Anders Arvesen

Integrated life-cycle assessment of electricity-supply scenarios confirms global environmental benefit of low-carbon technologies

Significance Life-cycle assessments commonly used to analyze the environmental costs and benefits of climate-mitigation options are usually static in nature and address individual power plants. Our paper presents, to our knowledge, the first life-cycle assessment of the large-scale implementation of climate-mitigation technologies, addressing the feedback of the electricity system onto itself and using scenario-consistent assumptions of technical improvements in key energy and material production technologies. Decarbonization of electricity generation can support climate-change mitigation and presents an opportunity to address pollution resulting from fossil-fuel combustion. Generally, renewable technologies require higher initial investments in infrastructure than fossil-based power systems. To assess the tradeoffs of increased up-front emissions and reduced operational emissions, we present, to our knowledge, the first global, integrated life-cycle assessment (LCA) of long-term, wide-scale implementation of electricity generation from renewable sources (i.e., photovoltaic and solar thermal, wind, and hydropower) and of carbon dioxide capture and storage for fossil power generation. We compare emissions causing particulate matter exposure, freshwater ecotoxicity, freshwater eutrophication, and climate change for the climate-change-mitigation (BLUE Map) and business-as-usual (Baseline) scenarios of the International Energy Agency up to 2050. We use a vintage stock model to conduct an LCA of newly installed capacity year-by-year for each region, thus accounting for changes in the energy mix used to manufacture future power plants. Under the Baseline scenario, emissions of air and water pollutants more than double whereas the low-carbon technologies introduced in the BLUE Map scenario allow a doubling of electricity supply while stabilizing or even reducing pollution. Material requirements per unit generation for low-carbon technologies can be higher than for conventional fossil generation: 11–40 times more copper for photovoltaic systems and 6–14 times more iron for wind power plants. However, only two years of current global copper and one year of iron production will suffice to build a low-carbon energy system capable of supplying the worlds electricity needs in 2050.

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.

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 Tg CO2-eq. Systems based on renewables with an even mix of wind and solar capacity generate impacts of 120–140 Tg CO2-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.

The Importance of Ships and Spare Parts in LCAs of Offshore Wind Power

We develop and assess life cycle inventories of a conceptual offshore wind farm using a hybrid life cycle assessment (LCA) methodology. Special emphasis is placed on aspects of installation, operation, and maintenance, as these stages have been given only cursory consideration in previous LCAs. The results indicate that previous studies have underestimated the impacts caused by offshore operations and (though less important) exchange of parts. Offshore installation and maintenance activities cause 28% (10 g CO(2)-Eq/kWh) of total greenhouse gas emissions and 31-45% of total impact indicator values at the most (marine eutrophication, acidification, particulates, photochemical ozone). Transport and dumping of rock in installation phase and maintenance of wind turbines in use phase are major contributory activities. Manufacturing of spare parts is responsible for 6% (2 g CO2-Eq/kWh) of greenhouse gas emissions and up to 13% of total impact indicator values (freshwater ecotoxicity). Assumptions on lifetimes, work times for offshore activities and implementation of NOx abatement on vessels are shown to have a significant influence on results. Another source of uncertainty is assumed operating mode data for vessels determining fuel consumption rates.

Energy Cost of Living and Associated Pollution for Beijing Residents

Chinas remarkable economic growth in the last 3 decades has brought about big improvements in quality of life while simultaneously contributing to serious environmental problems. The aim of all economic activities is, ultimately, to provide the population with products and services. Analyzing environmental impacts of consumption can be valuable for illuminating underlying drivers for energy use and emissions in society. This study applies an environmentally extended input-output analysis to estimate household environmental impact (HEI) of urban Beijing households at different levels of development. The analysis covers direct and indirect energy use and emissions of carbon dioxide (CO), sulfur dioxide (SO), and nitrogen oxide (NO). On the basis of observations of how HEI varies across income groups, prospects for near-future changes in HEI are discussed. Results indicate that in 2007, an urban resident in Beijing used, on average, 52 gigajoules of total primary energy supply. The corresponding annual emissions were 4.2 tonnes CO, 27 kilograms SO, and 17 kilograms NO. Of this, only 18% to 34% was used or emitted by the households directly. While the overall expenditure elasticity of energy use is around 0.9, there is a higher elasticity of energy use associated with transport. The results suggest that significant growth in HEI can be expected in the near future, even with substantial energy efficiency improvements.

Deriving life cycle assessment coefficients for application in integrated assessment modelling

Abstract The fields of life cycle assessment (LCA) and integrated assessment (IA) modelling today have similar interests in assessing macro-level transformation pathways with a broad view of environmental concerns. Prevailing IA models lack a life cycle perspective, while LCA has traditionally been static- and micro-oriented. We develop a general method for deriving coefficients from detailed, bottom-up LCA suitable for application in IA models, thus allowing IA analysts to explore the life cycle impacts of technology and scenario alternatives. The method decomposes LCA coefficients into life cycle phases and energy carrier use by industries, thus facilitating attribution of life cycle effects to appropriate years, and consistent and comprehensive use of IA model-specific scenario data when the LCA coefficients are applied in IA scenario modelling. We demonstrate the application of the method for global electricity supply to 2050 and provide numerical results (as supplementary material) for future use by IA analysts.

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

Environmental implications of large-scale adoption of wind power : a scenario-based life cycle assessment (vol 6, 045102, 2011))

Cooling aerosols and changes in albedo counteract warming from CO2 and black carbon from forest bioenergy in Norway

Climate impacts of forest bioenergy result from a multitude of warming and cooling effects and vary by location and technology. While past bioenergy studies have analysed a limited number of climate-altering pollutants and activities, no studies have jointly addressed supply chain greenhouse gas emissions, biogenic CO2 fluxes, aerosols and albedo changes at high spatial and process detail. Here, we present a national-level climate impact analysis of stationary bioenergy systems in Norway based on wood-burning stoves and wood biomass-based district heating. We find that cooling aerosols and albedo offset 60–70% of total warming, leaving a net warming of 340 or 69 kg CO2e MWh−1 for stoves or district heating, respectively. Large variations are observed over locations for albedo, and over technology alternatives for aerosols. By demonstrating both notable magnitudes and complexities of different climate warming and cooling effects of forest bioenergy in Norway, our study emphasizes the need to consider multiple forcing agents in climate impact analysis of forest bioenergy.