Sustainable Energy Science

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.

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.

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.

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.

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.

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.

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.

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.

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.

"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."

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.

Sustainable Energy - without the hot air (short version) [html] (Fri 15/2/08) | pdf file

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.

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.