Engineering Physics Commons^™

Lecture 12: Recent Advances In Time Integration Methods And How They Can Enable Exascale Simulations, Carol S. Woodward

Mathematical Sciences Spring Lecture Series

To prepare for exascale systems, scientific simulations are growing in physical realism and thus complexity. This increase often results in additional and changing time scales. Time integration methods are critical to efficient solution of these multiphysics systems. Yet, many large-scale applications have not fully embraced modern time integration methods nor efficient software implementations. Hence, achieving temporal accuracy with new and complex simulations has proved challenging. We will overview recent advances in time integration methods, including additive IMEX methods, multirate methods, and parallel-in-time approaches, expected to help realize the potential of exascale systems on multiphysics simulations. Efficient execution of these methods …

Magnetocaloric Effect Near Room Temperature In Quintenary And Sextenary Heusler Alloys, Benjamin D. White, R. I. Barabash, O. M. Barabash, I. Jeon, M. B. Maple

All Faculty Scholarship for the College of the Sciences

An inverse magnetocaloric effect is studied in Ni₂Mn_1+xX_1-x-type Heusler alloys. Principally known for their shape-memory properties, these alloys also exhibit significant entropy and temperature changes (ΔS and ΔT_Ad, respectively) under adiabatic conditions when a modest magnetic field is applied. We investigated the impact on magnetocaloric properties of introducing substantial chemical disorder on the X-site (X = Si, Ga, In), of replacing Ni with nonmagnetic Ag, and of replacing a small amount of Mn with Gd. While a reduction in ΔS is observed in the first two cases, we observe a significant enhancement …

Strengthening The Development Of The Short-Rotation Plantations Bioenergy Sector: Policy Insights From Six European Countries, Carlos Parra-Lopez, Martin Holley, Kevin Lindegaard, Samir Sayadi, Gonzalo Esteban-Lopez, Victor Duran-Zuazo, Christoph Knauer, Hans-Georg Von Engelbrechten, Ralf Winterber, Annika Henriksson, Annette Lamley, Anders Nylander, Susanne Paulrud, Pauline Leonard, Patrick Daly, Lukasz Drzewaszewski, Wojciech Rzewuski

Articles

This paper, based on a participatory methodological framework involving expert stakeholders and researchers from six European countries (Germany, Ireland, Poland, Spain, Sweden and UK), analyses the priority issues for the development of short-rotation plantations (SRP), and proposes a series of policy strategies to strengthen this development. The results indicate that there is a lack of awareness of the multifaceted benefits of SRP at the level of farmers, policy makers and public authorities. More research is required to put a value on the multifunctionality of SRP and justify its public support. Small-scale projects using established technologies are also required with energy …

Analyzing Major Challenges Of Wind And Solar Variability In Power Systems, Falko Ueckerdt, Robert Brecha, Gunnar Luderer

Physics Faculty Publications

Ambitious policy targets together with current and projected high growth rates indicate that future power systems will likely show substantially increased generation from renewable energy sources. A large share will come from the variable renewable energy (VRE) sources wind and solar photovoltaics (PV); however, integrating wind and solar causes challenges for existing power systems. In this paper we analyze three major integration challenges related to the structural matching of demand with the supply of wind and solar power: low capacity credit, reduced utilization of dispatchable plants, and over-produced generation. Based on residual load duration curves we define corresponding challenge variables …

Cost-Availability Curves For Hierarchical Implementation Of Residential Energy-Efficiency Measures, Roman Villoria-Siegert, Philip Brodrick, Kevin P. Hallinan, Robert J. Brecha

Physics Faculty Publications

Historical residential electricity data and natural gas consumption data were collected for, respectively, 1,200 and 178 residences in a small town in the USA. These data were merged with local building and weather databases, and energy consumption models were developed for each residence, revealing substantial variation in heating and cooling intensity. After estimating approximate physical building characteristics, energy profiles for each residence were calculated, and savings from adoption of the most cost-effective energy-efficiency measures for each residence were estimated. Effectively, we wish to leverage commonly available data sets to infer characteristics of building envelopes and equipment, without the need for …

Global Fossil Energy Markets And Climate Change Mitigation: An Analysis With Remind, Nico Bauer, Ioanna Mouratiadou, Gunnar Luderer, Lavinia Baumstark, Robert J. Brecha, Ottmar Edenhofer, Elmar Kriegler

Physics Faculty Publications

We analyze the dynamics of global fossil resource markets under different assumptions for the supply of fossil fuel resources, development pathways for energy demand, and climate policy settings. Resource markets, in particular the oil market, are characterized by a large discrepancy between costs of resource extraction and commodity prices on international markets. We explain this observation in terms of (a) the intertemporal scarcity rent, (b) regional price differentials arising from trade and transport costs, (c) heterogeneity and inertia in the extraction sector. These effects are captured by the REMIND model. We use the model to explore economic effects of changes …

The Carbon Rent Economics Of Climate Policy, Matthias Kalkuhl, Robert J. Brecha

Physics Faculty Publications

By reducing the demand for fossil fuels, climate policy can reduce scarcity rents for fossil resource owners. As mitigation policies ultimately aim to limit emissions, a new scarcity for “space” in the atmosphere to deposit emissions is created. The associated scarcity rent, or climate rent (that is, for example, directly visible in permit prices under an emission trading scheme) can be higher or lower than the original fossil resource rent. In this paper, we analyze analytically and numerically the impact of mitigation targets, resource availability, backstop costs, discount rates and demand parameters on fossil resource rents and the climate rent. …

Development Without Energy? Assessing Future Scenarios Of Energy Consumption In Developing Countries, Jan Christof Steckel, Robert J. Brecha, Michael Jakob, Jessica Strefler, Gunnar Luderer

Physics Faculty Publications

We analyze the relationship between economic development and energy consumption in the context of greenhouse gas mitigation. The main contribution of this work is to compare estimates of energy thresholds in the form of minimum energy requirements to reach high levels of development with output projections of per capita final energy supply from a group of integrated assessment models (IAMs). Scenarios project that reductions of carbon emissions in developing countries will be achieved not only by means of decreasing the carbon intensity, but also by making a significant break with the historically observed relationship between energy use and economic growth. …

Logistic Curves, Extraction Costs And Peak Oil, Robert J. Brecha

Physics Faculty Publications

Debates about the possibility of a near-term maximum in world oil production have become increasingly prominent over the past decade, with the focus often being on the quantification of geologically available and technologically recoverable amounts of oil in the ground. Economically, the important parameter is not a physical limit to resources in the ground, but whether market price signals and costs of extraction will indicate the efficiency of extracting conventional or nonconventional resources as opposed to making substitutions over time for other fuels and technologies. We present a hybrid approach to the peak-oil question with two models in which the …

Variable Renewable Energy In Modeling Climate Change Mitigation Scenarios, Falko Ueckerdt, Robert J. Brecha, Gunnar Luderer, Patrick Sullivan, Eva Schmid, Nico Bauer, Diana Böttger

Physics Faculty Publications

This paper addresses the issue of how to account for short‐term temporal variability of renewable energy sources and power demand in long‐term climate change mitigation scenarios in energy‐economic models. An approach that captures in a stylized way the major challenges to the integration of variable renewable energy sources into power systems has been developed. As a first application this approach has been introduced to REMIND‐D, a hybrid energy‐economy model of Germany. An approximation of the residual load duration curve is implemented. The approximating function endogenously changes depending on the penetration and mix of variable renewable power. The approach can thus …

Logistic Curves, Extraction Costs And The Effective Size Of Oil Resources, Robert J. Brecha

Physics Faculty Publications

The size of potential fossil fuel resources is an issue of perennial interest and controversy. Fundamentally, there appears to be a conflict in interpretation of available data for both past and future extraction histories. As fossil-fuel prices rose dramatically over the past several years, the question of resources once again became acute. In this paper we concentrate on conventional and non-conventional oil resources and make four main points, with the overarching theme that one can determine an effective oil resource that represents significantly less availability for consumption than usually posited by tallying resources in place.

First, looking at oil production …

Prioritizing Investment In Residential Energy Efficiency And Renewable Energy: A Case Study For The U.S. Midwest, Robert J. Brecha, Austin Mitchell, Kevin P. Hallinan, J. Kelly Kissock

Physics Faculty Publications

Residential building energy use is an important contributor to greenhouse gas emissions and in the United States represents about 20% of total energy consumption. A number of previous macro-scale studies of residential energy consumption and energy-efficiency improvements are mainly concerned with national or international aggregate potential savings. In this paper we look into the details of how a collection of specific homes in one region might reduce energy consumption and carbon emissions, with particular attention given to some practical limits to what can be achieved by upgrading the existing residential building stock. Using a simple model of residential, single-family home …

Establishing Building Recommissioning Priorities And Potential Energy Savings From Utility Energy Data, Kevin P. Hallinan, Philip Brodrick, Jessica Northridge, J. Kelly Kissock, Robert J. Brecha

Physics Faculty Publications

An energy reduction program for commercial buildings is implemented for a SW Ohio natural gas utility. The aim of this study is to demonstrate that historical utility data for individual building customers, along with knowledge of pertinent building information (square footage, year built, number of floors, height of floors, wall construction type, and use type) available in county auditor databases, could be used to identify the best candidate buildings for recommissioning in terms of energy savings and simple payback. A study is completed for all natural gas customers of a utility in Montgomery and Clinton counties in Ohio. A total …

Targeting Residential Energy Reduction For City Utilities Using Historical Electrical Utility Data And Readily Available Building Data, Kevin P. Hallinan, J. Kelly Kissock, Robert J. Brecha, Austin Mitchell

Physics Faculty Publications

Energy use data for the eight-year period 2003–2010 was analyzed for over 1200 single family residences in Village of Yellow Springs, Ohio. Electricity, natural gas, residential building, and weather databases are merged to permit determination of the energy intensity of each home in the village. The energy use intensity for each home is disaggregated into weather independent and weather dependent electric and natural gas use. This use is compared to typical baseline, cooling, and heating energy use for the region. From this comparison, priority homes are identified for energy reduction investment. Collective potential low cost energy reduction is estimated for …

Emissions Scenarios In The Face Of Fossil-Fuel Peaking, Robert J. Brecha

Physics Faculty Publications

Emissions scenarios used by the Intergovernmental Panel on Climate Change (IPCC) are based on detailed energy system models in which demographics, technology and economics are used to generate projections of future world energy consumption, and therefore, of greenhouse gas emissions. We propose in this paper that it is useful to look at a qualitative model of the energy system, backed by data from short- and medium-term trends, to gain a sense of carbon emission bounds. Here we look at what may be considered a lower bound for 21st century emissions given two assumptions: first, that extractable fossil-fuel resources follow the …

Measurement Of Currents In Lake Mead With The Deep Water Isotopic Current Analyzer (Dwica), J. J. Sartoris, D. A. Hoffman, Bureau Of Reclamation

Publications (WR)

In Nov 1967, a Deep Water Isotopic Current Analyzer (DWICA) was used to study current patterns in the Boulder Basin of Lake Mead to determine if low-quality water from Las Vegas Bay might enter the Southern Nevada Water Project intake on Saddle Island. Secondary objectives were to study the general current patterns in Boulder Basin and the effect of power discharges at Hoover Dam on these currents. Results of current measurements at 3 stations in Boulder Basin are given. Observations indicate a definite possibility that low-quality water from Las Vegas Bay might enter the water intake on Saddle Island. Current …