market clearing with stochastic security part i formulation the first of this two paper series formulates a stochastic security constrained multi period electricity market clearing problem with unit commitment the stochastic security criterion accounts for a pre selected set of random generator and line outages with known historical failure rates and involuntary load shedding as optimization variables unlike the classical deterministic reserve constrained unit commitment here the reserve services are determined by economically penalizing the operation of the market by the expected load not served the proposed formulation is a stochastic programming problem that optimizes concurrently with the pre contingency social welfare the expected operating costs associated with the deployment of the reserves following the contingencies this stochastic programming formulation is solved in the second companion paper using mixed integer linear programming methods two cases are presented a small transmission constrained three bus network scheduled over a horizon of four hours and the ieee reliability test system scheduled over 24 h the impact on the resulting generation and reserve schedules of transmission constraints and generation ramp limits of demand side reserve of the value of load not served and of the constitution of the pre selected set of contingencies are assessed

the tale of the tails canadian income inequality in the 1980s and 1990s we present new evidence on levels and trends in after tax income inequality in canada between 1980 and 2000 we argue that existing data sources may miss changes in the tails of the income distribution and that many of the changes in the income distribution have been in the tails for this reason we turn to an alternative source in particular we construct data on after tax and transfer income using census files augmented with predicted taxes based on information available from administrative tax data using these data we find that canadian after tax inequality levels are substantially higher than has been previously recognized primarily because income levels are lower at the bottom of the distribution than in commonly used survey data we also find larger long term increases in after tax income inequality and far more variability over the economic cycle this raises interesting questions about the role of the tax and transfer system in mitigating both trends and fluctuations in market income inequality les auteurs presentent de nouveaux resultats sur les niveaux et tendances de l inegalite des revenus apres impots au canada entre 1980 et 2000 on suggere que les donnees existantes peuvent avoir ignore des changements dans les extremites de cette distribution alors que le gros des changements y etait concentre pour cette raison les auteurs se sont tournes vers une autre source de donnees ils ont construit une base de donnees sur les revenus apres impots et les paiements de transfert en utilisant les donnees du recensement ainsi que des donnees additionnelles sur les impots prevus a partir de renseignements disponibles dans les dossiers administratifs on decouvre que les niveaux d inegalite des revenus apres impots sont beaucoup plus eleves que ce qu on a suggere jusqu ici d abord parce que les niveaux de revenus sont plus bas au pied de la distribution que ne le suggerent les donnees d enquetes on decouvre aussi un accroissement plus grand a long terme de l inegalite des revenus apres impots et une plus grande variabilite au cours du cycle economique voila qui souleve des questions interessantes a propos du role de la fiscalite et du systeme de paiements de transfert dans la modulation de la tendance et des fluctuations dans l inegalite des revenus du marche

stochastic modelling of renewable energy sources from operators point of view a survey abstract high penetration of renewable energy sources especially weather dependent sources has increased the power systems uncertainties for any analysis in power systems such as planning and operation it is essential to confront the stochastic nature of these sources in order to get much more precise results since operators need proper strategies and methods to decline negative effects of the stochastic behaviour of renewable power generators such as total operation cost growth this paper provides a review of different state of the art approaches from the operator s viewpoint for handling the stochastic behaviour of renewable sources hence in this paper three different strategies are categorized for stochastic analysis of these sources the first strategy is mathematical modelling including stochastic dependency and independency multi dimensional dependence forecast and scenarios afterwards demand side management which is one of the other approaches for dealing with these uncertainties is investigated and different demand response programs and some methods to model them are presented finally the effect of different electricity market schemes and relevant optimization methods to mitigate the variations of renewable energy sources are discussed the study demonstrates that an operator should choose one or a combination of these three approaches based on its requirements

portfolio and contract design for demand response resources abstract electricity generation from renewable energy sources has seen significant growth in recent years to improve grid integration of these volatile energy resources demand side flexibility can be operationalized through intelligent scheduling of flexible electrical loads prior research has mainly focused on determining dispatch schedules for exogenously given portfolios of flexible electricity demand we expand on this literature by considering both contracting and dispatch of flexible loads to this end we formulate a demand aggregator s problem of designing and dispatching a portfolio of supply volatile renewable and conventional generators and demand inflexible base shiftable and curtailable load assets as a stochastic program to account for different contracting regimes we consider three market scenarios 1 a liquid flexibility market where the energy retailer is a price taker 2 an opaque market where non strategic customers will accept any individually rational contract offer and 3 a bi level model with strategic customers optimally self selecting into available contracts in the last case we also explore the effect of price discrimination versus uniform pricing we evaluate these models using empirical load and generation data contrary to conventional wisdom we find that flexibility contracting is not monotone increasing in renewable generation capacities our research also suggests that curtailable load is a closer substitute to supply flexibility than shiftable load finally we find that contracting of curtailing flexibility will be harder to implement if the aggregator has limited market power

stochastic security for operations planning with significant wind power generation in their attempt to cut down on greenhouse gas emissions from electricity generation several countries are committed to install wind power generation up to and beyond the 10 20 penetration mark however the large scale integration of wind power represents a challenge for power system operations planning because wind power 1 cannot be dispatched in the classical sense and 2 its output varies as weather conditions change this warrants the investigation of alternative short term power system operations planning methods capable of better coping with the nature of wind generation while maintaining or even improving the current reliability and economic performance of power systems to this end this paper formulates a short term forward electricity market clearing problem with stochastic security capable of accounting for nondispatchable and variable wind power generation sources the principal benefit of this stochastic operation planning approach is that when compared to a deterministic worst case scenario planning philosophy it allows greater wind power penetration without sacrificing security

testing for poverty dominance an application to canada the paper proposes and applies statistical tests for poverty dominance that check for whether poverty comparisons can be made robustly over ranges of poverty lines and classes of poverty indices this helps provide both normative and statistical confidence in establishing poverty rankings across distributions the tests which can take into account the complex sampling procedures that are typically used by statistical agencies to generate household level surveys are implemented using the canadian survey of labour and income dynamics slid for 1996 1999 and 2002 although the yearly cumulative distribution functions cross at the lower tails of the distributions the more recent years tend to dominate earlier years for a relatively wide range of poverty lines failing to take into account slid s sampling variability as is sometimes done can inflate significantly one s confidence in ranking poverty taking into account slid s complex sampling design as has not been done before can also decrease substantially the range of poverty lines over which a poverty ranking can be inferred

market clearing with stochastic security part ii case studies this paper analyzes the market clearing formulation with stochastic security developed in its companion paper through two case studies solved using mixed integer linear programming techniques the generation and reserve schedules as well as the nodal prices of energy and security are assessed under various conditions such as a line flow limits b when nonspinning reserve is excluded from the formulation c demand side valuation of energy not served d generator ramping limits and e the set of pre selected contingencies

uncertainty management in the unit commitment problem uncertainty in power systems operations has been traditionally managed by multistage decision making and operating reserve requirements a familiar example of multistage decisions is day ahead unit commitment and real time economic dispatch an alternate approach for managing uncertainty is a stochastic formulation which allows the explicit modeling of the sources of uncertainty this paper compares stochastic and reserve methods and evaluates the benefits of a combined approach for the efficient management of uncertainty in the unit commitment problem numerical studies show that unit commitment solutions obtained for the combined approach are robust and superior with respect to the traditional approach in terms of both economics and reliability metrics

two stage stochastic programming model for market clearing with contingencies planning for contingencies typically results in the use of more expensive facilities before disruptions it leads to different prices and energy availability at various network locations depending on how the contingency analysis is performed in this paper we present a two stage stochastic programming model for incorporating contingencies the model is computationally demanding and made tractable by using an interior point log barrier method coupled with benders decomposition the second stage optimal recourse function rf defines the most economically efficient actions in the post contingency state for returning the system back to normal operating conditions the approach is illustrated with for two examples small with 8 buses 11 branches and ieee medium scale with 300 buses 411 branches

discussion of scheduling of spinning reserve considering customer choice on reliability the authors proposed a market model in which the energy and spinning reserve are cleared sequentially the experience has shown that this kind of market model can lead to quite undesirable situations such as price reversal problem the case of the pre 2001 california electricity market is the best example moreover by using sequential market clearing enough capacity may not be brought into the reserve market as a result post clearing market ad hoc manipulations would be required to turn on enough extra units to meet reliability targets lastly ignoring the coupling that exists between the energy and the reserve scheduling can lead to suboptimal or infeasible results

evolution toward standardized market design the evolution toward the standardized market design smd is presented in this paper with references to the market developments in new zealand australia pjm iso ne and ercot in the development of market designs two main objectives market liquidity facilitating bilateral trading and pricing efficiency facilitating congestion management have been pursued the efforts to balance the seemingly conflicting objectives led to most markets designed with a uniform or zonal pricing model introduction of locational marginal pricing and evolution of transmission rights from physical to financial form made it possible to harmonize the potentially conflicting goals in a market design the close coupling between energy and ancillary services requires that markets for these commodities be carefully coordinated different operational practices and reliability standard requirements have led to major differences in ancillary service market designs

risk constrained self scheduling of hydro wind units for short term electricity markets considering intermittency and uncertainty abstract in view of the intermittency and uncertainty associated with both the electricity production sector of restructured power system and their competitive markets it is necessary to develop an appropriate risk managing scheme so that it is desirable to trade off between optimum utilization of intermittent generation resources i e renewable energy resources uncertain market prices and related risks in order to maximize participants benefits and minimize the corresponding risks in the multi product market environment the main goal of this paper is to investigate risk management by introducing a novel multi risk index to quantify expected downside risk edr which is caused by both the wind power and market price uncertainties value at risk var method is used to assess the mentioned risk issue by the proposed weighted edr so that an optimal trade off between the profit and risk is made for the system operations also the roulette wheel mechanism is employed for random market price scenario generation wherein the stochastic procedure is converted into its respective deterministic equivalents moreover the autoregressive integrated moving average arima model is employed to characterize the stochastic wind farm wf generation by predetermined mean level and standard deviation of wind behavior as well as temporal correlation the problem is formulated as a mixed integer stochastic framework for a hydro wind power system scheduling and tested on a generation company genco

consistent testing for stochastic dominance under general sampling schemes we propose a procedure for estimating the critical values of the extended kolmogorov smirnov tests of stochastic dominance of arbitrary order in the general k prospect case we allow for the observations to be serially dependent and for the first time we can accommodate general dependence amongst the prospects which are to be ranked also the prospects may be the residuals from certain conditional models opening the way for conditional ranking we also propose a test of prospect stochastic dominance our method is based on subsampling and we show that the resulting tests are consistent and powerful against some n 1 2 local alternatives we also propose some heuristic methods for selecting subsample size and demonstrate in simulations that they perform reasonably we describe an alternative method for obtaining critical values based on recentring the test statistic and using full sample bootstrap methods we compare the two methods in theory and in practice

international comparisons of poverty intensity index decomposition and bootstrap inference this paper proposes an alternative formulation for the sen shorrocks thon sst index of poverty intensity that is appropriate for survey data with sampling weights it also decomposes the sst index into the poverty rate the average poverty gap ratio among the poor and the overall gini index of poverty gap ratios to account for sampling variation in estimates of poverty intensity this paper uses the bootstrap method to compute confidence intervals and presents international comparisons using luxembourg income study lis data from the 1970s to the 1990s cross sectional and longitudinal analyses indicate that the percentage change in poverty intensity can be approximated by the sum of percentage changes in the poverty rate and average poverty gap ratio since changes in the overall gini index of poverty gap ratios are negligible in the early 1970s poverty intensity in canada and the united states was almost indistinguishable but in the 1970s canadian poverty intensity decreased large increases in poverty intensity occurred in the 1980s in the united states the united kingdom and sweden

revisiting the sen poverty index a modification of the official sen poverty index yields an index which is not only continous in individual incomes and consistent with the transfer axiom but also admits a geometric interpretation in terms of the area beneath a graph called the inverse generalized lorenz curve for normalized poverty gaps by jenkins and lambert 1993 or the poverty gap profile by shorrocks 1994

three or two stage stochastic market clearing algorithm as the power industry considers moving from a deterministic paradigm to a stochastic one to clear the day ahead market in systems with significant stochastic production the following question arises how should a stochastic clearing algorithm be formulated our analyses indicate that a three stage stochastic approach is clearly superior to a two stage one to show this we propose a model that includes three stages the first one represents the day ahead market the second stage the intraday market and the third one the real time operation the objective is to clear the day ahead market but with a prognosis of the future the intraday market and the real time operation to assess the impact of the intraday market on the day ahead outcomes we compare the results obtained from the proposed model with those of a simpler but more common two stage model which represents the day ahead market and the real time operation

is being flexible advantageous for demands this paper analyzes the impacts of flexible demands on day ahead market outcomes in a system with significant wind power production we use a two stage stochastic market clearing model where the first stage represents the day ahead market and the second stage represents the real time operation on one hand flexibility of demands is beneficial to the system as a whole since such flexibility reduces the operation cost but on the other hand shifts in demands from peak periods to off peak periods may influence prices in such a way that demands may not be willing to provide flexibility specifically we investigate the impacts of different degree of demand flexibility on day ahead prices a number of scenarios modeling the uncertainty associated with wind production at the operation stage and nonconvexities due to start up costs of generators and their minimum power outputs are taken into account

a security constrained bid clearing system for the new zealand wholesale electricity market this paper reports upon the mathematical models and implementation of the scheduling pricing and dispatch spd application for the new zealand electricity market nzem spd analyzes bids for energy offers reserve offers and energy demands and recognizes explicitly the effects on bid clearing due to transmission congestion network losses reserve requirements and ramp rate limits advanced lp solution methods are utilized to solve the large scale constrained optimization problem results on a 67 bus test system and the nzem are included

a single settlement energy only electric power market for unpredictable and intermittent participants we discuss a stochastic programming based method for scheduling electric power generation subject to uncertainty such uncertainty may arise from either imperfect forecasting or moment to moment fluctuations and on either the supply or the demand side the method gives a system of locational marginal prices that reflect the uncertainty and these may be used in a market settlement scheme in which payment is for energy only we show that this scheme is revenue adequate in expectation

pricing energy and ancillary services in integrated market systems by an optimal power flow a detailed ac opf based formulation for procuring pricing and settling energy and ancillary service in simultaneous auctions by integrated market systems is presented the paper provides clear definitions of locational marginal prices for energy and ancillary service marginal prices in terms of lagrange multipliers the characteristics of the prices are analyzed especially when economic substitution among ancillary services is required the paper also evaluates the conditions under which opportunity costs are incurred to units that provide ancillary services it is particularly shown that the intuitive belief that the provision of regulation down service does not incur opportunity cost to the provider in general is not true

energy and reserve pricing in security and network constrained electricity markets this paper analyzes some unresolved pricing issues in security constrained electricity markets subject to transmission flow limits although the notion of separate reserve types as proposed by ferc can be precisely and unambiguously defined when transmission constraints are active the very existence of separate reserve prices and markets is open to question when the prices are based on marginal costs instead we submit here that the only products whose marginal costs can be separately and uniquely defined and calculated are those of energy and security at each node thus under marginal pricing at any given network bus all scheduled reserve types should be priced not at separate rates but at a common rate equal to the marginal cost of security at that bus furthermore we argue that nodal or area reserves cannot be prespecified but must be obtained as by products of the market clearing process simulations back up these conclusions

towards full integration of demand side resources in joint forward energy reserve electricity markets this paper proposes a security constrained forward market clearing algorithm within which the inherent characteristics of demand flexibility are acknowledged when the provision of reserve from the demand side is considered in the proposed formulation we co optimize the cost of scheduling the appropriate resources to guarantee the security of the system and the expected cost of operating under any credible system state in addition we consider that consumers can offer to provide spinning reserve capacity deployable by voluntary load reductions in response to contingencies due to the load recovery effect i e since energy usage is essentially postponed when demand side reserve is deployed in post contingency states any voluntary reduction in the load has to be accompanied by a subsequent increase in demand from the initial forecast we demonstrate that the marginal value of the reserve provided by the demand can only be calculated taking into account the cost of supplying the recovery consumption flexible consumers can reduce their payments on average if energy is settled through real time prices

market implications and pricing of dynamic reserve policies for systems with renewables static reserve policies are used within security constrained unit commitment scuc and security constrained economic dispatch sced to ensure reliability a common policy is that 10 min reserve must exceed the largest contingency however this condition does not guarantee reliability because voltage and thermal limits can hinder reserve deliverability many operators use zonal reserve markets to ensure reserves are dispersed across the grid such zonal models attempt to anticipate transmission bottlenecks which is a difficult task when the future system state is uncertain this paper examines the market implications of dynamic reserve policies used to mitigate uncertainty from renewable resources and contingencies we study the market implications of policies recently proposed in the literature such as hourly zones within day ahead scuc and an algorithm that formally disqualifies reserves that are expected to be undeliverable a locational reserve pricing scheme is also proposed in connection with scenario based reserve disqualification analysis on the rts 96 test case shows that dynamic zones and reserve disqualification along with the proposed compensation scheme help direct reserve payments toward resources that more effectively respond to contingencies

weekly self scheduling forward contracting and pool involvement for an electricity producer an adaptive robust optimization approach abstract this paper addresses the optimization under uncertainty of the self scheduling forward contracting and pool involvement of an electricity producer operating a mixed power generation station which combines thermal hydro and wind sources and uses a two stage adaptive robust optimization approach in this problem the wind power production and the electricity pool price are considered to be uncertain and are described by uncertainty convex sets to solve this problem two variants of a constraint generation algorithm are proposed and their application and characteristics discussed both algorithms are used to solve two case studies based on two producers each operating equivalent generation units differing only in the thermal units characteristics their market strategies are investigated for three different scenarios corresponding to as many instances of electricity price forecasts the effect of the producers approach whether conservative or more risk prone is also investigated by solving each instance for multiple values of the so called budget parameter it was possible to conclude that this parameter influences markedly the producers strategy in terms of scheduling profit forward contracting and pool involvement these findings are presented and analyzed in detail and an attempted rationale is proposed to explain the less intuitive outcomes regarding the computational results these show that for some instances the two variants of the algorithms have a similar performance while for a particular subset of them one variant has a clear superiority

estimating the effects of unions on wage inequality in a panel data model with comparative advantage and nonrandom selection this article considers the estimation of the structure of wages in union and nonunion sectors it proposes an estimator that extends standard panel data techniques to the case in which the return to the permanent component of the error term is differently rewarded in the two sectors the econometric model is used to estimate the effect of unions on both the level and the variance of wages in canada the findings indicate that unions increase the average wage of workers and compress the returns to observable measures of skill and to a time invariant unobservable measure of skill

stochastic optimization of sub hourly economic dispatch with wind energy we present a stochastic programming framework for a multiple timescale economic dispatch problem to address integration of renewable energy resources into power systems this framework allows certain slow response energy resources to be controlled at an hourly timescale while fast response resources including renewable resources and related network decisions can be controlled at a sub hourly timescale to this end we study two models motivated by actual scheduling practices of system operators using an external simulator as driver for sub hourly wind generation we optimize these economic dispatch models using stochastic decomposition a sample based approach for stochastic programming computational experiments conducted on the ieee rts96 system and the illinois system reveal that optimization with sub hourly dispatch not only results in lower expected operational costs but also predicts these costs with far greater accuracy than with models allowing only hourly dispatch our results also demonstrate that when compared with standard approaches using the extensive formulation of stochastic programming the sequential sampling approach of stochastic decomposition provides better predictions with much less computational time

pricing electricity in pools with wind producers this paper considers an electricity pool that includes a significant number of wind producers and is cleared through a network constrained auction one day in advance and on an hourly basis the hourly auction is formulated as a two stage stochastic programming problem where the first stage represents the clearing of the market and the second stage models the system operation under a number of plausible wind production realizations this formulation co optimizes energy and reserve and allows deriving both pool energy prices and balancing energy prices these prices result in both cost recovery for producers and revenue reconciliation a case study of realistic size is used to illustrate the functioning of the proposed pricing scheme

pricing energy and reserves using stochastic optimization in an alternative electricity market this paper presents a stochastic linear programming model that can be used for pricing in electrical energy and reserve markets it addresses capacity energy and reserve dispatch problems that may arise from n 1 contingency scenarios possible market solutions focusing on generator compensation using real time day ahead and hybrid schemes are enumerated along with opportunities for consumer pricing and transmission costing this model is illustrated on a 6 bus test system as well as a larger 66 bus system representing the ontario network a key difference among schemes is the degree of risk to the generators measured by variance in profit

interpreting the wage gap estimate from selectivity correction techniques using micro data abstract the selectivity correction techniques lead to two conceptually different wage gap estimates including the selectivity correction factors in the computation of the wage gap leads to a conditional estimate whereas excluding them leads to a potential estimate

canadian union nonunion wage differentials using extensive canadian longitudinal data from the years 1969 71 the authors estimate union nonunion wage differentials of 12 14 percent for 1969 and 13 16 percent for 1970 these estimates are not adjusted for selectivity because three different tests to identify selectivity yield no evidence of selectivity bias the authors argue that although testing for selectivity is often essential selectivity adjustments have resulted in greatly inflated estimates of union nonunion wage differentials in some studies and should therefore be used with caution

load following reserves procurement considering flexible demand side resources under high wind power penetration the variable and uncertain nature of the leading renewable energy resources such as wind power generation imposes the development of a sophisticated balance mechanism between supply and demand to maintain the consistency of a power system in this study a two stage stochastic programming model is proposed to procure the required load following reserves from both generation and demand side resources under high wind power penetration besides a novel load model is introduced to procure flexible reserves from industrial clients load following reserves from load serving entities lse are also taken into account as well as network constraints load shedding and wind spillage the proposed methodology is applied to an illustrative test system as well as to a 24 node system

economic valuation of reserves in power systems with high penetration of wind power this paper proposes a methodology to determine the required level of spinning and nonspinning reserves in a power system with a high penetration of wind power the computation of the required reserve levels and their costs is achieved through a stochastic programming market clearing model spanning a daily time horizon this model considers the network constraints and takes into account the cost of both the load shedding and the wind spillage the methodology proposed is illustrated using an example and a realistic case study some conclusions are finally drawn

on the choice of incentives in firms abstract simple models of individual and group incentives under uncertainty are compared and comparative performance is shown to depend upon various exogenous parameters the incentive effects of profit sharing will thus vary with organizational and other characteristics that may be difficult to observe and attempts to quantify productivity effects that neglect selection bias are likely to be misspecified significant selection effects are found in previously used firm level data and productivity effects of existing profit sharing are found to be much larger than potential effects in firms without sharing arrangements this throws doubt on policies to encourage sharing in isolation

the swiss reserve market stochastic programming in practice this paper presents the evolution and design of the swiss reserve market and describes its two stage stochastic market clearing model in switzerland the reserve market comprises weekly and daily auctions the decision making problem is to determine the amount of reserves that should be procured in each market stage the stochasticity stems from daily offers which are not available at the beginning of the week when the first stage decisions are made the new market clearing model minimizes expected procurement costs of reserves while taking reserve dimensioning criteria and market properties into consideration since the last week of january 2014 this model has been clearing the reserve market in switzerland to our knowledge this is the first real world implementation of a stochastic market clearing model in electricity markets

a stochastic programming model for a day ahead electricity market with real time reserve shortage pricing we present a multi period stochastic mixed integer programming model for power generation scheduling in a day ahead electricity market the model considers various scenarios and integrates the idea of reserve shortage pricing in real time instead of including all the possible scenarios we parsimoniously select a certain number of scenarios to limit the size of the model as realistic size models are still intractable for exact methods we propose a heuristic solution methodology based on scenario rolling that is capable of finding good quality feasible solutions within reasonable computation time

using a system model to decompose the effects of influential factors on locational marginal prices locational marginal prices lmps are influenced by various factors such as load uncertainty thermal limit capacity reserve and market power we build a system model to quantitatively analyze the effects of these individual factors and their interactions on the mean and standard deviation of the lmps assuming that the factors are either active or inactive according to the sensitivity analysis results from convex quadratic programming lmps are piecewise linear functions of demand variation which is a key property used in the computation this paper attempts to answer the following types of questions 1 to what extent does market power raise the lmps above the marginal cost 2 what effects will generation or transmission capacity expansion have on relieving high lmps under high demand scenarios an ieee 30 bus test system is used as an example to demonstrate our approach

modeling approaches for computational cost reduction in stochastic unit commitment formulations although stochastic commitment policies provide robust and efficient solutions they have high computational costs this letter considers two modeling approaches for the reduction of their computational effort the relaxation of the integrality constraint of fast start units and the modeling of generation outages as load increments these approaches are shown to reduce the computational cost while maintaining the good properties of stochastic policies

security constrained unit commitment for simultaneous clearing of energy and ancillary services markets this paper introduces a security constrained unit commitment scuc model with emphases on the simultaneous optimization of energy and ancillary services markets benders decomposition is used to decouple the scuc into a unit commitment uc master problem and hourly network security checking subproblems lagrangian relaxation is used to decouple the uc problem into individual single unit commitment problems dynamic programming is used to find the optimal commitment decision a simultaneous marginal curve algorithm is proposed to find the optimal values of energy and ancillary services a six bus system with three units and the ieee 118 bus system with 54 units are analyzed to illustrate the proposed model

electricity market clearing with improved scheduling of stochastic production abstract in this paper we consider an electricity market that consists of a day ahead and a balancing settlement and includes a number of stochastic producers we first introduce two reference procedures for scheduling and pricing energy in the day ahead market on the one hand a conventional network constrained auction purely based on the least cost merit order where stochastic generation enters with its expected production and a low marginal cost on the other a counterfactual auction that also accounts for the projected balancing costs using stochastic programming although the stochastic clearing procedure attains higher market efficiency in expectation than the conventional day ahead auction it suffers from fundamental drawbacks with a view to its practical implementation in particular it requires flexible producers those that make up for the lack or surplus of stochastic generation to accept losses in some scenarios using a bilevel programming framework we then show that the conventional auction if combined with a suitable day ahead dispatch of stochastic producers generally different from their expected production can substantially increase market efficiency and emulate the advantageous features of the stochastic optimization ideal while avoiding its major pitfalls a two node power system serves as both an illustrative example and a proof of concept finally a more realistic case study highlights the main advantages of a smart day ahead dispatch of stochastic producers

stochastic multiobjective market clearing of joint energy and reserves auctions ensuring power system security in this paper a stochastic multiobjective framework is proposed for day ahead joint market clearing the proposed multiobjective framework can concurrently optimize competing objective functions including augmented generation offer cost and security indices overload index voltage drop index and voltage stability margin besides system uncertainties including generating units and branches contingencies and load uncertainty are explicitly considered in the stochastic market clearing scheme the solution methodology consists of two stages which firstly employs roulette wheel mechanism and monte carlo simulation mcs for random adaptive 24 h scenario generation wherein the stochastic multiobjective market clearing procedure is converted into its respective deterministic equivalents scenarios in the second stage for each deterministic scenario a multiobjective mathematical programming mmp formulation based on the epsiv constrained approach is implemented for provision of spinning reserve sr and nonspinning reserve nsr as well as energy the mmp formulation of the market clearing process is optimized while meeting ac power flow constraints and expected interruption cost eic the ieee 24 bus reliability test system rts 24 bus is used to demonstrate the performance of the proposed method

convergence of the south and non south income distributions 1969 1979 income distribution and inequalities in the southern united states are analyzed and compared with data for the rest of the country the evidence presented in this paper reveals that in the 1970s the souths income distribution either converged or moved significantly closer to the income distribution of the rest of the country the degree of convergence depends on the definition of the recipient unit and to a degree on the particular cost of living index used to deflate southern and non southern incomes the convergence is attributed in part to the labor unionization in the northeast and the resulting relocation of companies to the south data are from the 1970 and 1980 censuses and concern total household income excerpt

economic and environmental implications of different approaches to hedge against wind production uncertainty in two settlement electricity markets a pjm case study abstract this paper examines the economic and environmental outcomes of four two settlement electricity market clearing designs the first design corresponds to a deterministic market clearing dmc similar to the mechanism currently used in organized wholesale electricity markets in the united states the other three designs account for the day ahead da wind power production uncertainty into the da market mechanisms either implicitly or explicitly an augmented deterministic market clearing admc design introduces da ramp capability products these products ensure adequate and ramp feasible electricity generation capacity commitments in the da stage to cope with the real time realization of wind power generation a hybrid deterministic market clearing hdmc design augments admc by explicitly integrating a characterization of wind power production uncertainty into the residual unit commitment ruc process which is run after the da market is closed using stochastic programming the last design referred to as stochastic market clearing smc uses stochastic optimization to explicitly account for wind power production uncertainty in the da market clearing mechanisms i e da unit commitment and economic dispatch the four market clearing designs are assessed by simulating the electricity market operations of a test system and comparing their results in terms of operating costs prices costs and revenues of different types of producers consumer s payments integration of wind power and air emissions the test system has 12 of the capacity of pjm s fossil fired power generation fleet and uses data on coincident demand and wind power production from the bonneville power administration bpa system during years 2010 2014 the simulations are performed hourly for a whole year results show that smc is superior as its costs reductions are more than two times the improvements attained by admc and hdmc also smc results in electricity prices that are better aligned with operation costs cuts the spread between the day ahead and real time prices by 40 reduces out of market short term revenue sufficiency payments by 58 reduces co2 emissions by 3 52 and decreases power plants cycling hdmc is a distant second best market design relative to dmc it achieves a reduction in total costs that is less than half the reduction achieved by smc a reduction in out of market payments that is 80 of the reduction attained by smc and an increase in wind power integration that is

on the measurement of poverty official statistics in the united states and the united kingdom show a rise in poverty between the 1970 s and the 1980 s but scepticism has been expressed with regard to these findings in particular the methods employed in the measurement of poverty have been the subject of criticism this paper re examines three basic issues in measuring poverty the choice of the poverty line the index of poverty and the relation between poverty and inequality one general theme running through the paper is that there is a diversity of judgments which enter the measurement of poverty and that it is necessary to recognize these explicitly in the procedures adopted there is likely to be disagreement about the choice of poverty line affecting both its level and its structure in this situation we may only be able to make comparisons and not to measure differences and the comparisons may lead only to a partial rather than a complete ordering the first section of the paper discusses the stochastic dominance conditions which allow such comparisons illustrating their application by reference to data for the united states the choice of poverty measure has been the subject of an extensive literature and a variety of measures have been proposed in the second section of the paper a different approach is suggested considering a class of measures satisfying certain general properties and seeking conditions under which all members of the class which includes many of those proposed give the same ranking those sceptical about measures of poverty often assert that poverty and inequality are being confounded the third section of the paper distinguishes four different viewpoints and relates them to theories of justice and views of social welfare

a robust optimization approach to energy and reserve dispatch in electricity markets abstract to a large extent electricity markets worldwide still rely on deterministic procedures for clearing energy and reserve auctions however increasing shares of the production mix consist of renewable sources whose nature is stochastic and non dispatchable as their output is uncertain and cannot be controlled by the operators of the production units stochastic programming models allow the joint determination of the day ahead energy and reserve dispatch accounting for the uncertainty in the output from these sources however the size of these models gets quickly out of hand as a large number of scenarios are needed to properly represent the uncertainty in this work we take an alternative approach and cast the problem as an adaptive robust optimization problem the resulting day ahead energy and reserve schedules yield the minimum system cost accounting for the cost of the redispatch decisions at the balancing real time stage in the worst case realization of the stochastic production within a specified uncertainty set we propose a novel reformulation of the problem that allows considering general polyhedral uncertainty sets in a case study we show that in comparison to a risk averse stochastic programming model the robust optimization approach progressively trades off optimality in expectation with improved performance in terms of risk these differences however gradually taper off as the level of risk aversion increases for the stochastic programming approach computational studies show that the robust optimization model scales well with the size of the power system which is promising in view of real world applications of this approach

social evaluations when populations differ in size assessments of social welfare do not usually take into account population sizes this can lead to serious social evaluation flaws particularly in contexts in which policies can affect demographic growth we develop in this paper a little known though ethically attractive approach to correcting the flaws of traditional social evaluations an approach that is sensitive to population sizes and that is based on critical level generalized utilitarianism clgu traditional clgu is extended by considering arbitrary orders of welfare dominance and ranges of poverty lines as well as values for the critical level of how much a life must be minimally worth to contribute to social welfare we apply these social evaluation methods to rank canada across 1976 1986 1996 and 2006 and to estimate normatively and statistically robust lower and upper bounds of critical levels over which these rankings can be made

uncertainty marginal price transmission reserve and day ahead market clearing with robust unit commitment the increasing penetration of renewable energy in recent years has led to more uncertainties in power systems these uncertainties have to be accommodated by flexible resources i e upward and downward generation reserves in this paper a novel concept uncertainty marginal price ump is proposed to price both the uncertainty and generation reserve at the same time the energy is priced at locational marginal price lmp a novel market clearing mechanism is proposed to credit the generation and reserve and to charge the load and uncertainty within the robust unit commitment in the day ahead market we derive the umps and lmps in the robust optimization framework ump helps allocate the cost of generation reserves to uncertainty sources we prove that the proposed market clearing mechanism leads to partial market equilibrium we find that transmission reserves must be kept explicitly in addition to generation reserves for uncertainty accommodation we prove that transmission reserves for ramping delivery may lead to financial transmission right ftr underfunding in existing markets the ftr underfunding can be covered by congestion fund collected from uncertainty payment in the proposed market clearing mechanism simulations on a six bus system and the ieee 118 bus system are performed to illustrate the new concepts and the market clearing mechanism

optimal response of a thermal unit to an electricity spot market this paper addresses the optimal response of a thermal unit to an electricity spot market the objective is to maximize the unit profit from selling both energy and spinning reserve in the spot market the paper proposes a 0 1 mixed integer linear programming approach that allows a rigorous modeling of i nonconvex and nondifferentiable operating costs ii exponential start up costs iii available spinning reserve taking into account ramp rate restrictions and iv minimum up and down time constraints this approach overcomes the modeling limitations of dynamic programming approaches and is computationally efficient results from realistic case studies are reported