valuation of dynamic reactive power support services for transmission access competitive procurement of reactive power support services is rapidly becoming a reality for deregulated electricity markets it has resulted in a great need to quantify the value of reactive power support from var sources this article presents research results on the development of new concepts and schemes for equitable reactive power support valuation performance characteristics of the proposed method are determined and practical application issues are addressed the validity of the method is verified through sensitivity studies this work emphasizes that the valuation of reactive power support services should be based on their contributions to system security and stability the dynamic var is the primary concern for the reactive power valuation problem

competitive procurement of ancillary services by an independent system operator this paper discusses the competitive procurement of ancillary services by an independent system operator iso the paper assumes the existence of an underlying market for energy and explains why this energy market must be accompanied by a market for ancillary services these services include operating reserves and automatic generation control agc both of which may require generators that are infra marginal in the energy market to choose between supplying energy or ancillary services the paper discusses the design of an auction for these services that has formed the basis for the california iso s ancillary services market the paper also discusses the real time dispatch of ancillary services

the demand for physician services evidence from a natural experiment this study exploits a natural experiment in belgium to estimate the effect of copayment increases on the demand for physician services it shows how a differences in differences dd estimator of the price effects can be decomposed into effects induced by the common average proportional price increase income effects and by the change in relative prices substitution effects the price elasticity of a uniform proportional price increase is relatively small 0 13 for men and 0 03 for women substitution effects are large especially for women but imprecisely estimated despite the substantial price increases the efficiency gain of the reform if any is modest

a survey of frequency and voltage control ancillary services part i technical features this two part paper surveys the frequency and voltage control ancillary services in power systems from various parts of the world in this second part essential economic features that must be taken into account when designing markets for ancillary services are first discussed the methods adopted in eight different systems australia france germany great britain new zealand pjm spain and sweden for trading frequency and voltage control ancillary services are then compared lastly new indicators for comparing volumes and costs of ancillary services across systems are proposed and calculated for the systems included in this survey the companion paper surveys the technical features of these ancillary services

calculation of the elastic demand curve for a day ahead secondary reserve market the level of secondary reserve needed in a power system is traditionally settled by system operators according to engineering criteria this paper proposes a novel methodology to determine the optimum level of secondary reserve based on both engineering and economic criteria within the proposed approach a price elastic quantity demand curve for the secondary reserve is built this approach assumes that the provision of secondary reserve is made under a competitive market in this market the supply curve that collects the bids from generators providing secondary reserve is matched with the calculated elastic demand cost curve the cross of the supply and demand curves determines the optimal level of secondary reserve and the price for provision of the service the developed approach is illustrated with a case study based on the current day ahead secondary reserve market in spain

incentive compatible imbalance settlement imbalance settlement markets are managed by the system operators and provide a mechanism for settling the inevitable discrepancies between contractual agreements and physical delivery in european power markets settlements schemes are mainly based on heuristic penalties these arrangements have disadvantages first they do not provide transparency about the cost of the reserve capacity that the system operator may have obtained ahead of time nor about the cost of the balancing energy that is actually deployed second they can be gamed if market participants use the imbalance settlement as an opportunity for market arbitrage for example if market participants use balancing energy to avoid higher costs through regular trade on illiquid energy markets third current practice hinders the market based integration of renewable energy and the provision of financial incentives for demand response through rigid penalty rules in this paper we try to remedy these disadvantages by proposing an imbalance settlement procedure with an incentive compatible cost allocation scheme for reserve capacity and deployed energy incentive compatible means that market participants voluntarily and truthfully state their valuation of ancillary services we show that this approach guarantees revenue sufficiency for the system operator and provides financial incentives for balance responsible parties to keep imbalances close to zero

simultaneous clearing of energy and reserves in multi area markets under mixed pricing rules the integration of the spot electricity markets in europe shall lead to multi area power exchanges that will substitute the local markets in such scheme market prices are affected by physical e g network constraints yet they should sometimes follow regulatory policy rules which do not necessarily reflect or depend on physical characteristics in some cases complex pricing rules should be implemented which impose price discrimination for supply and demand entities within the same area the methodology presented in this paper enables the balancing of supply and demand in a multi area market considering energy and reserve bids under complex pricing rules which mix energy and reserve prices a demand bid corresponds to the whole cost a demand entity is willing to pay for its participation in the energy market including the cost for the procurement of the necessary reserves the approach attains price integration of energy and reserves markets simultaneous settlement of energy and reserves and significant decrease of the payments through the uplift accounts the main principle is the formulation of a mixed complementarity problem for the system equilibrium conditions in which supply and demand are associated to explicitly or implicitly defined prices which may be different even in the same zone

coordinated fuzzy constrained optimal power dispatch for bilateral contract balancing electricity and ancillary services markets this paper proposes a coordinated fuzzy constrained optimal power dispatch cfcopd algorithm for bilateral contract balancing electricity and ancillary services markets the cfcopd problem is decomposed into social welfare fuzzy maximization subproblem which is solved by mixed integer fuzzy linear programming miflp and combined reactive power cost and cost of real power loss fuzzy minimization subproblem which is solved by fuzzy linear programming flp the proposed cfcopd algorithm is tested on the modified ieee 30 bus system and the thai power 424 bus system the dispatch results show that the social welfare of the fuzzy constrained competitive electricity and ancillary services price ceasp scheme with bilateral contract curtailment bids is higher than those of competitive electricity price cep scheme and ceasp scheme with and without bilateral contract curtailment bids leading to a lower average electricity price

optimal allocation of primary reserve services in energy markets this paper presents an optimization algorithm which provides generation economic dispatch minimizing simultaneously the cost of primary reserve services while ensuring the secure operation of the power system in the presence of disturbances the algorithm takes into consideration security constraints which are extracted from the chain rules provided by decision trees the proposed method is easy to implement in day ahead and real time balancing markets and is characterized from accuracy versatility and flexibility examples demonstrating application of the method on an actual power system model are presented and discussed

turnover in the afdc population an event history analysis the control group of families with female heads from the denver income maintenance experiment is utilized in this analysis of afdc turnover this study uses event history techniques a methodology that is more appropriate for exploring welfare dynamics than the logit approach of earlier work increases in age and the wage have significant negative effects on the rate of entering afdc a higher guarantee raises this rate significantly age and the guarantee have significant effects with opposite signs on the exit rate other variables are not systematically related to turnover the estimates are applied to projected changes in lengths of time spent on and off afdc and in afdc caseloads due to changes in the explanatory variables

business models for distributed energy resources a review and empirical analysis this paper presents a novel empirical analysis of the most common business models for the deployment of demand response and energy management systems electricity and thermal storage and solar pv distributed energy resources we classify the revenue streams customer segments electricity services provided and resources for 144 business models we use this assessment to identify a set of business model archetypes in each resource category our analysis leads us to five observations that have important implications for policymakers and regulators first our analysis highlights that business models are deeply embedded in myriad policy and regulatory frameworks second current der business models are driven more by regulatory and policy factors than by technological factors third the relatively small set of well defined der business model archetypes suggests that the determinants of success within a given archetype may include executional capabilities culture and other activities that are not captured in our framework fourth continued cost declines technological innovation and changing policy and regulatory landscapes mean the business models of tomorrow will likely look very different than the business models of today finally der business models compete within archetypes for market share in providing a limited set of electricity services

efficient use of generator resources in emerging electricity markets in the emerging electricity market generators sell ancillary services as well as energy to the system operator pricing of ancillary services makes the scheduling of units more difficult due to the resulting unit cost curves the new climate will encourage generators to exploit the flexibility of their units in terms of operating modes this paper uses the augmented hopfield neural network to deal with ancillary service prices specifically reserve and ramping prices submitted by generators and to schedule units with a choice of operating modes

a novel power market clearing model based on the equilibrium principle in microeconomics abstract clean energy dominant and electricity centric is the inevitable trend of the future energy development electric power industry has entered into an increasingly competitive era in recent years due to the deregulation of power systems however power market should not be fully competitive and need to be regulated strictly to satisfy the safe and reliable operation of power systems base on the market equilibrium principle in microeconomics a novel power market clearing model with limited competition was put forward in which the limited competition power satisfies the power flow adjustment and the network losses distribution further the free transaction ratio which can be regarded as the measurement of the degree of power market deregulation was analyzed according to the formulated market clearing model finally three case studies were made on the ieee 30 test system to verify the practicality and efficiency of the method the results show that different transaction ratio has significant influence on the operation of power systems and the optimal transaction ratio can be determined

the pretence of knowledge lecture to the memory of alfred nobel december 11 1974 this abstract was borrowed from another version of this item

optimal response of a power generator to energy agc and reserve pool based markets the electric power industry all over the world is undertaking major regulatory and operational changes the understanding of power supply as a public service is being replaced by the notion that competitive markets constitute a more appropriate framework to supply reliable and cheap electric energy to consumers as mandated by ferc orders 888 and 889 this paper considers simultaneously energy agc and reserve markets in a pool framework it provides a tool to enable a power generator to determine optimally its degree of involvement in each one of these markets a real world case study is analyzed and results are presented

advanced pricing in electrical systems i theory this paper sets forth a comprehensive theory for the real time pricing of electricity that includes selected ancillary services and extends the theory to incorporate constraints on power quality and environment impact that often influence the operation of a power system this paper is part i of a two paper set it sets forth the mathematical development of the extended model for real time pricing the formulation is novel in that it combines the dynamic equations for load frequency control with the static equations of a constrained optimal power flow part ii derives optimal nodal specific real time prices for both real and reactive power the prices derived include additive premia or opportunity costs reflecting the effects of voltage regulation maintenance of generation and transmission reserves regulation of frequency and tie line flows removal and or control of power harmonics and others

calculating short run marginal costs of active and reactive power production proper pricing of active and reactive power is an important issue for economic and secure operations of power systems in an open transmission access ota environment this paper presents a flexible formulation for this purpose the proposed formulation identifies an important price component for reactive power which is fundamentally different from those existing in the literature this makes the pricing of reactive power more understandable the proposed approach is efficient for real time application and allows for carrying out active and reactive power pricing simultaneously or independently through the use of the decoupled optimal power flow formulation price signals derived from this approach are quite meaningful from an engineering point of view in addition the proposed approach can be easily extended to evaluate nugs and wheeling transactions the paper includes test results on the 30 and 118 bus ieee standard systems

energy and reserve market designs with explicit consideration to lost opportunity costs the primary goal of this work is to investigate the basic energy and reserve dispatch optimization cooptimization in the setting of a pool based market of particular interest is the modeling of lost opportunity cost introduced by reserve allocation the authors derive the marginal costs of energy and reserves under a variety of market designs they also analyze existence algorithm and multiplicity of optimal solutions the results of this study are used to support the reserve market design and implementation in iso new england control area

work and welfare as determinants of female poverty and household headship this paper formulates and estimates a model of the determinants of female household headship headship responds to variations in the levels of well being a woman can expect if she marries or if she heads her own household the authors measure the opportunity cost of female headship and the effects of welfare benefits and womens work in the market on female headship and poverty they find that if welfare benefits were reduced there would be small reductions in the proportion of women heading households for whites and nonwhites but a substantial increase in poverty for nonwhites they also find that wives work in the market reduces poverty and female headship for nonwhites and reduces poverty but increases headship for whites the study is based on 1975 u s data excerpt

an ordinal optimization based bidding strategy for electric power suppliers in the daily energy market the deregulation and reconstruction of the electric power industry worldwide raises many challenging issues related to the economic and reliable operation of electric power systems traditional unit commitment or hydrothermal scheduling problems have been integrated with generation resource bidding but the development of optimization based bidding strategies is only at a very preliminary stage this paper presents a bidding strategy based on the theory of ordinal optimization that the ordinal comparisons of performance measures are robust with respect to noise and modeling error and the problems become much easier if the optimization goal is softened from asking for the best to good enough solution the basic idea is to use an approximate model that describes the influence of bidding strategies on the market clearing prices mcp a nominal bid curve is obtained by solving optimal power generation for a given set of mcps via lagrangian relaxation then n bids are generated by perturbing the nominal bid curve the ordinal optimization method is applied to isolate a good enough set s that contains some good bids with high probability by performing rough evaluation the best bid is then selected by solving full hydrothermal scheduling or unit commitment problems for each of the bids in s using ordinal optimization approach we are able to obtain a good enough bidding strategy with reasonable computational effort numerical results using historical mcps from the california market and a generation company with 10 units show that the ordinal optimization based method is efficient

unbundled reactive support service key characteristics and dominant cost component in this paper the authors present a systematic exposition of generator provided reactive support as an unbundled ancillary service under open access transmission they discuss the nature and salient physical characteristics of reactive support and analyze their implications in acquiring var support as one of the ancillary services the paper provides an analysis of the dominant component in the cost structure of this service this component is determined from the opportunity costs which are evaluated from the foregone profits of a generator in making sales in real power markets by providing reactive support instead of real power they illustrate the combined effects of the voltage set points of the generators and of the generator capability constraints on the transactions in competitive electricity markets both under normal and contingency operating conditions they discuss the key role of the grid operator in the provision of the reactive support and the key considerations in the acquisition and pricing of the reactive support service

social employment of welfare recipients in belgium an evaluation in belgium welfare agencies receive a subsidy to employ welfare recipients for a period sufficiently long to entitle them to unemployment benefits we investigate the effect of this programme on the exit rate from welfare we propose a grouping iv estimator of the programme effect that eliminates selection bias the estimator is consistent even if the selection into the programme depends on the average unobserved characteristics of welfare recipients in a region and in a welfare duration interval without correction for selectivity we find that the programme reduces welfare dependence but after correction this conclusion is reversed

private property and economic efficiency a study of a common pool resource abstract the british columbia halibut fishery provides a natural experiment of the effects of privatizing the commons using firm level data from the fishery 2 years before private harvesting rights were introduced the year they were implemented and 3 years afterward a stochastic frontier is estimated to test for changes in technical allocative and economic efficiency the study indicates that 1 the short run efficiency gains from privatization may take several years to materialize and can be compromised by restrictions on transferability duration and divisibility of the property right 2 substantial long run gains in efficiency can be jeopardized by preexisting regulations and the bundling of the property right to the capital stock and 3 the gains from privatization are not just in terms of cost efficiency but include important benefits in revenue and product form

pricing of reserves valuing system reserve capacity against spot prices in electricity markets this paper models the interdependencies between markets for secondary reserve capacity and spot electricity to derive the pricing of reserves under equilibrium conditions starting with the indifference condition between offering in both markets the reservation price is derived from the opportunity cost consideration and the unit commitment conditions in a fundamental interrelated market framework the reserve market examined compares widely to the german market for secondary reserves but the general approach may also be used to investigate other reserve markets the approach explores and formalizes the influence of reserve capacity on the spot market supply function a numerical solution procedure is provided to this non trivial case of market interaction the model is used to estimate the expected reservation price development over the last years in germany

optimal scheduling of spinning reserve effective control of spinning reserve can provide substantial cost reductions in large power systems this paper suggests that this goal can he achieved by tightly integrating a probabilistic reserve assessment with the unit commitment uc function this enables the reliability of individual units and the uncertainty of the load forecast to be considered for short term scheduling the generation can then be scheduled to meet a given risk index it is further argued that the optimal value of this risk index should be selected on the basis of a tradeoff between the total schedule cost obtained from the uc solution and the expected cost of energy not served which can be derived from the probabilistic reserve assessment finally the problem of over commitment of reserve in lagrangian relaxation based uc is reduced by means of a new unit decommitment technique incorporating a look ahead feature

optimal active reactive power dispatch under competition via bilevel programming this paper proposes an active reactive power dispatch procedure that is expressed via a bilevel optimization problem whose upper and lower level criteria are respectively the minimum opportunity cost and minimum offered price of active power it analyzes the impact of minimizing such criteria on system operation and it investigates the behavior of marginal prices and opportunity costs and their use in mechanisms to compensate generators for power provision the bilevel problem is solved using a version of interior point methods derived for mathematical programs with complementarity constraints results obtained with three test systems are analyzed

strategic bidding in secondary reserve markets electricity markets are based on several sequential energy and reserve trading mechanisms to constantly maintain the balance between generation and demand during the last years reserve markets are getting much importance all around the world with the increasing social awareness of the renewable energy benefits additional reserve quantities and larger remunerations are being implemented by the regulators since this renewable energy is highly dependent on weather conditions uncertainties utilities are therefore demanding more and more powerful models to better optimize their reserve bidding curves to be sent to the system operators this paper describes a new methodology to obtain an optimized real bidding curve for the secondary spinning reserve market the approach is based on the maximization of a company profit assuming a set of residual demand curves scenarios for its competitors representation and considering the day ahead market opportunity cost to build the reserve cost curve the case study validates the main features of the proposed methodology by its application to the spanish secondary reserve market this methodology is being daily used by one of the most important electricity companies in spain

dynamic scheduling of operating reserves in co optimized electricity markets with wind power we propose a probabilistic methodology to estimate a demand curve for operating reserves where the curve represents the amount that a system operator is willing to pay for these services the demand curve is quantified by the cost of unserved energy and the expected loss of load accounting for uncertainty from generator contingencies load forecasting errors and wind power forecasting errors the methodology addresses two key challenges in electricity market design integrating wind power more efficiently and improving scarcity pricing in a case study we apply the proposed operating reserve strategies in a two settlement electricity market with centralized unit commitment and economic dispatch and co optimization of energy and reserves we compare the proposed probabilistic approach to traditional operating reserve rules we use the illinois power system to illustrate the efficiency of the proposed reserve market modeling approach when it is combined with probabilistic wind power forecasting

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

defining a free market drivers of unsustainability as illustrated with an example of shrimp farming in the mangrove forest in south east asia we apply causal loop diagrams cld to picture how complex societal scenarios can be understood in terms of interdependent drivers and mechanisms between actors from the public and private sectors respectively and we show how un sustainable scenarios can be understood in terms of insufficient balancing feed back in the system we apply the methodology to picture such imbalances as funda mental drivers behind the tragedy of the commons and we apply it to go deeper into a specific business example in this context a complex case of resource exploitation in far east asia the cld analyses inform a discussion on the interplay between societies on the one hand represented by the government and its legislature and the private sector with its companies consumers and market on the other our study confirms that unsustainability can only be understood and addressed at the systemic level encom passing both natural and social systems where also the virtual and emergent systems of modern civi lization are considered the results show that a market economy can only be sustainable as well as really free when embedded in a systemic and balanced interplay between the actors on the arena the pro vision of the market arena with well thought through rules of the game offered by a well functioning democratic society is needed the challenge for leaders in business and society is to be able to grasp the causalities of the whole system and let this guide and shape sustainable goals as well as leadership and management in coherence with such goals

analyzing the length of welfare spells abstract this paper studies the determinants of the length of individual spells of welfare focusing on how the length of a spell affects the probability of its termination the analysis utilizes six years of monthly data on time spent in the afdc program among female household heads a variety of duration dependence models are estimated monthly afdc participation does not show strong evidence of duration dependence two distinct groups appear to utilize welfare one with a very low and constant probability of leaving welfare and a second group which is more affected by time on the program

operating reserve model in the power market most of the current research on operating reserve markets assumes that the required capacity is predetermined which means that the demand of operating reserve capacity is inelastic this paper considers that operating reserve capacity in a power system is flexible and that one should optimize it by cost benefit analysis based on the reliability evaluation of the generation system a clearing model of the operating reserve market is proposed to determine the optimal reserve capacity and simultaneously clear the operating reserve market the model is discussed on both uniform price and pay as bid auction mechanisms by using a heuristic method we suggest an efficient algorithm to solve the model case studies for reliability test system rts96 demonstrate the usefulness and efficiency of the proposed model

a market approach to long term security of supply the problem of ensuring that there is enough generation capacity to meet future demand has been an issue in market design since the beginning of the deregulation process although ideally the market itself should be enough to provide adequate investment incentives there are several factors that prevent this result from being achieved and some actual markets have already experienced problems related with a lack of generation capacity a regulatory framework to address this question is presented the procedure is based on an organized market where reliability contracts based on financial call options are auctioned so both their price and their allocation among the different plants are determined through competitive mechanisms this results in a stabilization of the income of the generators and provides a clear incentive for new generation investment with a minimum of regulatory intervention additionally the method represents a market compatible mechanism to hedge demand from the occurrence of high market prices

assessing distorted trading incentives of balance responsible parties based on the example of the swiss power system power systems require a continuous balance of supply and demand in europe this task is shared between balance responsible parties brps and transmission system operators tsos for this purpose the european electricity sector consists of several markets objective of this paper is to investigate distorted incentives that stem from loopholes in the market design which brps can use to undermine electricity balancing principles in favour of gaming opportunities between the domestic imbalance energy pricing and international wholesale markets these incentives are evaluated using historical data from the swiss power system which features a typical european imbalance pricing mechanism the results imply that little effort would have been needed to make a good profit at the expense of system security the major loophole arises from the interdependence between cross border trading and national imbalance energy pricing bearing in mind the european union s third energy package the importance of national balancing mechanisms will increase strongly in this context national remedies to cope with distorted incentives are outlined and the importance of harmonising balancing markets on an international level is elaborated

a reactive power capacity market using annual auctions this paper presents a new approach to design reactive power capacity markets under this approach annual auctions to procure reactive power capacity are conducted by the system operator two products are defined reactive power generation and absorption capacity which can be supplied by different independent var sources such as generators svcs capacitor banks and shunt reactors reactive power capacity is allocated using an optimization algorithm that matches capacity bids and system reactive power needs for peak and low demand hours the reactive power requirements are calculated taking into account system contingencies and the dynamic performance of the var sources under these situations another key proposal of the paper is the distribution of costs of the reactive power capacity market to the agents responsible for contingencies according to the use of the service by each market participant this remuneration approach provides fair and efficient economic signals to all market participants the applicability of the approach is illustrated with two case studies

balancing power and variable renewables three links abstract balancing power is used to quickly restore the supply demand balance in power systems the need for this tends to be increased by the use of variable renewable energy sources vre such as wind and solar power this paper reviews three channels through which vre and balancing systems interact the impact of vre forecast errors on balancing reserve requirements the supply of balancing services by vre generators and the incentives to improve forecasting provided by imbalance charges the paper reviews the literature provides stylized facts from german market data and suggests policy options surprisingly while german wind and solar capacity has tripled since 2008 balancing reserves have been reduced by 15 and costs by 50

flexible parametric estimation of duration and competing risk models in this paper we specify and estimate a flexible parametric proportional hazards model the model specification is flexibly parametric in the sense that the baseline hazard is non parametric while the effect of the covariates takes a particular functional form we also add parametric heterogeneity to the underlying hazard model specification we specify a flexible parametric proportional competing risks model which permits unrestricted correlation among the risks unemployment duration data are then analysed using the flexible parametric duration and competing risks specifications we find an important effect arising from the exhaustion of unemployment insurance and significantly different hazards for the two types of risks new jobs and recalls

shifting load through space the economics of spatial demand side management using distributed data centers demand side flexibility dsf in the electricity grid has become an active research area in recent years while temporal flexibility e g load shedding load shifting is already discussed intensively in literature spatial load migration still is an under researched type of dsf spatial load migration allows us to instantly migrate power consuming activities among different locations data centers dcs are power intensive and process information goods since information goods are easily transferable through communication networks power intensive processing of information goods is not necessarily tied to a specific location consequently geographically distributed dcs inherit in theory a considerable potential to globally migrate load we analyze the economics of spatially migrating load to provide balancing power using geographically distributed dcs we assure that neither of the participating electricity grids will be burdened by this mechanism by using historical data to evaluate our model we find reasonable economic incentives to migrate positive as well as negative balancing power in addition we find that current scenarios favor the migration of negative balancing power our research thus reveals realistic opportunities to virtually transfer balancing power between different market areas worldwide

reactive power as an ancillary service this paper addresses the problem of reactive power procurement by an independent system operator iso in deregulated electricity markets a reactive bid structure is proposed in the context of a reactive power market based on the reactive power price offers and technical constraints involved in reactive power planning a two tier approach is developed to determine the most beneficial reactive power contracts for the iso the reactive capability of a generator and therefore the opportunity costs in providing reactive power is also included in the model uncertainty in reactive demand and in reactive bids of participating parties is incorporated through monte carlo simulations and the expected reactive power procurement plan for the iso is hence determined the cigre 32 bus network approximately representing the swedish system is used for the studies

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

reliability and reserve in competitive electricity market scheduling power systems are typically scheduled at least cost subject to operational and security constraints generally no account is taken of generator reliability when scheduling units also the security criteria which include reserve are usually deterministic in nature this paper proposes a method to consider generator reliability explicitly in the scheduling problem a competitive structure is proposed which includes a market for reserve this is formulated as an augmented lagrangian dual function and is solved using a new recurrent neural network the price for reserve is used along with the unit reliability to find a balance between the cost of reserve and the risk of not providing it

unemployment insurance and unemployment spells this paper tests the effects of the level and length of unemployment insurance benefits on unemployment durations the paper particularly studies individual behavior during the weeks just prior to when benefits lapse higher unemployment insurance benefits are found to have a strong negative effect on the probability of leaving unemployment however the probability of leaving unemployment rises dramatically just prior to when benefits lapse individual data are used with accurate information of spell durations and the level and length of benefits the semiparametric estimation techniques used in the paper yield more plausible estimates than conventional approaches and provide useful diagnostics copyright 1990 by the econometric society

duration dependence in the exit rate out of unemployment in belgium is it true or spurious on the basis of aggregate data for the early 1990s we analyse the determinants of unemployment duration for laid off male workers in wallonia belgium our results indicate that if ranking in recruitment occurs the standard mixed proportional hazard specification can be too restrictive leading to an overstatement of the extent of true negative duration dependence we conclude that negative duration dependence is largely spurious we also decompose the time variation of the hazard in unobserved compositional and direct cyclical and seasonal effects we find counter cyclical variation in the quality of young workers but none for the prime aged copyright c 2004 john wiley sons ltd

entry and exit transitions in a government transfer program the case of aid to families with dependent children this study analyzes determinants of entry and exit transitions in the aid to families with dependent children program using data from the panel study of income dynamics the principal findings are that state controlled policy parameters such as the afdc guarantee the payment received when earnings are zero and the entry income limit the income level at which families become eligible for afdc payments have a significant but asymmetric impact on these transitions in addition evidence on the relationship between wages and such transitions tends to support efforts at reducing welfare dependency through programs which raise wages

development of modified rational buyer auction for procurement of ancillary services utilizing participation matrix abstract the rational buyer auction is based on a simultaneous auction that is the redesigned auction mechanism for ancillary services by the california independent system operator caiso the incentive for the rational buyer auction is caiso s intent to adopt a common sense rule of substituting higher quality lower cost services for lower quality higher cost services when it results in reduced total procurement cost for the purposes of designing a desirable auction where the minimum cost for the objective function as well as prevention of price reversal are achieved either the payment cost in marginal pricing auction must be lowered or price reversal in rational buyer auction must be avoided the objectives of this study are a to develop a newly proposed modified rational buyer auction that does not allow price reversal and b to propose and validate a solution procedure that is based on participation matrix and discrete programming the validation of the proposed solution procedure is accomplished through examination of two case studies available in the literature based on the first case study data it is shown that the newly developed modified rational buyer auction avoids price reversal occurrence while the total payment of iso is increased by 5 8 as compared with rational buyer auction also in comparison with marginal pricing auction the iso payment is lowered by 38 8 when the newly developed modified rational buyer auction is utilized for future work it is recommended that the application of the modified rational buyer auction to joint dispatch of energy and ancillary services is investigated

analysis of transition data by the minimum chi square method an application to welfare spells in belgium in this paper we analyze transition data by means of the minimum chi square mcs method instead of the more commonly used maximum likelihood ml method the analysis includes exits to multiple destinations and unmeasured heterogeneity in the empirical application turnover in the welfare system in belgium is found to be very high median duration is 4 5 months for men and 7 months for women although these figures overstate turnover in that exits out of welfare include those occurring as a consequence of recipients moving to another municipality while remaining on welfare

unemployment duration competing and defective risks this paper examines the determinants of unemployment duration in a competing risks framework with two destination states inactivity and employment the innovation is the recognition of defective risks a polynomial hazard function is used to differentiate between two possible sources of infinite durations the first is produced by a random process of unlucky draws the second by workers rejecting a destination state the evidence favors the mover stayer model over the search model refinement of the former approach using a more flexible baseline hazard function produces a robust and more convincing explanation for positive and zero transition rates out of unemployment

efficient scoring rule in multipart procurement auctions for power systems reserve in this paper scoring rules are analyzed based on the german markets for procuring power system reserves for paying accepted offers the pay as bid settlement rule is applied each offer consists of a reserve capacity and two prices the capacity price is for holding the capacity in reserve and the energy price is for delivery in case of actual use a scoring rule is applied to value the two part price bids today this scoring rule is based on procuring the offers in the rank order of the capacity prices a first analysis of historic price data indicates efficiency problems due to this scoring rule this leads to proposing to value the two part price bids based on the ex post knowledge of the actual use of the procured reserves it is shown that in contrast to today s scoring rule this duration curve approach gives incentives to reveal the variable generation costs in the energy price bids

localized reactive power markets using the concept of voltage control areas in this paper we present the design of a localized competitive market for reactive power ancillary services at the level of individual voltage control areas the concept of electrical distance has been used to identify the different voltage control areas within a power system the proposed reactive power market is settled on uniform price auction using a modified optimal power flow model uniform prices for various components of reactive power service are obtained for each voltage control area in the study cases described in the paper we examine whether such a localized reactive power market is more desirable than a common system wide reactive power market

opf for reactive pricing studies on the ngc system retail transmission services like those being provided by the national grid company ngc in england and wales pose new challenges for the pricing of reactive power supply a reactive power market approach has been proposed by ngc and continues to be evaluated such an approach includes a novel requirement for transmission constrained economic dispatch of var a problem in the security constrained optimal power flow opf class the problem formulations handled by the opf package in use could not accommodate ngc s requirements this paper describes the reactive pricing problem being addressed the modeling requirements and the resulting extensions made to the opf formulation and package it discusses the test results obtained to date on the ngc system

competitive acquisition of prioritizable capacity based ancillary services the rational buyer procedure provides the competitive procurement of capacity based ancillary services as in unbundled markets by the independent grid operator igo the capacity based as are prioritized in order of ascending response times prioritization allows substitutability of the as by automatically making the unused capacity of a higher priority as usable for any lower priority as without the need of submitting additional offers we develop an efficient scheme for the rational buyer procedure for the acquisition of the prioritizable capacity based as the scheme allows the simultaneous determination of the successful offers in the multiauction procedure through the effective deployment of discrete programming notions and the exploitation of the structural characteristics of the formulation a key feature is the incorporation of physical constraints such as capacity ramp rate and interzonal constraints the use of bounding techniques combined with procedures for the quick detection of infeasible combinations of the offer prices and the identification of avoidable calculations leads to reducing the computational burden the effectiveness and computational efficiency of the scheme are illustrated with representative numerical results including case studies based on the ieee 118 bus network

does the availability of high wage jobs for low skilled men affect welfare expenditures evidence from shocks to the steel and coal industries abstract we study shocks to the coal and steel industries to measure the effect of long term changes in demand for low skilled workers on welfare expenditures the coal and steel industries have historically paid high wages to low skilled men we find a substantial increase in welfare expenditures in response to the collapse of the steel and coal industries in the 1980s and an even more substantial reduction in welfare expenditures during the coal boom of the 1970s additional analysis indicates the reduction in welfare expenditures during the coal boom is due in part to a decline in single parent households