Greenhouse gas emissions from domestic hot water: heat pumps compared to most commonly used systems

We estimate the emissions of the two most important greenhouse gasses (GHG), carbon dioxide (CO2) and methane (CH4), from the use of modern high-efficiency heat pump water heaters compared to the most commonly used domestic hot water systems: natural gas storage tanks, tankless natural gas demand heaters, electric resistance storage tanks, and tankless electric resistance heaters. We considered both natural gas-powered electric plants and coal-powered plants as the source of the electricity for the heat pumps, the thermal electric storage tanks, and the tankless electric demand heaters. The time-integrated radiative forcing associated with using a heat pump water heater was always smaller than any other means of heating water considered in this study across all time frames including at 20 and 100 years. The estimated amount of CH4 lost during its lifecycle was the most critical factor determining the relative magnitude of the climatic impact. The greatest net climatic benefit within the 20-year time frame was predicted to be achieved when a storage natural gas water heater (the most common system for domestic hot water in the United States) fueled by shale gas was replaced with a high efficiency heat pump water heater powered by coal-generated electricity; the heat pump system powered by renewable electricity would have had an even greater climatic benefit, but was not explicitly modeled in this study. Our analysis provides the first assessment of the GHG footprint associated with using a heat pump water heater, which we demonstrate to be an effective and economically viable way of reducing emissions of GHGs.This study was funded by the Wallace Global Fund, the Park Foundation, and Cornell University

Proceedings of the Australian Summer Study on Energy Productivity

This collection includes the peer-reviewed papers presented during the 2016 Australian Summer Study on Energy Productivity

Some economic benefits of a synchronous earth observatory satellite

An analysis was made of the economic benefits which might be derived from reduced forecasting errors made possible by data obtained from a synchronous satellite system which can collect earth observation and meteorological data continuously and on demand. User costs directly associated with achieving benefits are included. In the analysis, benefits were evaluated which might be obtained as a result of improved thunderstorm forecasting, frost warning, and grain harvest forecasting capabilities. The anticipated system capabilities were used to arrive at realistic estimates of system performance on which to base the benefit analysis. Emphasis was placed on the benefits which result from system forecasting accuracies. Benefits from improved thunderstorm forecasts are indicated for the construction, air transportation, and agricultural industries. The effects of improved frost warning capability on the citrus crop are determined. The benefits from improved grain forecasting capability are evaluated in terms of both U.S. benefits resulting from domestic grain distribution and U.S. benefits from international grain distribution

Indoor acids and bases.

Numerous acids and bases influence indoor air quality. The most abundant of these species are CO2 (acidic) and NH3 (basic), both emitted by building occupants. Other prominent inorganic acids are HNO3 , HONO, SO2 , H2 SO4 , HCl, and HOCl. Prominent organic acids include formic, acetic, and lactic; nicotine is a noteworthy organic base. Sources of N-, S-, and Cl-containing acids can include ventilation from outdoors, indoor combustion, consumer product use, and chemical reactions. Organic acids are commonly more abundant indoors than outdoors, with indoor sources including occupants, wood, and cooking. Beyond NH3 and nicotine, other noteworthy bases include inorganic and organic amines. Acids and bases partition indoors among the gas-phase, airborne particles, bulk water, and surfaces; relevant thermodynamic parameters governing the partitioning are the acid-dissociation constant (Ka ), Henry's law constant (KH ), and the octanol-air partition coefficient (Koa ). Condensed-phase water strongly influences the fate of indoor acids and bases and is also a medium for chemical interactions. Indoor surfaces can be large reservoirs of acids and bases. This extensive review of the state of knowledge establishes a foundation for future inquiry to better understand how acids and bases influence the suitability of indoor environments for occupants, cultural artifacts, and sensitive equipment

Low carbon housing: lessons from Elm Tree Mews

This report sets out the findings from a low carbon housing trial at Elm Tree Mews, York, and discusses the technical and policy issues that arise from it. The Government has set an ambitious target for all new housing to be zero carbon by 2016. With the application of good insulation, improved efficiencies and renewable energy, this is theoretically possible. However, there is growing concern that, in practice, even existing carbon standards are not being achieved and that this performance gap has the potential to undermine zero carbon housing policy. The report seeks to address these concerns through the detailed evaluation of a low carbon development at Elm Tree Mews. The report: * evaluates the energy/carbon performance of the dwellings prior to occupation and in use; * analyses the procurement, design and construction processes that give rise to the performance achieved; * explores the resident experience; * draws out lessons for the development of zero carbon housing and the implications for government policy; and * proposes a programme for change, designed to close the performance gap

Developing Asia's Competitive Advantage in Green Products: Learning from the Japanese Experience

Right now, governments around the world are spending record amounts of money to kick-start their economies in response to the financial crisis. Fortunately, a great opportunity exists for this fiscal stimulus to be directed towards "green" economic growth, which can not only provide the new markets and jobs needed immediately for alleviating poverty, but also address the challenges of global warming. Working models already exist, proving that sustainable growth is possible. To achieve this will require social, technical and structural changes, as well as appropriate policies conducive to eco-innovation. For developing countries, there are lessons that can be learned from countries that have already gone through that process. The aim of this paper is to show what lessons can be learnt from the Japanese case. As the world's second largest economy, Japan is not only one of the most energy-efficient economies in the world; it also produces some of the world's leading green technologies. This paper focuses on current trends in the green product market and consumer behavior in Japan, which have been influenced by recent government policies, particularly the ¥15.4 trillion (more than US$100 billion) stimulus package. The aim of this paper is to provide some insight on, and present a repository of selected government policies promoting sustainable development. The scope of this paper will cover areas such as hybrid vehicles, renewable energy, energy efficient home appliances, and green certification schemes. It also provides a brief discussion on the environmental policies of the new Japanese government that came into power on 16 September 2009. The paper attempts to use the most recent data, from June to August 2009, however given the quickly-evolving global environment, these statistics may change drastically by the time this paper is presented.japanese government environmental policies; sustainable development; vehicle pollution policies

Market definition study of photovoltaic power for remote villages in developing countries

The potential market of photovoltaic systems in remote village applications in developing countries is assessed. It is indicated that photovoltaic technology is cost-competitive with diesel generators in many remote village applications. The major barriers to development of this market are the limited financial resources on the part of developing countries, and lack of awareness of photovoltaics as a viable option in rural electrification. A comprehensive information, education and demonstration program should be established as soon as possible to convince the potential customer countries and the various financial institutions of the viability of photovoltaics as an electricity option for developing countries

Social ties, homophily and heterophily in urban sustainability transitions: User practices and solar water heater diffusion in China

This paper aims to explore the potential of latecomer cities in sustainability transitions from the demand side. The case study investigates the role of users and their social ties in influencing the popularisation of solar water heaters in a latecomer city Dezhou, in contrast to a more developed counterpart, Beijing. The two cities show vast differences in user preferences towards the low-tech environmental innovation, and the stronger social ties in Dezhou facilitate the diffusion through not only frequent social learning and peer pressure, but also enhancing user-producer trust and relation. These findings suggest that latecomer cities could provide less harsh selection environments for disruptive environmental innovations and their comparatively homogenous social ties could be harnessed to empower niche development