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  • Journal article
    Kell AJM, McGough AS, Forshaw M, 2021,

    The impact of online machine-learning methods on long-term investment decisions and generator utilization in electricity markets

    , Sustainable Computing: Informatics and Systems, Vol: 30, Pages: 1-12, ISSN: 2210-5379

    Electricity supply must be matched with demand at all times. This helps reduce the chances of issues such as load frequency control and the chances of electricity blackouts. To gain a better understanding of the load that is likely to be required over the next 24h, estimations under uncertainty are needed. This is especially difficult in a decentralized electricity market with many micro-producers which are not under central control.In this paper, we investigate the impact of eleven offline learning and five online learning algorithms to predict the electricity demand profile over the next 24h. We achieve this through integration within the long-term agent-based model, ElecSim. Through the prediction of electricity demand profile over the next 24h, we can simulate the predictions made for a day-ahead market. Once we have made these predictions, we sample from the residual distributions and perturb the electricity market demand using the simulation, ElecSim. This enables us to understand the impact of errors on the long-term dynamics of a decentralized electricity market.We show we can reduce the mean absolute error by 30% using an online algorithm when compared to the best offline algorithm, whilst reducing the required tendered national grid reserve required. This reduction in national grid reserves leads to savings in costs and emissions. We also show that large errors in prediction accuracy have a disproportionate error on investments made over a 17-year time frame, as well as electricity mix.

  • Journal article
    Bakkaloglu S, Lowry D, Fisher R, France J, Brunner D, Chen H, Nisbet Eet al., 2021,

    Quantification of methane emissions from UK biogas plants

    , Waste Management, Vol: 124, Pages: 82-93, ISSN: 0956-053X

    The rising number of operational biogas plants in the UK brings a new emissions category to consider for methane monitoring, quantification and reduction. Minimising methane losses from biogas plants to the atmosphere is critical not only because of their contribution of methane to global warming but also with respect to the sustainability of renewable energy production. Mobile greenhouse gas surveys were conducted to detect plumes of methane emissions from the biogas plants in southern England that varied in their size, waste feed input materials and biogas utilization. Gaussian plume modelling was used to estimate total emissions of methane from ten biogas plants based on repeat passes through the plumes. Methane emission rates ranged from 0.1 to 58.7 kg CH4 hr-1, and the percentage of losses relative to the calculated production rate varied between 0.02 and 8.1%. The average emission rate was 15.9 kg CH4 hr-1, and the average loss was 3.7%. In general, methane emission rates from smaller farm biogas plants were higher than from larger food waste biogas plants. We also suggest that biogas methane emissions may account for between 0.4 and 3.8%, with an average being 1.9% of the total methane emissions in the UK excluding the sewage sludge biogas plants.

  • Journal article
    Machado PG, Cunha M, Walter A, Faaij A, Guilhoto JJMet al., 2021,

    Biobased economy for Brazil: Impacts and strategies for maximizing socioeconomic benefits

    , Renewable and Sustainable Energy Reviews, Vol: 139, Pages: 110573-110573, ISSN: 1364-0321
  • Journal article
    Sechi S, Giarola S, Lanzini A, Gandiglio M, Santarelli M, Oluleye G, Hawkes Aet al., 2021,

    A bottom-up appraisal of the technically installable capacity ofbiogas-based solid oxide fuel cells for self power generation in wastewatertreatment plants

    , Journal of Environmental Management, Vol: 279, Pages: 1-15, ISSN: 0301-4797

    This paper proposes a bottom-up method to estimate the technical capacity of solid oxide fuel cells to be installed in wastewater treatment plants and valorise the biogas obtained from the sludge through an efficient conversion into electricity and heat. The methodology uses stochastic optimisation on 200 biogas profile scenarios generated from industrial data and envisages a Pareto approach for an a posteriori assessment of the optimal number of generation unit for the most representative plant configuration sizes. The method ensures that the dominant role of biogas fluctuation is included in the market potential and guarantees that the utilization factor of the modules remains higher than 70% to justify the investment costs. Results show that the market potential for solid oxide fuel cells across Europe would lead up to 1,300 MW of installed electric capacity in the niche market of wastewater treatment and could initiate a capital and fixed costs reduction which could make the technology comparable with alternative combined heat and power solutions.

  • Journal article
    Rodrigues Teixeira AC, Machado PG, Borges RR, Felipe Brito TL, Moutinho dos Santos E, Mouette Det al., 2021,

    The use of liquefied natural gas as an alternative fuel in freight transport – Evidence from a driver's point of view

    , Energy Policy, Vol: 149, Pages: 112106-112106, ISSN: 0301-4215

    Nearly one-quarter of global greenhouse gas emissions are from the transport sector and around 30% of this are from road freight transport. Seeking to diversify the energy matrix and to reduce air pollution, we studied performance, emissions, and advantages/disadvantages of several alternative fuels compared to the conventional one (Diesel). This paper aims to analyze the driver's view about the use of Liquefied Natural Gas (LNG) in freight transport and set policy recommendations about it. A survey was conducted through a structure questionnarie in São Paulo (Brazil) to evaluate different aspects related to truck drivers in the use of LNG fuel technology. The results show that despite the lack of knowledge on LNG trucks, most of the respondents related it to an environmentally friendly and more economic option. Despite the higher purchase price, 68% of them would pay a loan for a longer period to acquire the technology. The main aspect about buying a conventional truck is safety (22.4%), however for LNG trucks, a tax reduction (23.1%) is the most crucial one. Lack of knowledge is a considerable barrier to the introduction of LNG for freight transport regarding technology, performance, prices, maintenance, and safety, which represent uncertainty when acquiring the technology.

  • Journal article
    Nikas A, Gambhir A, Trutnevyte E, Koasidis K, Lund H, Thellufsen JZ, Mayer D, Zachmann G, Miguel LJ, Ferreras-Alonso N, Sognnaes I, Peters GP, Colombo E, Howells M, Hawkes A, van den Broek M, Van de Ven DJ, Gonzalez-Eguino M, Flamos A, Doukas Het al., 2021,

    Perspective of comprehensive and comprehensible multi-model energy and climate science in Europe

    , Energy, Vol: 215, Pages: 1-8, ISSN: 0360-5442

    Europe’s capacity to explore the envisaged pathways that achieve its near- and long-term energy and climate objectives needs to be significantly enhanced. In this perspective, we discuss how this capacity is supported by energy and climate-economy models, and how international modelling teams are organised within structured communication channels and consortia as well as coordinate multi-model analyses to provide robust scientific evidence. Noting the lack of such a dedicated channel for the highly active yet currently fragmented European modelling landscape, we highlight the importance of transparency of modelling capabilities and processes, harmonisation of modelling parameters, disclosure of input and output datasets, interlinkages among models of different geographic granularity, and employment of models that transcend the highly harmonised core of tools used in model inter-comparisons. Finally, drawing from the COVID-19 pandemic, we discuss the need to expand the modelling comfort zone, by exploring extreme scenarios, disruptive innovations, and questions that transcend the energy and climate goals across the sustainability spectrum. A comprehensive and comprehensible multi-model framework offers a real example of “collective” science diplomacy, as an instrument to further support the ambitious goals of the EU Green Deal, in compliance with the EU claim to responsible research.

  • Journal article
    Machado PG, Teixeira ACR, Collaço FMA, Mouette Det al., 2021,

    Review of life cycle greenhouse gases, air pollutant emissions and costs of road medium and heavy‐duty trucks

    , WIREs Energy and Environment, ISSN: 2041-8396

    The desired energy transition to guarantee net‐zero greenhouse gases (GHGs) emissions needs to take place in every sector of the global economy. The transport sector is responsible for a large share of energy consumption and GHGs emissions while contributing to the increase in air pollution. Although new technologies are available, the use of diesel in road transport is still predominant. These new technologies, nonetheless, still present inconsistencies in their environment, economic performances and do not necessarily provide improvements when considering the entire fuel life cycle used in medium and heavy‐duty trucks. This systematic review addresses the uncertainties in life cycle studies regarding the road transport sector fuel consumption, GHGs, and air pollutant emissions economic analyses. Results show that there are higher chances of reducing GHGs emissions through biogas or fuel‐cell hydrogen trucks, while PM2.5 and NOx emissions have higher chances of being reduced with fuel‐cell hydrogen or natural gas trucks. There is, however, a reduced interest by the scientific community in the transport literature in dealing with air pollutants, and the focus is mainly on GHGs emissions. When it comes to economic viability, natural gas and hybrid trucks are the best substitutes.

  • Journal article
    Oluleye G, Gandiglio M, Santarelli M, Hawkes Aet al., 2021,

    Pathways to commercialisation of biogas fuelled solid oxide fuel cells in European wastewater treatment plants

    , Applied Energy, Vol: 282, ISSN: 0306-2619

    Fuel cell developments are driven by the need for more efficient and cleaner energy provision; however, current costs make it uneconomic in wastewater treatment plants. Interventions via policy instruments and business models may be required for cost reduction until the fuel cell is driven purely by market forces. In this work a novel market potential assessment methodology is developed and applied to quantify the impact of various interventions on biogas fuelled solid oxide fuel cell cost reduction and synthesize pathways to its commercialisation. The method is applied to 6181 plants in 27 European countries. Results show that 71% cost reduction is required for a medium sized fuel cell to be market driven. Existing incentives can trigger cost reduction by 13–38% but are not able to sustain it until the fuel cell is market driven. Innovations in business models, and incentivising business models instead of technologies can trigger and sustain cost reduction. Results also show that under today’s high capital cost, the number of economically attractive plants required to install fuel cells are lowest when business models are incentivised compared to other interventions. Incentivising new business models to encourage innovation in the sector has more impact that incentivising technologies. The framework is also relevant for creating narratives around the commercialisation of new technologies.

  • Conference paper
    Kell AJM, Forshaw M, Stephen McGough A, 2020,

    Exploring market power using deep reinforcement learning for intelligent bidding strategies

    , 2020 IEEE International Conference on Big Data (Big Data), Publisher: IEEE
  • Journal article
    Rodrigues Teixeira AC, Borges RR, Machado PG, Mouette D, Dutra Ribeiro FNet al., 2020,

    PM emissions from heavy-duty trucks and their impacts on human health

    , Atmospheric Environment, Vol: 241, Pages: 1-13, ISSN: 1352-2310

    The Brazilian transport system is based on the use of highways and road heavy-duty trucks are the main type of vehicle to perform this activity. There are more than 1 million km of highways in the country and the search for alternative technologies to reduce emissions from the transport industry is increasing. The Blue Corridor research started to replace heavy-duty vehicles fueled by conventional diesel to liquefied natural gas (LNG) and its effect on pollutant emissions reductions. In this context, this paper aims at evaluating the atmospheric dispersion of particulate matter (PM) from road heavy-duty trucks in 12 cities in the São Paulo State, assessing the impacts of the replacement of full fleet powered by diesel to LNG and the effects on the health of the local population. The model AERMOD was used to simulate the dispersion of PM produced by heavy-duty vehicles fuel combustion and the methodology suggested by the World Health Organization (WHO) was used to analyze the number of deaths attributed to the PM emitted. Results showed some municipalities with high PM concentrations, which exceeded the limits suggested by WHO. In terms of health issues, cardiovascular diseases in a population older than 30 years were the main cause of death from PM emissions. When it comes to fuel replacement, LNG helps to reduce PM emissions, but considering this reduction alone is not sufficient to avoid attributable deaths.

  • Journal article
    Chu C-T, Hawkes AD, 2020,

    Optimal mix of climate-related energy in global electricity systems

    , Renewable Energy, Vol: 160, Pages: 955-963, ISSN: 0960-1481

    Existing studies on high renewable share electricity systems are usually based on least cost optimization. Running the related models can be time-consuming when space-time resolution is high. This study investigates the optimal mix of climate-related energies for most countries in the world with optimization models based on three criteria: cost, residual load variability, and portfolio output variability. The objectives of minimizing residual load variability and portfolio output variability are to ensure the overall complementarity of the generation portfolio, which may result in less conventional dispatchable units needed in a system. Compromise solutions based on the three objectives are proposed as the optimal mix. This method can produce solutions in acceptable modelling time, and considers the portfolio output characteristics which can make higher climate-related energy penetration more practical. The results show that the compromise solutions can effectively minimize the three objective values in most countries. The results also suggest that wind power is crucial in higher renewable share systems while solar power does not reach over 50% capacity share.

  • Journal article
    Gerber Machado P, Rodrigues Teixeira AC, Mendes de Almeida Collaço F, Hawkes A, Mouette Det al., 2020,

    Assessment of greenhouse gases and pollutant emissions in the road freight transport sector: a case study for São Paulo state, Brazil

    , Energies, Vol: 13, Pages: 5433-5433, ISSN: 1996-1073

    This study analyzes the road freight sector of São Paulo state to identify the best options to reduce greenhouse gases emissions and local pollutants, such as particulate matter, nitrogen oxides, carbon monoxide, and hydrocarbons. Additionally, the investment cost of each vehicle is also analyzed. Results show that electric options, including hybrid, battery, and hydrogen fuel-cell electric vehicles represent the best options to reduce pollutants and greenhouse gases emissions concomitantly, but considerable barriers for their deployment are still in place. With little long-term planning on the state level, electrification of the transport system, in combination with increased renewable electricity generation, would require considerable financial support to achieve the desired emissions reductions without increasing energy insecurity.

  • Journal article
    Sesini M, Giarola S, Hawkes AD, 2020,

    The impact of liquefied natural gas and storage on the EU natural gas infrastructure resilience

    , Energy, Vol: 209, Pages: 1-13, ISSN: 0360-5442

    As the energy system progresses towards full decarbonization, natural gas could play an important role in it with its relatively low carbon characteristics and its abundant supply. At the core of the paper is a modelling analysis of the European Union (EU) natural gas network resilience in case of short-term supply disruption or unexpected increase in demand. The adopted linear programming model solves for the most cost effective transmission of gas flows, capacity and storage utilization in an interconnected EU gas system. Results presented in the paper show a significant increase in liquefied natural gas (LNG) costs (+40%) when commodity price increases (+40%) and LNG prices decreases (−20%), and an equally significant decline in transport and LNG costs (−30%,-50%) when storage volumes varies (−35%,+35%).The analysis highlights a complementary role between LNG and storage in ensuring a cost-effective response to a natural gas supply shock. It also indicates that LNG alone is inadequate in providing system resilience in case of an emergency in supply, stressing the importance of storage in the gas market and its intrinsic value in the system. The study emphasizes the need to further investigate the reliability and value of gas storage to reinforce energy security in Europe.

  • Journal article
    Budinis S, Sachs J, Giarola S, Hawkes Aet al., 2020,

    An agent-based modelling approach to simulate the investment decision of industrial enterprises

    , Journal of Cleaner Production, Vol: 267, ISSN: 0959-6526

    China is the leading ammonia producer and relies on a coal-based technology which makes the already energy intensive Haber-Bosch process, one of the most emission intensive in the world. This work is the first to propose an agent-based modelling framework to model the Chinese ammonia industry as it characterises the specific goals and barriers towards fuel switching and carbon capture and storage adoption for small, medium, and large enterprises either private or state-owned. The results show that facilitated access to capital makes investments in sustainable technologies more attractive for all firms, especially for small and medium enterprises. Without policy instruments such as carbon price, the decrease in emissions in the long-term is due to investments in natural gas-based technologies, as they typically have lower capital and operating costs, and also lower electricity consumption than coal-based production. Conversely, with policy instruments in place, a strong decrease in emissions occurs between 2060 and 2080 due to investors choosing natural gas and biomethane-based technologies, with carbon capture and storage. In the long term, natural gas and biomethane could compete, with the outcome depending on infrastructure, supply chain availability and land use constraints.

  • Journal article
    Huntington HG, Bhargava A, Daniels D, Weyant JP, Avraam C, Bistline J, Edmonds JA, Giarola S, Hawkes A, Hansen M, Johnston P, Molar-Cruz A, Nadew M, Siddiqui S, Vaillancourt K, Victor Net al., 2020,

    Key findings from the core North American scenarios in the EMF34 intermodel comparison

    , Energy Policy, Vol: 144, Pages: 1-23, ISSN: 0301-4215

    Within Canada, Mexico or the United States, policy-making organizations are evaluating energy markets and energy trade within their own borders often by ignoring how these countries’ energy systems are integrated with each other. These analytical gaps provided the main motivation for the Energy Modeling Forum (EMF) 34 study on North American energy integration and trade. This paper compares North American results from 17 models and discusses their policy motivation. Oil and natural gas production in the three major countries are modestly sensitive to crude oil and natural gas price changes, although these elasticities are below unity. Carbon taxes displace coal and some natural gas with renewables within all three power markets. Lower natural gas prices replace coal and some renewables with natural gas within electric generation. Higher intermittent renewable penetration in the power sector displaces coal and some natural gas. A key conclusion is that much remains to be done in integrating future analyses and in sharing and improving the quality and consistency of the underlying data.

  • Journal article
    Moya D, Budinis S, Giarola S, Hawkes Aet al., 2020,

    Agent-based scenarios comparison for assessing fuel-switching investment in long-term energy transitions of the India’s industry sector

    , Applied Energy, Vol: 274, Pages: 1-26, ISSN: 0306-2619

    This paper presents the formulation and application of a novel agent-based integrated assessment approach to model the attributes, objectives and decision-making process of investors in a long-term energy transition in India’s iron and steel sector. It takes empirical data from an on-site survey of 108 operating plants in Maharashtra to formulate objectives and decision-making metrics for the agent-based model and simulates possible future portfolio mixes. The studied decision drivers were capital costs, operating costs (including fuel consumption), a combination of capital and operating costs, and net present value. Where investors used a weighted combination of capital cost and operating costs, a natural gas uptake of ~12PJ was obtained and the highest cumulative emissions reduction was obtained, 2 Mt CO2 in the period from 2020 to 2050. Conversely if net present value alone is used, cumulative emissions reduction in the same period was lower, 1.6 Mt CO2, and the cumulative uptake of natural gas was equal to 15PJ. Results show how the differing upfront investment cost of the technology options could cause prevalence of high-carbon fuels, particularly heavy fuel oil, in the final mix. Results also represent the unique heterogeneity of fuel-switching industrial investors with distinct investment goals and limited foresight on costs. The perception of high capital expenditures for decarbonisation represents a significant barrier to the energy transition in industry and should be addressed via effective policy making (e.g. carbon policy/price).

  • Journal article
    Gerber Machado P, Tomei J, Hawkes A, de Oliveira Ribeiro Cet al., 2020,

    A simulator to determine the evolution of disparities in food consumption between socio-economic groups: A Brazilian case study

    , Sustainability, Vol: 12, Pages: 6132-6132, ISSN: 2071-1050

    Food is a fundamental right that deserves attention but is usually dealt with from the supply side in aggregated models that use macroeconomic variables to forecast the demand and the required supply. This study challenges this paradigm by developing a simulator to analyze food consumption from the demand side and estimate the evolution of disparity in food consumption over time with respect to region, sex, ethnicity, education, and income. This novel approach was applied to Brazil using household expenditure surveys to feed serial neural networks. Results show that the ‘poorer’ north and northeast of Brazil encounter the lowest consumption of food and are therefore the most food vulnerable regions. This trend continues to 2040. The ‘richer’ south and southeast regions have higher food consumption, which varies according to sex, ethnicity, education, and income. Brazil has contrasting issues with some groups having considerably higher food consumption, while other groups still have less than the threshold for healthy consumption. Now, the country not only has to deal with the food access by the most vulnerable due to the latest economic declines but also to deal with excess consumption, the so-called “double burden of malnutrition”.

  • Report
    Speirs J, Jalil-Vega F, Cooper J, Gerber Machado P, Giarola S, Brandon N, Hawkes Aet al., 2020,

    The flexibility of gas - what is it worth?

    , White Paper 5: The Flexibility of gas – what is it worth?, London, UK, Publisher: Sustainable Gas Institute, Imperial College London, 5

    What is the evidence on the flexibility value that gas vectors and gas networks can provide to support the future energy system?There is an increasing debate regarding the use of gas networks in providing support for the decarbonisation of energy systems.The perceived value of gas “vectors” – encompassing natural gas, hydrogen and biomethane – is that they may provide flexibility, helping to support daily and seasonal variation in energy demand, and increasingly intermittent electricity supply as renewable electricity generation increases as a proportion of the electricity mix.Arguments in support of gas suggest that electricity systems will find it difficult to maintain flexibility on their own, whilst also reducing greenhouse gas emissions and increasing production to meet new demand for heating and transport. Gas, on the other hand, is expected to provide flexibility at relatively low cost, and may be produced and used with relatively low greenhouse gas emissions.White Paper 5 investigates the evidence surrounding the flexibility provided by gas and gas networks and the cost of, and value provided by gas to the future energy system.

  • Journal article
    Grant N, Hawkes A, Napp T, Gambhir Aet al., 2020,

    The appropriate use of reference scenarios in mitigation analysis

    , Nature Climate Change, Vol: 10, Pages: 605-610, ISSN: 1758-678X

    Comparing emissions scenarios is an essential part of mitigation analysis, as climate targets can be met in various ways with different economic, energy system and co-benefit implications. Typically, a central ‘reference scenario’ acts as a point of comparison, and often this has been a no policy baseline with no explicit mitigative action taken. The use of such baselines is under increasing scrutiny, raising a wider question around the appropriate use of reference scenarios in mitigation analysis. In this Perspective, we assess three critical issues relevant to the use of reference scenarios, demonstrating how different policy contexts merit the use of different scenarios. We provide recommendations to the modelling community on best practice in the creation, use and communication of reference scenarios.

  • Journal article
    Miu LM, Hawkes A, 2020,

    Private landlords and energy efficiency: Evidence for policymakers from a large-scale study in the United Kingdom

    , Energy Policy, Vol: 142, ISSN: 0301-4215

    Energy use in British homes is a significant contributor to national greenhouse gas emissions, and the improvement of energy efficiency in residential buildings has long been an important topic in policy discussions. The lack of investment in energy-saving measures is particularly challenging in the private rented sector, and there are significant research and data gaps in understanding the retrofit behaviour of private landlords. In this study, we present the results of a detailed survey on retrofit behaviour of 1069 British private landlords. The survey assesses the engagement of landlords with 18 different energy efficiency measures, as well as their attitudes, perceptions, norms and a number of other characteristics. We use the data collected in the survey to produce 7 behavioural “typologies” of landlord retrofitters, by clustering respondents based on their socio-demographic and business characteristics. In addition to providing descriptive evidence of landlords' retrofit behaviour, our results reveal a number of opportunities for segmenting the landlord population into target groups for future policy interventions. By tailoring retrofit incentives to the needs and motivations of these groups, policy-makers can effectively engage landlords with specific energy-saving technologies, increasing the likelihood of retrofit uptake and accelerating the transition to an energy-efficient private rented sector.

  • Journal article
    Garcia Kerdan I, Giarola S, Hawkes A, 2020,

    Implications of future natural gas demand on sugarcane production, land use Change and related emissions in Brazil

    , Journal of Sustainable Development of Energy, Water and Environment Systems, Vol: 8, Pages: 304-327, ISSN: 1848-9257

    Due to its low share of energy-related emissions, energy systems models have overlooked the implications of technological transition in the agricultural sector and its interaction in the wider energy system. This paper explores the role of agriculture intensification by using a novel agricultural-based energy systems model. The aim is to explore the future role of Brazil’s agriculture and its dynamics with other energy sectors under two carbon constraint scenarios. The main focus has been to study resource competition between sugarcane and natural gas at a country level. Results show that in order to meet the future food and bioenergy demand, the agricultural sector would start intensifying by 2030, improving productivity at the expense of higher energy demand, however, land-related emissions would be minimised due to freed-up pasture land and reduction in deforestation rates. Additionally, the development of balanced bioenergy and natural gas markets may help limit the sugarcane expansion rates, preserving up to 12.6 million hectares of forest land, with significant emissions benefits.

  • Journal article
    Lyrio de Oliveira L, García Kerdan I, de Oliveira Ribeiro C, Oller do Nascimento CA, Rego EE, Giarola S, Hawkes Aet al., 2020,

    Modelling the technical potential of bioelectricity production under land use constraints: A multi-region Brazil case study

    , Renewable and Sustainable Energy Reviews, Vol: 123, Pages: 1-15, ISSN: 1364-0321

    In Brazil, bioelectricity generation from sugarcane bagasse and black liquor is regarded as a sustainable electricity supply option. However, questions regarding land use, investment decisions, and demand for paper, ethanol and sugar make its future role uncertain. The aim of this paper is to present a novel modelling framework based on a soft-link between a multi-sectoral Brazilian integrated assessment model (MUSE-Brazil) and an electricity portfolio optimisation model (EPOM). The proposed framework is capable of dynamically simulating sectoral electricity demand, regional bioenergy production under land use constraints and optimal power sector technological shares in each of the electricity subsystems. Considering Brazil under a 2 °C carbon budget, two scenarios based on economic attractiveness of producing second-generation ethanol have been investigated. Under the scenario where second-generation ethanol is not produced, outputs indicate that by 2050, Brazil would increase sugarcane and wood production by 68% and 49% respectively without causing direct or indirect deforestation. Agriculture intensification is evidenced as an alternative for reducing land use disruptions. Bioelectricity share is projected to remain around 9–10%. However, if second generation ethanol becomes cost-effective, thus limiting bagasse availability, the share of bioelectricity production would decrease to approximately 7.7%, with natural gas-fired plants playing a stronger role in the future power system expansion, causing an increase on electricity sector emissions.

  • Journal article
    Jalil Vega F, Garcia Kerdan I, Hawkes A, 2020,

    Spatially-resolved urban energy systems model to study decarbonisation pathways for energy services in cities

    , Applied Energy, Vol: 262, ISSN: 0306-2619

    This work presents the COMET (Cities Optimisation Model for Energy Technologies) model, a spatially-resolved urban energy systems model that takes into account energy service demands for heating, cooling, electricity, and transport, and finds cost-effective pathways for supplying these demands under carbon constraints, trading-off energy supply, network infrastructure, and end-use technologies. Spatially-resolved energy service demands were obtained for the city of Sao Paulo, and six scenarios were modelled. Results show that district cooling is cost-effective in the highest linear cooling density zones, with full penetration in zones with over 1100 kWh/m by 2050. This threshold diminishes with tighter carbon constraints. Heating is electrified in all scenarios, with electric boilers and air-source heat pumps being the main supply technologies for the domestic and commercial sectors respectively by 2050. In the most carbon constrained scenario with a medium decarbonised electricity grid, ground source heat pumps and hydrogen boilers appear as transition technologies between 2030 and 2045 for the commercial and domestic sectors respectively, reaching 95% and 40% of each sector’s heat installed capacity in 2030. In the transport sector, ethanol cars replace gasoline, diesel, and compressed natural gas cars; compressed natural gas buses replace diesel and electric buses; and lorries continue using diesel. In carbon constrained scenarios, higher penetrations of electric cars and buses are obtained, while no change is observed for lorries. Finally, the most expensive scenario was only 6% more expensive than the reference scenario, meaning that achieving decarbonisation targets is not much costlier when comparing scenarios from a system-wide perspective.

  • Journal article
    Chu C-T, Hawkes AD, 2020,

    A geographic information system-based global variable renewable potential assessment using spatially resolved simulation

    , Energy, Vol: 193, Pages: 1-11, ISSN: 0360-5442

    Variable renewable energy is set to become a key energy source worldwide, but there is concern regarding the impact of the intermittency of its output when penetration is high. Energy system models need to tackle this issue by improving modelling resolution and scope. To allow for such modelling, more and better input datasets are needed on variable renewable energy potentials and yields. These need to be of global scope, of sufficient spatial and temporal resolution, and generated with transparent, consistent methods. This study develops the methods and applies it to generate these datasets at subnational and hourly resolution. The assessment is carried out for wind and solar technologies with consistent constraints including geographical, social and economic aspects. Features from the OpenStreetMap are converted into land cover and land use datasets and applied. Hourly energy output is simulated using NASA MERRA-2 meteorological datasets, reconciled with resource maps from the Global Wind Atlas and Global Solar Atlas platforms. Capacity supply curves are provided for 731 terrestrial zones and 339 offshore zones worldwide, along with corresponding hourly output profiles over a 10-year simulation period. The proposed energy potentials are relative conservative compared with other studies. The datasets can serve as input for regional or global energy system models when analyzing high variable renewable energy shares.

  • Journal article
    Luh S, Budinis S, Giarola S, Schmidt TJ, Hawkes Aet al., 2020,

    Long-term development of the industrial sector – case study about electrification, fuel switching, and CCS in the USA

    , Computers & Chemical Engineering, Vol: 133, Pages: 1-14, ISSN: 0098-1354

    In the urgent quest for solutions to mitigate climate change, the industry is one of the most challenging sectors to decarbonize. In this work, a novel simulation framework is presented to model the investment decisions in industry, the Industrial Sector Module (ISM) of the ModUlar energy system Simulation Environment (MUSE). This work uses the ISM to quantify effects of three combined measures for CO2 emission reduction in industry, i.e. fuel switching, electrification, and adoption of Carbon Capture and Storage (CCS) and to simulate plausible scenarios (base scenario and climate ambitious scenario) for curbing emissions in the iron and steel sector in the USA between 2010 and 2050. Results show that when the climate ambitious scenario is applied, the cumulative emissions into the atmosphere (2,158 Mt CO2) are reduced by 40% in comparison to the base scenario (3,608 Mt CO2). This decarbonization gap between both scenarios intensifies over time; in the year 2050, the CO2 intensity in the climate ambitious scenario is 81% lower in comparison to the base scenario. The study shows that major contributions to industry decarbonization can come from the further uptake of secondary steel production. Results show also that a carbon tax drives the decarbonization process but is not sufficient on its own. In addition, the uptake of innovative low-carbon breakthrough technologies is necessary. It is concluded that industrial electrification is counterproductive for climate change mitigation, if electricity is not provided by low-carbon sources. Overall, fuel switching, industrial electrification, and CCS adoption as single measures have a limited decarbonization impact, compared to an integrated approach that implements all the measures together providing a much more attractive solution for CO2 mitigation.

  • Journal article
    Bosch J, Staffell I, Hawkes AD, 2019,

    Global levelised cost of electricity from offshore wind

    , Energy, Vol: 189, Pages: 116357-116357, ISSN: 0360-5442

    There is strong agreement across the energy modelling community that wind energy will be a key route to mitigating carbon emissions in the electricity sector. This paper presents a Geospatial Information System methodology for estimating spatially-resolved levelised cost of electricity for offshore wind, globally. The principal spatial characteristics of capital costs are transmission distance (i.e. the distance to grid connection) and water depth, because of the disparate costs of turbine foundation technologies. High resolution capacity factors are estimated from a bottom-up estimation of global wind speeds calculated from several decades of wind speed data. A technology-rich description of fixed and floating foundation types allows the levelised cost of electricity to be calculated for 1 × 1 km grid cells, relative to location-specific annual energy production, and accounting for exclusion areas, array losses and turbine availability. These data can be used to assess the economically viable offshore wind energy potential, globally and on a country basis, and can serve as inputs to energy systems models.

  • Journal article
    García Kerdan I, Jalil-Vega F, Toole J, Gulati S, Giarola S, Hawkes Aet al., 2019,

    Modelling cost-effective pathways for natural gas infrastructure: A southern Brazil case study

    , Applied Energy, Vol: 255, ISSN: 0306-2619

    Currently, natural gas in Brazil represents around 12.9% of the primary energy supply, with consistent annual growth during the last decade. However, Brazil is entering a time of uncertainty regarding future gas supply, mainly as import from Bolivia is being renegotiated. As such, diversification of gas supply sources and routes need to be considered. Energy systems and infrastructure models are essential tools in assisting energy planning decisions and policy programmes at regional and international levels. In this study, a novel combination of a simulation-based integrated assessment model (MUSE-South_Brazil) and the recently-developed Gas INfrastructure Optimisation model (GINO) is presented. The Brazilian region represented by the five southern states served by the Bolivian gas pipeline (GASBOL) has been investigated. Modelled projections suggest that regional gas demand would increase from 38.8 mcm/day in 2015 to 104.3 mcm/day by 2050, mainly driven by the increasing demand in the industry and power sectors. Therefore existing regional gas infrastructure would be insufficient to cover future demands. Three different renegotiation scenarios between Brazil and Bolivia were modelled, obtaining distinct cost-optimal infrastructure expansion pathways. Depending on the scenario, the model expects gas demand to be covered by other supply options, such as an increase in pre-salt production, LNG imports and imports from a new Argentinian pipeline.

  • Journal article
    da Hora MABP, Asrilhant B, Accioly RMS, Schaeffer R, Szklo A, Hawkes Aet al., 2019,

    Decision making to book oil reserves for different Brazilian fiscal agreements using dependence structure

    , ENERGY STRATEGY REVIEWS, Vol: 26, ISSN: 2211-467X
  • Journal article
    Miu LM, Mazur CM, Van Dam KH, Lambert RSC, Hawkes A, Shah Net al., 2019,

    Going smart, staying confused: perceptions and use of smart thermostats in British homes

    , Energy Research and Social Science, Vol: 57, ISSN: 2214-6296

    Given the significant contribution of housing to energy consumption, research into how residents use energy-saving technologies has been gathering pace. In this study, we investigate the perception and use of domestic smart heating controls by a small group of residents in London, UK. These residents are supplied by a district heat network (DHN) through underfloor heating systems, and took part in a trial where their controls were upgraded from traditional thermostats to smart thermostats. Pre- and post-trial interviews were used to assess changes in how residents interacted with and perceived their controls and heating systems. After the upgrade, more residents were satisfied with the usability of their controls and programmed heating schedules which matched their actual occupancy patterns, but they also made ad-hoc temperature and schedule adjustments more frequently. These changes provide insight into how a unique sample of residents, “twice removed” from the most intuitive methods of heating control, adjusted their behaviour and perceptions following a technology upgrade. Although the small sample size and lack of long-term monitoring limits the generalizability of our results, the findings open avenues for further research into whether smart heating controls change user behaviour in a way that improves the predictability of heating demand, a crucial aspect of improving DHN operation and reducing related emissions.

  • Journal article
    García Kerdan I, Giarola S, Jalil-Vega F, Hawkes Aet al., 2019,

    Carbon sequestration potential from large-scale reforestation and sugarcane expansion on abandoned agricultural lands in Brazil

    , Polytechnica, Vol: 2, Pages: 9-25, ISSN: 2520-8497

    Since 1850, over 145 ± 16 PgC (μ ± 1σ) has been emitted worldwide due to land-use change and deforestation. Besides industrial carbon capture and storage (CCS), storing carbon in forestry products and in regenerated forest has been recognized as a cost-effective carbon sequestration option, with an estimated worldwide sink potential of about 50–100 PgC (15–36 PgC from tropical forest alone). This paper proposes the expansion of a Brazilian integrated assessment model (MUSE-Brazil) by integrating a non-spatial biomass-growth model. The aim is to account for carbon sequestration potential from either reforestation or sugarcane expansion in abandoned agricultural lands. Modelling outputs suggest that Brazil has the potential to liberate up to 32.3 Mha of agricultural land by 2035, reaching 68.4 Mha by mid-century. If a sugarcane expansion policy is promoted, by 2050, the largest sequestration rates would come from above and below ground biomass pools; gradually releasing to the atmosphere around 1.6 PgC or 1.2% of the current Brazilian land carbon stock due to lower SOC carbon pools when turning agricultural lands into sugarcane crops. On the other hand, a reforestation-only scenario projects that by 2035 the baseline year carbon stock could be recovered and by 2050 the country’s carbon stock would have been increased by 3.2 PgC, reaching annual net sequestration rates of 0.1 PgC y−1, mainly supported by natural vegetation regeneration in the Cerrado biome.

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