practical operation strategies for pumped hydroelectric energy storage phes utilising electricity price arbitrage abstract in this paper three practical operation strategies 24optimal 24prognostic and 24hsitrocial are compared to the optimum profit feasible for a phes facility with a 360 mw pump 300 mw turbine and a 2 gwh storage utilising price arbitrage on 13 electricity spot markets the results indicate that almost all 97 of the profits can be obtained by a phes facility when it is optimised using the 24optimal strategy developed which optimises the energy storage based on the day ahead electricity prices however to maximise profits with the 24optimal strategy the day ahead electricity prices must be the actual prices which the phes facility is charged or the phes operator must have very accurate price predictions otherwise the predicted profit could be significantly reduced and even become a loss finally using the 24optimal strategy the phes profit can surpass the annual investment repayments required however over the 5 year period investigated 2005 2009 the annual profit from the phes facility varied by more than 50 on five out of six electricity markets considered considering the 40 year lifetime of phes even with low investment costs a low interest rate and a suitable electricity market phes is a risky investment without a more predictable profit

microstructure noise realized variance and optimal sampling a recent and extensive literature has pioneered the summing of squared observed intra daily returns realized variance to estimate the daily integrated variance of financial asset prices a traditional object of economic interest we show that in the presence of market microstructure noise realized variance does not identify the daily integrated variance of the frictionless equilibrium price however we demonstrate that the noise induced bias at very high sampling frequencies can be appropriately traded off with the variance reduction obtained by high frequency sampling and derive a mean squared error mse optimal sampling theory for the purpose of integrated variance estimation we show how our theory naturally leads to an identification procedure which allows us to recover the moments of the unobserved noise this procedure may be useful in other applications finally using the profits obtained by option traders on the basis of alternative variance forecasts as our economic metric we find that explicit optimization of realized variance s finite sample mse properties results in accurate forecasts and considerable economic gains copyright 2008 wiley blackwell

on the benefits of behind the meter rooftop solar and energy storage the importance of retail rate design abstract we investigate the impact of retail rate design on the investment incentives avoided utility costs and cost shifting concerns associated with rooftop solar plus battery storage systems that are located behind the meter to illustrate these interactions we consider recently proposed changes to california s time of use pricing policy for commercial and industrial consumers which shifts on peak prices from midday to the constrained evening hours we find that these rate adjustments reduce cost shifting concerns across consumers considerably but also decreases solar pv investment and has an ambiguous effect on storage investment we demonstrate that storage reduces utility costs but the magnitude of this effect varies critically with the prevailing retail rate structure importantly we show that a shift in the on peak period to the constrained evening hours does not always elevate the avoided cost associated with a battery system when demand charges are imposed on a consumer s private maximum demand we illustrate that this issue can be alleviated by imposing demand charges on consumption that arises in system constrained hours we find that while storage reduces the utility s costs it can also increase cost shifting concerns these findings demonstrate the potential trade offs between maximizing avoided costs and minimizing cost shifting concerns under commonly employed retail rate structures

why market rules matter optimizing pumped hydroelectric storage when compensation rules differ abstract policies markets and technologies interact to create the modern electrical system integrating large amounts of electricity generated by variable renewable resources such as from wind and sunlight into electricity systems may require energy storage technologies to synchronize electricity production with electricity demand electricity markets compensate the performance of these energy storage technologies for the services they provide and these markets are often operated by regional independent system operators isos that specify the market rules for this compensation to examine how different iso rules can affect the operation and profitability an energy storage technology we develop a dynamic programming model of pumped hydroelectric storage phes facility operation under the market rules from the midcontinent iso and iso new england we present how differences in rules between these isos produced different operational strategies and profits and how important they are for phes profitability

optimal operation of pumped hydro storage plants with continuous time varying power prices abstract pumped hydro storage plants are increasingly considered as a complement to intermittent renewable energy sources hence a profound understanding of their underlying economics gains in importance to this end we derive efficient operation programs for storage plants which operate in an environment with time varying but deterministic power prices optimal control theory thereby provides a consistent framework for analysis in continuous time taking into account the different specifics of pumped hydro setups with large not restricting and small restricting reservoirs an empirical illustration discusses storage operation in the german market showing that the profit potential for storage plants decreased significantly between 2008 and 2011 affecting both large and small reservoir plants

the effect of utility time varying pricing and load control strategies on residential summer peak electricity use a review abstract peak demand for electricity in north america is expected to grow challenging electrical utilities to supply this demand in a cost effective reliable manner therefore there is growing interest in strategies to reduce peak demand by eliminating electricity use or shifting it to non peak times this strategy is commonly called demand response in households common strategies are time varying pricing which charge more for energy use on peak or direct load control which allows utilities to curtail certain loads during high demand periods we reviewed recent north american studies of these strategies the data suggest that the most effective strategy is a critical peak price cpp program with enabling technology to automatically curtail loads on event days there is little evidence that this causes substantial hardship for occupants particularly if they have input into which loads are controlled and how and have an override option in such cases a peak load reduction of at least 30 is a reasonable expectation it might be possible to attain such load reductions without enabling technology by focusing on household types more likely to respond and providing them with excellent support a simple time of use tou program can only expect to realise on peak reductions of 5

economic feasibility of stationary electrochemical storages for electric bill management applications the italian scenario battery energy storage systems besss are expected to become a fundamental element of the electricity infrastructure thanks to their ability to decouple generation and demand over time besss can also be used to store electricity during low price hours when the demand is low and to meet the demand during peak hours thus leading to savings for the consumer this work focuses on the economic viability of bess from the point of view of the electricity customer the analysis refers to a lithium ion li ion an advanced lead acid a zinc based a sodium sulphur nas and a flow battery the total investment and replacement costs are estimated in order to calculate the cumulated cash flow the net present value npv and the internal rate of return irr of the investment a parametric analysis is further carried out under two different assumptions a varying the difference between high and low electricity prices b varying the peak demand charges the analysis reveals that some electrochemical technologies are more suitable than others for electric bill management applications and that a profit for the customer can be reached only with a significant difference between high and low electricity prices or when high peak demand charges are applied

health and work in the family evidence from spouses cancer diagnoses abstract using canadian administrative data from multiple sources we provide the first nationally representative estimates for the effect of spouses cancer diagnoses on individuals employment and earnings and on family income our identification strategy exploits unexpected health shocks and combines matching with individual fixed effects in a generalized difference in differences framework to control for observable and unobservable heterogeneity while the effect of spousal health shocks on labor supply is theoretically ambiguous we find strong evidence for a decline in employment and earnings of individuals whose spouses are diagnosed with cancer we interpret this result as individuals reducing their labor supply to provide care to their sick spouses and to enjoy joint leisure family income substantially declines after spouses cancer diagnoses suggesting that the financial consequences of such health shocks are considerable

electricity trading and negative prices storage vs disposal electricity cannot yet be stored on a large scale but technological advances leading to cheaper and more efficient industrial batteries make grid level storage of electricity surpluses a natural choice because electricity prices can be negative it is unclear how the presence of negative prices might affect the storage policy structure known to be optimal when prices are only nonnegative or even how important it is to consider negative prices when managing an industrial battery for fast storage a storage facility that can both be fully emptied and filled up in one decision period we show analytically that negative prices can substantially alter the optimal storage policy structure e g all else being equal it can be optimal to empty an almost empty storage facility and fill up an almost full one for more typical slow grid level electricity storage we numerically establish that ignoring negative prices could result in a considerable loss of value when negative prices occur more than 5 of the t

the operational economics of compressed air energy storage systems under uncertainty abstract a compressed air energy storage system is a means of storing energy which can then be used when the demand for energy increases in this system air is compressed in a cavern when power prices are low and this air is used to run a natural gas fired turbine to generate power when prices go up with the aim of profiting from the price difference this type of system can independently compress air generate electricity or do both however the prices of electricity and natural gas fluctuate which directly impacts the amount of revenue that can be made and this requires the calculating of estimates to optimize operation strategies and maximize profit for these reasons this is a crucial energy storage technology that requires economic analyses to justify investment decisions in power markets in this paper a mixed integer programming method is developed to schedule the operation of the system for forward market prices that are estimated using a markov based probabilistic model then an algorithm that includes two separate modules in a simulation is employed to optimize the annual operation of the system the paper presents a case study for turkey as well as economic analyses based on probabilistic forward prices and the profits obtained from the optimization module

the effects of regulation and competition in the nhs internal market the case of general practice fundholder prices the 1989 reforms of the uk national health service introduced competition in supply within a tightly regulated framework the paper examines whether this competition affects the prices posted by sellers of medical services we argue that despite regulation market forces may have an impact on price we test this using the posted prices for one of the two types of buyer general practice fundholders we find the regulatory rules are not observed and some evidence of the impact of market forces on price

married women s allocation of time to employment and care of elderly parents married women who have been shown in past research to exhibit relatively elastic labor supply constitute a group of particular interest with respect to decisions concerning time spent in parental care and time spent in market work this paper presents estimates of a simultaneousequations model of employment hours of work and the provision of care to an older parent the results provide no evidence of reduced propensities to be employed or of reduced conditional hours of work due to the provision of parent care these findings are consistent with other research on women s allocation of time to competing productive uses

financial storage rights should energy storage buy and sell power at wholesale prices like utilities and generators or should its physical and financial operation be asynchronyous as with transmission lines in the first case storage straightforwardly profits through intertemporal arbitrage also known as load shifting and peak shaving in this paper the latter case referred to as passive storage is examined because passive storage does not make nodal price transactions new mechanisms are necessary for its integration into electricity markets this issue is addressed by further developing the analogy between energy storage and transmission specifically financial rights are defined for storage and tracing is extended to multiperiod power flows linked by storage like flowgate transmission rights the new financial storage rights redistribute the system operator s merchandising surplus and enable risk averse market participants to hedge against nodal price volatility resulting from storage congestion simple examples are given demonstrating the implementation of the new mechanisms game theoretic analysis suggests that financial storage rights mitigate gaming when both the generator and load bid strategically

the earnings of informal carers wage differentials and opportunity costs a substantial proportion of working age individuals in britain are looking after sick disabled or elderly people often combining their work and caring responsibilities previous research has shown that informal care is linked with substantial opportunity costs for the individual due to forgone wages as a result of non labour market participation in this paper we show that informal carers exhibit further disadvantages even when participating using the british household panel study bhps we decompose wage differentials and show that carers can expect lower returns for a given set of characteristics with this wage penalty varying along the pay distribution and by gender furthermore opportunity costs from forgone wages and wage penalties are estimated and found to be substantial

econometric analysis of financial trade processes by discrete mixture duration models abstract we propose a new framework for modelling the time dependence in financial duration processes the pioneering autoregressive conditional duration acd model introduced by engle and russell 1998 autoregressive conditional duration a new model for irregularly spaced transaction data econometrica 66 5 1127 1162 will be extended in a way that the duration process is clouded by an unobservable stochastic process the idea will be put into practice by the discrete mixture acd framework which provides us with a flexible methodology it will be established by introducing a discrete valued latent regime variable which can be justified in the light of recent market microstructure theories the empirical application demonstrates its ability to capture specific characteristics of intraday transaction durations while alternative approaches fail

unpaid work and conformity why care we study the supply of unpaid eldercare in particular caring for parents in the uk focusing on both the division of care and caring tasks by gender and the effect of conformity to social norms in relation to caring we then investigate the effect of the amount of care on the well being of caregivers and whether agreeing with the care norm enhances their well being our results suggest that the eldercare reform neglects important aspects underlying the distribution of care hours and care tasks between caregivers and may potentially worsen intrahousehold inequality in earnings and well being in particular between men and women

spillover effect of japanese long term care insurance as an employment promotion policy for family caregivers we evaluate a spillover effect of the japanese public long term care insurance ltci as a policy to stimulate family caregivers labor force participation using nationally representative data from 1995 to 2013 we apply difference in difference propensity score matching to investigate the spillover effect in two periods before and after the introduction of the ltci in 2000 and before and after its major amendment in 2006 our results show that the ltci introduction has significant and positive spillover effects on family caregivers labor force participation and the effects vary by gender and age in contrast the ltci amendment is found to have generally negative spillover effects on their labor force participation we draw attention to these spillover effects as expanding labor market supply to sustain the economy would be a priority for japan and other rapidly aging countries in the coming decades

semiparametric duration models in this article we consider semiparametric duration models and efficient estimation of the parameters in a non iid environment in contrast to classical time series models where innovations are assumed to be iid we show that in for example the often used autoregressive conditional duration acd model the assumption of independent innovations is too restrictive to describe financial durations accurately therefore we consider semiparametric extensions of the standard specification that allow for arbitrary kinds of dependencies between the innovations the exact nonparametric specification of these dependencies determines the flexibility of the semiparametric model we calculate semiparametric efficiency bounds for the acd parameters discuss the construction of efficient estimators and study the efficiency loss of the exponential pseudolikelihood procedure this efficiency loss proves to be sizeable in applications for durations observed on the paris bourse for the alcatel stock in july and august 1

electricity price arbitrage with plug in hybrid electric vehicle gain or loss abstract customers utilities and society can gain many benefits from distributed energy resources ders including plug in hybrid electric vehicles phevs using battery on phev to arbitrage electricity price is one of the potential benefits to phev owners there is however disagreement on the magnitude of such profit this study uses a stochastic optimization model to estimate the potential profit from electricity price arbitrage of two types of phevs phev 10 and phev 40 under three scenarios with variant electricity tariff and phev owners over a five year period the simulation results indicate that under current market structure even with significant improvement in battery technologies e g higher efficiency lower cost the phev owners can t achieve a positive arbitrage profit this finding implies that expected arbitrage profit solely is not a viable option to engage phevs larger adoption subsidy and combining phev arbitraging with alternative phev services are required

the effect of informal care on work and wages cross sectional evidence in the united states finds that informal caregivers have less attachment to the labor force the causal mechanism is unclear do children who work less become informal caregivers or are children who become caregivers working less using longitudinal data from the health and retirement study we identify the relationship between informal care and work in the united states both on the intensive and extensive margins and examine wage effects we control for time invariant individual heterogeneity rule out or control for endogeneity examine effects for men and women separately and analyze heterogeneous effects by task and intensity we find modest decreases 2 4 percentage points in the likelihood of working for male caregivers providing personal care female chore caregivers meanwhile are more likely to be retired for female care providers who remain working we find evidence that they decrease work by 3 10hours per week and face a 3 percent lower wage than non caregivers we find little effect of caregiving on working men s hours or wages these estimates suggest that the opportunity costs to informal care providers are important to consider when making policy recommendations about the design and funding of public long term care programs

technical and economical assessment of distributed electrochemical storages for load shifting applications an italian case study abstract time of use tou energy cost management involves the use of energy storage systems esss by customers to reduce their electricity bills the ess is charged during off peak time periods when electricity energy prices are low and discharged during times when on peak energy prices are applied this article addresses the question whether it is economically viable to install medium scale distributed esss designed to lower the electricity cost for a customer side application assuming flexible electricity tariffs the technical economical evaluation is carried out referring to lithium ion li ion sodium sulfur nas and vanadium redox battery vrb technologies performing a parametric analysis by changing the capital cost of the batteries and the difference between the maximum and minimum electricity price a case study is performed to show the advantages disadvantages of the proposed approach the analysis reveals that at the current costs of esss the use of batteries for tou applications is economically advantageous for a public institution facility in italy only if there is a significant difference between the maximum and the minimum electricity price the decrease in the cost of storage stimulated by the implementation of support policies will make ess even more convenient for load shifting applications

estimation of high frequency volatility an autoregressive conditional duration approach we propose a method to estimate the intraday volatility of a stock by integrating the instantaneous conditional return variance per unit time obtained from the autoregressive conditional duration acd model called the acd icv method we compare the daily volatility estimated using the acd icv method against several versions of the realized volatility rv method including the bipower variation rv with subsampling the realized kernel estimate and the duration based rv our monte carlo results show that the acd icv method has lower root mean squared error than the rv methods in almost all cases considered this article has online supplementary material

stochastic valuation of energy storage in wholesale power markets abstract energy storage systems are well poised to mitigate uncertainties of renewable generation outputs grid scale energy storage projects are major investments which call for rigorous valuation and risk analysis this paper provides a stochastic energy storage valuation framework in wholesale power markets which considers all key revenue streams simultaneously as part of this framework an operational optimization model is developed to determine the energy storage system s optimal dispatch sequences a future curve model is built to capture the volatilities of electricity prices in addition a frequency regulation service price forecasting model is developed simulation results with a realistic battery storage system reveal that the majority of the market revenues comes from frequency regulation services simulation results also show that both round trip efficiency and power to energy ratio are crucial to the cost effectiveness of energy storage systems

perceived price complexity of dynamic energy tariffs an investigation of antecedents and consequences dynamic tariffs have the potential to contribute to a successful shift from conventional to renewable energies but tapping this potential in europe ultimately depends on residential consumers selecting them this study proposes and finds that consumer reactions to dynamic tariffs depend on the level of perceived price complexity that represents the cognitive effort consumers must engage in to compute the overall bill amount an online experiment conducted with a representative sample of 664 german residential energy consumers examines how salient characteristics of dynamic tariffs contribute to perceived price complexity subsequently a structural equation model sem reveals that the depth of information processing is central to understand how price complexity relates to consumers behavioral intentions the results suggest that it will be challenging to convince european consumers to select complex dynamic tariffs under the current legal framework policymakers will need to find ways to make these tariffs more attractive

the effect of care leave on burden and job performance in this article the expected effects of the introduction of a fully paid long term care leave programme in the netherlands are investigated in particular we are interested in the effects on perceived burden and job performance we analyse data from a survey among workers who care for a person in their social circle for longer than two weeks the caring workers with a high perceived burden and intention to participate in the programme were asked questions regarding the expected effects on burden an econometric model in which we account for these two potentially nonrandom selection mechanisms is set up to analyse the expected reduction in burden due to the intended take up of care leave as a result of the introduction of the programme about 60 of the intended participants who perceive a high burden expect a reduction in their burden the relation between burden and job performance shows that the programme would reduce the number of caring workers who perform less precise in their job by one third a mod

the chicken or the egg endogeneity in labour market participation of informal carers in england around 14 of the uk labour force has informal care responsibilities and almost everyone in society will be an informal carer in their lifetime a well known fact in the small economic literature on informal care is the apparent negative relation between care responsibilities and labour market participation yet caring and labour market participation may be endogenous using an instrumental variable approach and panel data techniques and employing data from the british household panel study from 1991 to 2002 this paper shows that not accommodating for endogeneity in the labour market participation equation may significantly overestimate the impact care exhibits on the employment decision of informal carers moreover it is shown that a negative impact on employment only applies to some care types policy implications are derived

the impact of electricity storage on wholesale electricity prices this paper analyzes the impact of electricity storage on the production cost of a power system and the marginal cost of electricity electricity price using a unit commitment model also real world data has been analyzed to verify the effect of storage operation on the electricity price using econometric techniques the unit commitment model found that the deployment of a storage system reduces the fuel cost of the power system but increases the average electricity price through its effect on the power system operation however the reduction in the production cost was found to be less than the increase in the consumer s cost of electricity resulting in a net increase in costs due to storage different storage and co2 price scenarios were investigated to study the sensitivity of these results the regression analysis supports the unit commitment results and finds that the presence of storage increases average wholesale electricity prices for the case study system

participation and hours of work two stages in the life cycle of married women abstract a 1979 cross section of dutch households is used to estimate an integrated labor force participation and hours of work labor supply model for women young women and older women are found to behave differently wage and income elasticities are always higher for older than for younger women in absolute terms and the relative importance of participation and hours elasticities is reversed as the average woman grows older thereby implying that younger women tend to be more preoccupied with the participation decision whereas older women are more concerned with the hours decision econometrically the paper builds on heckman s 1974 participation cum hours model by adapting the estimation method to allow for the fact that hours worked are only observed in intervals a maximum likelihood model in which we integrate over parts of the hours distribution is used this technique though computationally involved gave satisfying results we compare the results with estimates of a similar but much simpler probit model to identify the possible biases in the simpler approach

impact of optimal storage allocation on price volatility in energy only electricity markets recent studies show that the fast growing expansion of wind power generation may lead to extremely high levels of price volatility in wholesale electricity markets storage technologies regardless of their specific forms e g pump storage hydro large scale or distributed batteries are capable of alleviating the extreme price volatility levels due to their energy usage time shifting fast ramping and price arbitrage capabilities in this paper we propose a stochastic bilevel optimization model to find the optimal nodal storage capacities required to achieve a certain price volatility level in a highly volatile energy only electricity market the decision on storage capacities is made in the upper level problem and the operation of strategic regulated generation storage and transmission players is modeled in the lower level problem using an extended stochastic bayesian cournot based game the south australia sa electricity market which has recently experienced high levels of price volatility and a 30 bus ieee system are considered as the case studies our numerical results indicate that 50 price volatility reduction in the sa electricity market can be achieved by installing either 430 mwh regulated storage or 530 mwh strategic storage in other words regulated storage firms are more efficient in reducing the price volatility than strategic storage firms

who will care employment participation and willingness to supply informal care the impact of informal care responsibilities on the willingness and ability of caregivers to undertake paid employment has been the subject of a number of studies in contrast the effect of employment status on willingness to undertake informal care has been less well explored this paper concentrates on this less studied direction of causality using the data provided by 15 waves of the british household panel survey we find that employment participation and earnings both impact negatively on willingness to supply informal care this evidence has implications for health and social care policy since informal care has been shown to be a significant substitute for formal long term care

health time allocation and work empirical evidence from turkey abstractthis article investigates the relationship between health status and time allocation decisions of individuals although many studies address impacts of health on labour supply few studies

the opportunity costs of informal care does gender matter in this paper we investigate the costs borne by both male and female carers in terms of their forgone formal employment opportunities traditionally informal care was supplied by women but nowadays women are not only more likely to work but also likely to be significant contributors to family finances for women this implies that the size of any forgone earnings cost of informal care is increasing at the same time population ageing is making for increasing numbers requiring care from a policy perspective it is therefore helpful to consider a less traditional but nevertheless important source of informal care men we find that both male and female carers bear indirect costs in that they are less likely to be in paid work than otherwise similar non carers and when they are in paid work they earn significantly less however we find that the motivation for lower employment participation is not the same for men as it is for women

the labour market costs of community care this paper reports an empirical investigation into the influence of informal care responsibilities on the labour supply of women the objective is to examine the argument that the uk policy of caring for the chronic sick in the community involves a nontrivial opportunity cost in the form of the forgone labour supply of the informal carers upon which it relies we find that informal carers who care for less than 20 h per week are in fact more likely to participate in the labour market but tend to work for fewer hours per week than otherwise similar noncarers informal carers who care for 20 h or more a week are less likely to participate but only slightly however when they do undertake formal employment they tend to earn less per hour and work for fewer hours per week

arbitraging intraday wholesale energy market prices with aggregations of thermostatic loads we investigate the potential for aggregations of residential thermostatically controlled loads tcls such as air conditioners to arbitrage intraday wholesale electricity market prices via non disruptive load control we present two arbitrage approaches 1 a benchmark that gives us an optimal policy but requires local computation or real time communication and 2 an alternative based on a thermal energy storage model which relies on less computation communication infrastructure but is suboptimal we find that the alternative approach achieves around 60 80 of the optimal wholesale energy cost savings we use this approach to compute practical upper bounds for savings via arbitrage with air conditioners in california s intraday energy market we investigate six sites over four years and find that the savings range from 2 37 per tcl per year and depend upon outdoor temperature statistics and price volatility

on estimating market microstructure noise variance abstract we study the market microstructure noise variance estimation of high frequency stock prices based on the hansen and lunde 2006 approach we propose estimates using subsampling method at different time scales we conduct a monte carlo study to compare our method against others in the literature our results show that our proposed estimates have lower absolute mean error and root mean squared error and their performance is quite stable at different time scales

estimating the value of electricity storage in pjm arbitrage and some welfare effects significant increases in prices and price volatility of natural gas and electricity have raised interest in the potential economic opportunities for electricity storage in this paper we analyze the arbitrage value of a price taking storage device in pjm during the six year period from 2002 to 2007 to understand the impact of fuel prices transmission constraints efficiency storage capacity and fuel mix the impact of load shifting for larger amounts of storage where reductions in arbitrage are offset by shifts in consumer and producer surplus as well as increases in social welfare from a variety of sources is also considered

lifting the burden state care of the elderly and labor supply of adult children we use a reform in the federal funding of care for the elderly in norway to examine the effects of formal care expansion on the labor supply decisions of middle aged children we find a consistent and significant negative impact of formal care expansion on insured work absences for the adult daughters of single elderly parents this effect is particularly strong for daughters with no siblings who are also more likely to exceed earnings thresholds after the reform we find no impacts of the reform on daughters mobility or parental health and no effects on adult sons

online adaptive real time optimal dispatch of privately owned energy storage systems using public domain electricity market prices this paper aims to evaluate and improve the usefulness of publicly available electricity market prices for real time optimal dispatching rtod of a privately owned energy storage system ess in a competitive electricity market the rtod algorithm seeks to maximize the revenue by exploiting arbitrage opportunities available due to the inter temporal variation of electricity prices in the day ahead market the pre dispatch prices issued by the ontario independent electricity system operator and the corresponding ex post hourly ontario energy prices are employed as the forecast and the actual prices a compressed air ess is sized and employed for evaluations due to its lower capital expenditure and its ability to be positively influenced by the availability of waste heat first the conventional rtod algorithm is developed by formulating a mixed integer linear programming problem it is demonstrated that the forecast inaccuracy of publicly available market prices significantly reduces the ess revenue then a new adaptive algorithm is proposed and evaluated which adapts the objective function of the optimization problem online based on historical market prices available before real time the outcomes reveal that the proposed adaptive rtod can significantly increase the ess revenue compared to the conventional algorithm as well as the back casting method proposed in prior studies

social security income and the utilization of home care evidence from the social security notch this paper exploits social security law changes to identify the effect of social security income on the use of formal and informal home care by the elderly results from an instrumental variables estimation strategy show that as retirement income increases elderly individuals increase their use of formal home care and become less likely to rely on informal home care provided to them by their children this negative effect on informal home care is most likely driven by male children withdrawing from their caregiving roles the empirical results also suggest that higher social security benefits would encourage the use of formal home care by those who would not have otherwise used any type of home care and would also encourage the use of both types of home care services among elderly individuals

on the influence of jurisdiction on the profitability of residential photovoltaic storage systems a multi national case study policy makers in many jurisdictions have implemented incentive schemes such as feed in tariffs fit and upfront purchase subsidies to encourage consumers to self generate parts of their power requirements by solar energy we quantitatively study the impact of jurisdiction specific solar radiation profile the typical residential loads the cost of system components the price of grid electricity and incentive programs on photovoltaic pv and storage system profitability in germany ontario and austin texas in each jurisdiction for a range of pv and storage system sizes we compute the optimal use of the system and hence the best possible profitability of that system in that jurisdiction over a 20 year life span this methodology allows us to quantitatively estimate the influence of a jurisdiction on the best possible profitability of pv storage systems we find that the choice of jurisdiction has significant impact on the profitability of pv storage systems we also find that policy makers can use the price of grid electricity as well as upfront subsidies to influence profitability and therefore adoption

your next of kin or your own career caring and working among the 50 of europe an increasing demand for both formal and informal care is likely to result from the ongoing demographic transition at the same time as there is a further move away from the traditional domestic division of labour public policy making that aims at increasing the supply of informal care necessitates knowledge about the relative importance of various incentives for individual care providers this paper takes as a point of departure that the willingness to supply informal care is partly explained by the extent to which it adversely affects labour market outcomes and analyses the effect on labour market outcomes of providing informal care to one s elderly parent s among the 50 of europe data from share survey of health ageing and retirement in europe was used to examine the association between on the one hand hours of informal care provided and on the other 1 the probability of employment 2 hours worked and 3 wages respectively the results suggest that giving informal care to one s elderly parents is associated with significant costs in terms of foregone labour market opportunities and that these adverse effects vary between countries

do they care too much to work the influence of caregiving intensity on the labour force participation of unpaid caregivers in canada the recent growth of the home care sector combined with societal and demographic changes have given rise to concerns about the adequacy of the supply of family and friend caregivers potential caregivers face competing time pressures that pull them in the direction of the labour market on one hand and towards unpaid caregiving duties on the other this paper examines the influence of unpaid caregiving on the labour supply of a cohort of working aged caregivers in canada with particular emphasis on caregiving intensity results suggest that caregivers are heterogeneous in both their caregiving inputs and associated labour market responses thereby underscoring the importance of controlling for caregiving intensity when measuring labour supply the negative influence of primary caregiving on labour supply appears to be at the level of labour force participation rather than on hours of work or wages

the private and social economics of bulk electricity storage the ability to store excess intermittent renewable electricity is increasingly being seen as a key option for integrating large quantities of renewable capacity however intermittent energy sources currently account for very small amounts of total generation despite this fact policymakers have begun implementing requirements that will dramatically increase the amount of bulk storage capacity this paper examines the social benefits provided by bulk storage in the texas electricity market which has a large amount of renewable capacity relative to other states but still quite limited renewable penetration we focus on the impact of arbitraging electricity across time a major service of bulk storage using current storage technologies we demonstrate that electricity arbitrage will increase daily co2 emissions by an average of 0 19 tons for each mwh stored in addition daily so2 emissions will increase by an average of 1 89 pounds mwh while nox emissions will fall by an average of 0 15 pounds mwh

the role of smart metering and decentralized electricity storage for smart grids the importance of positive externalities because of its fluctuating nature the feed in of renewable energy sources into low voltage distribution grids complicates the balancing of demand and supply this carries the risk of grid instabilities causing damage to electronic devices and power outages which eventually lead to deadweight losses in principle the problems arising from fluctuating feed in can be solved by increasing demand elasticity or decoupling generation and consumption for the first an advanced metering infrastructure and for the second decentralized electricity storage are considered core enablers however to date the diffusion of these future smart grids core components is low the present study provides new insights for understanding and overcoming diffusion barriers for this purpose a qualitative research approach was chosen the most important stakeholders as well as related private costs and benefits are identified the findings show that both of these smart grid components are widely considered beneficial to society by experts however because the numerous private benefits are widely distributed among distinct players socially desired investments are hampered by positive externalities the importance of well designed and consistent regulatory and legal frameworks that provide economic incentives to involved stakeholders is highlighted in the results

optimal planning to include storage devices in power systems it is difficult to forecast renewable energy resources due to their variability high uncertainty of the resources increases the concern about the reliable operation of the electric power system storage devices have been considered a candidate to control variable energy resources and most studies on storage devices are performed in the economic dispatch therefore electric power adequacy may be an issue in this paper a new approach in the optimal power flow framework is proposed for deploying storage devices and the feasibility and economic impact analyses are discussed

is inexpensive natural gas hindering the grid energy storage industry abstract grid energy storage is a maturing technology and forecasts of the industry s growth have been promising however recent years have realized little growth in actual deployments of grid level storage and several high profile storage companies and projects have failed we hypothesize that falling natural gas prices have significantly reduced the potential profit from many u s energy storage projects since 2009 and quantify that effect we use engineering economic models to calculate the monthly revenue to energy storage devices providing frequency regulation and energy arbitrage in several electricity markets and compare that revenue to prevailing natural gas prices we find that flywheel devices providing frequency regulation were profitable in months when natural gas prices were above 7 mcf but face difficulties at current prices around 4 mcf for energy arbitrage alone we find that the breakeven capital cost for large scale storage was around 300 kwh in several key locations in 2004 2008 but is around 100 kwh in the same locations today though cost and performance improvements have been continually decreasing the effective cost of energy services from storage fundamental market signals indicating the need for energy storage are at or near 10 year lows for both energy arbitrage and frequency regulation

dynamic wage and employment effects of elder parent care this article formulates and estimates a dynamic discrete choice model of elder parent care and work to analyze how caregiving affects a woman s current and future labor force participation and wages the model incorporates parental health changes human capital accumulation and job offer availability the estimates indicate that women face low probabilities of returning to work or increasing work hours after a caregiving spell i use the estimated model to simulate the caregiving employment and welfare effects of a longer unpaid work leave than currently available under the family and medical leave act a paid leave and a caregiver allowance

cloud energy storage for grid scale applications in the uk abstract in this paper the uk s electricity market and battery technologies were researched to determine the economics of aggregating domestic batteries for grid scale services a feasibility study was conducted under three scenarios in order to estimate the value of advanced lead acid ala and lithium ion li batteries for domestic households in the uk a profit optimization model was built using historical market data and technical parameters of the batteries an aggregated system of 5000 batteries was simulated and used to compare and stack value streams of seven different grid scale services in the uk including energy arbitrage reserve and frequency regulation services the results showed that using a battery system for domestic services is currently not economically viable however grid scale provision of dynamic frequency response and fast reserve services yield sufficient annual revenue to compensate for these losses the annual profit margin per household obtained was 532 692 for ala and li batteries respectively allowing a shared margin of 230 300 after accounting for household costs the promotion of an aggregated storage system is hindered by current regulatory barriers in the uk such as a double payment structure for storage operators lack of subsidy and lack of separate definition for storage devices

solar energy storage in german households profitability load changes and flexibility abstract the developments of battery storage technology together with photovoltaic pv roof top systems might lead to far reaching changes in the electricity demand structures and flexibility of households the implications are supposed to affect the generation mix of utilities distribution grid utilization and electricity price using a techno economic optimization model of a household system we endogenously dimension pv system and stationary battery storage sbs the results of the reference scenario show positive net present values npv for pv systems of approx 500 1 800 eur kwp and npv for sbs of approx 150 500 eur kwh main influences are the demand of the households self consumption rates investment costs and electricity prices we integrate electric vehicles ev with different charging strategies and find increasing npv of the pv system and self consumption of approx 70 with further declining system prices for solar energy storage and increasing electricity prices pv systems and sbs can be profitable in germany from 2018 on even without a guaranteed feed in tariff or subsidies grid utilization substantially changes by households with ev and pv sbs we discuss effects of different incentives and electricity tariff options e g load limits or additional demand charges concluding solar energy storage systems will bring substantial changes to electricity sales

energy storage arbitrage under day ahead and real time price uncertainty electricity markets must match real time supply and demand of electricity with increasing penetration of renewable resources it is important that this balancing is done effectively considering the high uncertainty of wind and solar energy storing electrical energy can make the grid more reliable and efficient and energy storage is proposed as a complement to highly variable renewable energy sources however for investments in energy storage to increase participating in the market must become economically viable for owners this paper proposes a stochastic formulation of a storage owner s arbitrage profit maximization problem under uncertainty in day ahead and real time market prices the proposed model helps storage owners in market bidding and operational decisions and in estimation of the economic viability of energy storage case study results on realistic market price data show that the novel stochastic bidding approach does significantly better than the deterministic benchmark

multistage stochastic investment planning with multiscale representation of uncertainties and decisions we propose a multistage multiscale linear stochastic model to optimize electricity generation storage and transmission investments over a long planning horizon the multiscale structure captures large scale uncertainties such as investment and fuel cost changes and long run demand growth rates and small scale uncertainties such as hour to hour demand and renewable availability uncertainty the model also includes a detailed treatment of operating periods so that the effect of dispatch decisions on long term investments are captured the proposed model can be large in size the progressive hedging algorithm is applied to decompose the model by scenario greatly reducing computation times we also derive bounds on the optimal objective function value to assess solution quality we use a case study based on the state of texas to demonstrate the model and show the benefits of its detailed representation of the operating periods in making investment decisions

when energy storage reduces social welfare this paper examines the potential welfare effects of storage under different market structures this includes combinations of perfectly competitive and strategic generation and storage sectors and standalone and generator owned storage we demonstrate that if the generation sector is perfectly competitive and does not own storage then storage cannot be welfare diminishing otherwise generator owned storage or standalone storage in a market with strategic generating firms can reduce welfare compared to the no storage case this contradicts conventional wisdom that adding firms to an imperfectly competitive market typically reduces welfare losses

an hour ahead prediction model for heavy tailed spot prices abstract we propose an hour ahead prediction model for electricity prices that capture the heavy tailed behavior that we observe in the hourly spot market in the ercot texas and the pjm west hub grids we present a model according to which we separate the price process into a thin tailed trailing median process and a heavy tailed residual process whose probability distribution can be approximated by a cauchy distribution we show empirical evidence that supports our model

optimal energy commitments with storage and intermittent supply we formulate and solve the problem of making advance energy commitments for wind farms in the presence of a storage device with conversion losses mean reverting price process and an autoregressive energy generation process from wind we derive an optimal commitment policy under the assumption that wind energy is uniformly distributed then the stationary distribution of the storage level corresponding to the optimal policy is obtained from which the economic value of the storage as the relative increase in the expected revenue due to the existence of storage is obtained

estimation of time varying adjusted probability of informed trading and probability of symmetric order flow shock summary recently duarte and young 2009 studied the probability of informed trading pin proposed by easley et al 2002 and decomposed it into two parts the adjusted pin apin as a measure of asymmetric information and the probability of symmetric order flow shock psos as a measure of illiquidity they provide some cross section estimates of these measures using daily data over annual periods in this paper we propose a method to estimate daily apin and psos by extending the method in tay et al 2009 using high frequency transaction data our empirical results show that while pin is positively contemporaneously correlated with variance apin is not on the other hand psos is positively correlated with daily average effective spread and variance which is consistent with the interpretation of psos as a measure of illiquidity compared to apin psos exhibits clustering and sporadic bursts over time copyright 2012 john wiley sons ltd

economic assessment of concentrated solar power technologies a review abstract this paper surveys economic assessments of concentrated solar power csp technologies and finds two dominant assessment methods a majority of studies reported in the literature are based on the levelized cost of electricity lcoe while a small subset of studies consider time varying meteorological and electricity market conditions several studies argue that lcoe undervalues dynamic flexibility provided by thermal energy storage and does not consider revenue opportunities provided by electricity markets at different time scales as a result some studies find that both lcoe and revenue can in fact be conflicting metrics for certain designs and market conditions this review finds strong variations in lcoe and revenue estimates in the literature as comparisons between csp and other generation technologies e g fossil wind and photovoltaic are dictated by the chosen economic metric it is imperative that policy and investment decisions should carefully consider time varying effects and flexibility finally research directions are proposed to increasing the fidelity of economic assessments and to mitigate discrepancies

risk constrained bidding and offering strategy for a merchant compressed air energy storage plant electricity price forecasts are imperfect therefore a merchant energy storage facility requires a bidding and offering strategy for purchasing and selling the electricity to manage the risk associated with price forecast errors this paper proposes an information gap decision theory igdt based risk constrained bidding offering strategy for a merchant compressed air energy storage caes plant that participates in the day ahead energy markets considering price forecasting errors price uncertainty is modeled using igdt the igdt based self scheduling formulation is then used to construct separate hourly bidding and offering curves the theoretical approach to develop the proposed strategy is presented and validated using numerical simulations

conditional duration models for high frequency data a review on recent developments this paper reviews the recent literature on conditional duration modeling in high frequency finance these conditional duration models are associated with the time interval between trades price and volume changes of stocks traded in a financial market an earlier review by pacurar provides an exhaustive survey of the first and some of the second generation conditional duration models we consider almost all of the third generation and some of the second generation conditional duration models notable applications of these models and related empirical studies are discussed the paper may be seen as an extension to pacurar

informal care and long term labor market outcomes in this paper we estimate long run effects of informal care provision on female caregivers labor market outcomes up to eight years after care provision we compare a static version where average effects of care provision in a certain year on later labor market outcomes are estimated to a partly dynamic version where the effects of up to three consecutive years of care provision are analyzed our results suggest that there are significant initial negative effects of informal care provision on the probability to work full time the reduction in the probability to work full time by 4 percentage points or 2 4 5 0 if we move from point to partial identification is persistent over time short run effects on hourly wages are zero but we find considerable long run wage penalties

the political economy of long term care we build a two dimensional political economy model to explain the provision and financing of long term care and income redistribution voting agents differ in need and income opening up two conflicts one sets families with disabled parents who are in favor of a public long term care program against the ones without such parents who oppose public financing the other sets the poor against the rich with the former preferring heavier income taxation than the latter we show that a structure induced equilibrium always exists and that it is unique if informal care is provided in equilibrium the equilibrium not only explains the negative association of income inequality and long term care financing but also allows predictions about how demographic change might impact long term care arrangements and expenses

a semiparametric conditional duration model we propose a new semiparametric autoregressive duration sacd model which incorporates the parametric and nonparametric estimators of the conditional duration in a multiplicative way asymptotic properties for this combined estimator are presented the empirical application to the transaction duration of the us 2 year treasury note shows the outperformance of our sacd models over parametric acd models

using storage capacity rights to overcome the cost recovery hurdle for energy storage energy storage is unique in that it can provide multiple services this feature raises cost recovery issues for storage due to the combination of competitive markets and ratebased cost recovery used in many power systems today this hybrid regulatory paradigm relies on classifying assets as providing competitively prices or unpriced services and handling cost recovery based on that classification some recent regulatory precedents suggest that storage developers must choose between classifying their assets as providing competitively priced or unpriced services in the former case storage costs must be recovered through the market if an asset is classified as providing only unpriced services costs can be recovered through the ratebase this regulatory design can hamper cost recovery for storage and may lead to inefficient storage investment and use we propose an alternate solution whereby storage capacity rights are auctioned to third parties that use their rights for priced or unpriced services storage capacity rights disentangle storage cost recovery from the regulatory treatment of its end use we formulate the storage capacity auction model and demonstrate how to efficiently price storage capacity rights we show that the revenues earned by the storage owner through the auction equals the imputed marginal value of storage capacity as revealed by the market bids

extending the bidding format to promote demand response we propose an extended bidding structure to allow more realistic demand characteristics and behaviors to be expressed via flexible bids in today s iso run energy markets demand bid formats are all separable over time however a significant and growing segment of demand can be shifted across time and therefore has no way to bid its true valuation of consumption we propose additional bid types that allow deferrable adjustable and storage type loads to better express their value and thus elicit demand response in the most natural way via direct participation in the market we show that the additional bid types are easily incorporated into the existing market with no technological barrier and that they preserve the market s efficiency and incentive compatibility properties using real market data we give a numerical demonstration that the extended bid format could substantially increase social welfare and also present additional insight on storage expansion scenarios

assessing the economic value and optimal structure of large scale electricity storage large scale electricity storage can enable arbitrage between periods when electricity is abundant and cheap and periods when it is scarce in principle this could enable greater use of baseload generation and encourage investments in intermittent capacity such as wind and solar if storage is to penetrate the system the marginal value of storage capacity must be high enough to enable investments in storage to have a significant impact on investments in intermittent technologies it must be large enough to affect the prices on the system this research develops a theoretical framework to evaluate the marginal values of the components of a storage system and to characterize the impact of storage on the price patterns in the system the theoretical approach is applied to an example system to illustrate the changes in marginal values as storage penetrates the system and the impact on system prices

a comparative analysis of the value of pure and hybrid electricity storage significant natural gas and electricity price variation and volatility especially during the past few years raise questions about understanding the value drivers behind electricity storage the impact of these drivers for pure storage such as pumped hydroelectric storage and compressed air energy storage caes are different and in this paper we explore these differences in operation and net revenue over a variety of timescales we also consider the arbitrage value that is attainable in practice and explain why simple forecasting techniques based on historical data will generally be less successful for caes the breakeven cost of storage and how this can depend on regulatory treatment of storage and market structure is also considered

economics of electric energy storage for energy arbitrage and regulation in new york unlike markets for storable commodities electricity markets depend on the real time balance of supply and demand although much of the present day grid operates effectively without storage cost effective ways of storing electrical energy can help make the grid more efficient and reliable we investigate the economics of two emerging electric energy storage ees technologies sodium sulfur batteries and flywheel energy storage systems in new york state s electricity market the analysis indicates that there is a strong economic case for ees installations in the new york city region for applications such as energy arbitrage and that significant opportunities exist throughout new york state for regulation services benefits from deferral of system upgrades may be important in the decision to deploy ees market barriers currently make it difficult for energy limited ees such as flywheels to receive revenue for voltage regulation charging efficiency is more important to the economics of ees in a competitive electricity market than has generally been recognized