title: Improving multi-site benefit functions via Bayesian model averaging: A new approach to benefit transfer

authors: Leon-Gonzalez, Roberto

subjects: benefit transfer

abstract: A benefit function transfer obtains estimates of willingness-to-pay (WTP) for the evaluation of a given policy at a site by combining existing information from different study sites. This has the advantage that more efficient estimates are obtained, but it relies on the assumption that the heterogeneity between sites is appropriately captured in the benefit transfer model. A more expensive alternative to estimate WTP is to analyze only data from the policy site in question while ignoring information from other sites. We make use of the fact that these two choices can be viewed as a model selection problem and extend the set of models to allow for the hypothesis that the benefit function is only applicable to a subset of sites. We show how Bayesian model averaging (BMA) techniques can be used to optimally combine information from all models.

The Bayesian algorithm searches for the set of sites that can form the basis for estimating a benefit function and reveals whether such information can be transferred to new sites for which only a small data set is available. We illustrate the method with a sample of 42 forests from U.K. and Ireland. We find that BMA benefit function transfer produces reliable estimates and can increase about 8 times the information content of a small sample when the forest is ‘poolable’.

text: Improving multi-site benefit functions via Bayesian model averaging: A new approach to benefit transfer A benefit function transfer obtains estimates of willingness-to-pay (WTP) for the evaluation of a given policy at a site by combining existing information from different study sites. This has the advantage that more efficient estimates are obtained, but it relies on the assumption that the heterogeneity between sites is appropriately captured in the benefit transfer model. A more expensive alternative to estimate WTP is to analyze only data from the policy site in question while ignoring information from other sites. We make use of the fact that these two choices can be viewed as a model selection problem and extend the set of models to allow for the hypothesis that the benefit function is only applicable to a subset of sites. We show how Bayesian model averaging (BMA) techniques can be used to optimally combine information from all models.

The Bayesian algorithm searches for the set of sites that can form the basis for estimating a benefit function and reveals whether such information can be transferred to new sites for which only a small data set is available. We illustrate the method with a sample of 42 forests from U.K. and Ireland. We find that BMA benefit function transfer produces reliable estimates and can increase about 8 times the information content of a small sample when the forest is ‘poolable’.

year: 2008

title: Heat pump integration for total site waste heat recovery

authors: Liew, Peng Yen

abstract: Total Site Heat Integration (TSHI) promotes energy recovery between processes to enhance overall energy efficiency of an industrial complex. Various industrial waste heat utilisation technologies have been studied to improve the energy efficiency of energy system. Vapour compression as an open loop heat pump system has good potential to be used to upgrade the waste heat to useful heat in Total Site systems. Vapour compression systems upgrade low grade waste heat by supplying a low quantity of high pressure steam (thermocompressor) or mechanical work (mechanical-compressor) to generate higher pressure steam, as is common with evaporation systems. The vapour compression system recovers the latent heat content of the industrial waste heat, which reduces cooling demand, decreasing the demand for high quality steam and reducing boiler load. This paper introduces an effective Total Site targeting methodology to integrate open cycle heat pump systems, i.e. vapour compression technologies, into an integrated industrial energy system for enhancing overall site energy efficiency. Industrial waste heat and high quality steam demand are able to be reduced simultaneously though this integration. The energy reduction and cost-benefit of thermo-compressor and mechanical-compressor installations are compared through a literature case study. The case study showed a deficit of heat at the MPS and a surplus of heat the LPS, which was identified as a candidate for compression according to the appropriate placement principle for heat pumps. For the case study, a four-stage mechanical vapour compression system and two-stage thermal vapour compression system resulted in an energy cost reductions of 343,859 USD/y and 168,829 USD/y.

text: Heat pump integration for total site waste heat recovery Total Site Heat Integration (TSHI) promotes energy recovery between processes to enhance overall energy efficiency of an industrial complex. Various industrial waste heat utilisation technologies have been studied to improve the energy efficiency of energy system. Vapour compression as an open loop heat pump system has good potential to be used to upgrade the waste heat to useful heat in Total Site systems. Vapour compression systems upgrade low grade waste heat by supplying a low quantity of high pressure steam (thermocompressor) or mechanical work (mechanical-compressor) to generate higher pressure steam, as is common with evaporation systems. The vapour compression system recovers the latent heat content of the industrial waste heat, which reduces cooling demand, decreasing the demand for high quality steam and reducing boiler load. This paper introduces an effective Total Site targeting methodology to integrate open cycle heat pump systems, i.e. vapour compression technologies, into an integrated industrial energy system for enhancing overall site energy efficiency. Industrial waste heat and high quality steam demand are able to be reduced simultaneously though this integration. The energy reduction and cost-benefit of thermo-compressor and mechanical-compressor installations are compared through a literature case study. The case study showed a deficit of heat at the MPS and a surplus of heat the LPS, which was identified as a candidate for compression according to the appropriate placement principle for heat pumps. For the case study, a four-stage mechanical vapour compression system and two-stage thermal vapour compression system resulted in an energy cost reductions of 343,859 USD/y and 168,829 USD/y.

year: 2016

title: Kia Maanu, Kia Ora: Stay Afloat, Stay Alive – Acknowledging the significance of tikanga Māori in formulating and communicating water safety policies and practices

authors: Haimona, Mark

subjects: New Zealand

abstract: The traditional beliefs and practices of Māori demonstrate great respect for water, for its dangers as well as its life-giving properties, and Māori have, along with other Polynesian peoples, been known for their skill in swimming, fishing and canoeing. However, Māori now outnumber others in New Zealand in terms of the proportion involved in drowning and water-related injury. In seeking to promote water safety among Māori, Water Safety New Zealand has enlisted the help of Māori communities. Its message - Kia Maanu, Kia Ora (Stay Afloat, Stay Alive) - is underpinned by an acknowledgment of the need to reinforce the traditional respect for water that permeates the Māori worldview.

text: Kia Maanu, Kia Ora: Stay Afloat, Stay Alive – Acknowledging the significance of tikanga Māori in formulating and communicating water safety policies and practices The traditional beliefs and practices of Māori demonstrate great respect for water, for its dangers as well as its life-giving properties, and Māori have, along with other Polynesian peoples, been known for their skill in swimming, fishing and canoeing. However, Māori now outnumber others in New Zealand in terms of the proportion involved in drowning and water-related injury. In seeking to promote water safety among Māori, Water Safety New Zealand has enlisted the help of Māori communities. Its message - Kia Maanu, Kia Ora (Stay Afloat, Stay Alive) - is underpinned by an acknowledgment of the need to reinforce the traditional respect for water that permeates the Māori worldview.

year: 2007