<p> A team at the University of Colorado at Boulder is working with the Bill &amp; Melinda Gates Foundation to develop a novel technical solution for 2.5 billion people in the developing world with no access to basic sanitation. The university's Sol-Char toilet uses concentrated sunlight to convert human fecal sludge into biochar, which has potential as a value-added product. The feasibility of using feces-derived biochar as a solid fuel for heating and cooking is assessed, considering energy content and elemental analysis of biochars made under different reactor conditions, ease of briquetting, and durability of biochar briquettes. Fecal biochars made at 300&deg;C were similar in energy content to wood biochars and bituminous coal, possessing a higher heating value of 25.6 MJ/kg, while fecal chars made at 750&deg;C were significantly lower in energy content at 13.8 MJ/kg. Chars derived from simulant feces favored by other Bill &amp; Melinda Gates Foundation sanitation research projects were found to differ significantly from fecal char in their energy content and briquetting characteristics. A frequently used correlation between elemental composition of chars and their higher heating values was adapted to be more applicable to feces-derived chars based on a review of fecal char literature and experimental results. Fecal chars made at low temperatures and briquetted with molasses and lime binders yielded briquettes of comparable strength and energy content to commercial charcoal briquettes, suggesting that briquettes made from human feces could be a significant contribution to the sanitation value chain.</p>

<p> The purpose of this dissertation was to develop, test, and evaluate a framework to assist investors in photovoltaic (PV) power plants in dust-prone arid regions make informed decisions regarding selection among PV panel cleaning alternatives. Soiling of PV panels is a problem in dust-prone arid regions such as the Arabian Gulf where daily dust deposition and frequent dust storms coupled with lack of rainfall can compromise PV panel energy output. There are several alternatives to clean the PV panels. However, not much research has been done to determine the most favorable means to do so or how often it is feasible to perform the cleanup. Furthermore, the decision maker/investor might face difficulty in selecting among several cleaning alternatives given the competing requirements that must be considered in the selection process. Therefore, in this research a framework was developed to assist investors in PV power plants determine: (1) how often it is economically feasible to clean the PV panels using different cleaning alternatives, (2) what impacts those cleanups have on the overarching factors considered during the selection process, and (3) what the most favorable cleaning alternative is in light of several competing requirements. </p><p> A hypothetical 1 MW PV plant located in Riyadh, Saudi Arabia, was used to test the developed framework which was accomplished by: (1) estimating the PV plant's lifetime energy yield using a PV performance simulation program, (2) researching and estimating the effects of daily dust deposition and dust storms on the panels' output, (3) surveying and collecting PV panel cleaning alternative cost and performance data, (4) developing a spreadsheet program to simulate PV plant lifetime performance under different scenarios using input data from the previous 3 steps, (5) using a multi criteria decision method (MCDM) to select among cleaning alternatives in light of competing criteria, (6) performing a sensitivity check on the criteria weights in the MCDM to check the robustness of the results. </p><p> Research results indicated that although PV panel cleaning can consume large amounts of water and result in release of harmful emissions to the environment, the benefits of such cleaning can be worth it. The results also indicated that for each given scenario, an optimum cleaning threshold can be determined. It was also determined that initiating a cleanup when the soiling reaches a certain threshold is a preferable approach to cleaning using a fixed schedule. In addition, One-on-one interviews with subject matter experts to elicit their opinion resulted in determination of the selection criteria and priorities used in the MCDM which consequently resulted in selection of a preferred alternative. The results of the MCDM showed that opinion and preferences can vary drastically among different stakeholders and that, for each particular scenario, the set of relevant criteria and their priorities will depend on the stakeholders involved and their influence on the selection decision. Subject matter expert evaluation of the developed framework on whether it can improve selection among PV panel cleaning alternatives was accomplished via a questionnaire in which the experts rated the degree of their agreement or disagreement on a Likert scale. Average results indicated agreement that the study can improve selection among PV panel cleaning alternatives.</p>

<p>A method of exhaust heat recovery from a spark-ignition internal combustion engine was explored, utilizing a steam reforming thermochemical reactor to produce a hydrogen-rich effluent, which was then consumed in the engine. The effects of hydrogen in the combustion process have been studied extensively, and it has been shown that an extension of the lean stability limit is possible through hydrogen enrichment. The system efficiency and the extension of the operational range of an internal combustion engine were explored through the use of a methane fueled naturally aspirated single cylinder engine co-fueled with syngas produced with an on board methane steam reformer. It was demonstrated that an extension of the lean stability limit is possible using this system.

<p> Lipid-producing microalgae are a feedstock for commercial products such as nutritional supplements, aquatic animal feed, and biofuels. Unlike most algal phyla, the diatoms (Bacillariophyta) characteristically produce storage lipids throughout their entire lifecycle. In this study, lipids were extracted via chloroform-methanol and quantified as percent dry weight, &mgr;g/mL, and pg/100 &mgr;m³ and then analyzed for a phylogenetic signal by comparing the variability between lineages to the variability within lineages for each metric. These ten taxa were then paired with data gathered from the literature and examined for a phylogenetic signal using previously described methods. In the first analysis, there was greater variability between than within lineages during stationary growth when using percent dry weight as a metric. In the second analysis, a statistically significant phylogenetic signal was detected for nutrient-deplete growth experiments when examining the genus-level phylogeny (P = 0.013).</p>

<p> Electricity is an indispensable commodity to modern society, yet it is delivered via a grid architecture that remains largely unchanged over the past century. A host of factors are conspiring to topple this dated yet venerated design: developments in renewable electricity generation technology, policies to reduce greenhouse gas emissions, and advances in information technology for managing energy systems. Modern electric grids are emerging as complex distributed systems in which a portfolio of power generation resources, often incorporating fluctuating renewable resources such as wind and solar, must be managed dynamically to meet uncontrolled, time-varying demand. Uncertainty in both supply and demand makes control of modern electric grids fundamentally more challenging, and growing portfolios of renewables exacerbate the challenge. </p><p> We study three electricity grids: the state of California, the province of Ontario, and the country of Germany. To understand the effects of increasing renewables, we develop a methodology to scale renewables penetration. Analyzing these grids yields key insights about rigid limits to renewables penetration and their implications in meeting long-term emissions targets. We argue that to achieve deep penetration of renewables, the operational model of the grid must be inverted, changing the paradigm from load-following supplies to supply-following loads. </p><p> To alleviate the challenge of supply-demand matching on deeply renewable grids, we first examine well-known techniques, including altering management of existing supply resources, employing utility-scale energy storage, targeting energy efficiency improvements, and exercising basic demand-side management. Then, we create several instantiations of supply-following loads -- including refrigerators, heating and cooling systems, and laptop computers -- by employing a combination of sensor networks, advanced control techniques, and enhanced energy storage. We examine the capacity of each load for supply-following and study the behaviors of populations of these loads, assessing their potential at various levels of deployment throughout the California electricity grid. Using combinations of supply-following strategies, we can reduce peak natural gas generation by 19% on a model of the California grid with 60% renewables. We then assess remaining variability on this deeply renewable grid incorporating supply-following loads, characterizing additional capabilities needed to ensure supply-demand matching in future sustainable electricity grids.</p>

<p> This thesis attempted to synthesize biodiesel using indigenous materials and simple aboriginal techniques. Biodiesel requires plant oil, an alcohol and a catalyst. Coconut oil was extracted using the unrefined method and a 15% yield was obtained. Palm trees can produce ethanol when its palm juice is collected and is fermented to make palm wine. The distillation of palm wine separated an ethanol-water mixture with 35 wt% ethanol content. Calcium oxide, obtained from eggshells, is a catalyst that speeds up the transesterification reaction. Wasted eggshells undergo a calcinations process where calcium carbonate decomposes into calcium oxide and carbon dioxide. A scanning electron microscope confirmed the calcinations at the surface of the eggshells. The Fourier Transform Infrared Spectroscopy analysis of each step confirmed biodiesel synthesis. The successful creation of biodiesel from coconut oil, ethanol and calcium oxide creates a potential for people in small tropical rural villages to empower themselves with just local abundant resources.</p>

<p> Growing crops for biofuel production on agricultural land has caused a debate between whether we should grow corn grain on productive, agricultural lands to feed a growing human population or to fuel our vehicles. This has increased interest in growing cellulosic biofuel feedstocks on marginal lands. Switchgrass (<i>Panicum virgatum</i> L.), a warm-season perennial grass, has been shown to be a viable bioenergy crop because it produces high yields on marginal lands under low water and nutrient conditions. West Virginia contains immense acreages of reclaimed surface mine lands and could offer enough area for the production of switchgrass as a feedstock for a biofuel industry.</p><p> The first study was established in 2008 to determine switchgrass yields of three different cultivars on two mine sites in West Virginia. The first site, which was reclaimed in the early 1990s using top soil and treated municipal sludge, consistently had the highest yield of the two sites with a sixth-year yield of 8.4 Mg Dry Matter (DM) ha^-1 averaged across varieties. Cave-in-Rock variety produced 13.0 Mg ha^-1 of biomass which was more than the other two varieties. The other site, Hobet, was prepared using crushed, unweathered sandstone in 2008 and average yields were 1.0 Mg ha^-1 for the sixth year of production.</p><p> The second study was conducted on two sites which were reclaimed with a layer of topsoil over gray overburden and seeded with Cave-in-Rock 2011. Fertilizer was applied at rates of 0, 33.6, and 67 kg N ha^-1. No fertilizer treatment yielded 0.32 Mg ha^-1 while the fertilizer treatments produced significantly higher yields.</p><p> The objective of the third study was to determine if cultivars and samples from fertilizer treatments differed in composition and theoretical ethanol yield. Compositional analysis was done using near infrared reflectance spectroscopy. It was determined that cultivars did not differ in theoretical ethanol yield with averages ranging from 364 to 438 L Mg^-1. Theoretical ethanol production from Cave-in-Rock was significantly higher ranging from 6,092 to 7,348 L ha^-1 due to its high biomass production. Fertilizer treatments did not greatly effect composition of switchgrass, but since it did improve yield this was reflected in greater ethanol production for fertilized treatments. Based on the information presented here, high biomass should be the goal for switchgrass grown for biofuel production. With proper soil substrate and fertilizer regime, switchgrass grown on reclaimed surface mines may have high enough yield and quality to support ethanol production in the future. </p>

<p> With the increasing attention and support behind plug in hybrid electric vehicles, research must be conducted to examine the impacts of vehicles on electric distribution and transmission systems. This research aims first to model the behavior of vehicle battery chargers during system disturbances and mitigate any impacts. A distribution test system example is modeled and several different vehicle charger topologies are added. Faults are applied to the distribution system with vehicle chargers connected and the results are examined. Based on these results, a control strategy to mitigate their negative impacts is suggested. Photovoltaic panels are then added to the system and the study is repeated. </p><p> Several services that plug in hybrid electric vehicles are capable of providing to the electric system are presented in order to allow electric vehicles to be seen as an asset to electric systems rather than a burden. These services are particularly focused on an electric system such as might be found on a college campus, which in this case is represented by the Clemson University electric distribution system. The first service presented is dynamic phase balancing of a distribution system using vehicle charging. Distribution systems typically face problems with unbalance. At most large car parks, a three phase electric supply is expected even though current standardized chargers are single phase. By monitoring system unbalance and choosing which phase a vehicle is allowed to charge from, unbalance between phases is reduced in a distribution system. The second service presented is a decentralized vehicle to campus control algorithm based on time of use rates. Using time of use electricity prices, discharging vehicle batteries during high prices and recharging at low prices is explored. Battery degradation as well as limits placed by required vehicle range availability are included in the decision on whether to charge or discharge. Electric utilities will also benefit from a reduction of load at peak times if vehicles discharge back to the campus. A comparison with stationary battery energy storage is included.</p>

<p> Plant cell walls are under investigation as a source for biofuel production, yet conversion of cell walls (biomass) into biofuel is currently too expensive to be competitive with gasoline. Biomass is recalcitrant; that is, it resists enzymatic degradation by cellulases into monosaccharides such as glucose. One source of recalcitrance may be the presence of extensins, covalently bound cell wall proteins that are extremely insoluble.</p><p> To determine what influence, if any, extensins have on biomass recalcitrance, I performed several experiments. I first turned to poplar biomass, which is a model source for biofuels. I found that protease treatment of poplar biomass after liquid hot water pretreatment reduced the hydroxyproline content (a proxy for extensins). The reduction in hydroxyproline content correlated with reduced recalcitrance, seen as an increase in glucose release after cellulase digestion of poplar biomass. I also tested whether <i>Arabidopsis</i> T-DNA insertional mutations in the genes encoding enzymes that perform extensin post-translational modifications could reduce extensin content or cross-linking, and whether this reduction was associated with reduced biomass recalcitrance. I found that although these mutants were hypothesized to have reduced incorporation of extensin in cell walls, no significant effects on extensin content in inflorescence stem cell walls (an analog for woody biomass), nor on glucose release from biomass, were found in any mutant line. Finally, I looked at the effects of extensin overexpression on glucose release in transgenic Arabidopsis lines containing synthetic genes encoding the complete extensin domain from <i> SlLRX1</i> or a short C-terminal region of 20 amino acids of <i> SlLRX1,</i> fused to the red fluorescent reporter protein tdTomato. Observation of the tdTomato fluorescence in transgenic biomass after various chemical and enzymatic treatments indicated that the C-terminal 20 amino acids of <i> SlLRX1</i> are sufficient to allow a strong association with the cell wall, while the complete <i>SlLRX1</i> extensin domain leads to an even stronger, perhaps covalent linkage. Lines transformed with the complete <i> SlLRX1</i> extensin domain had more than twice the hydroxyproline content in their stems than wild-type, but this increase in hydroxyproline did not affect the amount of glucose released from stems upon cellulase digestion. </p><p> Since protease treatment reduced both hydroxyproline content and recalcitrance in poplar biomass, further experiments to assess the nature of the association between extensins and cell walls are warranted to attempt to further reduce recalcitrance. In the experiments I performed, the stems of extensin modification mutant Arabidopsis lines showed no change in extensin modification, and therefore no effect on recalcitrance was observed; stems of transgenic overexpression Arabidopsis lines showed increased extensin content, but again, no effect on recalcitrance was observed. My investigations in Arabidopsis focused on stem tissue, as this is analogous to material used in biofuel production. However, extensins are most abundantly expressed in roots in many plants, particularly in Arabidopsis. Examination of roots of both mutant and transgenic Arabidopsis may be more revealing of the interactions between extensins, cell walls, and recalcitrance.</p>

<p>Legislated renewable portfolio standards (RPSs) may not be the key to ensure forecast energy demands are met. States without a legislated RPS and with efficient permitting procedures were found to have approved and issued 28.57% more permits on average than those with a legislated RPS. Assessment models to make informed decisions about the need and effect of legislated RPSs do not exist. Decision makers and policy creators need to use empirical data and a viable model to resolve the debate over a nationally legislated RPS. The purpose of this cross-sectional study was to determine if relationships between the independent variables of RPS and insolation levels and the dependent variable of the percentage of permits approved would prove to be a viable model. The research population was 68 cities in the United States, of which 55 were used in this study. The return on investment economic decision model provided the theoretical framework for this study and the model generated. The output of multiple regression analysis indicated a weak to medium positive relationship among the variables. None of these relationships were statistically significant at the 0.05 level. A model using site specific data might yield significant results and be useful for determining which solar energy projects to pursue and where to implement them without Federal or State mandated RPSs. A viable model would bring about efficiency gains in the permitting process and effectiveness gains in promoting installations of solar energy-based systems. Research leading to the development of a viable model would benefit society by encouraging the development of sustainable energy sources and helping to meet forecast energy demands.