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Quantifying the green hydrogen demand across key sectors in Aotearoa New Zealand: Implications for electricity generation
Get PDFThe transition to green hydrogen presents a great opportunity for Aotearoa New Zealand to meet its long-term climate targets while decarbonising energy intensive sectors. With over 80% of electricity already generated from renewable sources, the country is well-positioned to produce green hydrogen through water electrolysis. However, the extent to which hydrogen demand may impact electricity generation capacity remains underexplored. This study quantifies projected hydrogen demand across four key sectors: steel, heavy-duty transport (trucks and coaches), methanol production, and fertilizer manufacturing, from 2025 to 2050. Historical production and activity data were collected from national and international sources and used to project future sectoral activity. Hydrogen demand was estimated under both ideal stoichiometric and real-world adjusted efficiency scenarios. These values were then converted into electricity requirements using efficiency benchmarks for Proton Exchange Membrane (PEM) and Solid Oxide Electrolyser Cell (SOEC) technologies. The results show that the transport and methanol sectors exhibit the highest hydrogen demand, followed by fertilizers and steel. Under real-world assumptions, electricity demand to produce hydrogen could reach between 30 and 55 terawatt-hours annually by 2050, potentially exceeding Aotearoa New Zealand’s current generation capacity. The findings highlight the importance of aligning hydrogen development with renewable electricity expansion and infrastructure planning. The study provides a replicable modelling approach for emerging hydrogen economies, particularly in the Global South. It contributes to the evolving body of knowledge by offering a sector-specific assessment of hydrogen demand, integrating technological parameters with national energy system planning, and informing future hydrogen strategy development in Aotearoa New Zealand and beyond
An investigation into low-inertia grid stability with high injection of variable renewable energy sources
Get PDFAs the world moves towards decarbonising the energy sector, variable renewable energy sources (VRES) are seen as an integral part of the transition. Much has been researched about the different forms of VRES, which are also known as inverter-based resources (IBR), and of the challenges of integrating them into pre-existing grid infrastructure. Nevertheless, the complex dynamics and impacts on grid stability, particularly within low-inertia grids, are case-specific and so warrant continued attention. This research analyses the specific response of one such grid, on Rakiura Stewart Island of Aotearoa New Zealand, to increasing solar photovoltaic capacity. Issues such as generator motoring and voltage rise are encountered, which suggest that the grid would also see frequency rises. As the capacity of VRES penetration increases, the effects are enhanced. Comparing the results show that negative effects are overall better mitigated by using a decentralised approach, as this offers more even distribution of the generation burden, lower line voltage drops, decreased line losses, and greater line loading reductions. Decentralised systems also have the advantage when it comes to decreasing loading on diesel generators in the grid, reducing fuel use and lengthening the lifespan of the generators. In exchange for these benefits, however, decentralised installations introduce higher node voltages and increase coordination complexity for seamless operation. Subsequent investigations should focus on the strategic integration of energy storage and power electronics, including flexible alternating current transmission system (FACTS) devices and static synchronous compensators (STATCOMs)
Possibility Frames and Forcing for Modal Logic
Get PDFThis paper develops the model theory of normal modal logics based on partial “possibilities” instead of total “worlds,” following Humberstone [1981] instead of Kripke [1963]. Possibility semantics can be seen as extending to modal logic the semantics for classical logic used in weak forcing in set theory, or as semanticizing a negative translation of classical modal logic into intuitionistic modal logic. Thus, possibility frames are based on posets with accessibility relations, like intuitionistic modal frames, but with the constraint that the interpretation of every formula is a regular open set in the Alexandrov topology on the poset. The standard world frames for modal logic are the special case of possibility frames wherein the poset is discrete. The analogues of classical Kripke frames, i.e., full world frames, are full possibility frames, in which propositional variables may be interpreted as any regular open sets.
We develop the beginnings of duality theory, definability/correspondence theory, and completeness theory for possibility frames. The duality theory, relating possibility frames to Boolean algebras with operators (BAOs), shows the way in which full possibility frames are a generalization of Kripke frames. Whereas Thomason [1975a] established a duality between the category of Kripke frames with p-morphisms and the category of complete (C), atomic (A), and completely additive (V) BAOs with complete BAO-homomorphisms (these categories being dually equivalent), we establish a duality between the category of full possibility frames with possibility morphisms and the category of CV-BAOs, i.e., allowing non-atomic BAOs, with complete BAO-homomorphisms (the latter category being dually equivalent to a reflective subcategory of the former). This parallels the connection between forcing posets and Boolean-valued models in set theory, but now with accessibility relations and modal operators involved. Generalizing further, we introduce a class of principal possibility frames that capture the generality of V-BAOs. If we do not require a full or principal frame, then every BAO has an equivalent possibility frame, whose possibilities are proper filters in the BAO. With this filter representation, which does not require the ultrafilter axiom, we are lead to a notion of filter-descriptive possibility frames. Whereas Goldblatt [1974] showed that the category of BAOs with BAO-homomorphisms is dually equivalent to the category of descriptive world frames with p-morphisms, we show that the category of BAOs with BAO-homomorphisms is dually equivalent to the category of filter-descriptive possibility frames with p-morphisms. Applying our duality theory to definability theory, we prove analogues for possibility semantics of theorems of Goldblatt [1974] and Goldblatt and Thomason [1975] characterizing modally definable classes of frames. In addition, we discuss analogues for possibility semantics of first-order correspondence results in the style of Lemmon and Scott [1977], Sahlqvist [1975], and van Benthem [1976a]. Finally, applying our duality theory to completeness theory, we show that there are continuum many normal modal logics that can be characterized by full possibility frames but not by Kripke frames, that all Sahlqvist logics can be characterized by full possibility frames that contain no worlds, and that all normal modal logics can be characterized by filter-descriptive possibility frames
Using Council Valuation Records to Estimate Auckland’s housing stock
Get PDFNew Zealand lacks timely estimates of its total and regional dwelling stocks. Such estimates would be useful for evaluating various policies to encourage housing supply. To address this deficiency, we propose and implement a method for estimating Auckland’s dwelling stock based on its district valuation roll (DVR). The district valuation roll is an administrative dataset maintained by all local councils for the purpose of levying property taxes. The estimates imply that there were 609,055 dwellings in Auckland as of August 2024, an increase of about 91,000 units – or 18% – since the Auckland Unitary Plan became operative in November 2016. We anticipate that DVR-based estimates can be constructed for other regions
Rēwena and Rabbit Stew: The Rural Kitchen in Aotearoa, 1800-1940.
Get PDFAttempting to describe, in detail, the rural kitchen of Aotearoa, is an almost impossible task. Of mosaic complexity, even the definitions of “kitchen” and “rural” are blurry, at best. No two kitchens are identical – each is influenced by its purpose, culture, time, gender, affluence, geography, available construction materials, whether farm or industry, and a host of factors relating to rural infrastructure and foodways
CROSSING BORDERS, SHIFTING VOICES— HISTORICAL AND CONTEMPORARY PERSPECTIVES ON L2 TRANSLATION
Get PDFThis volume gathers contributions originally presented at Crossing Broders, Shifting Voices— Historical and Contemporary Perspectives on L2 Translation, a one-day hybrid conference held at Te Herenga Waka–Victoria University of Wellington in November 2024. Conceived as a space for reflection and dialogue, the conference was organised as a collaborative initiative between Te Herenga Waka and the University of Ljubljana, building on shared research interests in translation directionality and multilingual practices. The hybrid event brought together scholars, practitioners and postgraduate students both in person and online. Their discussions examined the shifting roles of translation into a second language as a site of identity construction, an arena for ethical negotiation, and a practice shaped by evolving linguistic dynamics
Understanding Retirement Income in New Zealand: insights from microdata and modelling
Get PDFThis article brings together recent work from the New Zealand Treasury using microdata and microsimulation modelling to examine retirement incomes through four key lenses: intergenerational dynamics, income diversity, retirement transitions and work incentives. It highlights how demographic, behavioural and economic changes are reshaping retirement realities in New Zealand, and explores how policy design interacts with people’s lived experiences as they age
Competition and Profitability in New Zealand's General Insurance Sector: emerging policy issues
Get PDFThis article examines competition and profitability in New Zealand’s general insurance market. Given the country’s high exposure to earthquakes, severe weather and climate risks, effective competition is vital for ensuring that insurance markets deliver efficient risk pricing, protect consumers from excessive costs, and safeguard financial stability. Benchmarking against international peers using combined ratios, returns on equity and net profit margins shows that New Zealand insurers consistently report higher profitability. Although differences in data and scope limit the precision of these comparisons, the overall pattern is evident. While catastrophe exposure explains part of the divergence, the scale and persistence of ‘excess profits’ point to structural weaknesses in competition. Strengthening competition and improving affordability will be critical to protect households and support financial resilience
The Empire Look: the installation of the British Art Exhibit at the New Zealand International Exhibition 1906-07 at Christchurch
Get PDFOrganised under the aegis of New Zealand Premier Richard Seddon (1845-1906), the 1906-1907 New Zealand International Exhibition was designed to show the colony’s progress to the world and frame Aotearoa as a Better Britain. The British Art Section comprising 2,000 works was organised by the British government but paid for by the New Zealand government. It was housed in its own bespoke gallery in Hagley Park designed by a local architect. This installation remains the largest exhibition of British art in Aotearoa’s history, and purchases made by local government authorities formed the basis of metropolitan public art collections throughout Australasia. A principal motivation of the exhibit was to inculcate what was then considered good taste in colonial viewers, as well as to provide a version of the Royal Academy product to sell to middle-class art buyers nostalgic for reminders of Home. The British Government Representative for Fine and Applied Art, Alfred Longden (1875-1954), stated shortly after his arrival in Christchurch that the artworks were selected "with the idea of having [them] represented in the homes of the people there [New Zealand]. That is the motive that has actuated the artists. They have sent work which they feel would be suitable and acceptable for your houses and museums." Longden was also responsible for decorating the Art Gallery, fitting out the interior in an Arts and Crafts aesthetic style which was well-received by exhibition visitors. Sir Isidore Spielmann (1854-1925) who chose the works for exhibition but remained in Britain, noted in his 1907 report that "the general opinion was expressed that the rooms of the British Section were excellent in taste." The decorative scheme was also adopted for the rooms containing the Colonial Art Section, and this paper will address the ways in which the interior design framed the whole enterprise in terms of Empire
Revisiting the British World: New Voices and Perspectives.
Get PDFIn 2005, Rediscovering the British World sought to offer a study of the state and potential of British World scholarship. An edited collection, that text approached the British World as a transnational community which developed alongside Britain’s imperial expansion and the British diaspora
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