Search results

Networking of automated instruments on unmanned platforms has proved to be the most effective way to provide validation data for earth observation optical missions. However, with most current networks, such as AERONET-OC [1] for water and RADCALNET for land [2], the validation data are multispectral and/or limited in viewing geometries, resulting in modelling associated uncertainties to cover all spectral bands of all sensors and to correspond to satellite viewing geometries. Therefore, the HYPERNETS Project is developing a new hyperspectral radiometer to be integrated in automated networks. The main goal of the project is to acquire hyperspectral measurements of water and land reflectance and validate every optical earth observation satellite remote-sensing sensor in the Visible-Near Infrared (VNIR) and Short-wave Infrared (SWIR) spectral range. The present study reports the spectral characteristics of current and future earth observation missions. These characteristics represent the main drivers for the design of the HYPERNETS sensor.

1. Abstract The Cretaceous experienced several Oceanic Anoxic Events (or OAEs). Anoxia in these events is indicated by deposits of black shales, enriched in organic matter (OM) compared to the layers below and above, strong carbon isotope perturbations, often with a negative excursion at the onset of the OAEs followed by a positive excursion, and concentration of redox-sensitive trace-elements (RSTE) (Baudin & Riquier 2014). Considered to be the earliest Cretaceous OAE (Baudin & Riquier, 2014), the Faraoni level is a short event first defined in the late Hauterivian sections of the Umbria-Marche Apennines (Cecca et al. 1994). It presents black shales enriched in OM with high concentrations of RSTE but lacks an important positive δ13C excursion (Baudin & Riquier, 2014). This event follows the “Weissert” event, a ca. 2.3 million year carbon isotope perturbation event taking place during the late Valanginian-early Hauterivian (Sprovieri et al. 2006). This latter event is not considered to be an OAE, as anoxia indicators such as RSTE high concentrations or OM-rich layers are not observed at least in the western Tethys (Westermann et al. 2010). In order to link those two seemingly opposite events, sections of Late Valanginian to Early Barremian age were studied in the Umbria-Marche Apennines, Italy. Lesser magnitude black shale preceding the Faraoni level were identified. They were correlated in two sections using magnetostratigraphy (Fig. 1). Rock-Eval and palynofacies analyses reveal that they are part of a longer-term trend of increased organic matter preservation and burial. In the black shales this is hinted by a progressive increase of total organic carbon (TOC) content, of the hydrogen index (HI), and by increasingly better preserved amorphous organic matter (AOM) towards the Faraoni level (Fig.1). This increase starts in the upper part of the M5n magnetochron. This is coeval with an increase in mercury concentration interpreted to be due to volcanic activity that was measured among others in the Bosso section (Charbonnier et al., 2018). Palaeoenvironmental differences between the Bosso and Frontone sections is shown by differences in palynomorphs and in organic matter preservation, and by the presence of slumps found in Frontone only. Figure 1 : synthetic log of the Bosso and Frontone sections, with magnetostratigraphy and Rock Eval 6 results (TOC and HI) 2. References Baudin, F. & Riquier, L., 2014. The Late Hauterivian Faraoni ‘Oceanic Anoxic Event’: An Update. Bulletin de La Société Géologique de France, 185, 6, 359‑77. Cecca, F., Marini, A., Pallini, G., Baudin, F., & Begouen, V., 1994. A guide level of the uppermost Hauterivian (Lower Cretaceous) in the pelagic succession of Umbria Marches Apennines (Central Italy): the Faraoni level, Rivista Italiana di Paleontologia e Stratigrafia, 99, 4. Sprovieri, M., Coccioni, R., Lirer, F., Pelosi, N. & Lozar F., 2006. Orbital Tuning of a Lower Cretaceous Composite Record (Maiolica Formation, Central Italy). Paleoceanography, 21, 4. Westermann, S., Föllmi, K.B., Adatte, T., Matera, V., Schnyder, J., Fleitmann, D., Fiet, N., Ploch, I. & Duchamp-Alphonse S., 2010. The Valanginian δ13C Excursion May Not Be an Expression of a Global Oceanic Anoxic Event. Earth and Planetary Science Letters, 290, 1‑2, 118‑31. Charbonnier, G., Godet, A., Bodin, S., Adatte, T. & Föllmi, K. B. 2018. Mercury anomalies, volcanic pulses, and drowning episodes along the northern Tethyan margin during the latest Hauterivian-earliest Aptian. Palaeogeography. Palaeoclimatoly. Palaeoecology.

One of the greatest challenges of the last decades in the fight against climate change has been to achieve net-zero emissions by mid-century. According to the US EPA (2016), in 2014, global anthropogenic emissions of carbon dioxide (CO2) accounted for ~64% of the greenhouse effect. Carbon dioxide capture and storage (CCS) plays an irreplaceable part as a mitigation technology that avoids CO2 emissions at their source and bridges the transition into a non-carbon-based energy future. The International Energy Agency (IEA) estimates that the need to store CO2 will grow from 40 Mt/y at present to more than 5000 Mt/y by 2050. Additionally, in the IEA’s Sustainable Development Scenario, which aims for global net-zero CO2 emissions from the energy sector by 2070, CCS needs to become a global industry supporting emissions reductions across the overall energy system. CCS technologies essentially consist of capturing and compressing the CO2 at the source and then transport it towards deep suitable rock formations where it is injected to be permanently stored. The key to successful and permanent CO2 storage is the proper analysis and characterization of the reservoir and seal formation. Among the types of reservoir suitable for CO2 storage are unmined coal beds, depleted oil and gas fields, EOR/EGR, saline aquifers, man-made caverns, and basaltic formations (IPCC, 2005). The storage capacity of any of these reservoirs is the subsurface commodity whose quantities and properties are assessed when existing data is provided. Capacity estimations bring their own level of uncertainty and complexity according to the scale at which they are addressed and the nature of the geological conditions of the reservoir. This degree of uncertainty should be accounted for in every estimation (Bradshaw et al., 2007) Resource classification systems (RCS) are frameworks that establish the principles and boundaries for each level of capacity assessment. By making use of these frameworks, it is possible to properly allocate the stage of development of a resource (United Nations, 2020). For every level of assessment, the principles of the estimation change and so do the scale and purpose. As the analysis moves forward, a prospective site develops and exhaustive information is acquired, initial estimations are adjusted, and uncertainty is likely to reduce. Additionally, different economic, technical, regulatory, environmental and societal factors are integrated into the assessment to bring the estimations under present conditions. For instance, if the storage capacity is to be matched with a CO2 source, detailed simulations and analyses regarding injectivity, supply rate, potential routes and economic distances must be performed to achieve a realistic estimation. However, an assessment where the main goal is to merely quantify the space available to store CO2 in a reservoir, does not consider the aforementioned limitations and will carry higher risk and uncertainty in its estimation (Bradshaw et al., 2007). Even though resource classification systems provide a solid foundation for CCS projects, they do not provide the input parameters and analyses needed to reach every level of assessment. This is why storage capacity estimation methodologies go hand in hand with RCS given that the former can give information related to the parameters and constraints considered in the estimation. No standard process has been proposed that can be followed from the starting level of a CO2 storage capacity assessment until a fully developed carbon storage resource; that is, a CO2 storage site ready to become fully operational. This paper aims to develop a methodology where the fundamental steps needed to go through every level of the resource classification systems are standardized. This methodology intends to serve as a general baseline that, regardless of the geological settings and techno-socio-economic conditions, can be adopted for any CCS assessment. The proposed methodology is built by reviewing the available capacity estimation methods for every level of assessment and identifying social, technical and economic aspects that come into play as the resource is being developed. Considering that capacity estimation methodologies can vary their approach even for the same level of assessment, the rationales behind them are expected to be determined. Such rationales can be related to in-place policy restrictions, geographical economic behavior, or the nature of the parameters contemplated. Additionally, PSS, an in-house developed tool that can assess CO2 storage reservoirs at different levels, will be proposed within the methodology. This tool is a bottom-up geotechnical and economic forecasting simulator that can generate source-sink matching for CCS projects, where technical, economic, and geological uncertainties are handled through a Monte Carlo approach for limited foresight (Welkenhuysen et al., 2016). Acknowledgements This research is carried out under the LEILAC2 project, which receives funding from the European Union’s Horizon 2020 research and innovation program under grant agreement number 884170. The LEILAC2 consortium consists of: Calix Europe SARL, HeidelbergCement AG, Ingenieurbüro Kühlerbau Neustad GmbH (IKN), Centre for Research and Technology Hellas (CERTH), Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Politecnico di Milano (POLIMI), Geological Survey of Belgium (RBINS-GSB), ENGIE Laborelec, Port of Rotterdam, Calix Limited, CIMPOR-Indústria de Cimentos SA and Lhoist Recherche et Development SA. References Bradshaw, J., Bachu, S., Bonijoly, D., Burruss, R., Holloway, S., Christensen, N. P., & Mathiassen, O. M. (2007). CO2 storage capacity estimation: Issues and development of standards. International Journal of Greenhouse Gas Control, 1(1), 62–68. https://doi.org/10.1016/S1750-5836(07)00027-8 IPCC. (2005). Carbon Dioxide Capture and Storage. https://www.ipcc.ch/report/carbon-dioxide-capture-and-storage/ United Nations. (2020). United Nations Framework Classification for Resources: Update 2019. UN. https://doi.org/10.18356/44105e2b-en US EPA. (2016). Global Greenhouse Gas Emissions Data. US EPA. https://www.epa.gov/ghgemissions/global-greenhouse-gas-emissions-data Welkenhuysen, K., Brüstle, A.-K., Bottig, M., Ramírez, A., Swennen, R., & Piessens, K. (2016). A techno-economic approach for capacity assessment and ranking of potential options for geological storage of CO2 in Austria. Geologica Belgica. http://dx.doi.org/10.20341/gb.2016.012

Knowledge on the environmental impacts of geothermal energy is of major importance to understand the role this technology could play in the transition towards sustainable energy systems. Life cycle analysis (LCA) methodology is a widely used tool for assessing the environmental impacts of products and systems, which has been implemented numerous times on geothermal systems. Previous reviews on geothermal LCA studies identify large variability on the reported environmental impacts. In this work we aim to provide a more in-depth analysis to explain the variability across the different LCAs. We review 28 LCA studies on geothermal energy published between 2005 and 2020, following a four step reviewing sequence; in step 1 we identify the LCA methodological choices and the plant geo-technical characteristics, in step 2 we identify the LCA results and the LCI inputs, in step 3 we perform contribution analysis based on the reported results and in step 4 we investigate the sensitivity and scenario analysis performed in the studies. If the data is available we triangularly evaluate the reported impacts considering a) the plants’ geo-technical characteristics, b) the hotspot analyses results and c) the Life cycle inventory (LCI) inputs. We focus our analysis on the six most frequently assessed impact indicators (GWP, AP, HTP, FETP, CED, ADP)* and distinguish between the different energy conversion technologies used for geothermal energy exploitation. This way we aim to provide a more transparent picture on the variability of environmental impacts across the LCAs by focusing on the environmental hotspots and on the cause-effect relationships between geo-technical parameters and the environmental impacts. We also aim for drawing LCA guidelines for future LCA studies on geothermal systems and proposing methods for impact mitigation. The variability on the LCA results is caused by differences on the choices of the LCA practitioners, on the energy conversion technologies used, on geological parameters and on plant design parameters. Most studies focus on the GWP and AP impacts, while information for the rest of the impacts is much more limited. For flash and dry steam power plants the direct emissions of non-condensable gases (NCGs) emerging can cause high GWP, AP, FETP and HTP impacts depending on the geofluid’s composition. The CED and ADP impacts are dominated by the steel and diesel consumption during the development of the wells. Thus differences on the geo-technical parameters determining the power output and the total material and energy consumption cause the variability on the reported results. Direct emissions of NCGs do not emerge in plants utilizing binary technology. In these plants the development of the wells dominates the impacts and this phenomenon is more intense when EGS-binary plants are investigated due to the large depth drilled. Also the production of the working fluid used in the ORC and its annual leakage can highly affect the GWP impact in these plants depending on the type of working fluid used. In heating plants high amounts of grid-electricity are needed for the plant operation as no power is produced. Therefore differences in the fossil-fuel-intensity of the electricity mix supplying the plant can result in large variability. The choice of the LCA practitioner to include or not the heat distribution network in the boundaries of the system also affects the results, while a significant portion of the impacts is caused during the development of the wells. Combined heat and power plants using flash or binary technology present similar results. However the co-production of heat and power is expected to lead to some benefits. A direct correlation between the GHGs and the NH3/H2S direct emissions with the GWP and AC impacts, respectively, is observed for flash and dry steam power plants. Direct emissions are determined by the geofluid composition which highly varies between different reservoirs. For mitigating these impacts the installation of abatement systems shall be considered, while the identification of the geofluid composition and of the natural emissions emerging prior to the plant development is suggested for estimating the actual anthropogenic emissions. For plants utilizing binary technology and heating plants it is observed that higher capacity generally leads to lower GWP and AP impacts per functional unit. The capacity is a product function of the temperature and production flow. Similar observation can be extracted for the temperature while this is not the case for the flow. No clear correlation can be seen between the impacts and the depth. This is because larger depths lead –on the one hand– to higher impacts because of higher material and energy consumption which are compensated –on the other hand– to the increase on the fluid temperature and flow. For mitigating impacts caused during the construction phase the use of renewable energy sources for supplying the machinery used is suggested, while proper fluid re-injection should be designed for keeping the capacity constant during the operation. Also for binary plants the working fluid shall be selected such that its GWP impact is low, while for heating plants the installation of a small ORC unit shall be considered if the conditions are appropriate for meeting the pumping needs of the plant. The reviewed studies show that geothermal energy exploitation can lead to significant environmental benefits compared to fossil sources, as most of the times the impacts caused by geothermal plants are in the range of other renewable sources. Further research is needed on deep geothermal energy exploitation to better understand its environmental impacts. A significant portion of the impacts is caused during the operation of the plants regardless of the technology used (direct emissions, electricity consumption, working fluid losses, make-up well drilling). All of the LCA studies reviewed are static LCAs. Thus a dynamic LCA framework considering the time aspect is needed for better estimations of the environmental impacts. Also consequential LCAs on geothermal energy plants need to be conducted in order to assess how the global environmental impacts may change by the wider implementation of geothermal energy. In addition, future LCA studies shall also focus on environmental impacts other than the GWP as information regarding them is limited. Finally the sustainability of geothermal investments is to be further explored by investigating the social impacts of geothermal development and comparing them to other energy sources but also the financial aspect of such investments. Acknowledgments This research is carried out under the DESIGNATE project, which receives funding from the BELSPO BRAIN-be 2.0 research program under contract nr B2/191/P1/DESIGNATE. * GWP: Global Warming Potential, AP: Acidification Potential, HTP: Human Toxicity Potential, FETP: Freshwater EcoToxicity Potential, CED: Cumulative Energy Demand, ADP: Abiotic resources Depletion Potential