Preliminary Overview of Institutional Structures and Models: Information Systems for Energy/Environmental Planning and Management in GDR, Rhone-Alpes, and Wisconsin

This paper is one of a series describing a multidisciplinary IIASA research program on Integrated Energy System Modelling and Policy Analysis. The initial phase of this research program is focused on the energy systems of three regions: the State of Wisconsin in the U.S.A.; the German Democratic Republic; and the Rhone-Alpes Region in France. The primary purposes of the study are at least three-fold: (1) To identify existing patterns of regional energy use and supply at appropriate levels of disaggregation. (2) To compare alternative methodologies for regional energy forecasting, planning, and policy development. (3) To use the ,above methodologies to examine alternate energy policy strategies for each of the regions, to explore their implications from various perspectives using sets of indicators related to environmental impacts, energy use efficiency, etc., and to evaluate the adequacy of the alternative methodologies as policy tools. Out of these above three items should evolve improved methodologies for energy systems research and policy analysis. The comparative method, intersecting the different disciplines and nations which would be involved in this project, should serve as a powerful tool to the mutual benefit of the participating nations as well as to other countries facing similar energy problems. It could also serve as a prototype for similar studies on other resources such as materials, water, air, i.e. as a vehicle for development of an approach for improved resource management

Carbon capture from natural gas combined cycle power plants: Solvent performance comparison at an industrial scale

Natural gas is an important source of energy. This article addresses the problem of integrating an existing natural gas combined cycle (NGCC) power plant with a carbon capture process using various solvents. The power plant and capture process have mutual interactions in terms of the flue gas flow rate and composition vs. the extracted steam required for solvent regeneration. Therefore, evaluating solvent performance at a single (nominal) operating point is not indicative and solvent performance should be considered subject to the overall process operability and over a wide range of operating conditions. In the present research, a novel optimization framework was developed in which design and operation of the capture process are optimized simultaneously and their interactions with the upstream power plant are fully captured. The developed framework was applied for solvent comparison which demonstrated that GCCmax, a newly developed solvent, features superior performances compared to the monoethanolamine baseline solvent

Considerations of feed demand and supply for the evolution and expansion of beef cattle farming in Sabah, East Malaysia : a thesis presented in partial fulfilment of the requirements for degree of Doctor of Philosophy in Agronomy, Massey University, Institute of Agriculture and Environment, College of Sciences, Palmerston North, New Zealand

To develop a plan for the expansion and evolution of the beef industry in Sabah, it was decided to apply relevant farming information and technology from New Zealand pastoral systems. Based on expert recommendation in New Zealand, metabolic energy budgeting (MEB) was chosen as the vehicle for technology transfer, rather than a direct translocation of elements of farm practice between these two countries of vastly different climate. In Phase 1 of the study, farm system evolution in New Zealand over the last two and half decades was evaluated by modelling past systems from historic records for the author to gain experience of New Zealand pastoral systems and to develop MEB spreadsheet tools to identify principles of system improvement; and in Phase 2, the tools developed in New Zealand were applied for evaluation of opportunities for farm system improvement in Sabah. In Phase 1, an evaluation was carried out of cumulative changes on New Zealand lower North Island sheep and beef cattle farms from 1980–81/1985–86 to 2010–2011. Herbage harvested on the farms studied, as determined by MEB, was 7.43 t DM ha–1 yr–1 in 1980–81 and only 5.76 t DM ha–1 yr–1 in 2010– 11. Also herbage supply (based on GROW model calculations using weather data) had decreased from 9.64 t DM ha–1 yr–1 to 8.70 t DM ha–1 yr–1 (partly due to an apparent climate change effect). However, with the evolution of farm system configurations over the past quarter century focusing on efficiency gain, the feed conversion efficiency (based on national data) improved from 25 kg feed consumed per kg lamb weaned in 1980–81/1985–86 to 19 kg feed consumed per kg lamb weaned in 2010/2011 and the corresponding increases in meat production from 1980–81/1985–86 to 2010/2011 were a rise from 137 kg to 147 kg total beef and lamb carcass per ha per year. Two major drivers of the higher meat production were an increase in lambing percentage, and an increase in weight of lambs and bulls at sale. In Phase 2, a first study in Sabah using the MEB tools developed in New Zealand involved three cut-and-carry feedlots (Brahman, Bali and Droughtmaster cattle), and utilised 5,981 monthly liveweight records of 485 cattle farmed in this system for the period 2008–2013. A second study in Sabah involved five grazing units (Brahman cow-calf, Bali cow-calf, Droughtmaster cow-calf, and Heifer and Brahman bull Units), and included 30,166 monthly liveweight records for 1353 cattle farmed in this system during the same period. A third study involved three oil-palm-integrated cattle (OPIC) farms (two in 9 yr old plantations and one in a 12 yr old plantation) and 600–700 cattle farmed in this system in 2013 and 2014. In this study, animal growth rates were assumed based on records from the nearest government farm with animals of similar breed. For the three systems, herbage-cutting experiments were carried out in August–October 2014 to estimate herbage growth and nutritive value (metabolisable energy and protein contents), and soil samples collected to describe the soil nutrient content. In the cut-and-carry feedlot and grazing cattle farming systems, the herbage harvested, as indicated by the modelling in these systems, was lower (3.74–7.16 t DM ha–1 yr–1 herbage eaten) than the potential yield of the herbage extrapolated from the cutting experiments (6.9–21.3 t DM ha–1 yr–1). In the OPIC farming system, the modelled herbage harvested in 9 yr old plantations was 2.0–2.4 t DM ha–1 yr–1 and that of 12 yr old plantation was 1.4–1.7 t DM ha–1 yr–1. These values are higher than values for potential herbage supply (0.4–0.8 t DM ha–1 yr–1) reported in literature for plantations of similar ages. In all three systems, herbage nutritive value was low (7.0–8.9 MJ ME kg DM–1; 9%–14% CP), calving percentage was low (33%–47%); soil was acidic and soil nutrient content was low; while invasion of non-sown species (native grass) was high. The best average feed conversion efficiencies (FCE) for these systems were 21.3 kg DM kg LWG–1 (cut-and-carry feedlot), 40.2 kg DM kg LWG–1 (grazing), and 32.2 kg DM kg LWG–1 (OPIC). FCE was found to improve with application of N fertiliser and was not necessarily high when feed consumption was intensified (or at high system feed demand). A key statistic defining the stock-configuration in an efficient system for the cut-and-carry feedlot cattle farming system was 994 kg animal LWT ha–1, or a comparative stocking rate (CSR) of 96 kg animal liveweight per tonne feed consumed. For the grazing cattle farming system, the observed optimum was 506 kg animal LWT ha–1, or a CSR of 94 kg LWT t DM–1. The identification of an optimal CSR for the OPIC farming system was limited (by the data supplied by the farms), but the available data indicated that for 9OP1 the CSR was 89 kg LWT t DM–1, or approximately 231 kg animal LWT ha–1. From the series of studies in Sabah, it is concluded that the future focus of the beef industry to expand and improve the productivity should be first to adjust the farm system configuration especially the stocking rate for optimal FCE under the present forage supply regime (and for that purpose a-CSR type of statistics would be useful to determine the appropriate stocking rate), and only then, to develop a pasture husbandry and fertiliser recommendations aimed at improving herbage dry matter harvested towards a target of 14–20 t DM ha–1 yr–1, with ME of 9–10 MJ kg DM–1, and CP of 14%–16% at harvesting or grazing. The herbage production target for the OPIC farming system, however, cannot be determined until the time trajectory of the decreasing system herbage productivity with decreasing oil palm age is fully understood. The use of supplement in the three systems is optional, but if it is used, it should be targeted tactically to reduce liveweight loss and enhance cow reproductive performance

Calibration and validation of a combustion-cogeneration

This paper describes the calibration and validation of a combustion cogeneration model for whole-building simulation. As part of IEA Annex 42, we proposed a combustion cogeneration model for studying residentialscale cogeneration systems based on both Stirling and internal combustion engines. We implemented this model independently in the EnergyPlus, ESP-r and TRNSYS building simulation programs, and undertook a comprehensive effort to validate the model's predictions. Using established comparative testing and empirical validation principles, we vetted the model's theoretical basis and its software implementations. The results demonstrate acceptable-to-excellent agreement, and suggest the calibrated model can be used with confidence

Modelling of heat emitters embedded within third order lumped parameter building envelope model

A dynamic modelling approach for heat emitters embedded within an existing third order lumped parameter building envelope model is reported in this work. The model has been found to provide more accurate results with negligible expense of computational time compared to a conventional quasi-dynamic model. The dynamic model also is preferred over the quasi-dynamic model as it allows for modelling emitters with high thermal capacity such as under-floor heating. Recommendation for this approach is justified through a series of analyses and comparative tests for various circuit options, timesteps and control volumes

Small-Scale Compressed Air Energy Storage Application for Renewable Energy Integration in a Listed Building

In the European Union (EU), where architectural heritage is significant, enhancing the energy performance of historical buildings is of great interest. Constraints such as the lack of space, especially within the historical centers and architectural peculiarities, make the application of technologies for renewable energy production and storage a challenging issue. This study presents a prototype system consisting of using the renewable energy from a photovoltaic (PV) array to compress air for a later expansion to produce electricity when needed. The PV-integrated small-scale compressed air energy storage system is designed to address the architectural constraints. It is located in the unoccupied basement of the building. An energy analysis was carried out for assessing the performance of the proposed system. The novelty of this study is to introduce experimental data of a CAES (compressed air energy storage) prototype that is suitable for dwelling applications as well as integration accounting for architectural constraints. The simulation, which was carried out for an average summer day, shows that the compression phase absorbs 32% of the PV energy excess in a vessel of 1.7 m(3), and the expansion phase covers 21.9% of the dwelling energy demand. The electrical efficiency of a daily cycle is equal to 11.6%. If air is compressed at 225 bar instead of 30 bar, 96.0% of PV energy excess is stored in a volume of 0.25 m3, with a production of 1.273 kWh, which is 26.0% of the demand

A Modelling Approach for Evaluating Agri-Environmental Policies at Sector Level

This paper presents a new approach to evaluate the cost effectiveness of agri-environmental policies at sector level. Policy uptake, cumulative environmental effects and public expenditure are identified as the main determinants of cost-effectiveness. On the basis of the sector-consistent, comparative-static, farm group model FARMIS, the determinants of policy cost-effectiveness at sector level are addressed. Firstly, intensity levels for the FARMIS activities are defined in order to model uptake of agri-environmental policies with FARMIS, secondly, life-cycle assessment data is attached to these intensity levels to determine environmental effects of the policies and thirdly, public expenditure is calculated under consideration of transaction costs. This paper concludes delineating the strengths and limitations of the approach