The environmental relevance of freshwater consumption in global power production

Purpose: Freshwater use and consumption is of high environmental concern. While research has primarily focused on agricultural water use, industrial water use has recently become more prominent. Because most industries employ relatively low amounts of water, our study focuses on electricity production, which is involved in almost all economic activities and has a considerable share of the global water consumption. Materials and methods: Water consumption data for different power production technologies was calculated from literature. Due to the global importance of hydropower and the high variability of its specific water consumption, a climate-dependent estimation scheme for water consumption in hydroelectric generation was derived. Applying national power production mixes, we analyzed water consumption and related environmental damage of the average power production for all countries. For the European and North American countries, we further modeled electricity trade to assess the electricity market mix and the power-consumption related environmental damages. Using the Eco-indicator 99 single-score and compatible freshwater consumption damage assessments, the contribution of water consumption to the total environmental impact was quantified. Results and discussion: Water consumption dominates the environmental damage of hydropower, but is generally negligible for fossil thermal, nuclear, and alternative power production. However, as the impact of water consumption has high regional variation, it can be relevant for many power technologies in water-scarce areas. The variability among country production mixes is substantial, both from a water consumption and overall environmental impact perspective. The difference between electricity production and market mixes is negligible for most countries, especially for big countries such as the USA. In Europe, where intensive international electricity trade exists, the difference is more significant. When contrasted with the relatively high uncertainties in water consumption figures particularly for hydropower, the additional error from using production mixes instead of market mixes is rather small. Conclusions: Power production is one of the major global water consumers and involved in life cycles of almost any human activity. Covering the water-consumption-related environmental damage of power generation closes one important gap in life cycle assessment and also improves data availability for the emerging field of water footprint

Measuring Ecological Impact of Water Consumption by Bioethanol Using Life Cycle Impact Assessment

Purpose Though the development of biofuel has attracted numerous studies for quantifying potential water demand applying life cycle thinking, the impacts of biofuel water consumption still remain unknown. In this study, we aimed to quantify ecological impact associated with corn-based bioethanol water consumption in Minnesota in responding to different refinery expansion scenarios by applying a life cycle impact assessment method. Methods This ecological damage assessment method for quantifying water consumption impacts was proposed by Pfister et al. in 2009 (Environ Sci Technol 43: 4098–4104, 2009) using an impact characterization factor integrating terrestrial net primary production and precipitation. In this study, we derived the spatially explicit eco-damage characterization factors for 81 watersheds in Minnesota and compiled location-specific water consumption data for all current and planned bioethanol production facilities and feedstock production. The ecological damage caused by bioethanol production (ΔEQEtOH in m2⋅yr) was then calculated on both watershed and refinery-plant levels. Additional refinery expansion scenarios were established for testing the effectiveness in changing ΔEQEtOH. Results and discussion The results show that ecological impact ΔEQEtOH varied by more than a factor of 3 between watersheds. Minnesota consumed 40 billion liters of water to produce 2.3 billion liters of ethanol as of 2007 (17 L water per liter of ethanol). The geographical distribution of ΔEQEtOH was shown to be uneven with a cluster of high-impact regions around the center of the state. The planned refinery expansion is expected to increase the state’s corn ethanol production capacity by 75% and ΔEQEtOH by 65%. However, strategically locating the planned expansion in the low-impact areas is expected to minimize the increases in ΔEQEtOH down to 19% from 65%. Conclusions The scenario analysis shows that strategically sourcing corn from low-impact regions can result in significantly less water use impact compared to a baseline scenario. The results indicate that employing the water consumption impact assessment can provide additional insights in policy making. The environmental impacts related to the change of plant infrastructure and agricultural practices associated with the development of the renewable energy industry should be considered as well for identifying the most sustainable alternatives

Wind Power Electricity: The Bigger the Turbine, The Greener the Electricity?

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Taking into account water use impacts in the LCA of biofuels: an Argentinean case study

Purpose: The assessment of biofuels has until now mainly focused on energy demand and greenhouse gas emissions. Only little attention has been given to other impacts, although the general importance of water use for the life cycle assessment (LCA) of agricultural products has been recognized in recent publications. The aim of this work is to assess in detail the water consumption along a biofuel production chain taking into account irrigation efficiencies, levels of water scarcity, and type of feedstock, and to integrate those results in a full LCA. Furthermore, we compare the results for biofuels from various feedstocks and regions with conventional petrol. Methods: We calculate the water consumption and overall life cycle assessment results in a case study for the production of methyl ester from irrigated and non-irrigated rapeseed. The results are compared with other irrigated and non-irrigated biofuels based on different feedstocks. Results and discussion: Water consumption in biofuel production chains based on non-irrigated crops does not vary greatly and is in the same range as for fossil fuel. In contrast, as a consequence of irrigation, agricultural water consumption dominates the overall results of all irrigated crops. Consequently, the level of water scarcity plays a key role for the LCA results. In our case study, the environmental impacts of methyl ester from irrigated rapeseed in a water-scarce region, measured in aggregated Eco-Indicator 99 scores, are almost doubled by water consumption. Variations in irrigation efficiency, however, are of little influence on the results, as the assessment method used here is based on consumptive water, which depends mainly on the evapotranspiration of the crop. Conclusions: The focus on greenhouse gas emissions of the main regulatory schemes neglects other relevant environmental impacts and may provide the wrong incentives. Water consumption may thus become a major concern, offsetting the benefits of biofuel use with respect to climate chang

Exposure to Household Air Pollution from Biomass Cookstoves and Blood Pressure Among Women in Rural Honduras: A Cross‐Sectional Study

Growing evidence links household air pollution exposure from biomass cookstoves with elevated blood pressure. We assessed cross‐sectional associations of 24‐hour mean concentrations of personal and kitchen fine particulate matter (PM2.5), black carbon (BC), and stove type with blood pressure, adjusting for confounders, among 147 women using traditional or cleaner‐burning Justa stoves in Honduras. We investigated effect modification by age and body mass index. Traditional stove users had mean (standard deviation) personal and kitchen 24‐hour PM2.5 concentrations of 126 μg/m3 (77) and 360 μg/m3 (374), while Justa stove users’ exposures were 66 μg/m3 (38) and 137 μg/m3(194), respectively. BC concentrations were similarly lower among Justa stove users. Adjusted mean systolic blood pressure was 2.5 mm Hg higher (95% CI, 0.7‐4.3) per unit increase in natural log‐transformed kitchen PM2.5 concentration; results were stronger among women of 40 years or older (5.2 mm Hg increase, 95% CI, 2.3‐8.1). Adjusted odds of borderline high and high blood pressure (categorized) were also elevated (odds ratio = 1.5, 95% CI, 1.0‐2.3). Some results included null values and are suggestive. Results suggest that reduced household air pollution, even when concentrations exceed air quality guidelines, may help lower cardiovascular disease risk, particularly among older subgroups

Exposure to Household Air Pollution from Biomass Cookstoves and Levels of Fractional Exhaled Nitric Oxide (FeNO) among Honduran Women

Household air pollution is estimated to be responsible for nearly three million premature deaths annually. Measuring fractional exhaled nitric oxide (FeNO) may improve the limited understanding of the association of household air pollution and airway inflammation. We evaluated the cross-sectional association of FeNO with exposure to household air pollution (24-h average kitchen and personal fine particulate matter and black carbon; stove type) among 139 women in rural Honduras using traditional stoves or cleaner-burning Justastoves. We additionally evaluated interaction by age. Results were generally consistent with a null association; we did not observe a consistent pattern for interaction by age. Evidence from ambient and household air pollution regarding FeNO is inconsistent, and may be attributable to differing study populations, exposures, and FeNO measurement procedures (e.g., the flow rate used to measure FeNO)

Review of methods addressing freshwater use in life cycle inventory and impact assessment

Purpose: In recent years, several methods have been developed which propose different freshwater use inventory schemes and impact assessment characterization models considering various cause-effect chain relationships. This work reviewed a multitude of methods and indicators for freshwater use potentially applicable in life cycle assessment (LCA). This review is used as a basis to identify the key elements to build a scientific consensus for operational characterization methods for LCA. Methods: This evaluation builds on the criteria and procedure developed within the International Reference Life Cycle Data System Handbook and has been adapted for the purpose of this project. It therefore includes (1) description of relevant cause-effect chains, (2) definition of criteria to evaluate the existing methods, (3) development of sub-criteria specific to freshwater use, and (4) description and review of existing methods addressing freshwater in LCA. Results and discussion: No single method is available which comprehensively describes all potential impacts derived from freshwater use. However, this review highlights several key findings to design a characterization method encompassing all the impact pathways of the assessment of freshwater use and consumption in life cycle assessment framework as the following: (1) in most of databases and methods, consistent freshwater balances are not reported either because output is not considered or because polluted freshwater is recalculated based on a critical dilution approach; (2) at the midpoint level, most methods are related to water scarcity index and correspond to the methodological choice of an indicator simplified in terms of the number of parameters (scarcity) and freshwater uses (freshwater consumption or freshwater withdrawal) considered. More comprehensive scarcity indices distinguish different freshwater types and functionalities. (3) At the endpoint level, several methods already exist which report results in units compatible with traditional human health and ecosystem quality damage and cover various cause-effect chains, e.g., the decrease of terrestrial biodiversity due to freshwater consumption. (4) Midpoint and endpoint indicators have various levels of spatial differentiation, i.e., generic factors with no differentiation at all, or country, watershed, and grid cell differentiation. Conclusions: Existing databases should be (1) completed with input and output freshwater flow differentiated according to water types based on its origin (surface water, groundwater, and precipitation water stored as soil moisture), (2) regionalized, and (3) if possible, characterized with a set of quality parameters. The assessment of impacts related to freshwater use is possible by assembling methods in a comprehensive methodology to characterize each use adequatel