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Current energy market designs and pricing schemes fail to give investors the appropriate market signals. In particular, energy prices are not high enough to attract investors to build new or maintain existing power capacity. In this paper we propose a method to compute second-best Pareto optimal equilibrium prices for any market exhibiting non-convexities and, based on this result, an energy market design able to restore the correct energy price signals for supply investors.

The division of return stroke current among the arresters and groundings of two unenergized test distribution lines, one horizontally configured and the other vertically configured, was studied at the International Center for Lightning Research and Testing in Florida. The division of return stroke currents for the vertically configured line was initially similar to the division on the horizontally configured line: at the time the return stroke current reached peak value (after one microsecond, or so) the two closest arresters/grounds on both lines passed about 90% of the total current. However, the time during which the return stroke current flowed primarily through the closest arresters to the neutral conductor was significantly shorter on the vertically configured line. On that line, the arrester current was about equally divided among all four arresters after several tens of microseconds. The arrester current division as a function of time measured on the vertical line was successfully modeled using the published VI-characteristic, while the division on the horizontal line after some tens of microseconds was only successfully modeled if the residual voltage of the two arresters closest to the current injection point was reduced by 20%. Based on the triggered lightning current division observed on our line, the minimum energy absorbed in each of the two arresters closest to the strike point during a typical natural first stroke is estimated to be 40 kJ.

Abstract The proposed innovative approach identifies a new application for biomass. Bioenergy is used to drive a desalination unit which produces water for irrigating energy crops. Biomass is cultivated on artificial soil made by a mixture of local soil and organic compost from MSW (Municipal Solid Wastes). This agro-energy farm scheme aims at rescuing arid lands near to the sea. The study defines a techno-economic compromise among energy crops, biomass generator, desalination unit and irrigation system, considering an arid area (10 ha) of Tenerife as reference case study. A small experimental activity (100 m 2 ) has also been performed on site. A Sweet Sorghum cultivation, a bioenergy generator, a reverse osmosis plant and drip irrigation system have been chosen. The main result of the study is that the possibility of retaining some 14–20% surplus (in terms of biomass or energy or water) exists. The system is energetically feasible: rescued land can be doubled in approximately 4 yr. This approach is applicable to many Mediterranean coastal areas, as well as other similar situations elsewhere.

The effect of azeotropism on combustion characteristics of blended fuel pool fire was experimentally studied in an open fire test space of State Key Laboratory of Fire Science. A 30 cm × 30 cm square pool filled with n-heptane and ethanol blended fuel was employed. Flame images, burning rate and temperature distribution were collected and recorded in the whole combustion process. Results show that azeotropism obviously dominates the combustion behavior of n-heptane/ethanol blended fuel pool fire. The combustion process after ignition exhibits four typical stages: initial development, azeotropic burning, single-component burning and decay stage. Azeotropism appears when temperature of fuel surface reaches azeotropic point and blended fuel burns at azeotropic ratio. Compared with individual pure fuel, the effect of azeotropism on main fire parameters, such as flame height, burning rate, flame puffing frequency and centerline temperature were analyzed. Burning rate and centerline temperature of blended fuel are higher than that of individual pure fuel respectively at azeotropic burning stage, and flame puffing frequency follows the empirical formula between Strouhal and Froude number for pure fuel.

Abstract In this paper, coupled governing equations were proposed to simulate three-dimensional heat conduction and moisture transport in the nuclear waste repository. Because there will be a large temperature gradient near inner and outer boundaries of the bentonite buffer layer, and the heat driven moisture transport is introduced in the governing equation of moisture transport. By applying the Fourier and Laplace transforms, the governing equations were converted to the Bessel equations, and the Laplace-domain solutions to temperature and moisture distributions were derived through the inverse Fourier transform. The reliability of the proposed solutions was verified through comparative analysis with the line heat source model. These analytical solutions were applied to obtain the evolutions of temperature field and moisture distribution near the waste canister. Finally, a sensitivity study was performed to analyze the effects of relevant parameters on the heat driven moisture transport.

Abstract Molten salt reactors (MSRs) are a class of next-generation nuclear reactors that have received recent industrial and research interest. A generalized species transport solver was implemented in the Virtual Environment for Reactor Applications (VERA) computing suite to extend this tool to analyze liquid-fueled MSRs. This core simulator has been extended to model the transport of fission product gases into a collection of circulating gas bubbles with the purpose of removing the gases. This paper presents the governing species transport equation, along with various nuclear source terms. Development of the source term for phase migration is discussed, along with a simplified interfacial area tracking method. Finally, a case study on a simplified MSR loop is presented in which modeling parameters were varied to assess their impact on gas removal. The steady state results show that parameters such as bubble diameter, gas injection rate and mass transfer coefficient have a low to moderate effect on the fraction of xenon in the core region. Removal efficiency has the greatest effect on the fraction in the core region. After the pump bowl, bubble diameter has a minor effect on the fraction of xenon in the gas void. These results point out that increasing parameters such as mass transfer coefficient, gas injection rate, and removal efficiency drives the xenon into the circulating gas void, while decreasing bubble diameter also drives xenon into the gas void by increasing interfacial area.

In this study, pyrolysis of residual biomass from the agro-alimentary industry of Argentina was investigated. The studied biomasses were rice husk, peanut shell and wheat straw. The effect of pyrolysis temperature over solid (bio-char), liquid (bio-oil) and gas (bio-gas) fractions weight yields were evaluated for each biomass, in the range of 350-650 °C. The maximum yield of bio-oil was obtained at 550 °C for rice husk (45 wt%) and wheat straw (58 wt%), and at 500 °C for peanut shells (51 wt%). At those temperatures, the data recorded the smallest spread around the mean. Different characterization techniques of raw biomass were reported, namely, thermal behavior; proximate and ultimate analysis; content of Ca, Al, K, Si and Fe; and hemicellulose, cellulose and lignin composition. Bio-oils characterization included water content and chemical compounds identification. Furthermore, bio-char HHV and BET surface area were measured. Rice husk bio-oil showed 21% selectivity towards furans of which 75% corresponded to furfural and 5-HMF. Peanut shell bio-char presented the highest Higher Heating Value (7250 kcal/kg) and BET surface area (215 m2/g). In addition, co-pyrolysis reactions and the synergistic effects over obtained products completed this study. Co-pyrolysis bio-oils yields varied between 41 and 46 wt%, for all the mixtures. Bio-oil water content decreased up to 15% for rice husk mixed with peanut shell or wheat straw. Moreover, 5-HMF was detected in all bio-oils, and furfural selectivity was higher than 5% in the three mixtures investigated.

This paper presents a novel modified interactive honey bee mating optimization (IHBMO) base fuzzy stochastic long-term approach for determining optimum location and size of distributed energy resources (DERs). The Monte Carlo simulation method is used to model the uncertainties associated with long-term load forecasting. A proper combination of several objectives is considered in the objective function. Reduction of loss and power purchased from the electricity market, loss reduction in peak load level and reduction in voltage deviation are considered simultaneously as the objective functions. First, these objectives are fuzzified and designed to be comparable with each other. Then, they are introduced into an IHBMO algorithm in order to obtain the solution which maximizes the value of integrated objective function. The output power of DERs is scheduled for each load level. An enhanced economic model is also proposed to justify investment on DER. An IEEE 30-bus radial distribution test system is used to illustrate the effectiveness of the proposed method.

Abstract Thermal performance of three naturally ventilated public buildings in which the wind tower is an important architectural freature is studied. One of the three builidings as well as it's wind tower is instrumented for temperature, relative humidity and airflow velocity measurements, and the other two are instrumented for temperature measurement. The results have led to a discussion concerning the degree of wind tower effectiveness in achieving thermal comfort.