Matching Items (11)
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- All Subjects: Sustainability
- Creators: Phelan, Patrick
- Member of: ASU Electronic Theses and Dissertations
Description
Wind measurements are fundamental inputs for the evaluation of potential energy yield and performance of wind farms. Three-dimensional scanning coherent Doppler lidar (CDL) may provide a new basis for wind farm site selection, design, and control. In this research, CDL measurements obtained from multiple wind energy developments are analyzed and a novel wind farm control approach has been modeled. The possibility of using lidar measurements to more fully characterize the wind field is discussed, specifically, terrain effects, spatial variation of winds, power density, and the effect of shear at different layers within the rotor swept area. Various vector retrieval methods have been applied to the lidar data, and results are presented on an elevated terrain-following surface at hub height. The vector retrieval estimates are compared with tower measurements, after interpolation to the appropriate level. CDL data is used to estimate the spatial power density at hub height. Since CDL can measure winds at different vertical levels, an approach for estimating wind power density over the wind turbine rotor-swept area is explored. Sample optimized layouts of wind farm using lidar data and global optimization algorithms, accounting for wake interaction effects, have been explored. An approach to evaluate spatial wind speed and direction estimates from a standard nested Coupled Ocean and Atmosphere Mesoscale Prediction System (COAMPS) model and CDL is presented. The magnitude of spatial difference between observations and simulation for wind energy assessment is researched. Diurnal effects and ramp events as estimated by CDL and COAMPS were inter-compared. Novel wind farm control based on incoming winds and direction input from CDL's is developed. Both yaw and pitch control using scanning CDL for efficient wind farm control is analyzed. The wind farm control optimizes power production and reduces loads on wind turbines for various lidar wind speed and direction inputs, accounting for wind farm wake losses and wind speed evolution. Several wind farm control configurations were developed, for enhanced integrability into the electrical grid. Finally, the value proposition of CDL for a wind farm development, based on uncertainty reduction and return of investment is analyzed.
ContributorsKrishnamurthy, Raghavendra (Author) / Calhoun, Ronald J (Thesis advisor) / Chen, Kangping (Committee member) / Huang, Huei-Ping (Committee member) / Fraser, Matthew (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2013
Description
Urban water systems face sustainability challenges ranging from water quality, leaks, over-use, energy consumption, and long-term supply concerns. Resiliency challenges include the capacity to respond to drought, managing pipe deterioration, responding to natural disasters, and preventing terrorism. One strategy to enhance sustainability and resiliency is the development and adoption of smart water grids. A smart water grid incorporates networked monitoring and control devices into its structure, which provides diverse, real-time information about the system, as well as enhanced control. Data provide input for modeling and analysis, which informs control decisions, allowing for improvement in sustainability and resiliency. While smart water grids hold much potential, there are also potential tradeoffs and adoption challenges. More publicly available cost-benefit analyses are needed, as well as system-level research and application, rather than the current focus on individual technologies. This thesis seeks to fill one of these gaps by analyzing the cost and environmental benefits of smart irrigation controllers. Smart irrigation controllers can save water by adapting watering schedules to climate and soil conditions. The potential benefit of smart irrigation controllers is particularly high in southwestern U.S. states, where the arid climate makes water scarcer and increases watering needs of landscapes. To inform the technology development process, a design for environment (DfE) method was developed, which overlays economic and environmental performance parameters under different operating conditions. This method is applied to characterize design goals for controller price and water savings that smart irrigation controllers must meet to yield life cycle carbon dioxide reductions and economic savings in southwestern U.S. states, accounting for regional variability in electricity and water prices and carbon overhead. Results from applying the model to smart irrigation controllers in the Southwest suggest that some areas are significantly easier to design for.
ContributorsMutchek, Michele (Author) / Allenby, Braden (Thesis advisor) / Williams, Eric (Committee member) / Westerhoff, Paul (Committee member) / Arizona State University (Publisher)
Created2012
Description
An eco-industrial park (EIP) is an industrial ecosystem in which a group of co-located firms are involved in collective resource optimization with each other and with the local community through physical exchanges of energy, water, materials, byproducts and services - referenced in the industrial ecology literature as "industrial symbiosis". EIPs, when compared with standard industrial resource sharing networks, prove to be of greater public advantage as they offer improved environmental and economic benefits, and higher operational efficiencies both upstream and downstream in their supply chain.
Although there have been many attempts to adapt EIP methodology to existing industrial sharing networks, most of them have failed for various factors: geographic restrictions by governmental organizations on use of technology, cost of technology, the inability of industries to effectively communicate their upstream and downstream resource usage, and to diminishing natural resources such as water, land and non-renewable energy (NRE) sources for energy production.
This paper presents a feasibility study conducted to evaluate the comparative environmental, economic, and geographic impacts arising from the use of renewable energy (RE) and NRE to power EIPs. Life Cycle Assessment (LCA) methodology, which is used in a variety of sectors to evaluate the environmental merits and demerits of different kinds of products and processes, was employed for comparison between these two energy production methods based on factors such as greenhouse gas emission, acidification potential, eutrophication potential, human toxicity potential, fresh water usage and land usage. To complement the environmental LCA analysis, levelized cost of electricity was used to evaluate the economic impact. This model was analyzed for two different geographic locations; United States and Europe, for 12 different energy production technologies.
The outcome of this study points out the environmental, economic and geographic superiority of one energy source over the other, including the total carbon dioxide equivalent emissions, which can then be related to the total number of carbon credits that can be earned or used to mitigate the overall carbon emission and move closer towards a net zero carbon footprint goal thus making the EIPs truly sustainable.
Although there have been many attempts to adapt EIP methodology to existing industrial sharing networks, most of them have failed for various factors: geographic restrictions by governmental organizations on use of technology, cost of technology, the inability of industries to effectively communicate their upstream and downstream resource usage, and to diminishing natural resources such as water, land and non-renewable energy (NRE) sources for energy production.
This paper presents a feasibility study conducted to evaluate the comparative environmental, economic, and geographic impacts arising from the use of renewable energy (RE) and NRE to power EIPs. Life Cycle Assessment (LCA) methodology, which is used in a variety of sectors to evaluate the environmental merits and demerits of different kinds of products and processes, was employed for comparison between these two energy production methods based on factors such as greenhouse gas emission, acidification potential, eutrophication potential, human toxicity potential, fresh water usage and land usage. To complement the environmental LCA analysis, levelized cost of electricity was used to evaluate the economic impact. This model was analyzed for two different geographic locations; United States and Europe, for 12 different energy production technologies.
The outcome of this study points out the environmental, economic and geographic superiority of one energy source over the other, including the total carbon dioxide equivalent emissions, which can then be related to the total number of carbon credits that can be earned or used to mitigate the overall carbon emission and move closer towards a net zero carbon footprint goal thus making the EIPs truly sustainable.
ContributorsGupta, Vaibhav (Author) / Calhoun, Ronald J (Thesis advisor) / Dooley, Kevin (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2014
Description
Among the various end-use sectors, the commercial sector is expected to have the second-largest increase in total primary energy consump¬tion from 2009 to 2035 (5.8 quadrillion Btu) with a growth rate of 1.1% per year, it is the fastest growing end-use sectors. In order to make major gains in reducing U.S. building energy use commercial sector buildings must be improved. Energy benchmarking of buildings gives the facility manager or the building owner a quick evaluation of energy use and the potential for energy savings. It is the process of comparing the energy performance of a building to standards and codes, to a set target performance or to a range of energy performance values of similar buildings in order to help assess opportunities for improvement. Commissioning of buildings is the process of ensuring that systems are designed, installed, functionally tested and capable of being operated and maintained according to the owner's operational needs. It is the first stage in the building upgrade process after it has been assessed using benchmarking tools. The staged approach accounts for the interactions among all the energy flows in a building and produces a systematic method for planning upgrades that increase energy savings. This research compares and analyzes selected benchmarking and retrocommissioning tools to validate their accuracy such that they could be used in the initial audit process of a building. The benchmarking study analyzes the Energy Use Intensities (EUIs) and Ratings assigned by Portfolio Manager and Oak Ridge National Laboratory (ORNL) Spreadsheets. The 90.1 Prototype models and Commercial Reference Building model for Large Office building type were used for this comparative analysis. A case-study building from the DOE - funded Energize Phoenix program was also benchmarked for its EUI and rating. The retrocommissioning study was conducted by modeling these prototype models and the case-study building in the Facility Energy Decision System (FEDS) tool to simulate their energy consumption and analyze the retrofits suggested by the tool. The results of the benchmarking study proved that a benchmarking tool could be used as a first step in the audit process, encouraging the building owner to conduct an energy audit and realize the energy savings potential. The retrocommissioning study established the validity of FEDS as an accurate tool to simulate a building for its energy performance using basic inputs and to accurately predict the energy savings achieved by the retrofits recommended on the basis of maximum LCC savings.
ContributorsAgnihotri, Shreya Prabodhkumar (Author) / Reddy, T Agami (Thesis advisor) / Bryan, Harvey (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2011
Description
Pavement surface temperature is calculated using a fundamental energy balance model developed previously. It can be studied using a one-dimensional mathematical model. The input to the model is changed, to study the effect of different properties of pavement on its diurnal surface temperatures. It is observed that the pavement surface temperature has a microclimatic effect on the air temperature above it. A major increase in local air temperature is caused by heating of solid surfaces in that locality. A case study was done and correlations have been established to calculate the air temperature above a paved surface. Validation with in-situ pavement surface and air temperatures were made. Experimental measurement for the city of Phoenix shows the difference between the ambient air temperature of the city and the microclimatic air temperature above the pavement is approximately 10 degrees Fahrenheit. One mitigation strategy that has been explored is increasing the albedo of the paved surface. Although it will reduce the pavement surface temperature, leading to a reduction in air temperature close to the surface, the increased pavement albedo will also result in greater reflected solar radiation directed towards the building, thus increasing the building solar load. The first effect will imply a reduction in the building energy consumption, while the second effect will imply an increase in the building energy consumption. Simulation is done using the EnergyPlus tool, to find the microclimatic effect of pavement on the building energy performance. The results indicate the cooling energy savings of an office building for different types of pavements can be variable as much as 30%.
ContributorsSengupta, Shawli (Author) / Phelan, Patrick (Thesis advisor) / Kaloush, Kamil (Committee member) / Calhoun, Ronald (Committee member) / Arizona State University (Publisher)
Created2015
Description
In recent years, 40% of the total world energy consumption and greenhouse gas emissions is because of buildings. Out of that 60% of building energy consumption is due to HVAC systems. Under current trends these values will increase in coming years. So, it is important to identify passive cooling or heating technologies to meet this need. The concept of thermal energy storage (TES), as noted by many authors, is a promising way to rectify indoor temperature fluctuations. Due to its high energy density and the use of latent energy, Phase Change Materials (PCMs) are an efficient choice to use as TES. A question that has not satisfactorily been addressed, however, is the optimum location of PCM. In other words, given a constant PCM mass, where is the best location for it in a building? This thesis addresses this question by positioning PCM to obtain maximum energy savings and peak time delay. This study is divided into three parts. The first part is to understand the thermal behavior of building surfaces, using EnergyPlus software. For analysis, a commercial prototype building model for a small office in Phoenix, provided by the U.S. Department of Energy, is applied and the weather location file for Phoenix, Arizona is also used. The second part is to justify the best location, which is obtained from EnergyPlus, using a transient grey box building model. For that we have developed a Resistance-Capacitance (RC) thermal network and studied the thermal profile of a building in Phoenix. The final part is to find the best location for PCMs in buildings using EnergyPlus software. In this part, the mass of PCM used in each location remains unchanged. This part also includes the impact of the PCM mass on the optimized location and how the peak shift varies. From the analysis, it is observed that the ceiling is the best location to install PCM for yielding the maximum reduction in HVAC energy consumption for a hot, arid climate like Phoenix.
ContributorsPrem Anand Jayaprabha, Jyothis Anand (Author) / Phelan, Patrick (Thesis advisor) / Wang, Robert (Committee member) / Parrish, Kristen (Committee member) / Arizona State University (Publisher)
Created2018
Description
One of the key infrastructures of any community or facility is the energy system which consists of utility power plants, distributed generation technologies, and building heating and cooling systems. In general, there are two dimensions to “sustainability” as it applies to an engineered system. It needs to be designed, operated, and managed such that its environmental impacts and costs are minimal (energy efficient design and operation), and also be designed and configured in a way that it is resilient in confronting disruptions posed by natural, manmade, or random events. In this regard, development of quantitative sustainability metrics in support of decision-making relevant to design, future growth planning, and day-to-day operation of such systems would be of great value. In this study, a pragmatic performance-based sustainability assessment framework and quantitative indices are developed towards this end whereby sustainability goals and concepts can be translated and integrated into engineering practices.
New quantitative sustainability indices are proposed to capture the energy system environmental impacts, economic performance, and resilience attributes, characterized by normalized environmental/health externalities, energy costs, and penalty costs respectively. A comprehensive Life Cycle Assessment is proposed which includes externalities due to emissions from different supply and demand-side energy systems specific to the regional power generation energy portfolio mix. An approach based on external costs, i.e. the monetized health and environmental impacts, was used to quantify adverse consequences associated with different energy system components.
Further, this thesis also proposes a new performance-based method for characterizing and assessing resilience of multi-functional demand-side engineered systems. Through modeling of system response to potential internal and external failures during different operational temporal periods reflective of diurnal variation in loads and services, the proposed methodology quantifies resilience of the system based on imposed penalty costs to the system stakeholders due to undelivered or interrupted services and/or non-optimal system performance.
A conceptual diagram called “Sustainability Compass” is also proposed which facilitates communicating the assessment results and allow better decision-analysis through illustration of different system attributes and trade-offs between different alternatives. The proposed methodologies have been illustrated using end-use monitored data for whole year operation of a university campus energy system.
New quantitative sustainability indices are proposed to capture the energy system environmental impacts, economic performance, and resilience attributes, characterized by normalized environmental/health externalities, energy costs, and penalty costs respectively. A comprehensive Life Cycle Assessment is proposed which includes externalities due to emissions from different supply and demand-side energy systems specific to the regional power generation energy portfolio mix. An approach based on external costs, i.e. the monetized health and environmental impacts, was used to quantify adverse consequences associated with different energy system components.
Further, this thesis also proposes a new performance-based method for characterizing and assessing resilience of multi-functional demand-side engineered systems. Through modeling of system response to potential internal and external failures during different operational temporal periods reflective of diurnal variation in loads and services, the proposed methodology quantifies resilience of the system based on imposed penalty costs to the system stakeholders due to undelivered or interrupted services and/or non-optimal system performance.
A conceptual diagram called “Sustainability Compass” is also proposed which facilitates communicating the assessment results and allow better decision-analysis through illustration of different system attributes and trade-offs between different alternatives. The proposed methodologies have been illustrated using end-use monitored data for whole year operation of a university campus energy system.
ContributorsMoslehi, Salim (Author) / Reddy, T. Agami (Thesis advisor) / Lackner, Klaus S (Committee member) / Parrish, Kristen (Committee member) / Pendyala, Ram M. (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2018
Description
To date, the production of algal biofuels is not economically sustainable due to the cost of production and the low cost of conventional fuels. As a result, interest has been shifting to high value products in the algae community to make up for the low economic potential of algal biofuels. The economic potential of high-value products does not however, eliminate the need to consider the environmental impacts. The majority of the environmental impacts associated with algal biofuels overlap with algal bioproducts in general (high-energy dewatering) due to the similarities in their production pathways. Selecting appropriate product sets is a critical step in the commercialization of algal biorefineries.
This thesis evaluates the potential of algae multiproduct biorefineries for the production of fuel and high-value products to be economically self-sufficient and still contribute to climate change mandates laid out by the government via the Energy Independence and Security Act (EISA) of 2007. This research demonstrates:
1) The environmental impacts of algal omega-3 fatty acid production can be lower than conventional omega-3 fatty acid production, depending on the dewatering strategy.
2) The production of high-value products can support biofuels with both products being sold at prices comparable to 2016 prices.
3) There is a tradeoff between revenue and fuel production
4) There is a tradeoff between the net energy ratio of the algal biorefinery and the economic viability due to the lower fuel production in a multi-product model that produces high-value products and diesel vs. the lower economic potential from a multi-product model that just produces diesel.
This work represents the first efforts to use life cycle assessment and techno-economic analysis to assess the economic and environmental sustainability of an existing pilot-scale biorefinery tasked with the production of high-value products and biofuels. This thesis also identifies improvements for multiproduct algal biorefineries that will achieve environmentally sustainable biofuel and products while maintaining economic viability.
This thesis evaluates the potential of algae multiproduct biorefineries for the production of fuel and high-value products to be economically self-sufficient and still contribute to climate change mandates laid out by the government via the Energy Independence and Security Act (EISA) of 2007. This research demonstrates:
1) The environmental impacts of algal omega-3 fatty acid production can be lower than conventional omega-3 fatty acid production, depending on the dewatering strategy.
2) The production of high-value products can support biofuels with both products being sold at prices comparable to 2016 prices.
3) There is a tradeoff between revenue and fuel production
4) There is a tradeoff between the net energy ratio of the algal biorefinery and the economic viability due to the lower fuel production in a multi-product model that produces high-value products and diesel vs. the lower economic potential from a multi-product model that just produces diesel.
This work represents the first efforts to use life cycle assessment and techno-economic analysis to assess the economic and environmental sustainability of an existing pilot-scale biorefinery tasked with the production of high-value products and biofuels. This thesis also identifies improvements for multiproduct algal biorefineries that will achieve environmentally sustainable biofuel and products while maintaining economic viability.
ContributorsBarr, William James (Author) / Landis, Amy E. (Thesis advisor) / Westerhoff, Paul (Thesis advisor) / Rittmann, Bruce (Committee member) / Khanna, Vikas (Committee member) / Arizona State University (Publisher)
Created2016
Description
Ion exchange sorbents embedded with metal oxide nanoparticles can have high affinity and high capacity to simultaneously remove multiple oxygenated anion contaminants from drinking water. This research pursued answering the question, “Can synthesis methods of nano-composite sorbents be improved to increase sustainability and feasibility to remove hexavalent chromium and arsenic simultaneously from groundwater compared to existing sorbents?” Preliminary nano-composite sorbents outperformed existing sorbents in equilibrium tests, but struggled in packed bed applications and at low influent concentrations. The synthesis process was then tailored for weak base anion exchange (WBAX) while comparing titanium dioxide against iron hydroxide nanoparticles (Ti-WBAX and Fe-WBAX, respectively). Increasing metal precursor concentration increased the metal content of the created sorbents, but pollutant removal performance and usable surface area declined due to pore blockage and nanoparticle agglomeration. An acid-post rinse was required for Fe-WBAX to restore chromium removal capacity. Anticipatory life cycle assessment identified critical design constraints to improve environmental and human health performance like minimizing oven heating time, improving pollutant removal capacity, and efficiently reusing metal precursor solution. The life cycle environmental impact of Ti-WBAX was lower than Fe-WBAX as well as a mixed bed of WBAX and granular ferric hydroxide for all studied categories. A separate life cycle assessment found the total number of cancer and non-cancer cases prevented by drinking safer water outweighed those created by manufacture and use of water treatment materials and energy. However, treatment relocated who bore the health risk, concentrated it in a sub-population, and changed the primary manifestation from cancer to non-cancer disease. This tradeoff was partially mitigated by avoiding use of pH control chemicals. When properly synthesized, Fe-WBAX and Ti-WBAX sorbents maintained chromium removal capacity while significantly increasing arsenic removal capacity compared to the parent resin. The hybrid sorbent performance was demonstrated in packed beds using a challenging water matrix and low pollutant influent conditions. Breakthrough curves hint that the hexavalent chromium is removed by anion exchange and the arsenic is removed by metal oxide sorption. Overall, the hybrid nano-sorbent synthesis methods increased sustainability, improved sorbent characteristics, and increased simultaneous removal of chromium and arsenic for drinking water.
ContributorsGifford, James McKay (Author) / Westerhoff, Paul (Thesis advisor) / Hristovski, Kiril (Thesis advisor) / Chester, Mikhail (Committee member) / Arizona State University (Publisher)
Created2016
Description
Demand for green energy alternatives to provide stable and reliable energy
solutions has increased over the years which has led to the rapid expansion of global
markets in renewable energy sources such as solar photovoltaic (PV) technology. Newest
amongst these technologies is the Bifacial PV modules, which harvests incident radiation
from both sides of the module. The overall power generation can be significantly increased
by using these bifacial modules. The purpose of this research is to investigate and maximize
the effect of back reflectors, designed to increase the efficiency of the module by utilizing
the intercell light passing through the module to increase the incident irradiance, on the
energy output using different profiles placed at varied distances from the plane of the array
(POA). The optimum reflector profile and displacement of the reflector from the module
are determined experimentally.
Theoretically, a 60-cell bifacial module can produce 26% additional energy in
comparison to a 48-cell bifacial module due to the 12 excess cells found in the 60-cell
module. It was determined that bifacial modules have the capacity to produce additional
energy when optimized back reflectors are utilized. The inverted U reflector produced
higher energy gain when placed at farther distances from the module, indicating direct
dependent proportionality between the placement distance of the reflector from the module
and the output energy gain. It performed the best out of all current construction geometries
with reflective coatings, generating more than half of the additional energy produced by a
densely-spaced 60-cell benchmark module compared to a sparsely-spaced 48-cell reference
module.ii
A gain of 11 and 14% was recorded on cloudy and sunny days respectively for the
inverted U reflector. This implies a reduction in the additional cells of the 60-cell module
by 50% can produce the same amount of energy of the 60-cell module by a 48-cell module
with an inverted U reflector. The use of the back reflectors does not only affect the
additional energy gain but structural and land costs. Row to row spacing for bifacial
systems(arrays) is reduced nearly by half as the ground height clearance is largely
minimized, thus almost 50% of height constraints for mounting bifacial modules, using
back reflectors resulting in reduced structural costs for mounting of bifacial modules
solutions has increased over the years which has led to the rapid expansion of global
markets in renewable energy sources such as solar photovoltaic (PV) technology. Newest
amongst these technologies is the Bifacial PV modules, which harvests incident radiation
from both sides of the module. The overall power generation can be significantly increased
by using these bifacial modules. The purpose of this research is to investigate and maximize
the effect of back reflectors, designed to increase the efficiency of the module by utilizing
the intercell light passing through the module to increase the incident irradiance, on the
energy output using different profiles placed at varied distances from the plane of the array
(POA). The optimum reflector profile and displacement of the reflector from the module
are determined experimentally.
Theoretically, a 60-cell bifacial module can produce 26% additional energy in
comparison to a 48-cell bifacial module due to the 12 excess cells found in the 60-cell
module. It was determined that bifacial modules have the capacity to produce additional
energy when optimized back reflectors are utilized. The inverted U reflector produced
higher energy gain when placed at farther distances from the module, indicating direct
dependent proportionality between the placement distance of the reflector from the module
and the output energy gain. It performed the best out of all current construction geometries
with reflective coatings, generating more than half of the additional energy produced by a
densely-spaced 60-cell benchmark module compared to a sparsely-spaced 48-cell reference
module.ii
A gain of 11 and 14% was recorded on cloudy and sunny days respectively for the
inverted U reflector. This implies a reduction in the additional cells of the 60-cell module
by 50% can produce the same amount of energy of the 60-cell module by a 48-cell module
with an inverted U reflector. The use of the back reflectors does not only affect the
additional energy gain but structural and land costs. Row to row spacing for bifacial
systems(arrays) is reduced nearly by half as the ground height clearance is largely
minimized, thus almost 50% of height constraints for mounting bifacial modules, using
back reflectors resulting in reduced structural costs for mounting of bifacial modules
ContributorsMARTIN, PEDRO JESSE (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Phelan, Patrick (Committee member) / Wang, Liping (Committee member) / Arizona State University (Publisher)
Created2019