Uncertainty and Investment in Electricity Generation: the Case of Hydro-Québec

World wide the electricity industry is undergoing a substantial process of restructuring, with an emphasis on the introduction of competition in the generation sector. Competition is ostensibly going to lead to better incentives, both in the use of existing resources and in future investment decisions. One of the main drivers of this new environment will be the increased opportunity for energy sales between what had been, before the introduction of competition, fairly closed markets. These new opportunities may lead to new investments in generation and transmission capacity which will occur in order to take advantage of cost differentials between regions, one of the driving factors in the call for restructuring. Accounting for some of the underlying complexity of electricity systems, specifically equipment availability and load duration curves, this paper illustrates how uncertainty affects investment in generation. We offer a simple 2-region model to analyse this problem, based on the linear programming model of Chaton (1997). Specifically, we analyse the case where one region has access to four generation technologies, differentiated by cost characteristics as well as construction lead times. A second (neighbouring) region has access to only one of the generation technologies, hence the necessary asymmetry between producing regions. Uncertainty is present in the demand for energy in the first market, as well as in the input fuel prices. Given this uncertainty, and the possibility of electricity sales between regions, we investigate and characterise optimal generation investment in the first market as a function of the problem parameters. The model is calibrated with data from Hydro-Québec and the northeastern United States. This application is particularly interesting and relevant, given the abundance of relatively cheap hydroelectric power in Québec, and Hydro-Québec’s self-proclaimed strategic interests in increasing its exports to the northeastern markets. The numerical example illustrates the importance of appropriately modelling the complexity of the electrical system when considering the impacts of restructuring.Electricity Restructuring, Investment under Uncertainty

Inertia in the North American Electricity Industry: Can the Kyoto Protocol Objectives Be Realistically Met?

If they are to be attained, the objectives set in the Kyoto Protocol will impose fundamental changes on the structure of North America's economy. This text highlights the extent of the Kyoto challenge by clearly describing the historical inertia in terms of total market shares for different production technologies of the North American electricity industry. It also compares two potential scenarios of the industry changes needed to attain the Kyoto objectives. The results obtained suggest that it will be virtually impossible to reach the Kyoto objectives within the electricity industry.Kyoto Protocol, Electricity Industry, Technological Change

Competition along a river : Decentralizing hydropower production

We analyze the production of electricity from n power stations situated along a river in a dynamic model. Each power station's production of electricity is constrained by the quantity of water available to it (capacity constraint) as well as limitations of reservoir capacity (storage constraint). Due to the water flow, production from one power station affects the production capacity of the next downstream power station. We show that when no constraint (capacity or storage) is binding, competition dominates monopoly. We then provide some examples in which, because one power station is constrained, monopoly dominates competition. Finally, we illustrate the model with an empirical example.Hydropower, Electricity, Competition, Regulation, Water

L'ouverture du marché d'exportation d'électricité québécoise: réalité ou mirage à l'horizon

L'industrie de l'électricité subit une restructuration à l'échelle mondiale. La concurrence est introduite au niveau de la production alors que le transport et la distribution demeurent des monopoles réglementés par les gouvernements. Aux États-Unis, il y a déjà ouverture du marché de gros depuis le 1er janvier 1997, c'est-à-dire du marché entre les producteurs et les distributeurs. L'ouverture du marché de détail se dessine déjà à l'horizon. Les États de la Nouvelle-Angleterre et celui de New York ont des prix de l'électricité supérieurs à la moyenne américaine alors que le Québec a des prix parmi les plus bas au monde. Dans son plan stratégique pour la période 1998-2002, Hydro-Québec présente l'ouverture du marché de gros aux États-Unis comme une opportunité de croissance de ses exportations vers ce marché et de leur rentabilité. Dans ce texte, nous soulignons la présence de deux facteurs qui limitent la rentabilité des exportations québécoises d'électricité qui pourraient découler de l'ouverture du marché américain : premièrement, il y a le mode de tarification du réseau de transport selon le coût moyen et deuxièmement, il y a la tarification québécoise de l'électricité qui favorise la consommation domestique plutôt que l'exportation.

Macroeconomic trends and practice models impacting acute care surgery

Acute care surgery (ACS) diagnoses are responsible for approximately a quarter of the costs of inpatient care in the US government, and individuals will be responsible for a larger share of the costs of this healthcare as the population ages. ACS as a specialty thus has the opportunity to meet a significant healthcare need, and by optimizing care delivery models do so in a way that improves both quality and value. ACS practice models that have maintained or added emergency general surgery (EGS) and even elective surgery have realized more operative case volume and surgeon satisfaction. However, vulnerabilities exist in the ACS model. Payer mix in a practice varies by geography and distribution of EGS, trauma, critical care, and elective surgery. Critical care codes constitute approximately 25% of all billing by acute care surgeons, so even small changes in reimbursement in critical care can have significant impact on professional revenue. Staffing an ACS practice can be challenging depending on reimbursement and due to uneven geographic distribution of available surgeons. Empowered by an understanding of economics, using team-oriented leadership inherent to trauma surgeons, and in partnership with healthcare organizations and regulatory bodies, ACS surgeons are positioned to significantly influence the future of healthcare in the USA

Protection des habitats d'espèces menacées en terres privées: analyse d'instruments et de la politique canadienne

The preservation of biodiversity requires the protection of endangered species' habitats. In Canada, approximately 60% of these habitats are located on private lands. We start by analysing the obstacles to the protection of endangered species' habitats, with special attention to the compensation of private property owners affected by conservation efforts. After briefly reviewing the main measures adopted in Canada to protect natural habitats on private lands, we propose some conservation mechanisms that would not excessively burden public budgets. These measures should be discussed in the next proposal for a Canadian endangered species act. La préservation de la biodiversité nécessite la protection des habitats des espèces menacées. Au Canada, environ 60% de ces habitats sont situés sur des terres privées. Nous examinons la problématique de protection de ces habitats et notamment la question de la compensation des propriétaires privés. Nous analysons ensuite les principales mesures utilisées au Canada pour préserver les habitats naturels, et nous proposons des mécanismes de protection qui permettraient de dédommager les propriétaires terriens affectés tout en limitant les dépenses publiques. Ces mécanismes devraient être discutés lors de la prochaine proposition de loi sur la protection des espèces menacées au Canada.Biodiversité, habitats fauniques, instruments économiques

Globally, functional traits are weak predictors of juvenile tree growth, and we do not know why

1. Plant functional traits, in particular specific leaf area (SLA), wood density and seed mass, are often good predictors of individual tree growth rates within communities. Individuals and species with high SLA, low wood density and small seeds tend to have faster growth rates. 2. If community-level relationships between traits and growth have general predictive value, then similar relationships should also be observed in analyses that integrate across taxa, biogeographic regions and environments. Such global consistency would imply that traits could serve as valuable proxies for the complex suite of factors that determine growth rate, and, therefore, could underpin a new generation of robust dynamic vegetation models. Alternatively, growth rates may depend more strongly on the local environment or growth–trait relationships may vary along environmental gradients. 3. We tested these alternative hypotheses using data on 27 352 juvenile trees, representing 278 species from 27 sites on all forested continents, and extensive functional trait data, 38% of which were obtained at the same sites at which growth was assessed. Data on potential evapotranspiration (PET), which summarizes the joint ecological effects of temperature and precipitation, were obtained from a global data base. 4. We estimated size-standardized relative height growth rates (SGR) for all species, then related them to functional traits and PET using mixed-effect models for the fastest growing species and for all species together. 5. Both the mean and 95th percentile SGR were more strongly associated with functional traits than with PET. PET was unrelated to SGR at the global scale. SGR increased with increasing SLA and decreased with increasing wood density and seed mass, but these traits explained only 3.1% of the variation in SGR. SGR–trait relationships were consistently weak across families and biogeographic zones, and over a range of tree statures. Thus, the most widely studied functional traits in plant ecology were poor predictors of tree growth over large scales. 6. Synthesis. We conclude that these functional traits alone may be unsuitable for predicting growth of trees over broad scales. Determining the functional traits that predict vital rates under specific environmental conditions may generate more insight than a monolithic global relationship can offer

Effect of Sex and Prior Exposure to a Cafeteria Diet on the Distribution of Sex Hormones between Plasma and Blood Cells

It is generally assumed that steroid hormones are carried in the blood free and/or bound to plasma proteins. We investigated whether blood cells were also able to bind/carry sex-related hormones: estrone, estradiol, DHEA and testosterone. Wistar male and female rats were fed a cafeteria diet for 30 days, which induced overweight. The rats were fed the standard rat diet for 15 additional days to minimize the immediate effects of excess ingested energy. Controls were always kept on standard diet. After the rats were killed, their blood was used for 1) measuring plasma hormone levels, 2) determining the binding of labeled hormones to washed red blood cells (RBC), 3) incubating whole blood with labeled hormones and determining the distribution of label between plasma and packed cells, discounting the trapped plasma volume, 4) determining free plasma hormone using labeled hormones, both through membrane ultrafiltration and dextran-charcoal removal. The results were computed individually for each rat. Cells retained up to 32% estrone, and down to 10% of testosterone, with marked differences due to sex and diet (the latter only for estrogens, not for DHEA and testosterone). Sex and diet also affected the concentrations of all hormones, with no significant diet effects for estradiol and DHEA, but with considerable interaction between both factors. Binding to RBC was non-specific for all hormones. Estrogen distribution in plasma compartments was affected by sex and diet. In conclusion: a) there is a large non-specific RBC-carried compartment for estrone, estradiol, DHEA and testosterone deeply affected by sex; b) Prior exposure to a cafeteria (hyperlipidic) diet induced hormone distribution changes, affected by sex, which hint at sex-related structural differences in RBC membranes; c) We postulate that the RBC compartment may contribute to maintain free (i.e., fully active) sex hormone levels in a way similar to plasma proteins non-specific binding

Effect of Sex and Prior Exposure to a Cafeteria Diet on the Distribution of Sex Hormones between Plasma and Blood Cells

It is generally assumed that steroid hormones are carried in the blood free and/or bound to plasma proteins. We investigated whether blood cells were also able to bind/carry sex-related hormones: estrone, estradiol, DHEA and testosterone. Wistar male and female rats were fed a cafeteria diet for 30 days, which induced overweight. The rats were fed the standard rat diet for 15 additional days to minimize the immediate effects of excess ingested energy. Controls were always kept on standard diet. After the rats were killed, their blood was used for 1) measuring plasma hormone levels, 2) determining the binding of labeled hormones to washed red blood cells (RBC), 3) incubating whole blood with labeled hormones and determining the distribution of label between plasma and packed cells, discounting the trapped plasma volume, 4) determining free plasma hormone using labeled hormones, both through membrane ultrafiltration and dextran-charcoal removal. The results were computed individually for each rat. Cells retained up to 32% estrone, and down to 10% of testosterone, with marked differences due to sex and diet (the latter only for estrogens, not for DHEA and testosterone). Sex and diet also affected the concentrations of all hormones, with no significant diet effects for estradiol and DHEA, but with considerable interaction between both factors. Binding to RBC was non-specific for all hormones. Estrogen distribution in plasma compartments was affected by sex and diet. In conclusion: a) there is a large non-specific RBC-carried compartment for estrone, estradiol, DHEA and testosterone deeply affected by sex; b) Prior exposure to a cafeteria (hyperlipidic) diet induced hormone distribution changes, affected by sex, which hint at sex-related structural differences in RBC membranes; c) We postulate that the RBC compartment may contribute to maintain free (i.e., fully active) sex hormone levels in a way similar to plasma proteins non-specific binding

Isolation and Characterization of EstC, a New Cold-Active Esterase from Streptomyces coelicolor A3(2)

The genome sequence of Streptomyces coelicolor A3(2) contains more than 50 genes coding for putative lipolytic enzymes. Many studies have shown the capacity of this actinomycete to store important reserves of intracellular triacylglycerols in nutrient depletion situations. In the present study, we used genome mining of S. coelicolor to identify genes coding for putative, non-secreted esterases/lipases. Two genes were cloned and successfully overexpressed in E. coli as His-tagged fusion proteins. One of the recombinant enzymes, EstC, showed interesting cold-active esterase activity with a strong potential for the production of valuable esters. The purified enzyme displayed optimal activity at 35°C and was cold-active with retention of 25% relative activity at 10°C. Its optimal pH was 8.5–9 but the enzyme kept more than 75% of its maximal activity between pH 7.5 and 10. EstC also showed remarkable tolerance over a wide range of pH values, retaining almost full residual activity between pH 6–11. The enzyme was active toward short-chain p-nitrophenyl esters (C2–C12), displaying optimal activity with the valerate (C5) ester (kcat/Km = 737±77 s−1 mM−1). The enzyme was also very active toward short chain triglycerides such as triacetin (C2:0) and tributyrin (C4:0), in addition to showing good primary alcohol and organic solvent tolerance, suggesting it could function as an interesting candidate for organic synthesis of short-chain esters such as flavors