Environmental Research Institute - Doctoral Theses

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    Advancing Irish energy system modelling to inform residential policy
    (University College Cork, 2023) McGuire, Jason; Daly, Hannah E.; Rogan, Fionn; O'Gallachoir, Brian; Department of the Environment, Climate and Communications
    Anthropogenic greenhouse gas emissions are rising, and a lack of action towards climate policy has sparked a renewed determination to act. Energy Systems Optimisation Models (ESOMs) help guide energy policymaking to meet climate goals. This thesis uses a newly developed ESOM, TIMES Ireland Model (TIM), to explore Ireland’s decarbonisation pathways. TIM incorporates empirical internal temperature variations in buildings. Building Energy Rating (BER) assessments in Ireland, based on Energy Performance Certificates (EPC), measure a building’s expected energy consumption. However, it has been observed that standard BER assessments tend to overestimate residential energy consumption in Ireland by as much as 23%. When empirical internal temperatures are used in place of BER temperature assumptions, 6% fewer thermal retrofits are required to achieve the cost-optimal decarbonisation pathway, but energy savings are 114% less in this case. The new methodology better reflects energy consumption without overestimating the effect of thermal retrofits and provides more accurate climate policy insights. The Danish Energy Agency supported this thesis by exploring the feasibility of district heating (DH) in Ireland. Ireland is a country with low DH deployment, but it has significant surplus heat. Using scenarios that considered different connection rates and maximum annual growth, this thesis consistently showed that DH saturates the heat market before 2050 in all scenarios. If DH is excluded, the average sectoral marginal CO2 emission price over the model’s time horizon is €729/tCO2. However, when DH is permitted, this cost reduces by 13% to 25%, depending on the connection rate and maximum growth constraint. A policy-focused aspect of this thesis explored Ireland’s current fabric-first policy approach to understand if it is cost-effective. Alternative decarbonisation pathways allow for variations in heat pump subsidy thresholds connected to a dwelling’s Heat Loss Indicator (HLI). The thesis also accounted for sub-optimal heat pumps, which do not achieve peak performance due to high HLIs. The findings suggest that the current fabric-first approach is stringent, requiring a BER rating of B2 or equivalent energy consumption, which is not cost-effective. Significant savings can be made, especially post-2030. For example, post-2030, the fabric-first average sectoral marginal CO2 emission price is €675/tCO2. Simply by allowing sub-optimal heat pump installation, this reduces to €312/tCO2. Adjusting the HLI threshold to 2.3 W/K/m² could further reduce this cost to €273/tCO2. This research offers a detailed exploration of the Irish residential sector, emphasizing the complex interactions among different energy sectors and advocating for a more coherent energy planning approach. For policymakers, it is essential to better understand residential energy consumption, embrace district heating through spatial energy system planning, and reevaluate the fabric-first approach. By doing so, Ireland could effectively achieve its climate goals more cost-effectively.
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    Enhanced modelling of transport decarbonisation and policy pathways for Ireland
    (University College Cork, 2023) O'Riordan, Vera; Rogan, Fionn; Daly, Hannah E.; O'Gallachoir, Brian; Climate and Energy Modelling Services
    The release of increasing human-induced greenhouse gas emissions and the corresponding global temperature rise has prompted a growing political consensus on a decarbonised future to prevent any sustained economic or environmental harm. Many countries are using energy system modelling tools to develop strategies and policy measures to deliver timely and effective reductions of harmful greenhouse gas emissions across all energy-related sectors. Ireland, with ambitious legally binding carbon budgets, and decarbonisation targets for transport, is a country in the process of assessing and addressing key transport decarbonisation challenges faced by high-emitting countries. This thesis - with its scientific contributions on transport emissions, methodological advancements for transport and multi-sector energy systems simulation modelling, and policy recommendations on how effective measures have been in the past or could be in the future - serves as a small, but novel, piece of this process. The thesis updates the Irish Car Stock Model to investigate the importance of taxation policy using a novel bottom-up stock simulation approach. The simulation model evaluates the 2008 car tax policy in Ireland and finds that while the policy was effective at reducing CO2 emissions, it had a high cost of carbon abatement, between €1,500 – 2,200 per tCO2. The thesis develops the Irish Passenger Transport Emissions and Mobility (IPTEM) model, which for the first time, calculates the overall passenger transport demand in Ireland by trip purpose, trip distance, and mode type. The methodological advancement is in the combination of passenger transport demand from all modes of transport and information from the National Travel Survey, national transport providers, and the Irish Car Stock Model. The study finds that 82% of passenger transport demand is met by cars in Ireland, and the main reason for travel is for work (30%), shopping (19%), and companion journeys (16%). The study also finds that 40% of emissions come from journeys less than 8 kilometres. In Chapter 4, this thesis develops a new model, the LEAP Ireland ASI (Avoid-Shift-Improve) model which projects emissions and demand for passenger and freight transport up to 2030. It is novel in its application of the Avoid-Shift-Improve framework for scenarios focused on reducing the need to travel in the first instance (“Avoid”), then on modal shifting towards increased public transport use and active travel (“Shift”), and then on scenarios focused on improving the fuels used to ones with a lower carbon intensity (“Improve). These scenarios are modelling in combination with one another and the interaction between the policies is also determined. In Chapter 5, the thesis develops a new methodology for simulation modelling to project carbon dioxide emissions, how different scenarios could reduce carbon dioxide emissions, and how these fit in with sectoral emissions ceilings within carbon budgets. The thesis tracks past sectoral emissions and simulates the mitigation potential of a suite of scenarios for transport, residential, electricity, services, and industry sectors. The LEAP Ireland model developed in Chapter 5 can simulate the impact of additional policies, track policy performance, and simulate mitigation potential. The data sources, methodology, and carbon budget analysis are outlined in this novel simulation modelling framework designed to support countries with their carbon budgeting commitments. This thesis also examines the interaction effect between these policy scenarios and discusses their combinations' synergistic and antagonistic effects. The contribution of this thesis is the improvements made to the modelling methods and more robust evidence base for developing sound decarbonisation transport policy measures by shifting the focus beyond car efficiency and electrification.
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    Field measurements and atmospheric simulation chamber studies of selected biomass burning marker compounds
    (University College Cork, 2023) O'Sullivan, Niall Patrick; Wenger, John; Environmental Protection Agency; Irish Research Council
    Biomass burning is a key contributor to ambient air pollution, which has significant impacts on climate and health. Biomass burning emits both solid particles and gaseous species known as volatile organic compounds (VOCs) which can undergo chemical oxidation reactions in the atmosphere with hydroxyl (OH) and nitrate (NO3) radicals to produce secondary organic aerosols (SOA). While the particulate pollution has been well characterised, information on the VOCs associated with biomass burning is limited. To this end, a Time-of-Flight Chemical Ionisation Mass Spectrometer (ToF-CIMS) was deployed in Cork City, for the first comprehensive field study on the VOCs associated with residential burning of solid fuels (wood, peat, coal) in Ireland. In the field study, a range of phenols and their nitro derivatives were detected during air pollution events caused by residential solid fuel burning. By following the evolution of these biomass burning markers through the night, evidence was found for the atmospheric conversion of phenol compounds to their analogous nitrophenols via gas-phase reaction with NO 3 . Positive matrix factorisation was used to identify six different source categories for the VOCs which included fresh and atmospherically processed emissions from solid fuel burning, as well as oxidized emissions from local and regional background sources such as vehicles and agriculture. A series of simulation chamber studies was also performed on the OH-initiated oxidation of two biomass burning marker compounds, 4-methylcatechol and guaiacol. The ToF-CIMS identified a large range of gas and particle products including polyphenols, nitrophenols, benzoquinones, ring scission species and accretion products, generating new information on the atmospheric degradation pathways. The results confirm the importance of both OH addition and H-atom abstraction reactions in initiating the oxidation processes and interestingly, in the case of guaiacol, loss of the methoxy group to form catechol which also underwent similar degradation pathways. A wide range of highly oxidized and nitro-containing species were identified in the particle phase which experienced further chemical processing, thus providing new insights into the mechanisms for the formation and atmospheric aging of SOA produced from biomass burning.
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    Motivations, incentives, and commitments: financial benefits and citizen participation in onshore wind energy in Ireland
    (University College Cork, 2023) le Maitre, Julia; Ryan, Geraldine; Power, Bernadette; Horizon 2020; Irish Research Council; Sustainable Energy Authority of Ireland
    Social acceptance of onshore wind energy is a fundamental constraint for the delivery of sustainable electricity supply (Wüstenhagen et al., 2007). For a country such as the Republic of Ireland, this is a significant impediment to the decarbonisation of the energy sector (Brennan et al., 2017; Hallan and González, 2020; Van Rensburg et al., 2015), since onshore wind energy is expected to increase from approximately a third of the electricity mix to 80% by 2030 (SEAI, 2023). In 2019, Ireland introduced the Renewable Electricity Support Scheme with the aim of quadrupling its supply of onshore wind energy. The policy introduced a variety of financial benefits directed towards local communities to facilitate social acceptance, including community benefit funding and incentives focused on households closest to the wind farm, in the form of ‘near-neighbour’ compensation (DECC, 2021). The scheme also opened consideration for a new mechanism to encourage citizen investment into wind farms (DCCAE, 2020). The novelty, scope, and value of these mechanisms underscore the need for detailed research to identify how they could be designed and implemented to enhance their fairness, benefit, and acceptance. This thesis asks how specific attributes of financial participation mechanisms aimed at enhancing social acceptance influence citizens' willingness to accept, or to invest in, wind farms in their community. This thesis is based on two specialised surveys to examine how Irish citizens trade-off between different features of wind farm developments and their associated financial benefits. The research provides detailed insights into the preferences of supporters, conditional supporters, and non-supporters for wind farm developments in the community and presents recommendations concerning distributive and procedural issues across each phase of project development. Firstly, the findings show that citizens’ preferences for the distribution of financial benefits from wind farms are affected by procedural factors over planning, construction, and operation. Community participation in the governance of the community benefit fund and in the ownership of the wind farm have particularly high relative importance for strong supporters of wind farms. In addition, the developer and the proximity of the wind farm strongly influence willingness to accept. Secondly, the thesis contributes new evidence towards the design of citizen wind energy investments, and reveals a strong relationship between community acceptance, the proximity of the wind farm, and citizen investment preferences. Overall, financial attributes including the level of risk and expected return on investment have the greatest influence on citizen investment. However, the structure of voting rights, ownership and administration of the investment are generally regarded as having a higher relative importance if the wind farm is within 2km of the community, or a respondent is supportive of wind energy development. Thirdly, familiarity with a wind farm, whether a result of its proximity or phase of development, is a significant determinant of residents’ willingness to accept further development in the community. Critical points for local support of wind farms are at the earliest pre-planning / planning phases of development, as well as for households within the 2km radius of a wind farm. Other latent factors, such as attitudes towards wind electricity, trust in information provided by a developer, or awareness of community energy initiatives significantly affect community acceptance. Lastly, a comparative case study analyses the design of financial benefits, citizen investment and near-neighbour incentives in Ireland with corresponding mechanisms introduced by Denmark, Germany, and the United Kingdom. Based on a critical assessment of the design and adaptation of policy mechanisms over time, the findings suggest that it is becoming more common for these governments to endorse the development of community trusts or municipality community benefit funds. It also suggests that community-led wind farms experience difficulties related to the competitive nature of the auction regime. The chapter recommends that when defining eligibility or boundaries on citizen financial participation, policymakers could use a phased approach, first prioritising residents closest to a wind farm, and then opening opportunities across a wider geography in the second instance. The research is relevant for policy and practice. It enhances the understanding of citizens’ preferences for financial participation mechanisms in onshore wind farms, which is conducive to social acceptance and fairer local energy transitions. It would be valuable for future studies to develop on this evidence in the context of offshore wind energy and demand-side response which are increasingly important for the Irish energy transition. The diffusion of these innovative technologies similarly depends on citizen participation, fairness, and ultimately social acceptance.
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    Development of ultrasensitive electrochemical sensors based on nanocomposites for environmental applications
    (University College Cork, 2023) Albalawi, Ibtihaj; Moore, Eric; Ministry of Education – Kingdom of Saudi Arabia
    Water quality assessment is an essential component of environmental monitoring, which affects not only aquatic life but the surrounding ecosystem as well. The presence of organic and inorganic micropollutants such as carbamate pesticides and heavy metals in water is a crucial water problem generated from industrial effluents, mining wastes, or domestic sewage, and the widespread use of pesticides in pest control in the environment. In the last years, heavy metals have risen significantly, especially in the developed country where most pollutants are used. According to the World Health Organisation (WHO), with only 8 % of the world’s population, Germany, the United States, and Russia consume about 75 % of the most widely used metals in the world. The United States only consumes approximately 20 % of the metal pollutants and 25 % of the production of fossil fuels each year. Heavy metals such as lead, and cadmium are among the most critical pollutants and the focus of international legislative bodies because of their nonbiodegradability and toxicity and their long-term negative health effect. Carbamate pesticide use is extensively reported, and the trend in their use is anticipated to rise significantly in the next few decades. Among them, carbaryl is extensively applied in grain and has an adverse impact on the cellular metabolic mechanism and mitochondrial function. Moreover, the pH of the water solution is another vital factor affecting biological and chemical processes in water, which in turn affects the environment and human health. Typically, the used conventional analytical techniques are expensive and time-consuming due to sample transportation, trained personnel, and failure to deliver water quality parameters in real-time. Therefore, electrochemical sensing technology has the potential to change the way we see quality control analysis in the environment. It can provide a cheap, sensitive, portable, and easy-to-use method of application in quality control analysis. Thus, this research aims to develop multi-sensors based on screen-printed electrodes, which have characteristics of low cost, high sensitivity, selectivity, and rapid analysis. The novel methods in this research proved their efficiency to detect analytes of interest in environmental media with high sensitivity, excellent stability, short response time, and have the potential to be integrated into a multi-parameter system sensing for on-field monitoring.