For dealing with the large-scale penetration of intermittent generation resources in the Europe, ... more For dealing with the large-scale penetration of intermittent generation resources in the Europe, intraday market has been designed and now the integration of all European intraday markets is on the agenda. As both day-ahead and intraday markets are based on zonal pricing wherein physical characteristic of transmission network is not taken into account, large amount of unscheduled flows originating specifically from wind generators, makes it very difficult that network to be in balance close to the delivery time. In this paper, we suggest a new design for intraday market based on a coordinated multilateral trade approach. In our customized approach, participants submit their buy and sell orders to the shared order book continuously whenever they find it profitable and (batch) auctions are conducted by power exchange at frequent but discrete-time intervals. Each batch auction result is accepted by the TSO if no violation occurs in the network or is curtailed until no violation occurs....
Proceedings of the 52nd Hawaii International Conference on System Sciences, 2019
In the Norwegian electricity system, new consumption patterns and changing load profiles increase... more In the Norwegian electricity system, new consumption patterns and changing load profiles increase an already apparent need for reinvestment in the aging network infrastructure. This is very costly, and network operators consider alternative ways of increasing capacity, which are less costly and more flexible. One such option is end-user flexibility. In the paper, we give an overview of the Norwegian electricity market and regulation and the potential of end-user flexibility. We present an investment case provided by a network company, which illustrates that the choice of compensation method to customers have a large impact on the cost and/or revenue cap in the regulatory model. By issuing direct payments for flexibility services, end-user flexibility results in a lower efficiency, although the revenue cap may be higher, while redistribution of network tariffs have a marginal effect on efficiency and the revenue cap. Through redistribution of network tariffs, the network operator can defer investments without a notable change in the revenue cap or change in efficiency. This highlights some of the future challenges that the regulator faces in setting a regulatory framework for end-user flexibility and it challenges the vertical separation that has been a corner stone in the deregulated electricity market.
With greater penetration of renewable generation, the uncertainty faced in electricity markets ha... more With greater penetration of renewable generation, the uncertainty faced in electricity markets has increased substantially. Conventionally, generators are assigned a predispatch quantity in advance of real time based on estimates of uncertain quantities. Expensive real-time adjustments then need to be made to ensure demand is met as uncertainty takes on a realization. We propose a new stochastic-programming market-clearing mechanism to optimize predispatch quantities given the uncertainties’ probability distribution and the costs of real-time deviation. This model differs from similar mechanisms previously proposed in that predispatch quantities are not subject to any network or other physical constraints, nor do they have a dedicated financial settlement. We establish revenue adequacy in each scenario (as opposed to “in expectation”), welfare enhancement, and expected (but not with probability one) cost recovery (including deviation costs) for this market-clearing mechanism. We als...
In May 2015, the Flow-Based Market Coupling (FBMC) model replaced the Available Transfer Capacity... more In May 2015, the Flow-Based Market Coupling (FBMC) model replaced the Available Transfer Capacity (ATC) model in Central Western Europe to determine the power transfer among bidding zones in the day-ahead market. It might be easier to change the bidding zone configuration in the FBMC model than in the ATC model as the FBMC model does not need to determine the maximum trading volume between two bidding zones. In our study, we run a simulation in the IEEE RTS 24-bus test system and examine how the bidding zone configurations affect the performance of both the FBMC and ATC models. We show that by improving the zone configuration, the FBMC model outperform the ATC in terms of reducing the re-dispatching cost only when the systems operators have a higher level of cooperation in the real-time market. Our results also indicate that better cooperation among the system operators would help to reduce the need for load shedding.
In May 2015, the Flow-Based Market Coupling (FBMC) model replaced the Available Transfer Capacity... more In May 2015, the Flow-Based Market Coupling (FBMC) model replaced the Available Transfer Capacity (ATC) model in Central Western Europe to determine the power transfers between countries or price areas. The FBMC model aims to enhance market integration and to better monitor the physical power flows. The FBMC model is expected to lead to increased social welfare in the day-ahead market and more frequent price convergence between different market areas. This paper gives a discussion of the procedures of market clearing and a mathematical formulation of the FBMC model. Moreover, we discuss the relationships between the nodal pricing, ATC, and FBMC models. In addition to an illustrative 3-node example, we examine the FBMC model in two test systems and show the difficulties in implementing the model in practice. We find that a higher social surplus in the day-ahead market may come at the cost of more re-dispatching in real time. We also find that the FBMC model might fail to relieve network congestion and better utilize the power resources, even when compared to the ATC model.
We consider an electricity market organized with two settlements: one for a pre-delivery (day-ahe... more We consider an electricity market organized with two settlements: one for a pre-delivery (day-ahead) market and one for real time, where uncertainty regarding production from non-dispatchable energy sources as well as variable load is resolved in the latter stage. We formulate two models to study the eciency of this market design. In the myopic model, the day-ahead market is cleared independently of the real-time market, while in the integrated stochastic dispatch model the possible outcomes of the real-time market clearing are considered when the day-ahead market is cleared. We focus on how changes in the design of the electricity market inuence the eciency of the dispatch, measured by expected total cost or social welfare. In particular, we examine how relaxing network ow constraints and, for the stochastic dispatch model, even the balancing constraints in the day-ahead part of the dispatch models aects the overall eciency of the system. This allows the dispatch to be infeasible day-ahead, while these infeasibilities will be handled in the real-time market. For the stochastic dispatch model we nd that relaxing the network ows and balancing constraints in the dayahead part of the market provides additional exibility that can be valuable to the system. In our examples with high up-regulation cost we nd a value of "overbooking" that lead to lower total costs. In the myopic model the results are more ambiguous, however, leaving too many constraints to be resolved in the real-time market only, can lead to infeasibilities or high regulation cost.
We consider an electricity market with two sequential market clearings, for instance representing... more We consider an electricity market with two sequential market clearings, for instance representing a day-ahead and a real-time market. When the rst market is cleared, there is uncertainty with respect to generation and/or load, while this uncertainty is resolved when the second market is cleared. We compare the outcomes of a stochastic market clearing model, i.e. a market clearing model taking into account both markets and the uncertainty, to a myopic market model where the rst market is cleared based only on given bids, and not taking into account neither the uncertainty nor the bids in the second market. While the stochastic market clearing gives a solution with a higher total social welfare, it poses several challenges for market design. The stochastic dispatch may lead to a dispatch where the prices deviate from the bid curves in the rst market. This can lead to incentives for selfscheduling, require producers to produce above marginal cost and consumers to pay above their marginal value in the rst market. Our analysis show that the wind producer has an incentive to deviate from the system optimal plan in both the myopic and stochastic model, and this incentive is particularly strong under the myopic model. We also discuss how the total social welfare of the market outcome under stochastic market clearing depends on the quality of the information that the system operator will base the market clearing on. In particular, we show that the wind producer has an incentive to misreport the probability distribution for wind.
Revenue cap regulation is often combined with systematic benchmarking to reveal the managerial in... more Revenue cap regulation is often combined with systematic benchmarking to reveal the managerial inefficiencies when regulating natural monopolies. One example is the European energy sector, where benchmarking is based on actual cost data, which are influenced by managerial inefficiency as well as operational heterogeneity. This paper demonstrates how a conditional nonparametric method, which allows comparison of firms operating under heterogeneous technologies, can be used to estimate managerial inefficiency. A dataset of 123 distribution firms in Norway is used to show aggregate and firm-specific effects of conditioning. We compare the models presently used by the Norwegian regulator to a suggested conditional model, thus providing a viable alternative to distinguish between managerial inefficiency and operational heterogeneity. The use of the conditional model in this regulatory context leads, first, to a decrease in aggregate efficient costs and, second, to a reallocation effect that affects the relative profitability of firms and relative customer prices, thus providing a fairer basis for setting revenue caps.
Revenue cap regulation is often combined with systematic benchmarking to reveal the managerial in... more Revenue cap regulation is often combined with systematic benchmarking to reveal the managerial inefficiencies when regulating natural monopolies. One example is the European energy sector, where benchmarking methods are based on actual cost data, which are influenced by managerial inefficiency as well as operational heterogeneity. This paper demonstrates how a conditional nonparametric method, which allows the comparison of firms operating under heterogeneous technologies, can be used to estimate managerial inefficiency. A dataset of 123 distribution firms in Norway is used to show aggregate and firm-specific effects of conditioning. By comparing the unconditional model to our proposed conditional model and the model presently used by the Norwegian regulator, we see that the use of conditional benchmarking methods in revenue cap regulation may effectively distinguish between managerial inefficiency and operational heterogeneity. This distinction leads first to a decrease in aggregate efficient costs and second to a reallocation effect that affects the relative profitability of firms and relative customer prices, thus providing a fairer basis for setting revenue caps.
In the European market, the promotion of wind power leads to more network congestion. Zonal prici... more In the European market, the promotion of wind power leads to more network congestion. Zonal pricing (market coupling), which does not take the physical characteristics of transmission into account, is the most commonly used method to relieve congestion in Europe. Zonal pricing fails to provide adequate locational price signals regarding the energy resource scarcity and thus creates a large amount of unscheduled cross-border flows originating from wind-generated power, making the interconnected grid less secure. Prior studies show that full nodal pricing works better in integrating wind power into the grid. In this paper we investigate the effects of applying a hybrid congestion management model, i.e. nodal pricing model for one country embedded in a zonal pricing system for the rest of the market. We test how nodal pricing works in such a hybrid context with more wind power. We find that, compared to full nodal pricing, hybrid pricing fails to fully utilize all the resources in the network and some wrong price signals might be given. However, hybrid pricing still performs better than zonal pricing. The results from the hybrid pricing model of Poland, Germany, Slovakia and the Czech Republic show that, within the area applying nodal pricing (Poland), better price signals are given; the need for re-dispatching reduces; more congestion rent is collected and the unit cost of power is reduced. The results also show that international power exchange increases between the nodal pricing area and the zonal pricing areas, especially on windy days. Moreover, the nodal pricing area has less unscheduled crossborder power flow from the zonal pricing area entering its network and collects more cross-border congestion rent.
Norwegian distribution companies have been subjected to an incentive regulation scheme from 1997,... more Norwegian distribution companies have been subjected to an incentive regulation scheme from 1997, and the efficiency incentives were further strengthened with the introduction of yardstick regulation in 2007. We examine the productivity development for these companies in the period from 2004 to 2013. Using three benchmarking methods, DEA, SFA, and StoNED, we examine productivity change, with the usual decompositions into efficiency change, technical change, and scale efficiency change. Increasing investments and use of accounting-based capital costs in our analysis may lead to a negative bias in the productivity change estimates, and we therefore perform our analysis with and without capital costs. Our results indicate a negative productivity development for the whole period from 2004 to 2013, and we do not observe a positive effect of the change in regulation regime from 2007.
We study returns to scale in Norwegian electricity distribution companies. The scale issue of thi... more We study returns to scale in Norwegian electricity distribution companies. The scale issue of this sector has become an important political question, and it was for instance discussed by the Reiten commission (OED, 2014) in a study about the future structure and organization of the Norwegian electricity network industry. We use panel data from the Norwegian Water Resources and Energy Directorate (NVE) for the period from 2004 to 2010. The Data Envelopment Analysis (DEA) method and the Stochastic Nonparametric Envelopment of Data (StoNED) approach are applied to examine the scale issue. We show that a majority of the companies are smaller than the optimal size, in line with Kumbhakar et al. (2014). The performance of Norwegian distribution companies are influenced by a number of environmental factors, and some of these factors are negatively correlated with company size. However, our results show that controlling for environmental factors when estimating returns to scale does not have a big effect on the estimated optimal sizes.
We construct a Malmquist productivity index based on stochastic non-parametric envelopment of dat... more We construct a Malmquist productivity index based on stochastic non-parametric envelopment of data (StoNED) method, and we study how the distributional assumptions in the second StoNED stage affect productivity change and its decompositions. Our discussion show that the distributional assumptions do not affect the estimates of overall productivity change and scale efficiency change, but that estimates of efficiency change and technical change are affected. Data on Norwegian electricity distribution companies is used to illustrate our discussion.
2012 9th International Conference on the European Energy Market, 2012
Presently in the Nordic day-ahead market, zonal pricing or market splitting is used for relieving... more Presently in the Nordic day-ahead market, zonal pricing or market splitting is used for relieving congestion between a predetermined set of price areas. Constraints internal to the price areas are resolved by counter trading or redispatching in the regulation market. In a model of the Nordic electricity market we consider an hourly case from winter 2010 and present analyses of the effects of different congestion management methods on prices, quantities, surpluses and network utilization. We also study the effects of two different ways of taking into account security constraints.
SNF-prosjekt nr. 7550 Utvikling av praktisk normkostnadsmodell-med fokus på effektivitetsmåling o... more SNF-prosjekt nr. 7550 Utvikling av praktisk normkostnadsmodell-med fokus på effektivitetsmåling og investeringsintensiver Prosjektet er finansiert av Energibedriftenes landsforening (EBL)
We examine weight restrictions in the DEA model for distribution networks, taking as the starting... more We examine weight restrictions in the DEA model for distribution networks, taking as the starting point the NVE model with one input, total cost, and several outputs. In the unrestricted DEA models, we notice large differences in absolute and relative shadow prices, and for some companies, extreme weight on "geography" variables in the cost norms. There seems to be a tendency that companies, that have a large weight on geographic variables and / or a low weight on transported energy and customers, become super efficient. This seems unreasonable, and one remedy may be to restrict prices / weights for individual outputs, or combinations of outputs. We consider absolute, relative and virtual weight restrictions, and show how to formulate the LP problems and how to interpret the restrictions. We discuss the relative price restrictions suggested for geography and high voltage variables by NVE (2008), and consider an alternative approach, using virtual weight restrictions on the combination of the three geography variables; forest, snow, and coast. Comparing the effects of the virtual approach to the relative, we notice that with relative weight restrictions, more companies are affected, but to a lesser extent. An important task when introducing weight restrictions in the DEA analyses is to determine the specific limits on the weights. Finding reasonable limits, depends on which type of weight restrictions that are in consideration, and should be based on knowledge of cost and technology in the industry. An advantage of the virtual weight restrictions is that they are on a more aggregated level than the relative ones, and it may be easier to establish limits on the overall effects on the total cost norm from a subset of outputs, rather than reasonable pair-wise comparisons of outputs weights. Finally, the report discusses implementation of DEA models with weight restrictions, and gives a short overview of available software.
For dealing with the large-scale penetration of intermittent generation resources in the Europe, ... more For dealing with the large-scale penetration of intermittent generation resources in the Europe, intraday market has been designed and now the integration of all European intraday markets is on the agenda. As both day-ahead and intraday markets are based on zonal pricing wherein physical characteristic of transmission network is not taken into account, large amount of unscheduled flows originating specifically from wind generators, makes it very difficult that network to be in balance close to the delivery time. In this paper, we suggest a new design for intraday market based on a coordinated multilateral trade approach. In our customized approach, participants submit their buy and sell orders to the shared order book continuously whenever they find it profitable and (batch) auctions are conducted by power exchange at frequent but discrete-time intervals. Each batch auction result is accepted by the TSO if no violation occurs in the network or is curtailed until no violation occurs....
Proceedings of the 52nd Hawaii International Conference on System Sciences, 2019
In the Norwegian electricity system, new consumption patterns and changing load profiles increase... more In the Norwegian electricity system, new consumption patterns and changing load profiles increase an already apparent need for reinvestment in the aging network infrastructure. This is very costly, and network operators consider alternative ways of increasing capacity, which are less costly and more flexible. One such option is end-user flexibility. In the paper, we give an overview of the Norwegian electricity market and regulation and the potential of end-user flexibility. We present an investment case provided by a network company, which illustrates that the choice of compensation method to customers have a large impact on the cost and/or revenue cap in the regulatory model. By issuing direct payments for flexibility services, end-user flexibility results in a lower efficiency, although the revenue cap may be higher, while redistribution of network tariffs have a marginal effect on efficiency and the revenue cap. Through redistribution of network tariffs, the network operator can defer investments without a notable change in the revenue cap or change in efficiency. This highlights some of the future challenges that the regulator faces in setting a regulatory framework for end-user flexibility and it challenges the vertical separation that has been a corner stone in the deregulated electricity market.
With greater penetration of renewable generation, the uncertainty faced in electricity markets ha... more With greater penetration of renewable generation, the uncertainty faced in electricity markets has increased substantially. Conventionally, generators are assigned a predispatch quantity in advance of real time based on estimates of uncertain quantities. Expensive real-time adjustments then need to be made to ensure demand is met as uncertainty takes on a realization. We propose a new stochastic-programming market-clearing mechanism to optimize predispatch quantities given the uncertainties’ probability distribution and the costs of real-time deviation. This model differs from similar mechanisms previously proposed in that predispatch quantities are not subject to any network or other physical constraints, nor do they have a dedicated financial settlement. We establish revenue adequacy in each scenario (as opposed to “in expectation”), welfare enhancement, and expected (but not with probability one) cost recovery (including deviation costs) for this market-clearing mechanism. We als...
In May 2015, the Flow-Based Market Coupling (FBMC) model replaced the Available Transfer Capacity... more In May 2015, the Flow-Based Market Coupling (FBMC) model replaced the Available Transfer Capacity (ATC) model in Central Western Europe to determine the power transfer among bidding zones in the day-ahead market. It might be easier to change the bidding zone configuration in the FBMC model than in the ATC model as the FBMC model does not need to determine the maximum trading volume between two bidding zones. In our study, we run a simulation in the IEEE RTS 24-bus test system and examine how the bidding zone configurations affect the performance of both the FBMC and ATC models. We show that by improving the zone configuration, the FBMC model outperform the ATC in terms of reducing the re-dispatching cost only when the systems operators have a higher level of cooperation in the real-time market. Our results also indicate that better cooperation among the system operators would help to reduce the need for load shedding.
In May 2015, the Flow-Based Market Coupling (FBMC) model replaced the Available Transfer Capacity... more In May 2015, the Flow-Based Market Coupling (FBMC) model replaced the Available Transfer Capacity (ATC) model in Central Western Europe to determine the power transfers between countries or price areas. The FBMC model aims to enhance market integration and to better monitor the physical power flows. The FBMC model is expected to lead to increased social welfare in the day-ahead market and more frequent price convergence between different market areas. This paper gives a discussion of the procedures of market clearing and a mathematical formulation of the FBMC model. Moreover, we discuss the relationships between the nodal pricing, ATC, and FBMC models. In addition to an illustrative 3-node example, we examine the FBMC model in two test systems and show the difficulties in implementing the model in practice. We find that a higher social surplus in the day-ahead market may come at the cost of more re-dispatching in real time. We also find that the FBMC model might fail to relieve network congestion and better utilize the power resources, even when compared to the ATC model.
We consider an electricity market organized with two settlements: one for a pre-delivery (day-ahe... more We consider an electricity market organized with two settlements: one for a pre-delivery (day-ahead) market and one for real time, where uncertainty regarding production from non-dispatchable energy sources as well as variable load is resolved in the latter stage. We formulate two models to study the eciency of this market design. In the myopic model, the day-ahead market is cleared independently of the real-time market, while in the integrated stochastic dispatch model the possible outcomes of the real-time market clearing are considered when the day-ahead market is cleared. We focus on how changes in the design of the electricity market inuence the eciency of the dispatch, measured by expected total cost or social welfare. In particular, we examine how relaxing network ow constraints and, for the stochastic dispatch model, even the balancing constraints in the day-ahead part of the dispatch models aects the overall eciency of the system. This allows the dispatch to be infeasible day-ahead, while these infeasibilities will be handled in the real-time market. For the stochastic dispatch model we nd that relaxing the network ows and balancing constraints in the dayahead part of the market provides additional exibility that can be valuable to the system. In our examples with high up-regulation cost we nd a value of "overbooking" that lead to lower total costs. In the myopic model the results are more ambiguous, however, leaving too many constraints to be resolved in the real-time market only, can lead to infeasibilities or high regulation cost.
We consider an electricity market with two sequential market clearings, for instance representing... more We consider an electricity market with two sequential market clearings, for instance representing a day-ahead and a real-time market. When the rst market is cleared, there is uncertainty with respect to generation and/or load, while this uncertainty is resolved when the second market is cleared. We compare the outcomes of a stochastic market clearing model, i.e. a market clearing model taking into account both markets and the uncertainty, to a myopic market model where the rst market is cleared based only on given bids, and not taking into account neither the uncertainty nor the bids in the second market. While the stochastic market clearing gives a solution with a higher total social welfare, it poses several challenges for market design. The stochastic dispatch may lead to a dispatch where the prices deviate from the bid curves in the rst market. This can lead to incentives for selfscheduling, require producers to produce above marginal cost and consumers to pay above their marginal value in the rst market. Our analysis show that the wind producer has an incentive to deviate from the system optimal plan in both the myopic and stochastic model, and this incentive is particularly strong under the myopic model. We also discuss how the total social welfare of the market outcome under stochastic market clearing depends on the quality of the information that the system operator will base the market clearing on. In particular, we show that the wind producer has an incentive to misreport the probability distribution for wind.
Revenue cap regulation is often combined with systematic benchmarking to reveal the managerial in... more Revenue cap regulation is often combined with systematic benchmarking to reveal the managerial inefficiencies when regulating natural monopolies. One example is the European energy sector, where benchmarking is based on actual cost data, which are influenced by managerial inefficiency as well as operational heterogeneity. This paper demonstrates how a conditional nonparametric method, which allows comparison of firms operating under heterogeneous technologies, can be used to estimate managerial inefficiency. A dataset of 123 distribution firms in Norway is used to show aggregate and firm-specific effects of conditioning. We compare the models presently used by the Norwegian regulator to a suggested conditional model, thus providing a viable alternative to distinguish between managerial inefficiency and operational heterogeneity. The use of the conditional model in this regulatory context leads, first, to a decrease in aggregate efficient costs and, second, to a reallocation effect that affects the relative profitability of firms and relative customer prices, thus providing a fairer basis for setting revenue caps.
Revenue cap regulation is often combined with systematic benchmarking to reveal the managerial in... more Revenue cap regulation is often combined with systematic benchmarking to reveal the managerial inefficiencies when regulating natural monopolies. One example is the European energy sector, where benchmarking methods are based on actual cost data, which are influenced by managerial inefficiency as well as operational heterogeneity. This paper demonstrates how a conditional nonparametric method, which allows the comparison of firms operating under heterogeneous technologies, can be used to estimate managerial inefficiency. A dataset of 123 distribution firms in Norway is used to show aggregate and firm-specific effects of conditioning. By comparing the unconditional model to our proposed conditional model and the model presently used by the Norwegian regulator, we see that the use of conditional benchmarking methods in revenue cap regulation may effectively distinguish between managerial inefficiency and operational heterogeneity. This distinction leads first to a decrease in aggregate efficient costs and second to a reallocation effect that affects the relative profitability of firms and relative customer prices, thus providing a fairer basis for setting revenue caps.
In the European market, the promotion of wind power leads to more network congestion. Zonal prici... more In the European market, the promotion of wind power leads to more network congestion. Zonal pricing (market coupling), which does not take the physical characteristics of transmission into account, is the most commonly used method to relieve congestion in Europe. Zonal pricing fails to provide adequate locational price signals regarding the energy resource scarcity and thus creates a large amount of unscheduled cross-border flows originating from wind-generated power, making the interconnected grid less secure. Prior studies show that full nodal pricing works better in integrating wind power into the grid. In this paper we investigate the effects of applying a hybrid congestion management model, i.e. nodal pricing model for one country embedded in a zonal pricing system for the rest of the market. We test how nodal pricing works in such a hybrid context with more wind power. We find that, compared to full nodal pricing, hybrid pricing fails to fully utilize all the resources in the network and some wrong price signals might be given. However, hybrid pricing still performs better than zonal pricing. The results from the hybrid pricing model of Poland, Germany, Slovakia and the Czech Republic show that, within the area applying nodal pricing (Poland), better price signals are given; the need for re-dispatching reduces; more congestion rent is collected and the unit cost of power is reduced. The results also show that international power exchange increases between the nodal pricing area and the zonal pricing areas, especially on windy days. Moreover, the nodal pricing area has less unscheduled crossborder power flow from the zonal pricing area entering its network and collects more cross-border congestion rent.
Norwegian distribution companies have been subjected to an incentive regulation scheme from 1997,... more Norwegian distribution companies have been subjected to an incentive regulation scheme from 1997, and the efficiency incentives were further strengthened with the introduction of yardstick regulation in 2007. We examine the productivity development for these companies in the period from 2004 to 2013. Using three benchmarking methods, DEA, SFA, and StoNED, we examine productivity change, with the usual decompositions into efficiency change, technical change, and scale efficiency change. Increasing investments and use of accounting-based capital costs in our analysis may lead to a negative bias in the productivity change estimates, and we therefore perform our analysis with and without capital costs. Our results indicate a negative productivity development for the whole period from 2004 to 2013, and we do not observe a positive effect of the change in regulation regime from 2007.
We study returns to scale in Norwegian electricity distribution companies. The scale issue of thi... more We study returns to scale in Norwegian electricity distribution companies. The scale issue of this sector has become an important political question, and it was for instance discussed by the Reiten commission (OED, 2014) in a study about the future structure and organization of the Norwegian electricity network industry. We use panel data from the Norwegian Water Resources and Energy Directorate (NVE) for the period from 2004 to 2010. The Data Envelopment Analysis (DEA) method and the Stochastic Nonparametric Envelopment of Data (StoNED) approach are applied to examine the scale issue. We show that a majority of the companies are smaller than the optimal size, in line with Kumbhakar et al. (2014). The performance of Norwegian distribution companies are influenced by a number of environmental factors, and some of these factors are negatively correlated with company size. However, our results show that controlling for environmental factors when estimating returns to scale does not have a big effect on the estimated optimal sizes.
We construct a Malmquist productivity index based on stochastic non-parametric envelopment of dat... more We construct a Malmquist productivity index based on stochastic non-parametric envelopment of data (StoNED) method, and we study how the distributional assumptions in the second StoNED stage affect productivity change and its decompositions. Our discussion show that the distributional assumptions do not affect the estimates of overall productivity change and scale efficiency change, but that estimates of efficiency change and technical change are affected. Data on Norwegian electricity distribution companies is used to illustrate our discussion.
2012 9th International Conference on the European Energy Market, 2012
Presently in the Nordic day-ahead market, zonal pricing or market splitting is used for relieving... more Presently in the Nordic day-ahead market, zonal pricing or market splitting is used for relieving congestion between a predetermined set of price areas. Constraints internal to the price areas are resolved by counter trading or redispatching in the regulation market. In a model of the Nordic electricity market we consider an hourly case from winter 2010 and present analyses of the effects of different congestion management methods on prices, quantities, surpluses and network utilization. We also study the effects of two different ways of taking into account security constraints.
SNF-prosjekt nr. 7550 Utvikling av praktisk normkostnadsmodell-med fokus på effektivitetsmåling o... more SNF-prosjekt nr. 7550 Utvikling av praktisk normkostnadsmodell-med fokus på effektivitetsmåling og investeringsintensiver Prosjektet er finansiert av Energibedriftenes landsforening (EBL)
We examine weight restrictions in the DEA model for distribution networks, taking as the starting... more We examine weight restrictions in the DEA model for distribution networks, taking as the starting point the NVE model with one input, total cost, and several outputs. In the unrestricted DEA models, we notice large differences in absolute and relative shadow prices, and for some companies, extreme weight on "geography" variables in the cost norms. There seems to be a tendency that companies, that have a large weight on geographic variables and / or a low weight on transported energy and customers, become super efficient. This seems unreasonable, and one remedy may be to restrict prices / weights for individual outputs, or combinations of outputs. We consider absolute, relative and virtual weight restrictions, and show how to formulate the LP problems and how to interpret the restrictions. We discuss the relative price restrictions suggested for geography and high voltage variables by NVE (2008), and consider an alternative approach, using virtual weight restrictions on the combination of the three geography variables; forest, snow, and coast. Comparing the effects of the virtual approach to the relative, we notice that with relative weight restrictions, more companies are affected, but to a lesser extent. An important task when introducing weight restrictions in the DEA analyses is to determine the specific limits on the weights. Finding reasonable limits, depends on which type of weight restrictions that are in consideration, and should be based on knowledge of cost and technology in the industry. An advantage of the virtual weight restrictions is that they are on a more aggregated level than the relative ones, and it may be easier to establish limits on the overall effects on the total cost norm from a subset of outputs, rather than reasonable pair-wise comparisons of outputs weights. Finally, the report discusses implementation of DEA models with weight restrictions, and gives a short overview of available software.
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Papers by Endre Bjørndal