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Hans De Keulenaer

The World News and Society Articles - 21 Or 22 Good Reasons To Be A Green Business - 0 views

  • Clients and prospective customers prefer to do business with companies with common values. Client retention will increase while the base of new clients will expand. Public and private sector purchasing practices will increasingly consider a company’s environmental policies in the selection process.
Hans De Keulenaer

Small-scale wind energy | Carbon Trust - 0 views

  • Small-scale wind energy (wind turbines <50kW rated capacity) is receiving increasing interest as one of a number of microgeneration technologies with potential to reduce carbon emissions. Recent years have seen new products being made available on the UK market, which a survey by the British Wind Energy Association (BWEA) suggests is growing quickly.
Hans De Keulenaer

[0805.0939] Optimization of efficiency and energy density of passive micro fuel cells and g... - 0 views

  • A PEM micro fuel cell system is described which is based on self-breathing
    PEM micro fuel cells in the power range between 1 mW and 1W. Hydrogen is
    supplied with on-demand hydrogen production with help of a galvanic cell, that
    produces hydrogen when Zn reacts with water. The system can be used as a
    battery replacement for low power applications and has the potential to improve
    the run time of autonomous systems. The efficiency has been investigated as
    function of fuel cell construction and tested for several load profiles.
Hans De Keulenaer

Non-Deterministic Design of Utility Scale Wind Energy Systems - Georgia Tech's Institutiona... - 0 views

  • The wind is an increasingly significant source of energy with the rising price of non-renewable fuels. The purpose of this project is to determine the specific intensity and frequency of wind speed required to sustain a large-scale wind farm with power output on the order of hundreds of megawatts. To this end, a non-deterministic methodology will be developed to analyze the viability of wind energy systems. A deterministic analysis method considers the majority of design parameters to be known or fixed and may only perform trade studies on a few parameters at a time to optimize performance. In the case of the energy market though, this is not an advantageous strategy since several factors related to economic viability such as energy prices, interest rates, government incentives, acquisition costs and maintenance are highly variable and cannot be assumed to be known. A non-deterministic, statistical approach to wind turbine design has the advantage of predicting with corresponding levels of certainty the power output and economic viability of an energy system. The primary goal of this project is to define the envelope of operating conditions for a large-scale wind project while considering variables of both engineering and economic significance. The National Renewable Energy Laboratory’s (NREL) Hybrid Optimization Model for Electric Renewables (HOMER) will be incorporated into the previous analysis using YawDyn and PROPID to determine the economic returns on investment in hypothetical financing cases. Cost factors will now be assigned a mean value along with a probability distribution. Monte Carlo simulations will be run for a large number of variations in the assumed economic and engineering variables to develop an accurate estimate of the price per kilowatt-hour of energy produced from the simulated wind project for a variety of site conditions with the goal of finding the most suitable environment for sustainable wind development.
Sergio Ferreira

Improved Hydrogen storage - 0 views

  • he new analysis may point to a practical hydrogen storage material for automobile fuel cells and similar applications.
  • not only can store significant quantifies of hydrogen but also can release it at lower temperatures than the lithium amide alone (about 100 degrees Celsius) while generating much less ammonia.
Hans De Keulenaer

Report: Update on State Renewable Portfolio Standards - 0 views

  • According to a new report, "Renewables Portfolio Standards in the United States: A Status Report with Data through 2007," released by the Lawrence Berkeley National Laboratory, a growing number of states are supporting renewable electricity through the creation of renewable portfolio standards (RPS). The report provides a comprehensive overview of early experience with these state-level RPS policies.
Hans De Keulenaer

International Journal of Emerging Electric Power Systems - 0 views

  • This paper proposes a simple method of determining the distance to voltage collapse using some local information such as bus voltage magnitude and load current magnitude. First the voltage and current information are carefully processed to establish a voltage stability index (VSI) that varies almost linearly with load. The VSI is then used to estimate the distance to voltage collapse using linear extrapolation. The effects of generator reactive power limits, line tripping, non-uniform increase in load and additional shunt reactive power sources on the VSI are also investigated. The effectiveness of the proposed method of determining the distance to voltage collapse is then tested on the IEEE 30-bus system. The results obtained by the proposed method are also compared with the corresponding actual values found through repetitive power flow simulations and are observed to be in very good agreement.
Hans De Keulenaer

Journal of Agricultural & Food Industrial Organization - 0 views

  • Biofuels are prominent in current discussion both as a solution to problems and as a creator of problems. They have promise as a substitute for fossil fuels, particularly for petroleum as the raw material for transportation fuel. But biofuels also have pitfalls, especially when produced at a scale sufficient to replace a significant proportion of the world's use of petroleum. The articles in this special issue analyze key aspects of both the promise and pitfalls of biofuels. They address issues in the technology of producing raw materials for biofuels and converting these raw materials into fuel, resource constraints facing expansion of biofuel production, and the demand for fuels. Particular attention is paid to the relationship between expanded biofuel production and the cost of food. The economics of biofuels is inherently linked to policy issues as well as market analysis because biofuels in every country have received subsidies from governments. Consequently several articles address the welfare economics of governmental efforts to promote biofuels, with a focus on U.S. ethanol subsidies. These subsidies generate net social losses (deadweight costs) on a global scale, although not necessarily from the U.S. national viewpoint. Governmental promotion of biofuels can be justified on the grounds of externalities created by the use of fossil fuels, most notably in recent debates on global warming caused by the release of sequestered carbon in the form of carbon dioxide. This justification is weakened and perhaps even nullified by externalities in the production and use of biofuels. The articles in this issue consider a range of topics concerning these matters, and the welfare losses caused by biofuel subsidies absent net environmental gains from biofuels.
Hans De Keulenaer

EPQU Magazine Volume 3 Issue 1 | Leonardo ENERGY - 0 views

  • Highlights of the current issue include a series of case studies on power quality and energy efficiency in various industry sectors and a series of papers covering sector-specific power quality problems experienced in hospitals, large buildings or internet data centers. This issue also includes a number of vision statements on the future of power quality, i.e. its research needs, economics and regulatory framework.



    The issue contains 20 featured papers and reader contributions,
    3 video interviews and 4 reader questions.

Hans De Keulenaer

Green Buildings May Be Cheapest Way to Slow Global Warming: Scientific American - 0 views

  • "This is the cheapest, quickest, most significant way to make a dent in greenhouse gas emissions," says Jonathan Westeinde, chief executive of green developer Windmill Development Group in Ottawa, Ontario, and chair of the CEC report (who admits that green building regulations would be good for his business). But "buildings are not on the radar  of any governments … despite being an industry that represents 35 percent of greenhouse gas emissions."
Hans De Keulenaer

Peak Coal? | Webdiary - Founded and Inspired by Margo Kingston - 0 views

  • The New Scientist of 19 Jan 2008 carries an article, "Coal: Bleak outlook for the black stuff" (subscription required for full article), belatedly drawing attention to an interesting piece of analysis by Professor David Rutledge of CalTech in a lecture last October, where he suggests that world coal reserves are grossly overstated and could be substantially exhausted this century. It's well worth watching the whole hour of the lecture, because the PowerPoint alone [3MB] doesn't do his argument justice.
Hans De Keulenaer

Research - 0 views

  • The price of delivered electricity will rise if generators have to pay for
    carbon dioxide emissions through an implicit or explicit mechanism. There
    are two main effects that a substantial price on CO2 emissions would have
    in the short run (before the generation fleet changes significantly).
    First, consumers would react to increased price by buying less, described
    by their price elasticity of demand. Second, a price on CO2 emissions
    would change the order in which existing generators are economically
    dispatched, depending on their carbon dioxide emissions and marginal fuel
    prices. Both the price increase and dispatch changes depend on the mix of
    generation technologies and fuels in the region available for dispatch,
    although the consumer response to higher prices is the dominant effect. We
    estimate that the instantaneous imposition of a price of $35 per metric
    ton on CO2 emissions would lead to a 10% reduction in CO2 emissions in PJM
    and MISO at a price elasticity of -0.1. Reductions in ERCOT would be about
    one-third as large. Thus, a price on CO2 emissions that has been shown in
    earlier work to stimulate investment in new generation technology also
    provides significant CO2 reductions before new technology is deployed at
    large scale.
Hans De Keulenaer

Penn State Live - Solar cell directly splits water for hydrogen - 0 views

  • Plants trees and algae do it. Even some bacteria and moss do it, but scientists have had a difficult time developing methods to turn sunlight into useful fuel. Now, Penn State researchers have a proof-of-concept device that can split water and produce recoverable hydrogen.
Hans De Keulenaer

ScienceDirect - Renewable Energy : Microhydro: Cost-effective, modular systems for low head... - 0 views

  • Hans De Keulenaer
     
    This paper is an overview of a program that is in the final stages of developing a modular set of cost-effective microhydro schemes for site heads below those currently serviced by Pelton Wheels. The rationale has been that there is a multitude of viable low-head sites in isolated areas where microhydro is a realistic energy option, and where conventional economics are not appropriate, especially in Third World countries. The goals of this project have been to provide low-cost, soundly based turbine design solutions that systematically cover the 0.2-20 kW supply, that are uniquely resistant to debris blockage and are easily built by tradesmen of medium skills in regional workshops. The paper presents the results as a matrix of the most cost-effective penstocks matched to modular turbines using established electronic controls. It discusses practical issues of site selection and options for sites where exact matches are not achieved. It has been an object of the program to establish a benchmark for cost-effectiveness in the microhydro field.
Hans De Keulenaer

ScienceDirect - Renewable Energy : Solar thermal systems: Advantages in domestic integratio... - 0 views

  • Hans De Keulenaer
     
    Pollution represents a major issue, and so does the ability to utilize, when available, renewable energy sources instead of traditional ones. If, on the one hand, it is possible to utilize renewable energy sources in many contexts, on the other hand they are not exploited because of the high cost of the initial investment needed for the installation of these systems, above all when domestic usage is taken into account.

    This paper proposes a quantitative approach able to forecast the profitability of the introduction of domestic solar thermal systems operating in parallel with the most common systems for heating domestic sanitary water. The approach is developed firstly by analyzing the most common system for heating sanitary water from both the engineering and economic point of view. At the same time the technical-economic solutions related to the most commercialized solar heating systems, and their compatibility with the most common traditional heating systems are studied. This is carried out by using a differential economic analysis of different possible scenarios in which different matches between traditional and solar heating systems are shown, and their profitability is assessed as a function of the power installed.
Hans De Keulenaer

ScienceDirect - Renewable Energy : Opportunities for hydrogen production in connection with... - 0 views

  • Hans De Keulenaer
     
    This paper gives an overview of the opportunities that exist for combining wind power and hydrogen (H2) production in weak grids. It is described how H2 storage can be applied in both isolated and grid-connected systems, and how the produced H2 can be utilized for stationary energy supply and/or as a fuel for transportation. The paper discusses the benefits and limitations of the different H2 storage applications, and presents a logistic simulation model for performance evaluation of wind-H2 plants. A case study simulating the use of excess wind power in a weak distribution grid to produce H2 for vehicles has been presented. It is shown that the penetration of wind power can be significantly increased by introducing electrolytic H2 production as a controllable load. The results also indicate that there are large benefits of using the grid as backup for H2 production in periods with low wind speed, regarding the H2 storage sizing and the electrolyser operating conditions.
Hans De Keulenaer

ScienceDirect - Renewable Energy : A study on residential heating energy requirement and op... - 0 views

  • Hans De Keulenaer
     
    Heat loss from buildings has a considerable share in waste of energy especially in Turkey since no or little insulation is used in existing and new buildings. Therefore, energy savings can be obtained by determining of heat loss characteristics with using proper thickness of insulation. For this purpose, in this study, calculations of optimum insulation thickness are carried out on a prototype building in Bursa as a sample city. Considering long term and current outdoor air temperature records (from 1992 to 2005), degree-hour (DH) values are calculated, and the variation of annual energy requirement of the building is investigated for various architectural design properties (such as air infiltration rate, glazing type, and area). Then, the effects of the insulation thickness on the energy requirement and total cost are presented. Based on life cycle cost (LCC) analysis, the optimum insulation thicknesses are determined for different fuel types. As a conclusion, the length of the heating period is average 221 days, and the mean heating DH value is found as 45 113.2 besides changing between 38 000 and 55 000. The optimum insulation thicknesses for Bursa vary between 5.3 and 12.4 cm depending on fuel types. In addition to this, the variation in Turkey is more dramatically.
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