title: Smart charging strategies for Electric Vehicles utilising non-dispatchable renewable electricity generation

authors: Monigatti, Paul William

subjects: Electric Vehicles

abstract: Access to an inexpensive and reliable supply of energy is critical for the success of modern civilisation. Since the beginning of the Industrial Revolution in the mid 18th century, fossil fuels have enabled great advances across many aspects of society, which have increased the standard of living for many. Unfortunately, dwindling supplies and greenhouse gas emissions resulting from their use means that the continued utilisation of these fuels - particularly for electricity generation and transportation - is simply not sustainable.

Present-day electricity systems are built around the premise that generation is flexible and controllable, while load - generally speaking - is not. This leads to dispatch models where generation is scheduled to meet load, plus some additional capacity to accommodate forecast errors and potential equipment failure. Many renewable generation technologies, such as wind and solar photovoltaics, are non-dispatchable and cannot be scheduled to produce electricity on-demand. Successfully utilising these energy sources therefore requires flexibility in other parts of the system.

Electric Vehicles (EVs) produce no tailpipe emissions, and can be charged at any location with an electricity supply; at home, work, supermarket, or dedicated charging facilities. Because driving times tend to coincide with existing peak electricity demand, EV charging will occur at times of already high electricity demand if not controlled. Fortunately, there is substantial flexibility over the timing of charging, which can be exploited to minimise adverse impacts on electricity grids. Additional benefits are realised when energy is allowed to flow from the vehicle's battery back into the electricity grid; a concept known as vehicle-to-grid (V2G).

Through the development of a simulation based on future energy scenarios in New Zealand, the research presented in this thesis evaluates the extent to which the flexibility of EV charging may be exploited to support high levels of non-dispatchable renewable electricity generation. Several EV charging strategies are introduced and evaluated across a range of metrics with wind penetration levels ranging between 10% and 50% on an annual energy basis. With a V2G-enabled fleet consisting of one million vehicles (25% of New Zealand's projected light vehicle fleet size in 2030), it is found that EV charging is sufficiently flexible to the extent that electricity generation does not need to follow daily variations in load. The EV fleet is capable of meeting the power and ramping requirements of the electricity grid, in addition to its own transportation needs, so long as sufficient energy is generated within a few days of its consumption. Such flexibility is expected to greatly assist the future expansion of non-dispatchable renewable electricity generation in New Zealand.

text: Smart charging strategies for Electric Vehicles utilising non-dispatchable renewable electricity generation Access to an inexpensive and reliable supply of energy is critical for the success of modern civilisation. Since the beginning of the Industrial Revolution in the mid 18th century, fossil fuels have enabled great advances across many aspects of society, which have increased the standard of living for many. Unfortunately, dwindling supplies and greenhouse gas emissions resulting from their use means that the continued utilisation of these fuels - particularly for electricity generation and transportation - is simply not sustainable.

Present-day electricity systems are built around the premise that generation is flexible and controllable, while load - generally speaking - is not. This leads to dispatch models where generation is scheduled to meet load, plus some additional capacity to accommodate forecast errors and potential equipment failure. Many renewable generation technologies, such as wind and solar photovoltaics, are non-dispatchable and cannot be scheduled to produce electricity on-demand. Successfully utilising these energy sources therefore requires flexibility in other parts of the system.

Electric Vehicles (EVs) produce no tailpipe emissions, and can be charged at any location with an electricity supply; at home, work, supermarket, or dedicated charging facilities. Because driving times tend to coincide with existing peak electricity demand, EV charging will occur at times of already high electricity demand if not controlled. Fortunately, there is substantial flexibility over the timing of charging, which can be exploited to minimise adverse impacts on electricity grids. Additional benefits are realised when energy is allowed to flow from the vehicle's battery back into the electricity grid; a concept known as vehicle-to-grid (V2G).

Through the development of a simulation based on future energy scenarios in New Zealand, the research presented in this thesis evaluates the extent to which the flexibility of EV charging may be exploited to support high levels of non-dispatchable renewable electricity generation. Several EV charging strategies are introduced and evaluated across a range of metrics with wind penetration levels ranging between 10% and 50% on an annual energy basis. With a V2G-enabled fleet consisting of one million vehicles (25% of New Zealand's projected light vehicle fleet size in 2030), it is found that EV charging is sufficiently flexible to the extent that electricity generation does not need to follow daily variations in load. The EV fleet is capable of meeting the power and ramping requirements of the electricity grid, in addition to its own transportation needs, so long as sufficient energy is generated within a few days of its consumption. Such flexibility is expected to greatly assist the future expansion of non-dispatchable renewable electricity generation in New Zealand.

year: 2017

title: Thermal shock properties of Ti(Al,O)/Al₂O₃ and TiAl(O)/Al₂O₃ composite coatings

authors: Salman, Asma Siddiq

subjects: composite coating

abstract: Ti(Al,O)/Al₂O₃ and TiAl(O)/Al₂O₃ composite coatings have a potential to reduce dissolution and aluminium soldering tendency of H13 tool steel used in the aluminium processing industry. The thermal shock resistance of H13 tool steel coated with Ti(Al,O)/Al₂O₃ and TiAl(O)/Al₂O₃ composite powders sprayed using a high velocity oxygen fuel (HVOF) technique was studied. The thermal shock behaviour of the composite coatings was investigated by subjecting the coated coupons to a number of cycles, each cycle consisting of a holding time of 30 seconds in molten aluminium at 700 ± 10 °C followed by quenching into water. The surfaces of the coupons were examined for Al soldering and an evaluation of surface spallation. Any cracks found in the coatings were studied to explain their thermal shock behaviour. The results of this study showed that both Ti(Al,O)/Al₂O₃ and TiAl(O)/Al₂O₃ composite coatings on H13 tool steel have good thermal shock resistance with a thermal shock life between 300 to 400 cycles. The composite coatings and fracture surfaces were analyzed using scanning electron microscopy.

text: Thermal shock properties of Ti(Al,O)/Al₂O₃ and TiAl(O)/Al₂O₃ composite coatings Ti(Al,O)/Al₂O₃ and TiAl(O)/Al₂O₃ composite coatings have a potential to reduce dissolution and aluminium soldering tendency of H13 tool steel used in the aluminium processing industry. The thermal shock resistance of H13 tool steel coated with Ti(Al,O)/Al₂O₃ and TiAl(O)/Al₂O₃ composite powders sprayed using a high velocity oxygen fuel (HVOF) technique was studied. The thermal shock behaviour of the composite coatings was investigated by subjecting the coated coupons to a number of cycles, each cycle consisting of a holding time of 30 seconds in molten aluminium at 700 ± 10 °C followed by quenching into water. The surfaces of the coupons were examined for Al soldering and an evaluation of surface spallation. Any cracks found in the coatings were studied to explain their thermal shock behaviour. The results of this study showed that both Ti(Al,O)/Al₂O₃ and TiAl(O)/Al₂O₃ composite coatings on H13 tool steel have good thermal shock resistance with a thermal shock life between 300 to 400 cycles. The composite coatings and fracture surfaces were analyzed using scanning electron microscopy.

year: 2011

title: Maumahara Papahou: A mobile augmented reality memory treasure box based on Māori mnemonic aids

authors: Taia, Ivy

subjects: computer science

abstract: He aha te mea nui o te ao? He tangata, he tangata, he tangata.
What is the most important thing in the world? It is people, it is people, it is people.
Traumatic brain injury (TBI) is a worldwide “silent epidemic” causing a variety of memory issues for those affected. Although several software approaches aim to aid memory recollection, they are inadequate for many TBI survivors and none address aspects of cultural awareness in New Zealand. We explored design concepts of traditional Mäori cultural artefacts and techniques and how they helped Mäori people recall past information. This paper describes our research and development of Maumahara Papahou, a mobile app that uses augmented reality features to create a digital memory treasure box based on the concepts of Mäori mnemonic aids.

text: Maumahara Papahou: A mobile augmented reality memory treasure box based on Māori mnemonic aids He aha te mea nui o te ao? He tangata, he tangata, he tangata.
What is the most important thing in the world? It is people, it is people, it is people.
Traumatic brain injury (TBI) is a worldwide “silent epidemic” causing a variety of memory issues for those affected. Although several software approaches aim to aid memory recollection, they are inadequate for many TBI survivors and none address aspects of cultural awareness in New Zealand. We explored design concepts of traditional Mäori cultural artefacts and techniques and how they helped Mäori people recall past information. This paper describes our research and development of Maumahara Papahou, a mobile app that uses augmented reality features to create a digital memory treasure box based on the concepts of Mäori mnemonic aids.

year: 2019