title: Tracking battery state-of-charge in a continuous use off-grid electricity system

authors: Apperley, Mark

subjects: computer science

abstract: The growing importance of batteries in the delivery of primary energy, for example in electric vehicles and isolated off-grid electricity systems, has added weight to the demand for simple and reliable measures of a battery’s remaining stored energy at any time. Many approaches to estimating this battery state-of-charge exist, ranging from those based on a full appreciation of the chemistry and physics of the storage and delivery mechanisms used, and requiring extensive data on which to base an estimate, to the naïve and simple, based only, for example, on the terminal voltage of the battery. None, however, is perfect, and able to deliver a simple percentage-full figure, as in a fuel gauge. The shortcomings are due to a range of complicating factors, including the impact of rate of charge, rate of discharge, battery aging, and temperature, to name just some of these.
This paper presents a simple yet effective method for tracking state-of-charge in an off-grid electricity system, where batteries are in continuous use, preventing static parameter measurements, and where charge/discharge cycles do not necessarily follow an orderly sequence or pattern. A reliable indication of state-of-charge is, however, highly desirable, but need be only of fuel gauge precision, say to the nearest 12-20%. The algorithm described utilises knowledge of the past, and constantly adapts parameters such as charge efficiency and total charge capacity based on this knowledge, and on the occurrence of specific identifiable events such as zero or full charge.

text: Tracking battery state-of-charge in a continuous use off-grid electricity system The growing importance of batteries in the delivery of primary energy, for example in electric vehicles and isolated off-grid electricity systems, has added weight to the demand for simple and reliable measures of a battery’s remaining stored energy at any time. Many approaches to estimating this battery state-of-charge exist, ranging from those based on a full appreciation of the chemistry and physics of the storage and delivery mechanisms used, and requiring extensive data on which to base an estimate, to the naïve and simple, based only, for example, on the terminal voltage of the battery. None, however, is perfect, and able to deliver a simple percentage-full figure, as in a fuel gauge. The shortcomings are due to a range of complicating factors, including the impact of rate of charge, rate of discharge, battery aging, and temperature, to name just some of these.
This paper presents a simple yet effective method for tracking state-of-charge in an off-grid electricity system, where batteries are in continuous use, preventing static parameter measurements, and where charge/discharge cycles do not necessarily follow an orderly sequence or pattern. A reliable indication of state-of-charge is, however, highly desirable, but need be only of fuel gauge precision, say to the nearest 12-20%. The algorithm described utilises knowledge of the past, and constantly adapts parameters such as charge efficiency and total charge capacity based on this knowledge, and on the occurrence of specific identifiable events such as zero or full charge.

year: 2013-10

title: Partnerships and participation in catchment scale restoration: A study of the Manga-o-tama, Ōhaupō Peat Lakes to Waipā River Catchment Restoration Project

authors: Kingsford, Natasha

subjects: Multistakeholder partnerships

abstract: With a changing climate, rapidly declining ecosystems and an increasing population, the time to act and redefine society’s relationship with the environment is upon us (Chapin et al., 2012; Jenkins, 2018). Collaborative approaches to environmental management have emerged across the globe to better provide holistic and sustainable outcomes for people and the planet (Fenemor et al., 2011; Reo et al., 2017). At the heart of landscape scale collaboration lies the formation of multistakeholder partnerships. This study investigates the factors that influence the formation of successful multistakeholder partnerships in collaborative catchment scale restoration, in an Aotearoa New Zealand setting.

Using a case study, the Manga-o-tama, Ōhaupō Peat Lakes to Waipā River Catchment Restoration Project, this research explores the interconnected social, political, economic and environmental factors at play in a collaborative partnership. Ostrom’s (2007, 2009) social- ecological systems framework guided the organisation and analysis of this study. Qualitative research methods comprising a comprehensive literature review, nine semi-structured interviews, document analysis and observations were carried out in this case-study analysis.

The findings show that purposeful and ongoing participatory processes are required to support the development of an effective partnership and a shared understanding. Participants in this study are largely motivated by a connection to the environment and a community, with a sense of stewardship or sense of place being key to supporting participation and ongoing behaviour change. Organisational barriers and challenges, including that of funding, capacity issues and the need to further strengthen relationships between some stakeholder groups were identified. Project planning and funding models that allow for adaptative management and social and ecological learning were also identified as being highly valuable to establishing effective collaborative partnerships. This thesis contributes to the field of multistakeholder partnership and social-ecological systems research, with a specific focus on catchment scale collaborations in an Aotearoa New Zealand context.

text: Partnerships and participation in catchment scale restoration: A study of the Manga-o-tama, Ōhaupō Peat Lakes to Waipā River Catchment Restoration Project With a changing climate, rapidly declining ecosystems and an increasing population, the time to act and redefine society’s relationship with the environment is upon us (Chapin et al., 2012; Jenkins, 2018). Collaborative approaches to environmental management have emerged across the globe to better provide holistic and sustainable outcomes for people and the planet (Fenemor et al., 2011; Reo et al., 2017). At the heart of landscape scale collaboration lies the formation of multistakeholder partnerships. This study investigates the factors that influence the formation of successful multistakeholder partnerships in collaborative catchment scale restoration, in an Aotearoa New Zealand setting.

Using a case study, the Manga-o-tama, Ōhaupō Peat Lakes to Waipā River Catchment Restoration Project, this research explores the interconnected social, political, economic and environmental factors at play in a collaborative partnership. Ostrom’s (2007, 2009) social- ecological systems framework guided the organisation and analysis of this study. Qualitative research methods comprising a comprehensive literature review, nine semi-structured interviews, document analysis and observations were carried out in this case-study analysis.

The findings show that purposeful and ongoing participatory processes are required to support the development of an effective partnership and a shared understanding. Participants in this study are largely motivated by a connection to the environment and a community, with a sense of stewardship or sense of place being key to supporting participation and ongoing behaviour change. Organisational barriers and challenges, including that of funding, capacity issues and the need to further strengthen relationships between some stakeholder groups were identified. Project planning and funding models that allow for adaptative management and social and ecological learning were also identified as being highly valuable to establishing effective collaborative partnerships. This thesis contributes to the field of multistakeholder partnership and social-ecological systems research, with a specific focus on catchment scale collaborations in an Aotearoa New Zealand context.

year: 2022

title: Mahi Toi Skills in Contemporary Education, Training and Maori Development

authors: Joseph, Makarita Ngapine Tangitu

subjects: Kia mau ki nga taonga tuku iho o nga tupuna

abstract: Since the 1980’s, national investment in human capital and skill formation policy in education has been promoted as key to economic success and social inclusion. Social inclusion, however, is often expressed as helping citizens to become employable. Although employability is a key focus of skills formation and education policy, the context of the western ideologies that it derives from and caters to perpetuates the exclusion of mahi toi (arts and crafts) skills in education. Using a kaupapa Māori approach, two key informants who specialise and teach mahi toi skills, either rāranga (weaving) or pounamu (jade/greenstone), were interviewed. The aim was to get a better understanding of how these skills can contribute to personal, professional and Māori development in the 21st century, and to provide information indicating where and how these skills can be learnt, either through private training enterprises (PTE) or public tertiary educational institutions (TEI), thereby highlighting the value of teaching and learning rāranga and pounamu skills. Findings from analysing their pūrākau indicate that learning rāranga or pounamu skills can provide a foundation for believing in your potential, contribute to cultural identity, improve confidence and communication skills, help an individual be bestowed or acquire mana, offer a type of therapy, enhance career progression and professional identity, provide financial rewards and stability, and help with the revitalisation and transfer of cultural knowledge. Ultimately, it is concluded that mahi toi skills such as rāranga and pounamu can contribute to the development of an individual’s personal and professional lives, but also has benefits for the organisation where they become employed as well as extended whānau, hapū and iwi.

text: Mahi Toi Skills in Contemporary Education, Training and Maori Development Since the 1980’s, national investment in human capital and skill formation policy in education has been promoted as key to economic success and social inclusion. Social inclusion, however, is often expressed as helping citizens to become employable. Although employability is a key focus of skills formation and education policy, the context of the western ideologies that it derives from and caters to perpetuates the exclusion of mahi toi (arts and crafts) skills in education. Using a kaupapa Māori approach, two key informants who specialise and teach mahi toi skills, either rāranga (weaving) or pounamu (jade/greenstone), were interviewed. The aim was to get a better understanding of how these skills can contribute to personal, professional and Māori development in the 21st century, and to provide information indicating where and how these skills can be learnt, either through private training enterprises (PTE) or public tertiary educational institutions (TEI), thereby highlighting the value of teaching and learning rāranga and pounamu skills. Findings from analysing their pūrākau indicate that learning rāranga or pounamu skills can provide a foundation for believing in your potential, contribute to cultural identity, improve confidence and communication skills, help an individual be bestowed or acquire mana, offer a type of therapy, enhance career progression and professional identity, provide financial rewards and stability, and help with the revitalisation and transfer of cultural knowledge. Ultimately, it is concluded that mahi toi skills such as rāranga and pounamu can contribute to the development of an individual’s personal and professional lives, but also has benefits for the organisation where they become employed as well as extended whānau, hapū and iwi.

year: 2018