title: Assessing effects of changes to nutrient loads on Lake Tarawera water quality: Model simulations for 2010 to 2020

authors: Abell, Jonathan Michael

abstract: Lake Tarawera is a nationally significant lake that is highly valued by tangata whenua, local residents and the regional community. Monitoring shows that lake water quality does not presently meet the target, based on a Trophic Level Index (TLI) value of 2.6 identified in the Tarawera Lakes Restoration Plan1. Between 2010 and 2020 annual observed TLI was frequently as high as 2.9. Managing nutrient loads to the lake is necessary to achieve desired lake water quality and interim nutrient reduction targets have been established. An objective of this study was to evaluate these targets by improving estimates of ‘sustainable nutrient loads’, which are the external loads of nitrogen and phosphorus that would result in meeting the TLI target.

text: Assessing effects of changes to nutrient loads on Lake Tarawera water quality: Model simulations for 2010 to 2020 Lake Tarawera is a nationally significant lake that is highly valued by tangata whenua, local residents and the regional community. Monitoring shows that lake water quality does not presently meet the target, based on a Trophic Level Index (TLI) value of 2.6 identified in the Tarawera Lakes Restoration Plan1. Between 2010 and 2020 annual observed TLI was frequently as high as 2.9. Managing nutrient loads to the lake is necessary to achieve desired lake water quality and interim nutrient reduction targets have been established. An objective of this study was to evaluate these targets by improving estimates of ‘sustainable nutrient loads’, which are the external loads of nitrogen and phosphorus that would result in meeting the TLI target.

year: 2020-12

title: A renewed look at Greenstone: Lessons from the second decade

authors: Bainbridge, David

subjects: computer science

abstract: The Greenstone Digital Library Software has helped spread the practical impact of digital library technology around the globe. As Greenstone enters its third decade, this article takes are newed look at its development, the challenges that have been faced, and the lessons that have been learned in deploying a comprehensive open-source system for the construction of digital libraries internationally. In particular, we outline architectural changes in the software that have occurred over time, and highight how the user interfaces have evolved to provide a more immersive,interactive user experience, made possible through advancements in the underlying web technologies.

text: A renewed look at Greenstone: Lessons from the second decade The Greenstone Digital Library Software has helped spread the practical impact of digital library technology around the globe. As Greenstone enters its third decade, this article takes are newed look at its development, the challenges that have been faced, and the lessons that have been learned in deploying a comprehensive open-source system for the construction of digital libraries internationally. In particular, we outline architectural changes in the software that have occurred over time, and highight how the user interfaces have evolved to provide a more immersive,interactive user experience, made possible through advancements in the underlying web technologies.

year: 2020

title: Me ko Māui: Harnessing the sun to provide better outcomes for marae and communities

authors: Greensill, Waikauri

abstract: Marae are the cultural centres of Māori communities, providing a space for important gatherings both joyful and sad. With the advent of solar energy capture technologies and rising electricity bills, many marae are becoming interested in whether a solar powered system will be beneficial for them. However, marae have unique electricity demand profiles, distinct from commonly modelled building types such as residential or commercial buildings. It is thus difficult to estimate an appropriate solar and battery system size based on annual or even monthly electricity usage data, which may be the only data readily available, requiring more in-depth analysis at a highly site-specific level to find an answer. This thesis aims to increase understanding around how solar power could benefit marae, first by investigating the characteristic electricity demand profile of marae, then by observing how proposed system configurations meet the demand. The potential community benefits arising from such a system was also investigated. Using a year’s worth of half-hourly data from three marae, five characteristic day types were found in the analysis of the demand profile, namely a “Non-Event” profile that maintained a low baseload and accounted for 70% of the days in a year, a “1-Day Event” profile that lasted only a few hours, and for events spanning multiple days a “Start”, “Middle” and “End” day profile that varied greatly in demand magnitude. The demand profiles were then used to develop an annual demand profile for an average marae that was broadly representative of a wide range of marae. Different configurations of solar and battery powered systems were then applied to the annual demand and a technoeconomic analysis performed to determine whether a specific configuration met the needs of the average marae or not, which then produced a range of acceptable system sizes based on the needs specified. Not many solar and battery configurations resulted in positive economic returns for the marae alone, but widening the scope of the analysis to the surrounding community allows other interests such as local grid resilience to be considered, some of which may justify a marae’s decision to invest in a non-economic system to gain better community benefits. While investigating the use of peer-to-peer energy trading and community energy scenarios, sharing excess energy generated by a system with the wider community was also found to improve the economic outlook of solar for marae.

text: Me ko Māui: Harnessing the sun to provide better outcomes for marae and communities Marae are the cultural centres of Māori communities, providing a space for important gatherings both joyful and sad. With the advent of solar energy capture technologies and rising electricity bills, many marae are becoming interested in whether a solar powered system will be beneficial for them. However, marae have unique electricity demand profiles, distinct from commonly modelled building types such as residential or commercial buildings. It is thus difficult to estimate an appropriate solar and battery system size based on annual or even monthly electricity usage data, which may be the only data readily available, requiring more in-depth analysis at a highly site-specific level to find an answer. This thesis aims to increase understanding around how solar power could benefit marae, first by investigating the characteristic electricity demand profile of marae, then by observing how proposed system configurations meet the demand. The potential community benefits arising from such a system was also investigated. Using a year’s worth of half-hourly data from three marae, five characteristic day types were found in the analysis of the demand profile, namely a “Non-Event” profile that maintained a low baseload and accounted for 70% of the days in a year, a “1-Day Event” profile that lasted only a few hours, and for events spanning multiple days a “Start”, “Middle” and “End” day profile that varied greatly in demand magnitude. The demand profiles were then used to develop an annual demand profile for an average marae that was broadly representative of a wide range of marae. Different configurations of solar and battery powered systems were then applied to the annual demand and a technoeconomic analysis performed to determine whether a specific configuration met the needs of the average marae or not, which then produced a range of acceptable system sizes based on the needs specified. Not many solar and battery configurations resulted in positive economic returns for the marae alone, but widening the scope of the analysis to the surrounding community allows other interests such as local grid resilience to be considered, some of which may justify a marae’s decision to invest in a non-economic system to gain better community benefits. While investigating the use of peer-to-peer energy trading and community energy scenarios, sharing excess energy generated by a system with the wider community was also found to improve the economic outlook of solar for marae.

year: 2024