scholarly journals Case Study of a Hybrid Wind and Tidal Turbines System with a Microgrid for Power Supply to a Remote Off-Grid Community in New Zealand

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3636
Author(s):  
Navid Majdi Nasab ◽  
Jeff Kilby ◽  
Leila Bakhtiaryfard
Keyword(s):  
New Zealand ◽  
Power Supply ◽  
Electricity Generation ◽  
Tidal Energy ◽  
Coastal Communities ◽  
Diesel Generator ◽  
Tidal Turbines ◽  
Local Residents ◽  
The Cost

This paper evaluates the feasibility of using a hybrid system consisting of wind and tidal turbines connected to a microgrid for power supply to coastal communities that are isolated from a main supply grid. The case study is Stewart Island, where the cost of electricity, provided by a central diesel power station, is higher than the grid network in New Zealand. Local residents believe that reducing the consumption of diesel and having a renewable source of electricity generation are two of the island’s highest priorities. Merging a tidal energy source (predictable) with wind (unpredictable) and diesel (back-up), through a microgrid, may be a way to increase reliability and decrease the cost of generation. Several off-grid configurations are simulated using HOMER and WRPLOT software. Using two wind and four tidal turbines, plus one diesel generator for back-up, is the best design in terms of lower greenhouse gas emissions, higher renewable fraction, and reduced net present cost.

scholarly journals Passive flow control mechanisms with bioinspired flexible blades in cross-flow tidal turbines

2021 ◽  
Vol 62 (5) ◽  
Author(s):  
Stefan Hoerner ◽  
Shokoofeh Abbaszadeh ◽  
Olivier Cleynen ◽  
Cyrille Bonamy ◽  
Thierry Maître ◽  
...  
Keyword(s):  
Turbine Blades ◽  
Cross Flow ◽  
Tidal Energy ◽  
Control Mechanisms ◽  
Passive Flow Control ◽  
Turbine Efficiency ◽  
Tidal Turbines ◽  
Passive Flow ◽  
Axial Turbines ◽  
The Cost

Abstract State-of-the-art technologies for wind and tidal energy exploitation focus mostly on axial turbines. However, cross-flow hydrokinetic tidal turbines possess interesting features, such as higher area-based power density in array installations and shallow water, as well as a generally simpler design. Up to now, the highly unsteady flow conditions and cyclic blade stall have hindered deployment at large scales because of the resulting low single-turbine efficiency and fatigue failure challenges. Concepts exist which overcome these drawbacks by actively controlling the flow, at the cost of increased mechatronical complexity. Here, we propose a bioinspired approach with hyperflexible turbine blades. The rotor naturally adapts to the flow through deformation, reducing flow separation and stall in a passive manner. This results in higher efficiency and increased turbine lifetime through decreased structural loads, without compromising on the simplicity of the design. Graphic abstract

scholarly journals Modelling the cost differential between healthy and current diets: the New Zealand case study

2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Stefanie Vandevijvere ◽  
Nick Young ◽  
Sally Mackay ◽  
Boyd Swinburn ◽  
Mark Gahegan
Keyword(s):  
New Zealand ◽  
Cost Differential ◽  
The Cost

scholarly journals Investigation of solar-powered drip irrigation: The case study of the Jordan Valley 

2017 ◽  
Vol 63 (No. 4) ◽  
pp. 168-171
Author(s):  
Perakis Christoforos ◽  
Kyriakarakos George ◽  
Hani Nabeel Bani ◽  
Hammad Shaker ◽  
Damasiotis Markos
Keyword(s):  
Drip Irrigation ◽  
Energy System ◽  
Electricity Production ◽  
Diesel Generator ◽  
Jordan Valley ◽  
Battery System ◽  
Electrical Grid ◽  
Solar Powered ◽  
The Cost

Agriculture is the sector that consumes by far most water globally. Much research efforts aim at minimizing losses through the use of drip irrigation. Rural agricultural areas often do not have access to a main electrical grid to power the pumps needed for drip irrigation; it reduces the options in paying for a grid extension, getting a diesel generator or investing in an off-grid renewable energy system. In this paper, these alternatives are assessed technically and economically under real world conditions through the Jordan Valley case study. The results show that the autonomous photovoltaic (PV)-battery system is preferable to the use of a diesel generator, as well as it is preferable to the main grid extension in many cases depending on the cost of grid electricity and distance from the grid. For current subsidized grid electricity retail price to farmers, the PV-battery system becomes more attractive above a 300 m distance from the grid, while if the actual cost of electricity production in Jordan is taken into account, then it breaks even to 128 m. 

scholarly journals Potential for anaerobic digestion of dairy farm effluent in New Zealand

2015 ◽  
Vol 77 ◽  
pp. 71-76 ◽  
Author(s):  
A.Milet J.S. Rowarth ◽  
F.G. Scrimgeour
Keyword(s):  
Renewable Energy ◽  
New Zealand ◽  
Anaerobic Digestion ◽  
Power Supply ◽  
Dairy Farm ◽  
Energy Profile ◽  
Potential Environmental Impact ◽  
Land Disposal ◽  
The Cost ◽  
Reducing Potential

Efficient effluent management allows capturing of nutrient benefits while reducing potential environmental impact. In New Zealand research has focussed on ponds and land disposal, whereas digesters are being implemented overseas. When biogas produced by anaerobic digestion is collected, it can be used to produce heat and electricity; this has been done in some countries trying to increase their renewable energy profile (e.g., France), but the cost is not always offset by the benefits. Analysis of policies concerning power supply in France and New Zealand revealed very large differences between the two countries, which, in combination with differences in population density, availability of co-digestion products and dairy shed effluent type, means that the establishment of biodigesters is unlikely in New Zealand unless there are changes in policy to encourage greater renewable energy via implementation assistance. Keywords: Biodigester, co-digestion, energy

scholarly journals Optimization of a Grid-Connected Microgrid Using Tidal and Wind Energy in Cook Strait

Fluids ◽  
2021 ◽  
Vol 6 (12) ◽  
pp. 426
Author(s):  
Navid Majdi Nasab ◽  
Md Rabiul Islam ◽  
Kashem Muttaqi ◽  
Danny Sutanto
Keyword(s):  
New Zealand ◽  
Electricity Generation ◽  
Wind Farm ◽  
Fossil Fuels ◽  
Offshore Wind ◽  
Tidal Power ◽  
Renewable Sources ◽  
Tidal Turbines ◽  
Cook Strait ◽  
Strong Winds

The Cook Strait in New Zealand is an ideal location for wind and tidal renewable sources of energy due to its strong winds and tidal currents. The integration of both technologies can help to avoid the detrimental effects of fossil fuels and to reduce the cost of electricity. Although tidal renewable sources have not been used for electricity generation in New Zealand, a recent investigation, using the MetOcean model, has identified Terawhiti in Cook Strait as a superior location for generating tidal power. This paper investigates three different configurations of wind, tidal, and wind plus tidal sources to evaluate tidal potential. Several simulations have been conducted to design a DC-linked microgrid for electricity generation in Cook Strait using HOMER Pro, RETScreen, and WRPLOT software. The results show that Terawhiti, in Cook Strait, is suitable for an offshore wind farm to supply electricity to the grid, considering the higher renewable fraction and the lower net present cost in comparison with those using only tidal turbines or using both wind and tidal turbines.

scholarly journals Supported Independent Accommodation for Older New Zealanders: a Review of Current Policy and Innovative Practice

2021 ◽  
Author(s):  
◽  
Maxwell F Reid
Keyword(s):  
New Zealand ◽  
Older People ◽  
Models Of Care ◽  
Policy Implications ◽  
Service Development ◽  
Intersectoral Collaboration ◽  
Study Approach ◽  
The Cost ◽  
Care For Older People

<p>Existing research establishes a clear link between poor housing and poor health. There is also growing evidence that the physical, mental and social wellbeing of individuals and households can be improved by ensuring their access to suitable accommodation. Despite the growing body of research documenting the benefits of supported independent accommodation (SIA) as a means of maintaining the independence and wellbeing particularly of older people, there is little research evaluating the place of such accommodation within the New Zealand context. This thesis aims to address that gap. It reviews the existing body of literature surrounding this topic - exploring population and accommodation demographics, and analysing government policy in relation to both housing and health. It considers six New Zealand examples of SIA - each selected on the basis of their distinctiveness and innovation - documents these, and compares them using a case study approach. Adopting a general inductive methodology, each case study is then analysed against themes identified in the literature review, identifying any further trends, and the implications of these for ongoing policy and service development. Intersectoral collaboration is identified as having had particular bearing upon the development of SIA within the New Zealand context. This thesis concludes that SIA will play an increasingly important role in the continuum of accommodation and care for older people. It offers an alternative to more institutionalised models of care for older people, maintaining their independence and social integration within their own community. As demographic and economic factors drive up the cost of more traditional models of residential care, SIA offers government an equally important alternative. However, ongoing development in this area is not without it challenges. To this end, a number of policy implications are also identified and discussed.</p>

scholarly journals Supported Independent Accommodation for Older New Zealanders: a Review of Current Policy and Innovative Practice

2021 ◽  
Author(s):  
◽  
Maxwell F Reid
Keyword(s):  
New Zealand ◽  
Older People ◽  
Models Of Care ◽  
Policy Implications ◽  
Service Development ◽  
Intersectoral Collaboration ◽  
Study Approach ◽  
The Cost ◽  
Care For Older People

<p>Existing research establishes a clear link between poor housing and poor health. There is also growing evidence that the physical, mental and social wellbeing of individuals and households can be improved by ensuring their access to suitable accommodation. Despite the growing body of research documenting the benefits of supported independent accommodation (SIA) as a means of maintaining the independence and wellbeing particularly of older people, there is little research evaluating the place of such accommodation within the New Zealand context. This thesis aims to address that gap. It reviews the existing body of literature surrounding this topic - exploring population and accommodation demographics, and analysing government policy in relation to both housing and health. It considers six New Zealand examples of SIA - each selected on the basis of their distinctiveness and innovation - documents these, and compares them using a case study approach. Adopting a general inductive methodology, each case study is then analysed against themes identified in the literature review, identifying any further trends, and the implications of these for ongoing policy and service development. Intersectoral collaboration is identified as having had particular bearing upon the development of SIA within the New Zealand context. This thesis concludes that SIA will play an increasingly important role in the continuum of accommodation and care for older people. It offers an alternative to more institutionalised models of care for older people, maintaining their independence and social integration within their own community. As demographic and economic factors drive up the cost of more traditional models of residential care, SIA offers government an equally important alternative. However, ongoing development in this area is not without it challenges. To this end, a number of policy implications are also identified and discussed.</p>

scholarly journals Rethinking Science, Religion and Nature in Environmental History: Drought in Early Twentieth-Century New Zealand

2020 ◽  
Author(s):  
James Beattie
Keyword(s):  
Twentieth Century ◽  
New Zealand ◽  
Environmental History ◽  
Science And Religion ◽  
Early Twentieth Century ◽  
Social Opportunities ◽  
Local Residents ◽  
Settler Society ◽  
Scientific Ideas

This article investigates popular and elite conceptions of science and religion in an early twentieth-century European settler society. It uses the case-study of rainmaking experiments and prayers in North Otago, New Zealand, in 1907, to challenge two dominant paradigms about New Zealand society: first, that scientific rationalism was automatically antipathetic to religion and, second, that by the early twentieth century scientific ideas were secularizing New Zealand society. North Otago's residents viewed prayer and experiment as complementary activities designed to meet the same ends; there was no distinctive, hermetically sealed division between the secular and the profane. Rainmaking also offers a fascinating way of exploring contested notions of science. While local residents enthusiastically embraced the use of explosives to bring rain, meteorologists decried these measures as unscientific and amateurish, thereby attempting to increase the legitimacy of their own profession. The reaction to North Otago's rainmaking prayers and experiments differed considerably from that of other societies such as in England and Australia in which similar prayers and experiments were undertaken. These differences reflected the special social and cultural characteristics of each country and, in New Zealand's case, its greater religious tolerance and social opportunities.

scholarly journals Is Voluntary Product Stewardship for E-Waste Working in New Zealand? A Whangarei Case Study

2019 ◽  
Vol 11 (11) ◽  
pp. 3063 ◽  
Author(s):  
Vicktoria Blake ◽  
Trisia Farrelly ◽  
Jonathon Hannon
Keyword(s):  
New Zealand ◽  
Online Survey ◽  
National Policy ◽  
Municipal Services ◽  
Limited Data ◽  
Product Stewardship ◽  
Repair Ability ◽  
Asking Questions ◽  
The Cost

New Zealand currently manages its annually-generated 99,000 tonnes of e-waste via voluntary product stewardship schemes. Limited data is available to determine the success of this approach. This lack of data is cited as the logic preventing the declaration of e-waste as a priority product by the Minister for the Environment which would trigger the enforcement of mandatory product stewardship. This case study involved an online survey of 264 Whangarei District householders asking questions about e-waste creation and management, as well as analyses of local services, and local and national policy. It found that only 1.8% of the estimated e-waste created in the district is recycled by municipal services, with the ‘cost to recycle’ and ‘a lack of knowledge’ presenting barriers to engagement in these services. The ‘lack of ability to repair/the cost to repair’ was found to be the most significant driver for e-waste creation. The adoption of mandatory product stewardship for e-waste was recommended to ensure robust and transparent data collection, see recycling services become more accessible, and raise awareness of these services, thus reducing the value-action gap. Mandatory e-waste management would also impact product design to ensure affordable repair-ability, further supporting a circular economy for electronic goods.

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