Effektabonnement: relevante erfaringer fra USA

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Simulations of the Capacity Balance in Norway and Sweden

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The value of load shifting. An estimate for Norway using the EMPS model

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A Stochastic mixed integer linear programming formulation for the balancing energy activation problem under uncertainty

In the activation market, the Transmission System Operator selects and activates balancing energy bids to cover the system imbalance. Growing use of intermittent energy sources increases uncertainty in system operation and new EU regulations, including a so-called Activation Optimization Function and new Standard Products for manual frequency restoration reserves (mFRR), will change the activation process significantly. However, commonly used price-based bid selection approaches are incapable of taking intertemporal constraints and uncertainty into account in the activation process. This paper presents a new optimization formulation, built on stochastic unit commitment principles, using imbalance forecast scenarios to propose bid activation schedules minimizing expected activation costs. Unlike earlier approaches, intertemporal characteristics of the proposed mFRR product are modeled in detail. The optimization procedure is implemented in a rolling horizon simulation and demonstrated using Norwegian imbalance and market data. Compared to a corresponding deterministic approach, the stochastic strategy significantly reduces activation costs

Simulations of the Capacity Balance in Norway and Sweden

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Utilizing end-user flexibility for demand management under capacity subscription tariffs

The Norwegian regulator has proposed a new grid tariff, based on capacity subscription, where the consumer pays an excess fee whenever he exceeds the subscribed level. We compare this tariff with a variant of capacity subscription where demand is physically limited to the subscribed level, but where the limitation is activated only when there is grid congestion. The results show that this can be an attractive option if demand can be flexibly controlled to stay below the subscribed limit, which is increasingly possible. Use of a battery is also attractive, but the investment costs are still much too high.submittedVersion© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

Utilizing end-user flexibility for demand management under capacity subscription tariffs

The Norwegian regulator has proposed a new grid tariff, based on capacity subscription, where the consumer pays an excess fee whenever he exceeds the subscribed level. We compare this tariff with a variant of capacity subscription where demand is physically limited to the subscribed level, but where the limitation is activated only when there is grid congestion. The results show that this can be an attractive option if demand can be flexibly controlled to stay below the subscribed limit, which is increasingly possible. Use of a battery is also attractive, but the investment costs are still much too high

Interconnector participation in capacity mechanisms: A new de-rating approach

Abstract—In countries with Capacity Mechanisms in place, where Explicit Interconnector Participation model is to be used,one of the key market design questions to be answered is how the amount of interconnector capacity that is allowed to participate in the auctions should be determined. This paper argues for an interconnector capacity de-rating approach. In order for the de-rating factor to be representative of stochasticity inherent in the system, the concept of Interconnector Effective Load Carrying Capability is postulated in this paper. A method with probabilistic basis that allows for converting the name-plate capacity of a transmission line connecting two areas into a de-rated capacity is proposed. The proposed probabilistic methodology takes into account the technical availability of the line and captures the impact of simultaneous or co-incident scarcity. A simple case-study is presented to exemplify the proposed principle and methodology

Interconnector Participation in Capacity Mechanisms: A New De-rating Approach

Abstract—In countries with Capacity Mechanisms in place, where Explicit Interconnector Participation model is to be used,one of the key market design questions to be answered is how the amount of interconnector capacity that is allowed to participate in the auctions should be determined. This paper argues for an interconnector capacity de-rating approach. In order for the de-rating factor to be representative of stochasticity inherent in the system, the concept of Interconnector Effective Load Carrying Capability is postulated in this paper. A method with probabilistic basis that allows for converting the name-plate capacity of a transmission line connecting two areas into a de-rated capacity is proposed. The proposed probabilistic methodology takes into account the technical availability of the line and captures the impact of simultaneous or co-incident scarcity. A simple case-study is presented to exemplify the proposed principle and methodology

Distributed balancing energy activitation and exchange optimisation

European balancing markets are presently fragmented and mostly national. Integrating them on common platforms requires the ability to identify optimal balancing energy volumes to be activated and exchanged to cover imbalances across the interconnected system, but this leads to new challenges. To avoid balancing energy flows compromising operational security, capacity limitations in the transmission network should be taken into account in the optimisation. However, a zonal market structure and limited computational time inhibit using detailed models in the optimisation. This study describes and demonstrates a distributed formulation for optimisation of activation and exchange of balancing energy. Using Benders decomposition, the optimisation is separated into local activation problems that are smaller and less complex, distributing the computational effort. A single exchange problem identifies the optimal exchange volumes between geographical areas using optimality cuts obtained in the local subproblems. The proposed formulation is capable of optimising balancing decisions across a large, interconnected system, while still keeping a zonal market structure and taking detailed network constraints into account