• Energy Research
• 13. Climate action close
• 7. Clean energy close
• US close
• University of Calgary close

Between 2008 and 2012, the delivered price of natural gas to the U.S. power sector fell 60 percent. This paper addresses, in theory and in practice, the effects of this negative price shock on electricity consumers and the environment. We demonstrate with a simple model that the larger the effects of gas prices on consumer welfare, the smaller the effects on pollution emissions and the smaller the increase in profits of existing natural gas-fired generators. Using detailed data on electricity prices, fuel consumption, and fuel prices from 2001 to 2012, we confirm this hypothesis. Regions that experience greater reductions in pollution emissions experience smaller reductions in electricity prices and consumer welfare.

This paper proposes an approach for analyzing the impacts of large-scale wind power integration on electricity market equilibria. A pool-based oligopolistic electricity market is considered including a day-ahead market and a number of real-time markets. Wind power is considered within the generation portfolio of the strategic producers, and the uncertainty of wind power production is modeled through a set of plausible scenarios. The strategic behavior of each producer is modeled through a stochastic bilevel model. The resulting nonlinear equilibrium problem with equilibrium constraints (EPEC) is linearized and then solved. Numerical results for a test case with increasing levels of the wind power penetration is provided.

Purpose: To examine the effects of the world's most challenging mountain ultramarathon (MUM, 330 km, cumulative elevation gain of +24,000 m) on the energy cost and kinematics of different uphill gaits. Methods: Before (PRE) and immediately after (POST) the competition, 19 male athletes performed three submaximal 5-min treadmill exercise trials in a randomized order: walking at 5 km·h-1, +20%; running at 6 km·h-1, +15%; and running at 8 km·h-1, +10%. During the three trials, energy cost was assessed using an indirect calorimetry system and spatiotemporal gait parameters were acquired with a floor-level high-density photoelectric cells system. Results: The average time of the study participants to complete the MUM was 129 h 43 min 48 s (range: 107 h 29 min 24 s to 144 h 21 min 0 s). Energy costs in walking (-11.5 ± 5.5%, P < 0.001), as well as in the first (-7.2 ± 3.1%, P = 0.01) and second (-7.0 ± 3.9%, P = 0.02) running condition decreased between PRE and POST, with a reduction both in the heart rate (-11.3, -10.0, and -9.3%, respectively) and oxygen uptake only for the walking condition (-6.5%). No consistent and significant changes in the kinematics variables were detected (P-values from 0.10 to 0.96). Conclusion: Though fatigued after completing the MUM, the subjects were still able to maintain their uphill locomotion patterns noted at PRE. The decrease (improvement) in the energy costs was likely due to the prolonged and repetitive walking/running, reflecting a generic improvement in the mechanical efficiency of locomotion after ~130 h of uphill locomotion rather than constraints imposed by the activity on the musculoskeletal structure and function.

Abstract An economic analysis oj a project to "skim" pyrolysis tars from thermal coal at the Calgary Power Keephills station by the Lurgi-Ruhrgas process has been performed. Upgrading to 886.7 kg/m3 (28 °API) synthetic crude oil by hydrotreating with the necessary hydrogen produced from natural gas yields a DCF rate of return of 21.2% based on the production of 2360 m3/d (14,844 bpsd) valued at $145.23/m3 ($23:09/bbl) from a plant costing $362 million, both in 1980 dollars. The evaluation, although not optimized in terms of plant size, indicates a high potential for contemporary implementation. Better yield data for Highvale subbituminous B coal are required. Introduction Background Coal must ultimately play an important role in Alberta's energy future because of the quality and the abundance of this Resource(1,2,3). Enormous coal reserves" coupled with an impending shortage of crude oil, raise important questions regarding the most applicable coal liquefaction process, the most likely timing if such processes are to be used and the resulting economics. The current status of coal liquefaction technology has been adequately reviewed by a number of authors(4,5,6,7,8), and only a brief review is undertaken to justify the selection of a process and situation which are deemed most favourable in an Alberta context. In this discussion, the term "synthetic crude oil" will refer to a highly aromatic and napthenic, ash-free product of no more than 921.3 kg/m3 (&gt;22 ° API) containing approximately 0.1% sulphur by weight and appreciable quantities of oxygen and nitrogen. The objective of coal liquefaction processes is to obtain a liquid product with a higher H/C ratio and lower average molecular weight than the parent coal. The coal molecule, with an empirical formula of C135H97O9NS(9), is a complex three dimensional, heterocyclic structure with aromatic rings joined by aliphatic, oxygen and sulphur bridges: Over 70% of the carbon atoms are in aromatic rings and the structure is so tightly condensed that many carbon atoms have no hydrogen attached to them. Figure 1 illustrates three main routes by which coal liquids may be obtained: pyrolysis, which improves the H/C ratio by carbon rejection through the production of byproduct coke; hydrogenation, involving hydrogen addition; and synthesis, involving both the addition of hydrogen via partial oxidation to H2 and CO and rejection of carbon by CO2 removal prior to catalytic reaction of the synthesis gas. Comparison of Economics Economics have been published for many coal liquefaction processes, but meaningful comparisons of such figures may only be made if all evaluation parameters are consistent. Equivalent timing, location, type of product, scale of plant, financing parameters, feedstock cost and offsite facilities must all be considered. A method developed by Herring(10) has been used to bring these parameters to a consistent baseline for several of the more advanced liquefaction processes. A 15,900-m3/d (100,000-bbl/d) facility, located in the U.S., earning a 12% DCF ROR and producing a synthetic crude oil product from coal valued at $0.47/ GJ ($0.50/mmBtu) in 1980, has been considered.

SummarySupercapacitors are crucial elements in advanced industrial electronic systems particularly when supplied from renewable energy sources. Here, we derive expressions for the current, power, and stored energy in a supercapacitor excited with a step voltage signal. Although, it is not common practice to charge supercapacitors using a step voltage, these devices are sometimes used in switching‐type applications where they are subject to this type of signal. We validate the derived mathematical expression of the current via experiments on four different commercial devices. By fitting the measured current data to the derived expression, the parameters of these devices, which are modeled as a series connection of an internal resistance and a constant phase element (CPE), are also estimated. Power and energy are then evaluated followed by the estimation of the effective capacitance for each device. Our analysis makes use of fractional order calculus as opposed to classical integer‐order models.

AbstractDecarbonizing the energy system is critical for addressing climate change. Given the dominance of fossil fuels in the energy system, decarbonization requires rapid and significant industrial transition of the energy supply at scale. This includes explicit and coordinated plans not only for zero carbon phase‐in, but for fossil carbon phase‐out. Even very rapid decarbonization will likely take decades, leading to a medium‐term future where the conventional, fossil‐based energy system coexists with a new, zero‐carbon energy system. Each imposes operational constraints on the other: what we call the mid‐transition. Notably, this coexistence means that the new, zero‐carbon system will develop under fossil carbon system constraints. The mid‐transition will therefore likely require specific analytical metrics designed to support decision making under dynamic and uncertain conditions. Many aspects of transition will be felt, and shaped, directly by individuals because of our direct interactions with energy systems. Even rare missteps are likely to have significant and potentially system design‐relevant impacts on perception, political support, and implementation. Comparisons of the new system to the old system are likely to rest on experience of a world less affected by climate change, such that concerns about lower reliability, higher costs, and other challenges might be perceived as inherent to zero‐carbon systems, versus energy systems facing consequences of climate change and long‐term underinvestment. This review assesses and evaluates medium‐term challenges associated with the mid‐transition in the United States, emphasizing the need for explicit planning for joint and coordinated phase‐in and phase‐out.This article is categorized under: The Carbon Economy and Climate Mitigation > Decarbonizing Energy and/or Reducing Demand

Abstract Two thirds of Canadians reside in urban areas and 85% of recent population growth occurs in these areas. The intensity and duration of extreme hot weather events are predicted to increase in Canadian cities and in cities globally. It is well established that human suffering due to extreme heat is exacerbated in urban as compared to rural environments. Understanding the characteristics of urban landscapes that play the greatest roles in exacerbating the human health impact of extreme heat is thus imperative. This study explores the relationship between the amount of canopy cover from trees and the incidence of heat-related morbidity during extreme heat events in 544 neighbourhoods of Toronto, Ontario, Canada. Four extreme heat events from three years were studied. Heat-related ambulance calls were found to be 12.3% higher during the heat events than in the preceding or the following week. The number of heat-related ambulance calls was negatively correlated to canopy cover (Spearman Rank rho = −0.094, p = 0.029) and positively correlated to hard surface cover (Spearman Rank rho = 0.150, p 5% could reduce heat-related ambulance calls by approximately 80%. These results have important implications for human health during heat events, particularly in the context of global climate change and urban heat islands, both of which are trending toward hotter urban environments in future.

There is uncertainty about the response of the climate system to future trajectories of radiative forcing. To quantify this uncertainty we conducted face-to-face interviews with 14 leading climate scientists, using formal methods of expert elicitation. We structured the interviews around three scenarios of radiative forcing stabilizing at different levels. All experts ranked “cloud radiative feedbacks” as contributing most to their uncertainty about future global mean temperature change, irrespective of the specified level of radiative forcing. The experts disagreed about the relative contribution of other physical processes to their uncertainty about future temperature change. For a forcing trajectory that stabilized at 7 Wm -2 in 2200, 13 of the 14 experts judged the probability that the climate system would undergo, or be irrevocably committed to, a “basic state change” as ≥0.5. The width and median values of the probability distributions elicited from the different experts for future global mean temperature change under the specified forcing trajectories vary considerably. Even for a moderate increase in forcing by the year 2050, the medians of the elicited distributions of temperature change relative to 2000 range from 0.8–1.8 °C, and some of the interquartile ranges do not overlap. Ten of the 14 experts estimated that the probability that equilibrium climate sensitivity exceeds 4.5 °C is > 0.17, our interpretation of the upper limit of the “likely” range given by the Intergovernmental Panel on Climate Change. Finally, most experts anticipated that over the next 20 years research will be able to achieve only modest reductions in their degree of uncertainty.