Engineering

New Zealand imports its vehicle fleet and essentially all transportation fuel. With introduction of fuelcell vehicles, New Zealand can become self sufficient in hydrogen fuel. A study undertaken by the Sustainable Energy Initiatives program at UNITEC evaluates the economic and environmental factors of fossil and non-fossil energy sources for production of hydrogen. It examines the transition for hydrogen fuel from on-board production from hydrocarbons to large-scale centralised electrolytic production. The paper extrapolates historic data on population, vehicle transport, and electric energy and examines the basis for introducing hydrogen fuel into the national economy in the 2010 -2050 period.

New Zealand is a small isolated country in the South Pacific with a population of 4.3 million people that has a strong commitment to reducing greenhouse gas emissions stemming both from its drive for global branding of principal export commodities and a desire to invest in new green technologies. New Zealand's renewable electricity generation reserve using biomass and wind alone is as much as 11 times the 2009 annual electricity demand. In this study the practical limits of fossil fuel reductions in the electricity and road transport sectors of the New Zealand economy are investigated using the multi-region partial equilibrium economic model UniSyD to examine a low carbon scenario in which oil reaches a maximum of US$200/bbl in 2030 in conjunction with a carbon tax of US$200 per tonne of carbon dioxide equivalent. In this scenario biofuel and electric drive vehicles are found to constitute 8% and 36% of the light vehicle fleet in 2050 respectively, with the balance of 56% still being fossil fuel vehicles. Government regulation is likely needed to reduce the proportion of fossil fuel vehicles to below 30% of the total fleet.

Electric energy Vehicle fleet Battery electric Fuel cell Renewable energy a b s t r a c t Within the current outlook for sustainable electric energy supply with concomitant reduction in emission of greenhouse gases, accelerated attention is focusing on the long-term development of hydrogen fuel cell and all-electric battery vehicles to provide alternative fuels to replace petroleum-derived fuels for automotive national fleets. The potential varies significantly between large industrially developed nations and smaller industrially developing nations. The requirement for additional electric energy supply from low-specific energy renewable resources and high-specific energy nuclear resources depends strongly on individual national economic, environmental, and political factors. Analysis of the additional electric energy supply required for the two potential large-scale technologies for fueling future national transportation sectors is compared for a large Organization for Economic Co-operation and Development (OECD) nation (USA) with a small OECD nation (New Zealand), normalized on a per-capita basis. ª (P. Kruger). A v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / h e i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 3 5 ( 2 0 1 0 ) 1 1 2 8 4 e1 1 2 9 0

New Zealand imports its vehicle fleet and essentially all transportation fuel. With introduction of fuelcell vehicles, New Zealand can become self sufficient in hydrogen fuel. A study undertaken by the Sustainable Energy Initiatives program at UNITEC evaluates the economic and environmental factors of fossil and non-fossil energy sources for production of hydrogen. It examines the transition for hydrogen fuel from on-board production from hydrocarbons to large-scale centralised electrolytic production. The paper extrapolates historic data on population, vehicle transport, and electric energy and examines the basis for introducing hydrogen fuel into the national economy in the 2010 -2050 period.

System dynamics software STELLA is used to obtain mass and thermal balances of a spring in the Orakeikorako geothermal field, New Zealand, based on field measurements of water level, barometric pressure, rainfall and spring temperature. The model identifies the interactions of the principal influences on spring behaviour of rainfall, groundwater, geothermal steam and barometric pressure. The geothermal steam inflow estimated from the model, of about 0.022 kg/s, confirms the existence of a weak hydraulic connection with a deeper geothermal reservoir.

Technician Surveyors in New Zealand are a vital component of a profession that has a well known history and long standing reputation in the country for high quality work undertaken with integrity. Surveying is a profession that is experiencing considerable change that brings not only new challenges but also opportunities, and Unitec Institute of Technology is focused on the building the capacity to deliver sustainable long-term technician training in New Zealand. Unitec, along with the University of Otago are the only providers of conventional survey education in New Zealand. The National Diploma in Surveying (NDS) was successfully delivered by Unitec for the first time in 1999 after replacing the New Zealand Certificate in Land Surveying (NZCLS). The ongoing challenge for Unitec has been to maintain the viability of a programme with only approximately 50 equivalent full time students (EFTS). Ten years on the NDS continues to operate with a steady number of students, however, to increase the sustainability of the programme it is proposed to integrate the first year of study with a New Zealand Diploma in Engineering (Civil) programme with a number of common courses and also specialist land survey papers. In 2011 the updated programme will still be called the National Diploma in Surveying (NDS) and will utilise the latest Version 5 Unit Standards from the New Zealand Qualifications Authority (NZQA).

Water level data from a shallow monitor well in the Rotorua geothermal field in New Zealand is used to compare signal processing techniques, namely discrete Fourier transform and wavelet analyses. Characteristic pressure fluctuations are identified over a wide range of frequencies indicative of influences that include tides due to celestial bodies. The techniques used for data analysis provide complimentary information on characteristic fluctuations.

This thesis presents the analysis of a series of experimental measurements from a selection of springs, geysers and wells at Te Aroha, Rotorua and Orakeikorako in New Zealand aimed at the identification of the frequencies of any characteristic variations with a period of 25 hours or less. The measurements taken from these sources collectively recorded water level, conductivity, temperature, rainfall and barometric pressure. The measurements involve the collection of data with high accuracy instrumentation and high sampling rates of 5 minutes to 1 hour over periods exceeding 1400 hours in both exploited and unexploited hydrothermal systems. The measurements are filtered using both an adaptive wavelet based filter and Fourier analysis to extract the influence of gravity tides, rainfall, and barometric pressure with the residual dominant frequencies being attributed to sub-surface thermodynamic processes. A review of the development of techniques for the determination of the pressure r...

A method is presented for determining casing shoe depths by probabilistic criteria. Analyses are performed and equations developed for buckling of an uncemented length of casing and str-esses at wellheads. Helical buckling of liners is reviewed.

The Orakei Korako geothermal field in the North Island of New Zealand is an unexploited field consisting of over 30 small active geysers and about 100 hot springs. It provides an excellent opportunity to examine the naturally occurring fluctuations in geothermal surface activity. Contemporaneous measurements of conductivity, temperature, water level, barometric pressure and rainfall were collected at 5 minute intervals over a 2 month period from two springs 150 metres apart. Spectral analysis by both wavelet and Fourier transforms was used to minimise the effects of non-Gaussian signal spikes and examine spectral windows of each set of data. Analysis shows that spring fluctuations are driven predominantly by solar thermal effects with negligible influence from soli-lunar gravity tides. In addition to solar thermal tidal variations, the springs have periodic fluctuations of 11.5 minutes and 24 minutes respectively. A low barometric efficiency indicates that transmissivity in the rese...

UniSyD_IS is an energy system model with endogenous road transport energy demand. Possible transition paths to low-carbon road transport system in Iceland are explored. Vehicle choice sector accounts for social influences and consumers' preferences. Supply-push costs can be offset by mitigation benefits and fuel cost savings.

This paper presents a comparative analysis of electric, hydrogen and biofuel transitional pathways to a future sustainable road transport in Iceland, a country with a renewable-based energy system. The analysis is based on a system-dynamics model of Icelandic energy and transport systems (UniSyD_IS). The model is divided into four main modules: fuel supply, fuel prices, refueling stations, and fuel demand. It simulates the long-term evolutions of light and heavy-duty vehicles, taking into account the supply and utilization stages of alternative fuels. Three scenarios are defined to promote the fuel supply infrastructure for three cases of hydrogen, biofuel and electric vehicles. The simulation results for these scenarios are compared in terms of different energy, economic, and environmental indicators. The findings indicate that the electricity pathway has advantages over others in reduction of total fuel demand, mitigation cost, and profitability of fuel supply. The biofuel pathway would be the most attractive alternative in terms of emissions reduction, share of alternative fuels, and consumer economic benefits. The analysis shows that the hydrogen scenario could be advantageous in reducing fuel import and consumer fuel costs, although it has the highest cost of vehicle ownership and infrastructure development.