A novel energy systems model to explore the role of land use and reforestation in achieving carbon mitigation targets: A Brazil case study

Due to its low global share of direct energy consumption and greenhouse gas emissions (1–2%), the implications of technological transitions in the agricultural and forestry sector on the energy system have been overlooked. This paper introduces the Agriculture and Land Use Sector module part of the ModUlar energy System Environment (MUSE), a novel energy system simulation model. The study presents a generalisable method that enables energy modellers to characterise agricultural technologies within an energy system modelling framework. Different mechanisation processes were characterised to simulate intensification/extensification transitions in the sector and its wider implications in the energy and land use system aiming at providing reliable non-energy outputs similarly to those found in dedicated land use models. Additionally, a forest growth model has been integrated to explore the role of reforestation alongside decarbonisation measures in the energy system in achieving carbon mitigation pathways. To illustrate the model's capabilities, Brazil is used as case study. Outputs suggest that by 2030 under a 2 °C mitigation scenario, most of Brazil agricultural production would move from ‘transitional’ to ‘modern’ practices, improving productivity and reducing deforestation rates, at the expense of higher energy and fertiliser demand. By mid-century Brazil has the potential to liberate around 24.4 Mha of agricultural land, where large-scale reforestation could have the capacity to sequester around 5.6 GtCO2, alleviating mitigation efforts in the energy system, especially reducing carbon capture and storage technology investments in the industry and power sector

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

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

A comparison of an energy/economic-based against an exergoeconomic-based multi-objective optimisation for low carbon building energy design

This study presents a comparison of the optimisation of building energy retrofit strategies from two different perspectives: an energy/economic-based analysis and an exergy/exergoeconomic-based analysis. A recently retrofitted community centre is used as a case study. ExRET-Opt, a novel building energy/exergy simulation tool with multi-objective optimisation capabilities based on NSGA-II is used to run both analysis. The first analysis, based on the 1st Law only, simultaneously optimises building energy use and design's Net Present Value (NPV). The second analysis, based on the 1st and the 2nd Laws, simultaneously optimises exergy destructions and the exergoeconomic cost-benefit index. Occupant thermal comfort is considered as a common objective function for both approaches. The aim is to assess the difference between the methods and calculate the performance among main indicators, considering the same decision variables and constraints. Outputs show that the inclusion of exergy/exergoeconomics as objective functions into the optimisation procedure has resulted in similar 1st Law and thermal comfort outputs, while providing solutions with less environmental impact under similar capital investments. This outputs demonstrate how the 1st Law is only a necessary calculation while the utilisation of the 1st and 2nd Laws becomes a sufficient condition for the analysis and design of low carbon buildings

Thermodynamic and thermal comfort optimisation of a coastal social house considering the influence of the thermal breeze

Tropical coastal areas are characterised by high levels of wind and solar resources with large potentials to be utilised for low-energy building design. This paper presents a multi-objective optimisation framework capable of evaluating cost-efficient and low-exergy coastal building designs considering the influence of the thermal breeze. An integrated dynamic simulation tool has been enhanced to consider the impacts of the sea-land breeze effect, aiming at potentiating natural cross-ventilation to improve occupant's thermal comfort and reduce cooling energy demand. Furthermore, the technological database considers a wide range of active and passive energy conservation measures. As a case study, a two-storey/two-flat detached social house located in the North-Pacific coast of Mexico has been investigated. The optimisation problem has considered the minimisation of: i. annual exergy consumption, ii. life cycle cost, and iii. thermal discomfort. Optimisation results have shown that adequate building orientation and window opening control to optimise the effects of the thermal breeze, combined with other passive and active strategies such as solar shading devices, an improved envelope's physical characteristics, and solar assisted air source heat pumps have provided the best performance under a limited budget. Compared to the baseline design, the closest to utopia design has increased thermal comfort by 93.8% and reduced exergy consumption by 10.3% whilst increasing the life cycle cost over the next 50 years by 18.5% (from US$39,864 to US$47,246). The importance of renewable generation incentives is further discussed as a counter effect measure for capital cost increase as well as unlocking currently high-cost low-exergy technologies

Modelling the energy and exergy utilisation of the Mexican non-domestic sector: A study by climatic regions

This paper presents the development of a bottom-up stock model to perform a holistic energy study of the Mexican non-domestic sector. The current energy and exergy flows are shown based on a categorisation by climatic regions with the aim of understanding the impact of local characteristics on regional efficiencies. Due to the limited data currently available, the study is supported by the development of a detailed archetype-based stock model using EnergyPlus as a first law analysis tool combined with an existing exergy analysis method. Twenty-one reference models were created to estimate the electric and gas use in the sector. The results indicate that sectoral energy and exergy annual input are 95.37. PJ and 94.28. PJ, respectively. Regional exergy efficiencies were found to be 17.8%, 16.6% and 23.2% for the hot-dry, hot-humid and temperate climates, respectively. The study concludes that significant potential for improvements still exists, especially in the cases of space conditioning, lighting, refrigeration, and cooking where most exergy destructions occur. Additionally, this work highlights that the method described may be further used to study the impact of large-scale refurbishments and promote national regulations and standards for sustainable buildings that takes into consideration energy and exergy indicators

Thermodynamic and exergoeconomic analysis of a non-domestic Passivhaus retrofit

This paper presents a thermodynamic and exergoeconomic analysis of a recently-retrofitted Passivhaus non-domestic building. The selected case study, a Community Centre located in London, underwent a deep-energy retrofit in 2011, becoming the first ‘non-domestic Passivhaus’ retrofit in the country. As the building was retrofitted per Passivhaus standards, which is based solely on First Law analysis, a thermodynamic investigation can provide a novel means by which to assess its exergy efficiency and cost-effectiveness. As such, the aim of this paper is to conduct a comprehensive exergy and exergoeconomic analysis, presenting novel performance indicators for the pre-retrofit and post-retrofit Passivhaus building. First law outputs show that the improvement presents high levels of energy savings (75.6%), reductions in carbon emissions (64.5%), and occupant thermal comfort improvement (28.8%). Second law outputs present a reduction in primary exergy input reduction of 56.4% and exergy destructions of 60.4%, leading to improve building exergy efficiency from 9.8% to 18.0%. Nevertheless, exergoeconomically the building did not perform as expected due to high capital cost and exergy destructions cost rates. These results give an insight into the thermodynamic impact of the Passivhaus approach, providing a critical assessment of the strengths and limitations of the standard under both thermodynamic laws

Thermal performance evaluation of a passive building wall with CO2-filled transparent thermal insulation and paraffin-based PCM

Novel thermal insulation materials and wall configurations have the potential to play a major role in reducing energy demand and carbon emissions from the building sector. In this study, a passive heating wall system composed by a CO2-filled transparent thermal insulation (TTI) and an organic phase change material (PCM), and a passive cooling system composed by a Tromble Wall with nano-film and a CO2-filled TTI are proposed and evaluated. The aim is to present a detailed analytical model for rapidly calculating thermal performance of the proposed wall configurations. As case study, a 108 m2 south façade of a building located in Mexico has been used. Outputs suggest that as a passive heating measure, the system has the potential to supply heat in the order of 118 W, 126 W, 134 W, and 157 W, during the months of December, January, February, and March respectively. Additionally, thermal performance and air velocity simulations suggest that for the heating case, considering an outdoor and indoor temperature conditions of 0 °C and 21 °C respectively, the internal layer surface reaches a temperature of 9.2 °C; while for the cooling case, considering outdoor and indoor temperature conditions of 25 °C and 21 °C respectively, it reaches 22.5 °C with a maximum indoor air velocity of 0.5 m/s. Compared to other gases, CO2 could hold a greater potential due to its low thermal conductivity and capital costs. Large-scale implementation of such systems could make the building sector an interesting option as an artificial sink for carbon storage

Negotiating Boundaries: The Nurse Family Member Caring for Her Own Relative in Palliative Care

This research illuminates the challenges of living well within one's own family as a nurse caring for her own relative who is dying of a cancer-related illness. Developing a deeper awareness of the consequences of this caring work has been the central focus for inquiry in this research. Nursing requires epistemologies that encompass new ways of understanding how we live within our own families and communities and practice as nurses. The theoretical framework that guides this research interprets the French Philosopher Michel Foucault's (1926-1984) critical history of thought as an ethical project for nursing. It uses conceptual tools developed in his later writing and interviews to draw attention to how discursive knowledge and practices constitute subjectivity in relations of truth, power and the self's relation to the self. The first aspect of the analysis, landscapes of care examines the techniques of discourse as relations of power and knowledge that constitute nurse family members as subjects who have relationships with their own families and other health professionals. The second aspect analyses care of the self and others as self work undertaken to form the self as a particular kind of subject and achieve mastery over one's thoughts and actions. Nurses are called to care because they are present within their families with knowledge and expertise that makes a difference to how a dying relative experiences palliative care. Caring discourse positions nurses with responsibilities to their own; responsibilities that require sensitivity in knowing how to negotiate the relational spaces that constitute relationships with other family members and health professionals. Family discourse calls nurse family members to care as daughters, daughters-in-law, wives or mothers within normative understandings about the obligations that families have to care for their ill or dependent members. The discourse of expertise in knowing as a nurse positions nurse family members as interpreters of information for their families and observers who use their inside knowledge of how the health system works to watch over the ill person's clinical care. This expertise, which becomes visible as the exercise of professional authority in practising nursing, challenges the normative frameworks that classify and demarcate professional and lay roles in caring for the dying person. As an exploration of the complex and contradictory subjectivities of the nurse family member, this research illuminates the forms and limits of nursing practice knowledge. It shows how nursing is practised, and the identity of the nurse is created, through intellectual, political and relational work, undertaken on the self in relation to others, as modes of ethical engagement. Within this ethical engagement, nurse family members work to transform the self into discursive subjects, with the knowledge, skills and other capacities that are necessary to honour their commitments and responsibilities for care of another person. The experience of caring for their own relative transforms nurse family members' previously held values about how nurses ought to be with others in their professional work, creating a deeper sense of interest in and concern for the vulnerability of other people in palliative care

Using the forward movement of a container ship navigating in the Arctic to air-cool a marine organic Rankine cycle unit

Ice coverage in the Arctic is declining, opening up new shipping routes which can drastically reduce voyage lengths between Asia and Europe. There is also a drive to improve ships energy efficiency to meet international emissions design regulations such as the mandated Energy Efficiency Design Index. The organic Rankine cycle is one thermodynamic cycle that is being actively examined to improve the design and operational efficiency of ships. Low heat sink temperatures can significantly increase waste heat recovery systems thermal efficiency. In Arctic regions, the ambient air temperature can be much lower than the sea temperature, presenting interesting opportunities. However, using air as the cooling medium requires larger condensers and power compared to a water-cooled system. This paper investigates the exploitation of the forward movement of a container ship navigating in the Arctic and density-change induced flows as means of moving air through the condenser to reduce the fan power required. The organic Rankine cycle unit uses the waste heat available from the scavenge air to produce electric power. A two-step optimisation method is used with the objective of minimising the annual CO2 emissions of the ship. The results suggest that the supportive cooling could reduce the fan power by up to 60%, depending on ambient air temperature

Plan implementation and medium density housing outcomes: measuring the effect of Wellington City District Plan Change 56

The Wellington City District Plan, operative since the year 2000, set goals for housing intensification. Residential development is encouraged within the existing footprint of the urban area of Wellington City. Intensification means housing development must incorporate a greater mix of housing typologies denser than the currently predominant low density single detached dwellings. To deliver intensification, planning in Wellington aims to incorporate medium density housing typologies that result in more dwellings while using less land. In 2007 Plan Change 56: Managing the Quality of Infill Housing was introduced. The plan change responded to concerns about the quality of housing outcomes being delivered by intensification. The implementation framework was amended through changing and adding a number of policies and rules and the Multiunit Developments Design Guide was replaced with the Residential Design Guide. The Plan Change kept policies for intensification, while policies controlling quality of medium density housing were amended. This research measured the effect of Plan Change 56 on the quality of medium density housing outcomes. Success in planning was found to be defined by the way plan implementation contributes to built outcomes meeting a plan’s goals and objectives. To measure outcomes, a method of assessing case studies was applied based on a range of prior New Zealand research. The Ministry for the Environment’s Medium-density Housing Case Study Assessment Methodology was used to assess and compare Wellington case studies of medium density housing from the periods before and after Plan Change 56. The selected case studies give evidence that Plan Change 56 did not cause an improvement in the quality of medium density housing outcomes. The key finding is that the treatment of open space is significant in defining the quality of medium density housing outcomes. Plan Change 56 made a number of amendments to the District Plan in terms of the way open space is treated around dwellings. Despite this, it was the most significant reason for post-Plan change case studies achieving low quality outcomes. Detailed comparison showed that changes to the District Plan rules for open space did not cause the quality of outcomes to improve. The application of the Residential Design Guide was compared to the superseded Multi Unit Developments Design Guide. The most significant amendments by Plan Change 56 related to guidelines for the design of building along street frontages in terms of volumes, orientation, and façade treatments. The case study results showed there was little difference in the way each design guide was used to assess Resource Consent applications. The results conclusively show that Plan Change 56 did not cause an improvement in the quality of medium density housing outcomes in Wellington