Pattern Recognition Residential Demand Response: An Option for Critical Peak Demand Reduction in New Zealand

Influencing households to adopt sustainable energy consumption behaviour is important to the transition towards a sustainable energy future. However, if one aims at influencing the energy consumption habits of people, one should also be able to estimate the resulting effects on the entire energy system. Residential demand response to reduce load on the electricity network has largely been impeded by information barriers and a lack of proper understanding of consumers’ behaviour. What are not well understood and are of great interest include load disaggregation, the behaviour of customers when responding to demand response request, load shifting models and their impact on the load curve of the utility. There is concern among demand response practitioners, for example, that demand response in the residential sector may simply move the peak problem with scale from one point in time to another. However, unavailability of appliance-level demand data makes it difficult to study this problem. In this paper, a generalized statistical model for generating load curves of the individual residential appliances is presented. These data allow one to identify the relative contribution of the different components of the residential load on a given residential feeder. This model has been combined with demand response survey in a neighbourhood with 400 households in Christchurch, New Zealand, to determine the effect of customers’ behaviour in reducing the neighbourhood’s winter peak demand. The results show that when customers’ are given enhanced information, they would voluntarily act to reduce their peak demand by about 10% during the morning peak hours and 11% during the evening peak hours. The demand responsiveness of the individual appliances is also presented. The effectiveness of customer behaviour modification in maintaining system reliability is also presented

Commissioning, initial testing and results from an experimental one kilowatt organic Rankine cycle

Organic Rankine Cycle (ORC) systems are capable of utilising low-enthalpy heat sources to generate power. The aim of the Above Ground Geothermal and Allied Technologies (AGGAT) research programme is to develop ORC systems within New Zealand. For the design, component selection and operation of ORC systems, it is important to understand process parameters and component behaviour. An experimental scale ORC system, known as ORC-B, has been built and tested at the University of Canterbury to assist in furthering our knowledge of ORC system design and construction. This paper presents experimental results from running a 1 kW ORC-B system using HFC-M1 refrigerant, a zeotropic mixture of R245fa and R365mfc as the working fluid under several operating conditions. Hot exhaust combustion products from a 30kW CapstoneTM Gas Turbine are used as the heat source and heat is transferred via a thermal oil loop to the working fluid through a plate heat exchanger. A scroll expander magnetically coupled to an AC generator is used for work extraction and energy conversion. A thermodynamic analysis of the component performance is undertaken, factoring in several practical aspects of the system and its design. Details on the applied aspects of obtaining accurate results from an experimental ORC system are included, such as the effect of restriction to the flow path, heat losses, pump motor slippage and measurement uncertainty

The sustainability ballast framework for design of remote electrification

The UN sustainable development goal No 7 aims to achieve affordable and clean energy for all, but this is not yet achieved for approximately one billion people in remote communities. Small scale systems can provide benefits, but existing approaches are primarily top-down ap-proaches that are developed by experts, and focus on the electrical engineering, economics, and policy aspects. These are not always successful, because the sociological aspects are overlooked. A new approach to addressing remote energy development is required that better addresses the societal component. The objective was to develop a conceptual framework whereby the sociologi-cal values of indigenous communities were better included in electrification decision-making.A grounded theory approach was used to interview members of a rural indigenous community and identify key features of their world view. Several categories of values were identified, referred to as ’ballasts’. The idea of balance between these was a strong theme that emerged from the community discussion. A composite index was then constructed. Case study results are presented for a remote rural Amazonian community, Kabakaburi in Guyana. Nine sustainability ballasts were identified as part of the indigenous community’s world view: biological capacity, social capacity, autonomy, equity & equality, electric utility, health, education, communication, and products and services. This paper develops a new framework to include the values and world-view aspects of indigenous communities in electrification decision-making

Phase Field Model of Faceted Anatase TiO2 Dendrites in Low Pressure Chemical Vapor Deposition

Anatase TiO2 nanorods with a well-defined h110i texture have been studied using a model-based characterization technique based on a previous modeling framework. Intricate secondary side facets characteristic of tilt angles of 26.5◦ have been indexed and a h112i growth direction of the well-aligned facets is identified. These results have not been accessed experimentally but crucial in understanding the nature of the most abundant facets and their structural properties. We find agreement between our results and indirect experimental measurements. Highly exposed {116} facets are found to be responsible for the excellent electrochemical surface properties in the nanostructured anatase TiO2 thin films

New Zealand transition engineering retro-analysis

To meet New Zealand’s emission commitments, the government has prioritized the up-take of Electric Vehicles (EVs), as personal transportation is a large consumer of fossil fuels. Extrapolating figures from official sources (Ministry of Transport and Ministry of Business, Innovation & Employment) we estimate that passenger transportation is responsible for at least 30% of New Zealand’s fossil fuel consumption. Given New Zealand has a large share of renewable sources (78%) the simple conclusion is that the uptake of EVs would directly reduce carbon emissions, however the interaction of EVs with the power system is complex and requires a comprehensive approach. Transition Engineering (TE) is an emerging field that addresses sustainability in design and management of engineered systems. Within the context of the TE methodology we investigated the implication of EV targets on the New Zealand Energy System and associated Greenhouse Gas Emissions. We utilized a Retro Analysis approach, using the transport activity and grid composition of 2012, superimposing various policy objectives into that system to understand the costs, benefits, consequences and utility of the policy. An energy system model was developed using the Longrange Energy Alternatives Planning System (LEAP). The model incorporated seasonal availability of power plants along with sector specific energy consumption profiles reported in official datasets. We defined a set of scenarios to examine the impact of different EV targets, charging behavior, modal shift, transport behavior and changes to grid composition. The implications of the intermittent nature of renewable resources were explored along with potential demand additions (EV charging) on the power system

Modelling Unsteady Processes with the Direct Simulation Monte Carlo Technique

Over the past 40 years, the Direct Simulation Monte Carlo (DSMC) technique has been developed into a flexible and effective solver for flow problems in the rarefied to near continuum regime. However, even with modern parallelised code, the efficient computation of unsteady near-continuum flows, which are important in processes such as Pulsed Pressure Chemical Vapour Deposition (PP-CVD), remains a challenge. We have developed an unsteady parallel DSMC code (PDSC) utilising advanced features such as transient adaptive sub-cells to ensure nearest neighbour collisions and a temporal-variable time step to reduce computation time. This technique is combined with a unique post-processor called the DMSC Rapid Ensemble Averaging Method (DREAM) which reduces the statistical scatter in the data sets produced by PDSC. The combined method results in a significant memory and computational reduction over ensemble averaging DSMC, while maintaining low statistical scatter in the results. The unsteady code has been validated by simulation of shock-tube flow and unsteady Couette flow, and a number of test cases have been demonstrated including shock impingement on wedges. The technique is currently being used to model the development of an underexpanded jet in a PP-CVD reactor

Titania-based Photocatalytic Coatings on Stainless Steel Hospital Fixtures

A scaled-up pulsed-pressure MOCVD system was used to deposit TiO2 coatings from tetra-isopropoxide precursor solution on stainless steel substrates and on 3- D objects. The objective of the work is the production of antimicrobial coatings for handles in health care facilities. Antimicrobial coatings are sought to manage the transmission of hospital acquired infections (HAI’s), which are reported to cost around one million pounds per annum in the UK alone. Titania is a promising material for this application due to the photocatalytic production of reactive oxygen species that are crucial for the destruction of organic pathogens. TiO2 coatings of 0.2 to 13 μm thickness were deposited at temperatures between 375 oC and 475 oC. The crystallite size and photocatalytic activity are influenced by deposition temperature. No dependence of stoichiometry on the deposition temperature has been observed. The films on stainless steel exhibit reasonably good photocatalytic performance. The photocatalytic performance and the stoichiometry improve with the film thickness. A three dimensional object (door handle) was coated with good conformity. The reactor scale-up for coating production on door handles is proposed for future wear and hygiene performance testing

High efficiency water splitting photoanodes composed of nano-structured anatase-rutile TiO2 heterojunctions by pulsed-pressure MOCVD

In this article, thin solid films are processed via pulsed-pressure metal organic chemical vapour deposition (PP-MOCVD) on FTO substrates over a range of processing times to produce a range of thicknesses and microstructures. The films are highly nanostructured anatase-rutile TiO2 composite films with unique single crystal dendrites. After annealing, carbon was removed, and materials showed improved water splitting activity; with IPCEs above 80% in the UV, photocurrents of ∼1.2 mA cm−2 at 1.23 VRHE at 1 sun irradiance and an extension of photoactivity into the visible range. The annealed material exhibits minimal recombination losses and IPCEs amongst the highest reported in the literature; attributed to the formation of a high surface area nanostructured material and synergetic interactions between the anatase and rutile phases

Copper and nanostructured anatase rutile and carbon coatings induce adaptive antibiotic resistance

Contaminated surfaces are vehicles for the spread of infectious disease-causing microorganisms. A strategy to prevent their spread is applying antimicrobial coatings to surfaces. Both nanostructured anatase rutile and carbon (NsARC), a TiO₂ formulation, and copper are examples of antimicrobial agents that are used in making or coating door handles and similar surfaces, to reduce microbial loads. Antimicrobial surfaces have been extensively tested for antimicrobial activity but not sublethal effects, such as exposure-associated multiple antibiotic resistance phenotypes usually caused by induction of efflux pump genes. The possibility of NsARC and copper inducing indicative efflux pump pathways was investigated by monitoring the expression of mScarlet fluorescent protein (FP) in two reporter strains of Escherichia coli. There was an increase in the expression of FP in the reporter strains exposed to NsARC and copper relative to the inert control composed of stainless steel. Furthermore we tested E. coli and Staphylococcus aureus following 8 h of exposure to NsARC for changes in resistance to selected antibiotics. E. coli that were exposed to NsARC became more susceptible to kanamycin but there was no significant change in susceptibility of S. aureus to any tested antibiotics. These findings suggests that even though NsARC and copper are antimicrobial, they also have some potential to cause unintended phenotypes