• Energy Research

The power system requires an additional amount of flexibility to process the large-scale integration of renewable energy sources. Community Energy Storage (CES) is one of the solutions to offer flexibility. In this paper two scenarios of CES ownership are proposed. Firstly, an Energy Arbitrage (EA) scenario is studied where an aggregator aims to minimize costs and CO2-emissions of an energy portfolio. Secondly, an Energy Arbitrage - Peak Shaving (EA-PS) scenario is assessed, which is based on a shared ownership between a Distribution System Operator (DSO) and an aggregator. A multi-objective Mixed Integer Linear Programming (MILP) optimization model is developed to minimize the operation costs and CO2-emissions of a community situated in Cernier (Switzerland), using different battery technologies in the CES system. The results demonstrate a profitable system design for all Lithium-ion-Batteries (LiBs) and the Vanadium Redox Flow Battery (VRFB), for both the EA and EA-PS scenarios. The economic and environmental performance of the EA-PS scenario is slightly worse compared to the EA scenario, due to power boundaries on grid absorption and injection to achieve peak shaving. Overall, the differences between the EA and EA-PS scenarios, in economic and environmental performance, are small. Therefore, the EA-PS is recommended to prevent problematic loads on the distribution transformer. In addition, the Pareto frontiers demonstrate that LiBs perform best on both economic and environmental performance, with the best economic and environmental performance for the Lithium-Nickel-Manganese-Cobalt (NMC-C) battery.

AbstractHydrogen will play a key role in decarbonizing economies. Here, we quantify the costs and environmental impacts of possible large-scale hydrogen economies, using four prospective hydrogen demand scenarios for 2050 ranging from 111–614 megatonne H2 year−1. Our findings confirm that renewable (solar photovoltaic and wind) electrolytic hydrogen production generates at least 50–90% fewer greenhouse gas emissions than fossil-fuel-based counterparts without carbon capture and storage. However, electrolytic hydrogen production could still result in considerable environmental burdens, which requires reassessing the concept of green hydrogen. Our global analysis highlights a few salient points: (i) a mismatch between economical hydrogen production and hydrogen demand across continents seems likely; (ii) region-specific limitations are inevitable since possibly more than 60% of large hydrogen production potentials are concentrated in water-scarce regions; and (iii) upscaling electrolytic hydrogen production could be limited by renewable power generation and natural resource potentials.

Prospective energy scenarios usually rely on carbon dioxide removal (CDR) technologies to achieve the climate goals of the Paris Agreement. CDR technologies aim at removing CO2 from the atmosphere in a permanent way. However, the implementation of CDR technologies typically comes along with unintended environmental side-effects such as land transformation or water consumption. These need to be quantified before large-scale implementation of any CDR option by means of life cycle assessment (LCA). Direct air carbon capture and storage (DACCS) is considered to be among the CDR technologies closest to large-scale implementation, since first pilot and demonstration units have been installed and interactions with the environment are less complex than for biomass related CDR options. However, only very few LCA studies - with limited scope - have been conducted so far to determine the overall life-cycle environmental performance of DACCS. We provide a comprehensive LCA of different low temperature DACCS configurations - pertaining to solid sorbent-based technology - including a global and prospective analysis.

The operation and production of batteries is associated with environmental impacts that can be quantified with Life Cycle Assessment methodologies. Current life cycle impact assessment methodologies do not assess metal criticality: they are based on geological availability or resource depletion only and do not consider socio-economic factors. Such factors are included by the concept of metal criticality. This paper determines the metal criticality of six home-based battery systems (Li-Ion: LFP-C, NMC-C, NCA-C, NCA-LTO; VRLA battery and the VRFB) for a photovoltaics self-consumption application based on a Life Cycle Assessment approach. Cumulative life cycle inventory results on extraction of metal resources are coupled with characterization factors of 13 metals derived from three state-of-the-art criticality methodologies. The results are presented for two functional units: (1) the installed battery system per kWh of energy delivered (per cycle); (2) additionally including necessary replacements of battery packs during the system lifetime. Due to substantial differences in terms of battery lifetimes between battery technologies, the latter functional unit turns out to be more meaningful. In general, there is a correlation between lower metal criticality scores (i.e. better performance) and batteries with a higher specific energy, longer battery lifetime and lower mass of metal consumption. LFP-C battery shows both low metal criticality scores and comparatively robust results, while VRFB exhibits low metal criticality but associated with relatively high uncertainties. In contrast, the VRLA battery performs the worst due to low discharge efficiency and relatively short battery lifetime. We argue that metal criticality could be reduced by improving the specific energy of the battery, by selecting low metal-intensive and low-critical metal containing components, by increasing the use of secondary metals and by selecting batteries with longer battery lifetimes.

This work quantifies current and future costs as well as environmental burdens of large-scale hydrogen production systems on geographical islands, which exhibit high renewable energy potentials and could act as hydrogen export hubs.

This review provides a perspective on how to conduct future Life Cycle Assessment (LCA) studies of carbon dioxide removal technologies in a consistent way avoiding common mistakes, which should be addressed to aid informed decision making.

Novel energy technologies are typically associated with large investments and environmental impacts generated in the construction phase. In this work, we present a systematic approach to optimally design residential energy systems, considering (prospective) costs and life cycle greenhouse gas (GHG) emissions of a large set of low-carbon energy technologies and sources. To achieve this, an optimization problem has been formulated and is tested on several scenarios considering climate-specific heat and electricity demand as well as scenario-specific conditions, such as the flexibility of grid electricity tariffs and associated GHG intensities. With GHG-intensive grid electricity supply and flexible energy tariffs, we recommend to implement policy measures to encourage the investment in residential solar PV-coupled batteries and heat pumps, especially in the near future. The inclusion of environmental impacts generated from the production of energy technologies cannot be neglected; they should be considered during the design phase of residential energy systems. Current high electricity and natural gas prices result in the installation of low-carbon energy system components. This implies that battery systems are already an effective option to reduce the reliance on carbon-intensive and expensive energy supply. And lastly, the large-scale deployment of residential lithium-ion batteries might be limited by global lithium production. This implies that energy system designers should consider alternative electricity storage technologies in their energy technology portfolio. Applied Energy, 331 ISSN:0306-2619 ISSN:1872-9118