A comprehensive assessment of the energy performance of the full range of electricity generation technologies deployed in the United Kingdom

We performed a comprehensive and internally consistent assessment of the energy performance of the full range of electricity production technologies in the United Kingdom, integrating the viewpoints offered by net energy analysis (NEA) and life cycle assessment (LCA). Specifically, the energy return on investment (EROI), net-to-gross energy output ratio (NTG) and non-renewable cumulative energy demand (nr-CED) indicators were calculated for coal, oil, gas, biomass, nuclear, hydro, wind and PV electricity. Results point to wind, and to a lesser extent PV, as the most recommendable technologies overall in order to foster a transition towards an improved electricity grid mix in the UK, from both points of view of short-term effectiveness at providing a net energy gain to support the multiple societal energy consumption patterns, and long-term energy sustainability (the latter being inversely proportional to the reliance on non-renewable primary energy sources). The importance to maintain a sufficient installed capacity of readily-dispatchable gas-fired electricity is also recognized

Life-cycle carbon emissions and energy return on investment for 80% domestic renewable electricity with battery storage in California (U.S.A.)

This paper presents a detailed life-cycle assessment of the greenhouse gas emissions, cumulative demand for total and non-renewable primary energy, and energy return on investment (EROI) for the domestic electricity grid mix in the U.S. state of California, using hourly historical data for 2018, and future projections of increased solar photovoltaic (PV) installed capacity with lithium-ion battery energy storage, so as to achieve 80% net renewable electricity generation in 2030, while ensuring the hourly matching of the supply and demand profiles at all times. Specifically—in line with California’s plans that aim to increase the renewable energy share into the electric grid—in this study, PV installed capacity is assumed to reach 43.7 GW in 2030, resulting of 52% of the 2030 domestic electricity generation. In the modelled 2030 scenario, single-cycle gas turbines and nuclear plants are completely phased out, while combined-cycle gas turbine output is reduced by 30% compared to 2018. Results indicate that 25% of renewable electricity ends up being routed into storage, while 2.8% is curtailed. Results also show that such energy transition strategy would be effective at curbing California’s domestic electricity grid mix carbon emissions by 50%, and reducing demand for non-renewable primary energy by 66%, while also achieving a 10% increase in overall EROI (in terms of electricity output per unit of investment)

What are the energy and environmental impacts of adding battery storage to photovoltaics? A generalized life cycle assessment

Renewable electricity generation is intermittent and its large‐scale deployment will require some degree of energy storage. Although best assessed at grid level, the incremental energy and environmental impacts of adding the required energy storage capacity may also be calculated specifically for each individual technology. This paper deals with the latter issue for the case of photovoltaics (PV) complemented by lithium‐ion battery (LIB) storage. A life cycle assessment (LCA) of a 100MW ground‐mounted PV system with 60MW of (lithium‐manganese oxide) LIB, under a range of irradiation and storage scenarios, show that energy pay‐back time and life‐cycle global warming potential increase by 7% to 30% (depending on storage duration scenarios), with respect to those of PV without storage. Thus the benefits of PV when displacing conventional thermal electricity (in terms of carbon emissions and energy renewability) are only marginally affected by the addition of energy storage

Exploring Avoided Environmental Impacts as Well as Energy and Resource Recovery from Microbial Desalination Cell Treatment of Brine

Seawater represents a potential resource to ensure sustainable availability of water for population and irrigation purpose, especially in some areas of the world. Desalination processes allow the production of fresh water, but they generate also brine as waste product. Sustainable brine man-agement should be identified to ensure proper disposal, and potentially resource recovery. This ex-perimental study shows that emerging technologies such as Microbial Desalination Cells (MDCs) may provide a valuable contribution to the sustainability of seawater desalination sector. In this paper, we report results on lab-scale desalination brine treatments applying MDCs – which allow energy savings, resource recovery, environmental impact minimization, and reduction of the or-ganic load in municipal wastewater. Our results show that MDCs treatment allows the removal of approximately 33 g of salts (62% of the total) – including chlorides, bromides, and sulphates – from 20 mL of brine within 96 hours. The MDCs, according to the source of energy and the presence of mature biofilm at the anode, spent 7.2 J, 7.9 J and 9.6 J in the desalination process, with the higher amount of energy required by the abiotic system and the lesser by the MDCs fed with just wastewater. Our approach also shows environmental and energy reductions because of potential metal recovery instead of returning them into marine environment. We quantify the avoided life cy-cle human and marine eco-toxicity impacts as well as the reduction of cumulative energy demand of recovered metals. The main benefit in terms of avoided toxicity would arise from the mercury and copper recovery, while potential economic advantages would derive from the recovered cobalt that represents a strategic resource for many products such as battery storage systems

Life-cycle carbon emissions and energy implications of high penetration of photovoltaics and electric vehicles in California

California has set two ambitious targets aimed at achieving a high level of decarbonization in the coming decades, namely (i) to generate 60% and 100% of its electricity using renewable energy (RE) technologies, respectively, by 2030 and by 2045, and (ii) introducing at least 5 million zero emission vehicles (ZEVs) by 2030, as a first step towards all new vehicles being ZEVs by 2035. In addition, in California, photovoltaics (PVs) coupled with lithium-ion battery (LIB) storage and battery electric vehicles (BEVs) are, respectively, the most promising candidates for new RE installations and new ZEVs, respectively. However, concerns have been voiced about how meeting both targets at the same time could potentially negatively affect the electricity grid’s stability, and hence also its overall energy and carbon performance. This paper addresses those concerns by presenting a thorough life-cycle carbon emission and energy analysis based on an original grid balancing model that uses a combination of historical hourly dispatch and demand data and future projections of hourly demand for BEV charging. Five different scenarios are assessed, and the results unequivocally indicate that a future 80% RE grid mix in California is not only able to cope with the increased demand caused by BEVs, but it can do so with low carbon emissions (<110 g CO2-eq/kWh) and satisfactory net energy returns (EROIPE-eq = 12–16)

Net energy analysis and life cycle energy assessment of electricity supply in Chile: present status and future scenarios

Chile is one of the fastest-growing economies in Latin America, with a mainly fossil fuelled electricity demand and a population projected to surpass 20 million by 2035. Chile is undergoing a transition to renewable energies due to ambitious national targets, namely to generate 60% of its electricity from local renewable energy by 2035, and to achieve a 45%renewable energy share for all new electric installed capacity. In this work, we present a comprehensive energy analysis of the electricity generation technologies currently deployed in Chile. Then, we analyse potential future scenarios, considering a large deployment of RE, mainly PV and wind, to replace coal-fired electricity. The life cycle assessment (LCA) and net energy analysis (NEA) methods are applied in parallel to provide complementary indicators, respectively nr-CED and EROI, and identify weak spots and future opportunities. Special focus is given to the effect on EROI of transporting fossil fuels to Chile. Results show that a large deployment of PV and wind can significantly improve the overall net energy performance of electricity generation in Chile, while leading to an electricity supply mix that is >60% less reliant on non-renewable energy

A multi-method analysis of UK grid mix scenarios with large-scale PV deployment

The increasing contribution of renewable energies to electricity grids in order to address impending environmental challenges implies a reduction in non-renewable resource use and an alignment with a global transition toward a low-carbon electric sector. In this paper, four future UK grid mix scenarios with increased photovoltaic (PV) installed capacity are assessed and compared to a benchmark “Low PV” scenario, from 2016 to 2035. The complexity of the issue requires a multi-disciplinary approach to evaluate the availability of net energy, environmental aspects and technical performance. Hence, the comparison between scenarios includes short-term and long-term energy metrics as well as greenhouse gas (GHG) and technical metrics. Also, the paper considers the viewpoints offered by both an “integrative” and a “dynamic” approach to net energy analysis. Results for all five analysed scenarios indicate that increased PV deployment will not be detrimental to the UK grid performance from the points of view of a wide range of system-level technical (% renewable energy curtailment to ensure grid stability), energy (energy return on investment and non-renewable cumulative energy demand) and environmental (greenhouse gas emis

Is organizational commitment fixed at the formative and first experience of work? a multi-method, interdisciplinary approach

​Increasing distributed renewable electricity generation is one of a number of technology pathways available to policy makers to meet environmental and other sustainability goals. Determining the efficacy of such a pathway for a national electricity system implies evaluating whole system change in future scenarios. Life cycle assessment (LCA) and net energy analysis (NEA) are two methodologies suitable for prospective and consequential analysis of energy performance and associated impacts. This paper discusses the benefits and limitations of prospective and consequential LCA and NEA analysis of distributed generation. It concludes that a combined LCA and NEA approach is a valuable tool for decision makers if a number of recommendations are addressed. Static and dynamic temporal allocation are both needed for a fair comparison of distributed renewables with thermal power stations to account for their different impact profiles over time. The trade-offs between comprehensiveness and uncertainty in consequential analysis should be acknowledged, with system boundary expansion and system simulation models limited to those clearly justified by the research goal. The results of this approach are explorative, rather than for accounting purposes; this interpretive remit, and the assumptions in scenarios and system models on which results are contingent, must be clear to end users