120 results found
Allison J, Bell K, Clarke J, et al., 2018, Assessing domestic heat storage requirements for energy flexibility over varying timescales, Applied Thermal Engineering, Vol: 136, Pages: 602-616, ISSN: 1359-4311
© 2018 The Authors This paper explores the feasibility of storing heat in an encapsulated store to support thermal load shifting over three timescales: diurnal, weekly and seasonal. A building simulation tool was used to calculate the space heating and hot water demands for four common UK housing types and a range of operating conditions. A custom sizing methodology calculated the capacities of storage required to fully meet the heat demands over the three timescales. Corresponding storage volumes were calculated for a range of heat storage materials deemed suitable for storing heat within a dwelling, either in a tank or as an integral part of the building fabric: hot water, concrete, high-temperature magnetite blocks, and a phase change material. The results indicate that with low temperature heat storage, domestic load shifting is feasible over a few days. Beyond this timescale, the very large storage volumes required make integration in dwellings problematic. Supporting load shifting over 1–2 weeks is feasible with high temperature storage. Retention of heat over periods longer than this is challenging, even with significant levels of insulation. Seasonal storage of heat in an encapsulated store appeared impractical in all cases modelled due to the volume of material required.
Baker J, Papadopoulou L, Sheate W, 2018, United Kingdom, Biodiversity Offsets: European Perspectives on No Net Loss of Biodiversity and Ecosystem Services, Pages: 211-239, ISBN: 9783319725819
© Springer International Publishing AG 2018. Before the mid-2000s biodiversity offsetting was not part of the environmental policy discourse in the United Kingdom (UK). Since that time, of the UK’s four national administrations, England has been the most pro-active with regard to biodiversity offsetting. As a result this chapter focuses on the policy and practice of England with a short section summarising relevant developments in Wales, Scotland and Northern Ireland.
Balcombe P, Brandon NP, Hawkes AD, 2018, Characterising the distribution of methane and carbon dioxide emissions from the natural gas supply chain, JOURNAL OF CLEANER PRODUCTION, Vol: 172, Pages: 2019-2032, ISSN: 0959-6526
Balcombe P, Speirs J, Johnson E, et al., 2018, The carbon credentials of hydrogen gas networks and supply chains, Renewable and Sustainable Energy Reviews, Vol: 91, Pages: 1077-1088, ISSN: 1364-0321
© 2018 Elsevier Ltd Projections of decarbonisation pathways have typically involved reducing dependence on natural gas grids via greater electrification of heat using heat pumps or even electric heaters. However, many technical, economic and consumer barriers to electrification of heat persist. The gas network holds value in relation to flexibility of operation, requiring simpler control and enabling less expensive storage. There may be value in retaining and repurposing gas infrastructure where there are feasible routes to decarbonisation. This study quantifies and analyses the decarbonisation potential associated with the conversion of gas grids to deliver hydrogen, focusing on supply chains. Routes to produce hydrogen for gas grids are categorised as: reforming natural gas with (or without) carbon capture and storage (CCS); gasification of coal with (or without) CCS; gasification of biomass with (or without) CCS; electrolysis using low carbon electricity. The overall range of greenhouse gas emissions across routes is extremely large, from − 371 to 642 gCO 2 eq/kW h H2 . Therefore, when including supply chain emissions, hydrogen can have a range of carbon intensities and cannot be assumed to be low carbon. Emissions estimates for natural gas reforming with CCS lie in the range of 23–150 g/kW h H2 , with CCS typically reducing CO 2 emissions by 75%. Hydrogen from electrolysis ranges from 24 to 178 gCO 2 eq/kW h H2 for renewable electricity sources, where wind electricity results in the lowest CO 2 emissions. Solar PV electricity typically exhibits higher emissions and varies significantly by geographical region. The emissions from upstream supply chains is a major contributor to total emissions and varies considerably across different routes to hydrogen. Biomass gasification is characterised by very large negative emissions in the supply chain and very large positive emissions in the gasification process. Therefore, improvements in total emissions
Crow DJG, Giarola S, Hawkes AD, 2018, A dynamic model of global natural gas supply, APPLIED ENERGY, Vol: 218, Pages: 452-469, ISSN: 0306-2619
Giarola S, Forte O, Lanzini A, et al., 2018, Techno-economic assessment of biogas-fed solid oxide fuel cell combined heat and power system at industrial scale, Applied Energy, Vol: 211, Pages: 689-704, ISSN: 0306-2619
© 2017 Elsevier Ltd Wastewater treatment plants (WWTP) are currently very energy and greenhouse gas intensive processes. An important opportunity to reduce both of these quantities is via the use of biogas produced within the treatment process to generate energy. This paper studies the optimal energy and economic performance of a wastewater treatment facility fitted with a solid oxide fuel cell (SOFC) based combined heat and power (CHP) plant. An optimisation framework is formulated and then applied to determine cost, energy and emissions performance of the retrofitted system when compared with conventional alternatives. Results show that present-day capital costs of SOFC technology mean that it does not quite compete with the conventional alternatives. But, it could become interesting if implemented in thermally-optimised WWTP systems. This would increase the SOFC manufacturing volumes and drive a reduction of capital and fixed operating costs.
Jalil Vega FA, Hawkes A, 2018, The effect of spatial resolution on outcomes from energy systems modelling of heat decarbonisation, Energy, Vol: 155, Pages: 339-350, ISSN: 0360-5442
Spatial resolution is often cited as a crucial determinant of results from energy systems models. However, there is no study that comprehensively analyses the effect of spatial resolution. This paper addresses this gap by applying the Heat Infrastructure and Technology heat decarbonisation optimisation model in six UK Local Authorities representing a range of rural/urban areas, at three levels of spatial resolution, in order to systematically compare results. Results show the importance of spatial resolution for optimal allocation of heat supply technologies and infrastructure across different urban/rural areas. Firstly, for the studied cases, differences of up to 30% in heat network uptake were observed when comparing results between different resolutions for a given area. Secondly, for areas that generally exhibit the high and low extremes of linear heat density, results are less dependent on spatial resolution. Also, spatial resolution effects are more significant when there is higher variability of linear heat density throughout zones. Finally, results show that it is important to use finer resolutions when using optimisation models to inform detailed network planning and expansion. Higher spatial resolutions provide more detailed information on zones that act as anchors that can seed network growth and on location of network supply technologies.
Jalil-Vega F, Hawkes AD, 2018, Spatially resolved model for studying decarbonisation pathways for heat supply and infrastructure trade-offs, APPLIED ENERGY, Vol: 210, Pages: 1051-1072, ISSN: 0306-2619
Jalil-Vega FA, Hawkes AD, 2018, Spatially Resolved Optimization for Studying the Role of Hydrogen for Heat Decarbonization Pathways, ACS SUSTAINABLE CHEMISTRY & ENGINEERING, Vol: 6, Pages: 5835-5842, ISSN: 2168-0485
Oluleye G, Allison J, Kelly N, et al., 2018, An optimisation study on integrating and incentivising Thermal Energy Storage (TES) in a dwelling energy system
© 2018 by the authors. Licensee MDPI, Basel, Switzerland. In spite of the benefits from thermal energy storage (TES) integration in dwellings, the penetration rate in Europe is 5%. Effective fiscal policies are necessary to accelerate deployment. However, there is currently no direct support for TES in buildings compared to support for electricity storage. This could be due to lack of evidence to support incentivisation. In this study, a novel systematic framework is developed to provide a case in support of TES incentivisation. The model determines the costs, CO 2 emissions, dispatch strategy and sizes of technologies, and TES for a domestic user under policy neutral and policy intensive scenarios. The model is applied to different building types in the UK. The model is applied to a case study for a detached dwelling in the UK (floor area of 122 m 2 ), where heat demand is satisfied by a boiler and electricity imported from the grid. Results show that under a policy neutral scenario, integrating a micro-Combined Heat and Power (CHP) reduces the primary energy demand by 11%, CO 2 emissions by 21%, but with a 16 year payback. Additional benefits from TES integration can pay for the investment within the first 9 years, reducing to 3.5-6 years when the CO 2 levy is accounted for. Under a policy intensive scenario (for example considering the Feed in Tariff (FIT)), primary energy demand and CO 2 emissions reduce by 17 and 33% respectively with a 5 year payback. In this case, the additional benefits for TES integration can pay for the investment in TES within the first 2 years. The framework developed is a useful tool is determining the role TES in decarbonising domestic energy systems.
© 2018 Elsevier Ltd There is an ongoing debate over future decarbonisation of gas networks using biomethane, and increasingly hydrogen, in gas network infrastructure. Some emerging research presents gas network decarbonisation options as a tractable alternative to ‘all-electric’ scenarios that use electric appliances to deliver the traditional gas services such as heating and cooking. However, there is some uncertainty as to the technical feasibility, cost and carbon emissions of gas network decarbonisation options. In response to this debate the Sustainable Gas Institute at Imperial College London has conducted a rigorous systematic review of the evidence surrounding gas network decarbonisation options. The study focuses on the technologies used to generate biomethane and hydrogen, and examines the technical potentials, economic costs and emissions associated with the full supply chains involved. The following summarises the main findings of this research. The report concludes that there are a number of options that could significantly decarbonise the gas network, and doing so would provide energy system flexibility utilising existing assets. However, these options will be more expensive than the existing gas system, and the GHG intensity of these options may vary significantly. In addition, more research is required, particularly in relation to the capabilities of existing pipework to transport hydrogen safely.
Vijay A, Hawkes A, 2018, Impact of dynamic aspects on economics of fuel cell based micro co-generation in low carbon futures, Energy, Vol: 155, Pages: 874-886, ISSN: 0360-5442
This article evaluates the impact of a range of dynamic performance parameters on the techno-economics of fuel cell based micro co-generation. The main novelties in methodology are: (1) Analysis in the context of future power system decarbonisation, (2) Use of the Long Run Marginal Cost of electricity, (3) Combination of the above with dynamic aspects such as start-up cost, ramping limit, turn down ratio, minimum up time and minimum down time and (4) Identification of sensitive parameters for future research. To this end it combines a national level energy systems model with an individual heating system model. A case study of the United Kingdom is considered for the year 2035. Economic viability of fuel cell based micro co-generation hinges upon the use of an optimized control strategy. With such a control strategy, a hot start-up approach offers much greater economic potential than a cold start-up approach. The best case ratio of maximum allowable hot standby power to the nominal value is 4.2 while the ratio for cold start is only 1.1. Combinations involving low ramping limits less than 70 W/min and limited turn down ratios above 35% need to be avoided as they seriously hinder economic performance.
Balcombe P, Anderson K, Speirs J, et al., 2017, The Natural Gas Supply Chain: The Importance of Methane and Carbon Dioxide Emissions, ACS SUSTAINABLE CHEMISTRY & ENGINEERING, Vol: 5, Pages: 3-20, ISSN: 2168-0485
Bosch J, Staffell I, Hawkes AD, 2017, Temporally-explicit and spatially-resolved global onshore wind energy potentials, ENERGY, Vol: 131, Pages: 207-217, ISSN: 0360-5442
Budinis S, Giarola S, Sachs J, et al., 2017, Modelling the impacts of investors' decision making on decarbonisation pathways in industry, 10th Annual Meeting of the IAMC, Publisher: IAMC
The Paris Climate agreement calls for dramatic changes in the energy system. This will be challenging for demand sectors like industry, which is notoriously energy intensive. Although increased efficiency has proven to be suitable options to reduce energy and environmental impacts, stringent regulations on carbon will require this sector to undergo an unprecedented innovation effort, which will go well beyond cost efficiency measures to include the deployment of novel technologies and, most likely, of carbon capture and storage (CCS).This manuscript focuses on the uptake of novel technologies in the industrial sector and the barriers which might prevent or slow down the pace of innovation. Some of these barriers are technological as they depend on the availability and the technology readiness level of a specific technology. Others are instead related to the attitude that investors show towards innovative and the inherent level of risk. Among the many innovation options in the industrial sector, the focus here is on the uptake of the carbon capture and storage technologies.The industrial sector is modelled including the top-energy intensive industries, such as those manufacturing pulp and paper, iron and steel, chemicals and petrochemicals, the non-ferrous metals as well as non-metallic minerals. The simulations are carried out using a novel energy systems model, MUSE, the Modular energy systems Simulation Environment.
Budinis S, Mac Dowell N, Krevor S, et al., 2017, Can carbon capture and storage unlock `unburnable carbon'?, 13th International Conference on Greenhouse Gas Control Technologies (GHGT), Publisher: Elsevier Science BV, Pages: 7504-7515, ISSN: 1876-6102
The concept of ‘unburnable carbon’ emerged in 2011, and stems from the observation that if all known fossil fuel reserves are extracted and converted to CO2(unabated), it would exceed the carbon budget and have a very significant effect on the climate. Therefore, if global warming is to be limited to the COP21 target, some of the known fossil fuel reserves should remain unburnt. Several recent reports have highlighted the scale of the challenge, drawing on scenarios of climate change mitigation and their implications for the projected consumption of fossil fuels. Carbon Capture and Storage (CCS) is a critical and available mitigation opportunity and its contributionto timely and cost-effective decarbonisation of the energy system is widely recognised. However, while some studies have considered the role of CCS in enabling access to more fossil fuels, no detailed analysis on this issue has been undertaken. This paper presents a critical review focusing on the technologies that can be applied to enable access to, or ‘unlock’, fossil fuel reserves in a way that will meet climate targets and mitigate climate change. It also quantifies the impact of CCS in unlocking unburnable carbon in the first and in the second half of the century.
Chavez-Rodriguez MF, Dias L, Simoes S, et al., 2017, Modelling the natural gas dynamics in the Southern Cone of Latin America, APPLIED ENERGY, Vol: 201, Pages: 219-239, ISSN: 0306-2619
Clark R, Budinis S, Hawkes A, et al., 2017, Analysis of power production and emission reduction through the use of biogas and carbon capture and storage, Editors: Espuna, Graells, Puigjaner, Publisher: ELSEVIER SCIENCE BV, Pages: 2635-2640
Few S, Gambhir A, Napp T, et al., 2017, The Impact of Shale Gas on the Cost and Feasibility of Meeting Climate TargetsA Global Energy System Model Analysis and an Exploration of Uncertainties, ENERGIES, Vol: 10, ISSN: 1996-1073
Gambhir A, Drouet L, McCollum D, et al., 2017, Assessing the Feasibility of Global Long-Term Mitigation Scenarios, ENERGIES, Vol: 10, ISSN: 1996-1073
Gambhir A, Napp T, Hawkes A, et al., 2017, The Contribution of Non-CO2 Greenhouse Gas Mitigation to Achieving Long-Term Temperature Goals, ENERGIES, Vol: 10, ISSN: 1996-1073
Giarola S, Budinis S, Sachs J, et al., 2017, Long-term decarbonisation scenarios in the industrial sector, International Energy Workshop
Decarbonisation targets will drive every sector in the energy system to rapidly adopt innovativetechnologies to achieve the dramatic emissions reductions required. Among all, sectors like in-dustry, which currently exhibit a very high energy intensity, are likely to undergo major changes.This manuscript focuses on the appraisal of the effects of a CO2tax in the investment and operationdecisions in industry. Within the larger modelling framework typical of an integrated assessmentmodel, the sector is modelled including the top-energy intensive industries, such as those man-ufacturing pulp and paper, iron and steel, chemicals and petrochemicals, the non-ferrous metalsas well as non-metallic minerals. The simulations are carried out using a novel energy systemsmodel, MUSE, the Modular Universal energy systems Simulation Environment model.
Napp T, Bernie D, Thomas R, et al., 2017, Exploring the Feasibility of Low-Carbon Scenarios Using Historical Energy Transitions Analysis, ENERGIES, Vol: 10, ISSN: 1996-1073
Sachs J, Giarola S, Hawkes AD, 2017, Agent-based model for energy-related investment decisions in the residential building sector, International Energy Workshop, Publisher: International Energy Workshop
Schmidt O, Gambhir A, Staffell I, et al., 2017, Future cost and performance of water electrolysis: An expert elicitation study, INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, Vol: 42, Pages: 30470-30492, ISSN: 0360-3199
Schmidt O, Hawkes A, Gambhir A, et al., 2017, The future cost of electrical energy storage based on experience rates, NATURE ENERGY, Vol: 2, ISSN: 2058-7546
Sechi S, Giarola S, Lanzini A, et al., 2017, Techno-economic assessment of the effects of biogas rate fluctuations on industrial applications of solid-oxide fuel cells, Pages: 895-900, ISSN: 1570-7946
© 2017 Elsevier B.V. Wastewater treatment is an energy and greenhouse gas intensive process. An important opportunity to reduce both of these quantities is via the use of biogas in co-generation systems. Solid-oxide fuel cells (SOFCs) are the generator types studied in this work. The feasibility of the retrofitting of a wastewater treatment facility fitted with a SOFC combined heat and power energy provision system is assessed including effects of uncertainties in biogas availability on cost and energy performance. A two-stage stochastic optimization framework is proposed to provide feedback on the co-generation system design. Results quantify standard deviations in the biogas rate beyond which the SOFC capacity factor might drop below 80% and change the optimal size of the modules to install.
Vijay A, Fouquet N, Staffell I, et al., 2017, The value of electricity and reserve services in low carbon electricity systems, APPLIED ENERGY, Vol: 201, Pages: 111-123, ISSN: 0306-2619
Vijay A, Hawkes A, 2017, The techno-economics of small-scale residential heating in low carbon futures, Energies, Vol: 10, ISSN: 1996-1073
Existing studies that consider the techno-economics of residential heating systems typically focus on their performance within present-day energy systems. However, the energy system within which these technologies operate will need to change radically if climate change mitigation is to be achieved. This article addresses this problem by modelling small-scale heating techno-economics in the context of significant electricity system decarbonisation. The current electricity market price regime based on short run marginal costs is seen to provide a very weak investment signal for electricity system investors, so an electricity price regime based on long run marginal energy costs is also considered, using a case study of the UK in 2035. The economic case for conventional boilers remains stronger in most dwelling types. The exception to this is for dwellings with high annual heat demand. Sensitivity studies demonstrate the impact of factors such as price of natural gas, carbon intensity of the central grid and thermodynamic performance. Fuel cell micro combined heat and power shows most potential under the long run electricity price regime, and heat pumps under the short run electricity price regime. This difference highlights the importance of future electricity market structure on consumer choice of heating systems in the future.
Budinis S, Krevor S, Mac Dowell N, et al., 2016, Can technology unlock unburnable carbon?
In 2015, the Conference Of the Parties in Paris (COP21) reached a universal agreement on climate change with the aim of limiting global warming to below 2 °C. In order to stay below 2 °C, the total amount of carbon dioxide (CO2) released, or ‘carbon budget’ must be less than 1,000 gigatonnes (Gt) of CO2. At the current emission rate, this budget will be eroded within the next thirty years. Meeting this target on a global scale is challenging and will require prompt and effective climate change mitigation action.The concept of ‘unburnable carbon’ emerged in 2011, and stems from theobservation that if all known fossil fuel reserves are extracted and converted to CO2 (unabated), it would exceed the carbon budget and have a very significant effect on the climate. Therefore, if global warming is to be limited to the COP21 target, some of the known fossil fuel reserves should remain unburnt.Several recent reports have highlighted the scale of the challenge, drawing on scenarios of climate change mitigation and their implications for the projected consumption of fossil fuels. Carbon capture and storage (CCS) is a critical and available mitigation opportunity that is often overlooked. The positive contribution of CCS technology to timely and cost-effective decarbonisation of the energy system is widely recognised. However, while some studies have considered the role of CCS in enabling access to more fossil fuels, no detailed analysis on this issue has been undertaken.This White Paper presents a critical review focusing on the technologies that can be applied to enable access to, or ‘unlock’, fossil fuel reserves in a way that will meet climate targets and mitigate climate change.The paper includes an introduction to the key issues of carbon budgets and fossil fuel reserves, a detailed analysis of the current status of CCS technology, as well as a synthesis of a multi-model comparison study on global climate change mitigation strat
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