport related energy use to total HEC will increase significantly. Without major efficiency improvements, huge increases in transport related energy use is to be expected towards 2015. Air conditioners will be the most important single electrical appliance contributing to increased residential electricity consumption in the near future.Due to significant uncertainty, the figures should be taken as rough guides to the magnitude of different types of energy use only. Nonetheless, it is the author's opinion that the study produces valuable insights that can add to our understanding of the underlying drivers of energy use in the Beijing society. The estimates are considered sufficiently accurate to serve as a basis for making some recommendations for improving the energy efficiency of the society. Based on the findings of the study, the author calls on central and local governments to: 1) Further incorporate the important role of consumer behaviour and lifestyle into energy conservation policies; 2) Make strong efforts to mitigate transport related environmental problems, focusing attention both on producers and consumers; 3) Give high priority to constructing energy efficient buildings; 4) Further strengthen and expand the performance standard and labelling scheme for electrical appliances; 5) Consider imposing constraints on the promotion of consumerism by the mass media and advertising industry

Environmental implications of large-scale adoption of wind power: a scenario-based life cycle assessment

We investigate the potential environmental impacts of a large-scale adoption of wind power to meet up to 22% of the world's growing electricity demand. The analysis builds on life cycle assessments of generic onshore and offshore wind farms, meant to represent average conditions for global deployment of wind power. We scale unit-based findings to estimate aggregated emissions of building, operating and decommissioning wind farms toward 2050, taking into account changes in the electricity mix in manufacturing. The energy scenarios investigated are the International Energy Agency's BLUE scenarios. We estimate 1.7–2.6 Gt CO2-eq climate change, 2.1–3.2 Mt N-eq marine eutrophication, 9.2–14 Mt NMVOC photochemical oxidant formation, and 9.5–15 Mt SO2-eq terrestrial acidification impact category indicators due to global wind power in 2007–50. Assuming lifetimes 5 yr longer than reference, the total climate change indicator values are reduced by 8%. In the BLUE Map scenario, construction of new capacity contributes 64%, and repowering of existing capacity 38%, to total cumulative greenhouse gas emissions. The total emissions of wind electricity range between 4% and 14% of the direct emissions of the replaced fossil-fueled power plants. For all impact categories, the indirect emissions of displaced fossil power are larger than the total emissions caused by wind power

Assessing the life cycle environmental impacts of wind power: A review of present knowledge and research needs

We critically review present knowledge of the life cycle environmental impacts of wind power. We find that the current body of life cycle assessments (LCA) of wind power provides a fairly good overall understanding of fossil energy use and associated pollution; our survey of results that appear in existing literature give mean values (± standard deviation) of, e.g., 0.060 (±0.058) kWh energy used and 19 (±13) g CO2e emitted per kWh electricity, suggesting good environmental performance vis-à-vis fossil-based power. Total emissions of onshore and offshore wind farms are comparable. The bulk of emissions generally occur in the production of components; onshore, the wind turbine dominates, while offshore, the substructure becomes relatively more important. Strong positive effects of scale are present in the lower end of the turbine size spectrum, but there is no clear evidence for such effects for MW-sized units. We identify weaknesses and gaps in knowledge that future research may address. This includes poorly understood impacts in categories of toxicity and resource depletion, lack of empirical basis for assumptions about replacement of parts, and apparent lack of detailed considerations of offshore operations for wind farms in ocean waters. We argue that applications of the avoided burden method to model recycling benefits generally lack transparency and may be inconsistent. Assumed capacity factor values are generally higher than current mean realized values. Finally, we discuss the need for LCA research to move beyond unit-based assessments in order to address temporal aspects and the scale of impacts

More caution is needed when using life cycle assessment to determine energy return on investment (EROI)

Cumulative energy demand (CED) estimates from life cycle assessments (LCAs) are increasingly used to determine energy return on investment (EROI), but the difference in indicators can lead to a misclassification of energy flows in the assessment. The core idea of EROI is to measure the relation of energy diverted from society to make energy available to society. CED, on the other hand, includes forms of energy that are not appropriated by society, such as fugitive methane emissions from oil wells as well as losses of heating value of coal during transport and storage. Such energy forms should be excluded from EROI; failure to do so leads to results that are inconsistent with the intention of EROI and potentially misleading. We demonstrate how this problem is at least partially rectifiable by adopting consistent energy accounting, but also note that among the energy flows not appropriated by society occurring in CED, not all flows can easily be removed. Further, we point to inconsistencies in heating value assumptions in a widely used database that have misled analysts. Finally, we argue that the differential weighting of primary energy forms in published CED-based EROI work is unsubstantiated and should be reconsidered.(c) 2014ElsevierLtd.Allrightsreserved. This is the authors' accepted and refereed manuscript to the article. Locked until 2017-01-15 due to copyright restrictions