On the Participation of Power-To-Heat Assets in Frequency Regulation Markets—A Danish Case Study

Due to the new green energy policies, district heating companies are being increasingly encouraged to exploit power-to-heat assets, e.g., heat pumps and electric boilers, in their distribution networks besides the traditional central combined heat and power units. The increased utilization of these assets will generate a more complex interaction between power distribution grids and district heating networks including markets for provision of ancillary services. Enabling the participation of power-to-heat units in the ancillary service markets, e.g., frequency reserves, may increase the revenue streams for assets’ owners. However, some technical challenges must first be addressed, including optimization of portfolios of assets that accounts for ancillary service markets, new coordination and operational schemes for portfolio of assets, increase data exchange and interactions with transmission system operators, and new local control schemes for units. This paper proposes a systematic model based design approach for assessment of provision of frequency regulation by power-to-heat assets using the smart grid architecture model. The proposed approach is demonstrated in a Real-Time Control Hardware-in-the-Loop laboratory environment

Combined bidding at power and ancillary service markets

Power and ancillary service markets are strongly coupled. However, at the moment auctions are organized in such a manner that the coupling is not taken into account. Every market participant submits bids at power and/or AS markets without possibility to adjust with respect to the outcome of the other market. Inexact approximations of the actual market price induce deviations from the optimal social welfare value. In this paper, we firstly describe and analyze the consequences of power and ancillary service market coupling. Secondly, we present two different market design strategies, both of which are based on the idea of iterative auction and have the goal to optimally account for power and AS coupling, enabling the overall system to maximize its social welfare. An illustrative example is used to present potential benefits and downsides that might arise as a result of introducing proposed market arrangements

Balancing Power Auctions - Theoretical and Empirical Analyses

The European-wide goal of increasing the share of final electricity consumption from renewable sources to 27% by 2030 increases the supply volatility of the power system considerably. To manage this volatility, ancillary services for the power system become increasingly important. The most important short-term ancillary service is balancing power: it balances the electricity demand and supply instantaneously and, thus, ensures a constant frequency over time in alternating current grids. In most liberalized electricity markets worldwide, the procurement of balancing power is organized with the help of auctions. This thesis analyzes balancing power auctions theoretically and empirically and focuses on the current Austrian-German and the future European-wide Secondary Balancing Power (aFRR) auction design

Determining Utility System Value of Demand Flexibility From Grid-interactive Efficient Buildings

This report focuses on ways current methods and practices that establish the value to electric utility systems of distributed energy resource (DER) investments can be enhanced to determine the value of demand flexibility in grid-interactive efficient buildings that can provide grid services. The report introduces key valuation concepts that are applicable to demand flexibility that these buildings can provide and links to other documents that describe these concepts and their implementation in more detail.The scope of this report is limited to the valuation of economic benefits to the utility system. These are the foundational values on which other benefits (and costs) can be built. Establishing the economic value to the grid of demand flexibility provides the information needed to design programs, market rules, and rates that align the economic interest of utility customers with building owners and occupants. By nature, DERs directly impact customers and provide societal benefits external to the utility system. Jurisdictions can use utility system benefits and costs as the foundation of their economic analysis but align their primary cost-effectiveness metric with all applicable policy objectives, which may include customer and societal (non-utility system) impacts.This report suggests enhancements to current methods and practices that state and local policymakers, public utility commissions, state energy offices, utilities, state utility consumer representatives, and other stakeholders might support. These enhancements can improve the consistency and robustness of economic valuation of demand flexibility for grid services. The report concludes with a discussion of considerations for prioritizing implementation of these improvements

Optimized Energy Management Strategy for Wind Plants with Storage in Energy and Reserve Markets

This paper addresses the joint operation of wind plants with energy storage systemsin multiple markets to increase the value of wind energy from an economic and technical point of view. The development of an optimized energy management allows scheduling the wind generation in energymarkets, as well as contributing to the system stability through the joint participation in frequency ancillary services. The market optimization maximizes market revenuesconsidering overallstoragecosts, while avoidingenergy imbalancesand market penalties. Moreover, wind power fluctuations, forecast errors and real-time reserverequirementsare controlledby the energy storagesystem and managed afterward through the participation in continuous intraday market. Furthermore, model predictive control approach enables a high compliance of reserve requirementsand a hugereduction of energy imbalancesin real-time operation. Different energy storagecapacities are selected in order to evaluate theircost-effectiveness enhancing the wind plant operation underthe considered study case.This work was partially supported by the Basque Government under Project Road2DC (ELKARTEK Research Program KK-2018/00083)

Spinning Reserves from Responsive Loads

Report ORNL/TM-2003/1

Grid Integration Costs of Fluctuating Renewable Energy Sources

The grid integration of intermittent Renewable Energy Sources (RES) causes costs for grid operators due to forecast uncertainty and the resulting production schedule mismatches. These so-called profile service costs are marginal cost components and can be understood as an insurance fee against RES production schedule uncertainty that the system operator incurs due to the obligation to always provide sufficient control reserve capacity for power imbalance mitigation. This paper studies the situation for the German power system and the existing German RES support schemes. The profile service costs incurred by German Transmission System Operators (TSOs) are quantified and means for cost reduction are discussed. In general, profile service costs are dependent on the RES prediction error and the specific workings of the power markets via which the prediction error is balanced. This paper shows both how the prediction error can be reduced in daily operation as well as how profile service costs can be reduced via optimization against power markets and/or active curtailment of RES generation.Comment: Accepted for SUSTECH 2014, Portland, Oregon, USA, July 201

Optimizing energy storage participation in emerging power markets

The growing amount of intermittent renewables in power generation creates challenges for real-time matching of supply and demand in the power grid. Emerging ancillary power markets provide new incentives to consumers (e.g., electrical vehicles, data centers, and others) to perform demand response to help stabilize the electricity grid. A promising class of potential demand response providers includes energy storage systems (ESSs). This paper evaluates the benefits of using various types of novel ESS technologies for a variety of emerging smart grid demand response programs, such as regulation services reserves (RSRs), contingency reserves, and peak shaving. We model, formulate and solve optimization problems to maximize the net profit of ESSs in providing each demand response. Our solution selects the optimal power and energy capacities of the ESS, determines the optimal reserve value to provide as well as the ESS real-time operational policy for program participation. Our results highlight that applying ultra-capacitors and flywheels in RSR has the potential to be up to 30 times more profitable than using common battery technologies such as LI and LA batteries for peak shaving