Solar versus fossil fuels : A net energy analysis of domestic solar hot water systems in Australia

It is commonly assumed that solar hot water systems save energy and reduce greenhouse gas emissions compared to conventional electric and gas hot water systems. Very rarely has the life-cycle energy requirements (including the embodied energy of manufacture) of solar hot water systems been analysed. The extent to which solar hot water systems can save energy compared to conventional electric or gas hot water systems can be shown through a comparative net energy analysis. This method determines the ‘energy payback period’, including consideration of the difference in operational energy savings and energy embodied in the devices relative to a base case. Dr Robert Crawford, Deakin University, Australia presents the results of a net energy analysis that compared solar and conventional hot water systems for a southern (Melbourne) and a northern (Brisbane) Australian climate.

What is wrong with a big house?

ln Australia in the 1950s, the average house size was approximately 100 mz. By 2008, the average size of a new house had risen to approximately 238 mz i.e. an increase of nearly 140%. Over the same period, occupancy levels have fallen by nearly one third from 3.7 to 2.5 persons per household. The aim of this paper is to contrast the total and per capita resource demand (direct and embodied energy, water and materials) for two houses typical of their respective era and draw some conclusions from the results. Using the software Autodesk Revit Architecture and drawings for typical 1950 and 2009 houses, the material quantities for these dwellings have been determined. Using known coefficients, the embodied energy and water in the materials have been calculated. Operating energy requirements have been calculated using NatHERS estimates. Water requirements have been calculated using historical and current water data. The greenhouse gas emissions associated with the resource use have also been calculated using established coefficients. Results are compared on a per capita basis. The research found that although the energy to operate the modern house and annual water use had fallen, the embodied energy and associated greenhouse gas emissions from material use had risen significantly. This was driven by the size of the house and the change in construction practices.

Office buildings and the environment : the increasing importance of ESD

The links between the built environment and sustainability issues such as fossil fuel consumption and climate change is clear. In developed countries buildings contribute around half of all carbon dioxide emissions and offer considerable scope for a significant contribution to sustainability through ecologically aware design and increased energy efficiency (BRE, 1996). The Australian commercial stock emits 12% of all greenhouse gas emissions however the commercial property market has some inherent barriers to sustainability (DSE, 2005). A substantial proportion of the stock is owned by institutional investors who are unconvinced by the need to improve their stock and pass on running costs to tenants (Callender & Key, 1997). As capital values are not greatly affected by sustainability, owners react by doing little or nothing and the effect is to limit sustainability related investment and undermine efforts to deliver sustainability in the sector.

Furthermore the efficiency of buildings declines over time and whilst energy efficiency is important to new design, the existing stock must be improved if urban built environment greenhouse gas emissions are to be reduced. Much of the property and surveying research has previously adopted an illustrative case study approach advocating the benefits of ESD and energy efficiency in existing buildings. This research adopts a radically different approach and profiles the entire office stock of a global CBD, namely Melbourne, which is seeking to become a carbon neutral city by 2020. The research also employs scenario forecasting to model future changes to the stock over a fifteen year period. This paper sets out the rationale for the research and establishes the methodological approach adopted by the research team.

Office buildings and the environment : the increasing role of facility managers

The Australian commercial stock emits 12% of all greenhouse gas emissions however the commercial property market has some inherent barriers to sustainability (DSE, 2005). A substantial proportion of the stock is owned by institutional investors who are unconvinced by the need to improve their stock and pass on running costs to tenants (Callender & Key, 1997). The links between the built environment and sustainability issues such as fossil fuel consumption and climate change is clear. In developed countries buildings contribute around half of all carbon dioxide emissions and offer considerable scope for a significant contribution to sustainability through ecologically aware design and increased energy efficiency (BRE, 1996). As capital values are not greatly affected by sustainability, owners react by doing little or nothing and the effect is to limit sustainability-related investment and undermine efforts to deliver sustainability in the sector. Facility managers are in an influential position to help address sustainability issues via an increased awareness of energy efficiency and CO2 emissions.

Even though the efficiency of buildings is primarily focused on new stock, with an existing churn replacement rate of approximately 2-3% the existing stock must be improved if urban built environment greenhouse gas emissions are to be reduced – clearly the management of existing stock must therefore contribute to substantial savings in energy use. Much of the property and surveying research has previously adopted an illustrative case study approach advocating the benefits of ESD and energy efficiency in existing buildings. This research adopts a radically different approach and profiles the entire office stock of a global CBD, namely Melbourne, which is seeking to become a carbon neutral city by 2020 (City of Melbourne, 2003). The research also employs scenario forecasting to model future changes to the stock over a fifteen year period. This paper sets out the rationale for the research and establishes the methodological approach adopted by the research team. The results provides a unique insight into the variations between different building types and grades of office buildings, which in turn will allow facility managers to gain a better understanding of where gains in energy efficiency can be made.

The role of the surveying profession in reducing carbon emissions of existing office stock in the Melbourne CBD

As professionals, surveyors and property professionals are in the front line and have a moral and ethical duty to take a lead when advising clients appropriately on measures to reduce greenhouse gas emissions from their buildings. As such, surveying professionals and the profession must increase their knowledge base and enhance their skills in respect of built environment sustainability. This research conducted a detailed analysis of energy efficiency in the Melbourne CBD office stock and examined all office buildings to identify what was likely to happen between 2005 and 2020 in respect of carbon emissions. The research profiled a business-as-usual or no change approach, a minor change approach, an intermediate approach, and a major change approach. The study examined variables such as building size, number of employees, occupancy levels, visual appearance and age. After modelling all CBD office buildings, it was recommended that an intermediate change scenario should be adopted. This course of action incorporates a transition period and includes increasing ‘green power’, increasing the number of employees per buildings, as well as reducing electricity and gas consumption. It was concluded that the surveying profession should adopt a proactive stance towards office buildings and climate change, which is currently being stifled by barriers such as a lack of education and perception concerning the long-term benefits of energy efficient office buildings. To date there has been much debate and promotion of policies to encourage the uptake of sustainability practices within the property sector; however, this research concludes that action is needed if targets are to be met.

Using building adaptation to deliver sustainability in Australia

Purpose – This paper seeks to establish the rationale for existing office building adaptation within Melbourne, Australia, as the city strives to become carbon neutral by 2020. The problems faced by policy makers to determine which buildings have the optimum adaptation potential are to be identified and discussed.

Design/methodology/approach – This research adopts the approach of creating a database of all the buildings in the Melbourne CBD including details of physical, social, economic and technological attributes. This approach will determine whether relationships exist between attributes and the frequency of building adaptation or whether triggers to adaptation can be determined.

Findings – This research provided evidence that a much faster rate of office building adaptation is necessary to meet the targets already set for carbon neutrality. The findings demonstrate that a retrospective comprehensive examination of previous adaptation in the CBD is a unique and original approach to determining the building characteristics associated with adaptation and whether triggers can be identified based on previous practices. The implication is that a decision-making tool should be developed to allow policy makers to target sectors of the office building stock to deliver carbon neutrality within the 2020 timeframe.

Practical implications – Drastic reductions in greenhouse gas emissions are required to mitigate global warming and climate change and all stakeholders should be looking at ways of reducing emissions from existing stock.

Originality/value – This paper adds to the existing body of knowledge by raising awareness of the way in which the adaptation of large amounts of existing stock can be fast tracked to mitigate the impact of climate change and warming associated with the built environment, and in addition it establishes a framework for a decision-making tool for policy makers.

Delivering sustainability through the adaptive reuse of commercial buildings : the Melbourne CBD challenge

The City of Melbourne is aiming to be carbon neutral by 2020 (Arup 2008) and have set a target of adapting twelve hundred commercial buildings to incorporate sustainability initiatives to reduce greenhouse gas emissions from the sector (AECOM 2008). In order to meet this target the City of Melbourne is taking a proactive approach to establish strategies to deliver sustainability in the built environment within the 2020 timeframe. With regards to upgrading and building maintenance 71% of investment is used for such works (Department of the Environment 2008) and the total Australian property stock was worth over $6 trillion in June 2008. Given that building services in commercial buildings typically lasts between 20-30 years and the average age of the stock is 31 years – it appears that many properties are due for adaptation and there is major opportunity for adaptation that alleviates the impact of global warming and climate change.

Uncertainty surfaces such as; how much adaptation of existing stock is typically undertaken? And is the target of 1200 adaptations before 2020 achievable? Furthermore how could the City identify which buildings are most probable to be adapted prior to 2020? This paper details the configuration of a database of Melbourne buildings populated with data about physical, social, economic legislative and environmental attributes. There is a discussion about how the database will be used to determine; how much adaptive reuse has been undertaken historically; if any triggers to adaptation can be identified; and whether any relationships between adaptation physical, social, economic, legislative and environmental attributes and adaptation exist. The relevance of this research is obvious to all policy makers where adaptation of existing commercial buildings is perceived a as key component of delivering sustainability.

Social and environmental accounting research : major contributions and future directions for developing countries

A review is provided of major contributions in social and environmental accounting literature focussing on the issues of developing countries. The review of prior research shows that the major contributions have been related to the motivations for social and environmental disclosure. However, other important research areas such ethical/accountability issues and how to cost externalities which have already been considered within the context of developed countries are yet to emerge within the
developing country context. Contemporary social and environmental issues such as climate change and greenhouse gas emissions affecting the global community also appear to be key issues of research to scholars in both developed and developing countries. Finally, some future research directions are identified.

Regulatory challenges in the move to a low-carbon environment

An outcome of the international climate conference in Copenhagen (COP 15, 2009) was that a number of governments have undertaken to reduce their nations' greenhouse gas (GHG) emissions and some have provided targets and deadlines for the achievement of their stated goals. While the transition to a low-carbon environment has the potential to stimulate growth, create jobs and opportunities, and to bring benefits to the economy, there are many challenges in the process. This is an exploratory paper aimed at identifying the major regulatory and governance issues associated with the move to a low-carbon environment. In terms of business governance, CEOs and other executives responsible for corporate oversight will need to monitor, assess, and manage compliance with climate change and carbon-related regulation. In the transition period government regulation encouraging appropriate carbon costs classification and measurement, financial sustainability reporting and disclosure, and responsible carbon citizenship are expected to be predominant.

Context dependency of comfort and energy performance in mixed mode offices

This article investigates the context dependency of comfort and energy performance in mixed-mode offices in the climate of Athens, Greece. It is based on a parametric study using the simulation software EnergyPlus. Context refers to different building design priorities on the real estate market (prestige, low cost and green), occupant behaviour scenarios (ideal and worst case) and cooling strategies (fixed and adaptive set points). Results are evaluated according to energy consumption and related greenhouse gas emissions, daylight autonomy, view and percentage of working time when heating and cooling are operating. The results indicate that a holistic approach to comfort and energy performance evaluation focused on the specific context of a building and its occupants is necessary to develop appropriate optimization strategies. In early design stages, such specific information is not yet available and ideal/worst-case scenarios can indicate the magnitude of influence of occupants compared to building design.

Fermentative production of rhamnosidase from Staphylococcus xylosus MAK 2 in a bioreactor for bio-energy generation

Increasing concern about the environment, food and feed shortages and hike in the price of petroleum have stimulated interest in new ways of producing biofuels. The interest is rapidly increasing towards converting agricultural wastes to commercially valuable products. Biofuels made from waste biomass can offer immediate and sustained greenhouse gas advantages. In this direction, we are focusing on Citrus processing waste, a byproduct of juice manufacture, which contains high amount of flavonoids and polysaccharides. There is a considerable industrial interest in the enzymatic transformation of flavonoids to hydrolysis products; that offers a pathway to bio-energy generation. Rhamnosidase of bacterial origin are very few and thus are potentially subject for research.

Staphylococcus xylosus, Gram positive cocci, a nonpathogenic member of CNS family, isolated from soil was used to produce α-L-rhamnosidase. This new strain, so far unknown for the production of α-L-Rhamnosidase, was identified and characterized as Staphyloccocus sp. through biochemical tests and 16S DNA sequence analysis. Effect of various medium and process parameters like pH, temperature, aeration and agitation rates and inducer concentration were studied. Further, the enzyme activity was enhanced by adding the inducer and divalent metal ion to the optimised fermentation medium. We have recovered important sugars “rhamnose” and “galacturonic acid” from the processed waste which would be utilized for ethanol production. This presentation will summarize current efforts to develop an enzymatic treatment which would facilitate the economical processing of citrus waste for bioenergy generation.

Green roofs in Melbourne - potential and practice

In Melbourne, green roofs are increasingly being included in the new and retrofitted buildings that claim to be ‘sustainable’ or ‘green’. This enthusiasm follows overseas experience where a variety of benefits have been recorded; these include a reduction in heating and cooling loads. This benefit is of particular importance because of the urgent need to reduce the greenhouse gas emissions associated with air conditioning. What is the potential for such savings and to what extent are some of the existing green roofs likely to achieve these benefits? This paper begins with a review of the overseas experience to reduce conditioning loads, particularly cooling, in temperate climates. Some observations on the potential and practice of green roofs in Melbourne is then presented. The results of measurements of plant canopy, soil and hard surface temperatures on two green roofs in the Melbourne Central Business District are discussed and future on-going work is outlined.

Animal–plant–microbe interactions : direct and indirect effects of swan foraging behaviour modulate methane cycling in temperate shallow wetlands

Wetlands are among the most important ecosystems on Earth both in terms of productivity and biodiversity, but also as a source of the greenhouse gas CH₄. Microbial processes catalyzing nutrient recycling and CH₄ production are controlled by sediment physico-chemistry, which is in turn affected by plant activity and the foraging behaviour of herbivores. We performed field and laboratory experiments to evaluate the direct effect of herbivores on soil microbial activity and their indirect effects as the consequence of reduced macrophyte density, using migratory Bewick’s swans (Cygnus columbianus bewickii Yarrell) feeding on fennel pondweed (Potamogeton pectinatus L.) tubers as a model system. A controlled foraging experiment using field enclosures indicated that swan bioturbation decreases CH₄ production, through a decrease in the activity of methanogenic Archaea and an increased rate of CH₄ oxidation in the bioturbated sediment. We also found a positive correlation between tuber density (a surrogate of plant density during the previous growth season) and CH₄ production activity. A laboratory experiment showed that sediment sterilization enhances pondweed growth, probably due to elimination of the negative effects of microbial activity on plant growth. In summary, the bioturbation caused by swan grazing modulates CH₄ cycling by means of both direct and indirect (i.e. plant-mediated) effects with potential consequences for CH₄ emission from wetland systems.

Examining and quantifying the drivers behind alterations and extensions to commercial buildings in a central business district

The drive to undertake building adaptation has increased in momentum, the primary reason being adaptation can be less expensive than new build and conventionally result in faster project delivery times. The issue of sustainable development is another clear driver for adaptation and collectively buildings contribute around half of all greenhouse gas emissions. At the same time governments seek effective and efficient ways of reducing the contribution of cities to climate change and building adaptation appears to offer a practical means of reducing building-related emissions. One example is the ‘1200 building program’ which aims to increase adaptation rates with a target of 1200 city centre office adaptations by 2020 as part of the strategy to achieve carbon neutrality. Through a longitudinal examination of building adaptations it is possible to identify the nature and extent of typical levels of adaptation, as well as determining the inter-relationship between different types of adaptation and building attributes. Melbourne city centre was used for a case study which analysed 5290 building adaptation events between 1998 and 2008. The findings promote the adaptive reuse of buildings in specific circumstances and are directly applicable for increasing sustainability in the built environment. The case study focused on existing buildings in a global city to ensure relevance to urban centres where existing commercial buildings can become part of the solution to mitigate climate change.