Analysing impact and performance
A key part of the Lochiel Park Research Project has been the evaluation of performance and impacts of various renewable energy programs and technologies, as well as their application to low-carbon households. As an environmentally friendly precinct, Lochiel Park is an opportunity to study how contemporary digital age living impacts the effectiveness of low-carbon households.
Research Projects
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Do the numbers stack up? Lessons from a near zero carbon housing estate
Many countries are searching for ways to reduce the energy and carbon impact of housing. The terms net zero-energy home and net zero-carbon home have entered the policy lexicon, without clear definitions and without widespread understanding of the likely policy impact. Is the concept limited to bespoke architect driven buildings for specific green clients, or does it have relevance in the mainstream house building sector and typical households? When we consider volume house building and contemporary lifestyles, what is the energy end-use reality of so called zero-energy homes? Can government policy instruments deliver housing estates that are thermally comfortable, energy efficient and powered by renewable energy?
The Lochiel Park Green Village in South Australia represents a genuine attempt through government policy processes to create a suburb of (nearly) zero-energy homes in a near zero-carbon estate. The development includes 103 highly energy efficient homes of various sizes, all utilising solar thermal and solar photovoltaic sources, and built to stringent environmental urban design guidelines. The energy used and generated at each house is being monitored and analysed to extend our understanding of what happens when families bring their energy habits to near zero-energy homes. Appliance and equipment audits are conducted to extend our knowledge of the energy services utilised in contemporary digital-age lifestyles.
This paper provides an insight into the quanta of energy using appliances and equipment that fill our homes and satisfy our ever-growing needs. The paper presents key results from two years of monitoring for the initial tranche of houses, demonstrating that although significant reductions in operating energy use has been achieved, few households have reached a net zero energy standard. The research highlights the extent to which our choice of energy systems and our individual behaviour affect the total annual energy use. The energy end-use and energy generation results are examined to identify the contribution of near zero-energy homes to the twin policy challenges of anthropogenic climate change and peak power demand. Using empirical evidence from extensive monitoring, this paper throws new light on the energy use of actual families in contemporary near zero-energy homes.
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The impact of niche green developments on transforming the building sector
Energy use in residential buildings is a significant contributor to global carbon emissions. The South Australian Government responded to concern for anthropogenic greenhouse gas emissions by creating a model development of near zero energy homes in a near zero carbon impact estate. The creation of the Lochiel Park Green Village challenged a collective of industry experts and policy makers to set objectives, performance targets and regulatory guidelines outside existing institutional and professional norms. Literature suggests that the creation of niche events can help the transition away from dominant technologies, practices and beliefs, and lead to organisations embracing new tools, construction practices, technologies, standards and policies.
By applying a multi-level socio-technical framework, and utilising evidence collected from a series of interviews with key government and industry leaders, this paper examines how, under the influence of landscape pressures, structural change at the regime level can come from the incubation of ideas and experiences at the niche level.
The available evidence finds that the creation of the Lochiel Park Green Village has allowed many individuals and organisations to gain a more detailed and practical understanding of sustainable housing, and has given organisations the confidence to change industry practices, government policies, and regulatory standards.
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Performance of rooftop PV systems: Theoretical vs. Actual output
With the expansion of domestic rooftop solar photovoltaic (PV) systems throughout Australia and their potential increasing impact on the energy market, household energy bills and the electricity grid, there has been little evidence on how installed PV systems actually perform. This paper compares the theoretical and actual monitored gross solar generation for a cluster of low-energy houses within the Lochiel Park Green Village in South Australia.
Comprehensive monitoring of energy generation of five grid connected dwellings for a continuous period of 12 months is presented. The minimum solar system capacity required is 1kWp per 100m2 habitable floor area. The data collected from these systems is compared with theoretical mathematical predictions based on solar system information such as inclination and azimuth angles of the installed panels, the peak power rating and efficiency of the panels and the inverter, and 1-minute solar irradiation data.
Graphs: (left) Histogram comparing the monitored solar power generation of L30OO before and after fault rectified; and (right) Comparison of monthly gross solar energy before and after a fault was rectified.
The research has found that the monitoring systems are valuable tools for determining whether a PV system is operating at all or at the expected level, and can be used to identify issues caused by shading, disconnected panels or inverter problems. In addition, the paper provides examples of how the installed monitoring systems have been used to identify solar system installation issues and major faults. Finally, the paper discusses observations on inverter failures, and installation trends regarding panel and inverter specifications.
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Energy efficient lighting system performance
Lighting technologies have witnessed remarkable improvements in energy efficiency over the past few decades with the developments in compact fluorescent and light emitting diode technologies. But has the application of energy efficient lighting delivered a lower energy use outcome? This paper compares the domestic lighting energy use of a number of comprehensively monitored houses within two Australian housing developments constructed a decade apart. The Mawson Lakes estate was built in the early 2000’s, whilst the Lochiel Park estate was designed to be nearly zero energy and was constructed in 2009-2015. Whilst the lighting technology applied at Mawson Lakes was more typical of standard construction practice at that time, strict urban design guidelines and encumbrances were sanctioned in Lochiel Park to reduce the energy used for lighting as well as other major energy services including thermal comfort and water heating.
Graph: Individual and average normalised annual lighting circuit energy per development
Graph: Individual and average peak lighting power per development
The application of energy efficient lighting technologies at Lochiel Park has resulted in significant energy savings. Analysis of the monitored house energy data within each estate shows that the near zero energy houses use, on average, 40% less energy for lighting than those in the nearby Mawson Lakes estate. In addition, there was a reduction of average peak power drawn by the low energy housing lighting circuits of 61%. This is despite the wiring convention used in Australia which combines the ceiling and wall-mounted light fittings together with other devices such as ceiling fans and bathroom exhaust fans and heat lamps which are more prevalent at Lochiel Park. The case studies indicate that the application of energy efficient lighting technologies, in the context of contemporary lifestyles, reduces both energy end-use and peak energy loads.
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Peak energy load: Impact of distributed solar generation in low energy housing on the electrical grid
The aggregated results for some 30 Lochiel Park households provide reliable data on the overall impact of low energy housing generating solar power on the electrical grid. Operating under the Adelaide climate, the study has shown that on average, the domestic solar electrical energy generated ranges from 2.4kWh/kWp in June to 5.5kWh/kWp in January with an annual average of around 4.0kWh/kWp. While only one house consistently produced excess energy and negative emissions, 50% of the monitored dwellings produced more electricity than they consumed and 40% of them produced negative net emissions during the period October to April due to the high output of the photovoltaic systems during that period.
The significant feature of air conditioning system usage is the relatively low hours when air conditioning was needed in comparison with similar Adelaide homes with the worst of the houses investigated needing a maximum of 3kW of electrical power with some systems needing below 1kW. This demand is well below typical air conditioning systems previously monitored. The impact on the local and state peak demand during hot spells and cost of associated with transmission/distribution infrastructure is significant.
Graph: Average measured consumed, solar, imported, exported, and net electricity power profile of 27 houses for the two hottest days of the year
Graph: Monitored consumed electrical (Consumed Elec), air conditioner (AC), imported (IMP Elec) and solar power, of two Lochiel Park houses during the hottest February day in 2010
Graph: Monitored 15 minute average instantaneous consumed electrical (Consumed Elec), and air conditioner (AC) powers, of five Mawson Lakes houses, during the 2003 peak electrical demand day
The data analysis provides real world evidence to support the development of energy regulatory framework and future energy policy directions in the housing and appliance sectors. The monitoring of current and new dwellings, including a number of smaller units will continue for the next three years and beyond. The lessons learnt from this project, while significant along the path towards zero energy housing, demonstrate the need for better design integration to ensure the achievement of low energy dwellings which are also affordable, comfortable and aesthetically acceptable. The project also highlights the need to pay particular attention to minimising the peak demand alongside energy and emissions reduction in order to reduce the reliance on the electrical grid. A potential avenue for designing a no peak demand home is the integration of electrical and/or thermal storage systems.
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The actual performance of solar water heaters
Through analysing the detailed monitoring data of 27 solar hot water systems in the Lochiel Park Green Village, it was possible to investigate the details and evaluate actual performance and compare with the results of TRNSYS modelling. The study highlights a number of common installation and usage issues which contribute to the systems performing well below those estimated through the TRNSYS modelling as per the associated standard AS/NZS 4234:2008/Amdt 1:2011.
One of the major causes of lower performance is the lack of information to households and installers which is often due to competing health, safety and performance demands associated with hot water systems. This has, in some instances, resulted in using more auxiliary energy than necessary through incorrect thermostat and boosting period settings.
Graph: Normalised daily average hot water load profile for both the storage and instantaneous systems based, and the ORER profile. Note that i) the storage and instantaneous systems are normalised to 22.5 and 57MJ/day, respectively, and ii) LP, STOR, and INST are acronyms for Lochiel Park, storage, and instantaneous, respectively
The results of the study demonstrate the soundness of the TRNSYS evaluation methodology and assumptions, the one major outcome of the study is the potential impact of the solar hot water load profile. The results showed a dependence of the quantity of hot water use on the number of residents in the house. However, most systems monitored consumed a hot water load profile close to that of a small reference load. This has been shown to have a direct impact on the STC values awarded. The study indicates the need to reconsider the basis for assigning appropriate annual energy consumption associated with reference hot water systems as detailed the Australian standard.
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The health and wellbeing impacts of near zero energy homes
Given the well documented health and wellbeing relationship with building thermal performance and indoor air quality, what are the implications of this policy approach? Combining interviews from 25 households and monitored energy data from over 50 near zero energy homes at Lochiel Park, this paper examines the validity of this policy goal from a health and wellbeing perspective.
The evidence shows households receive high levels of thermal comfort, enjoy lower energy bills, and believe their behaviour has been positively influenced by the building and its energy systems. Yet many remain concerned that the building industry is unable to produce homes that maintain the level of thermal comfort required to facilitate good sleeping conditions during summer. Whilst the near zero energy home policy appears valid from a health and wellbeing perspective, the case study highlights the substantial task ahead for researchers to quantify the impacts, identify opportunities to improve the health and wellbeing outcomes for end-users, and support the policy transition to zero energy homes.
