Analysis of Solar Energy Aggregation under Various Billing Mechanisms

Ongoing reductions in the cost of solar photovoltaic (PV) systems are driving their increased installations by residential households. Various incentive programs such as feed-in tariff, net metering, net purchase and sale that allow the prosumers to sell their generated electricity to the grid are also powering this trend. In this paper, we investigate sharing of PV systems among a community of households, who can also benefit further by pooling their production. Using cooperative game theory, we find conditions under which such sharing decreases their net total cost. We also develop allocation rules such that the joint net electricity consumption cost is allocated to the participants. These cost allocations are based on the cost causation principle. The allocations also satisfy the standalone cost principle and promote PV solar aggregation. We also perform a comparative analytical study on the benefit of sharing under the mechanisms favorable for sharing, namely net metering, and net purchase and sale. The results are illustrated in a case study using real consumption data from a residential community in Austin, Texas.Comment: 12 page

Understanding the value of net metering outcomes for different averaging time steps

The installation of distributed energy resources (DER) heavily impacts on the power patterns of the prosumers. In fact, the variability of the generation, together with the technical characteristics of the storage systems, may introduce a huge variety in the shape of the net power curves seen from the point of common coupling (PCC). This leads to completely rethink the definition of the time series required to create homogeneous group of prosumers, for providing useful tools to manage the emerging paradigms in the electricity system, such as energy communities and local energy markets. Moreover, the differences between the local energy production and consumption at the PCC could become hidden, if the local energy management has to be considered as a private decision of the local user. In this case, only net metering (that implies a unique measurement of the net electricity taken from the grid) will be used to evaluate the impact on the network of the net power curves. Hence, new approaches are required to properly measure the electricity exchange at the PCC. This paper addresses how the net metering outcomes depend on the time resolution of the measured data, and how the information taken from net metering can be valued by giving different price rates to positive and negative values. Specific examples are provided to remark the importance of the time resolution to properly characterise the prosumers

Sharing Storage in a Smart Grid: A Coalitional Game Approach

Sharing economy is a transformative socio-economic phenomenon built around the idea of sharing underused resources and services, e.g., transportation and housing, thereby reducing costs and extracting value. Anticipating continued reduction in the cost of electricity storage, we look into the potential opportunity in electrical power system where consumers share storage with each other. We consider two different scenarios. In the first scenario, consumers are assumed to already have individual storage devices and they explore cooperation to minimize the realized electricity consumption cost. In the second scenario, a group of consumers is interested to invest in joint storage capacity and operate it cooperatively. The resulting system problems are modeled using cooperative game theory. In both cases, the cooperative games are shown to have non-empty cores and we develop efficient cost allocations in the core with analytical expressions. Thus, sharing of storage in cooperative manner is shown to be very effective for the electric power system

Coalitional Game Theory based Value Sharing in Energy Communities

This paper presents a coalitional game for value sharing in energy communities (ECs). It is proved that the game is super-additive, and the grand coalition effectively increases the global payoff. It is also proved that the model is balanced and thus, it has a nonempty core. This means there always exists at least one value sharing mechanism that makes the grand coalition stable. Therefore, prosumers will always achieve lower bills if they join to form larger ECs. A counterexample is presented to demonstrate that the game is not convex and value sharing based on Shapley values does not necessarily ensure the stability of the coalition. To find a stabilizing value sharing mechanism that belongs to the core of the game, the worst-case excess minimization concept is applied. In this concept, however, size of the optimization problem increases exponentially with respect to the number of members in EC. To make the problem computationally tractable, the idea of clustering members based on their generation/load profiles and considering the same profile and share for members in the same cluster is proposed here. K-means algorithm is used for clustering prosumers’ profiles. This way, the problem would have several redundant constraints that can be removed. The redundant constraints are identified and removed via the generalized Llewellyn’s rules. Finally, value sharing in an apartment building in the southern part of Finland in the metropolitan area is studied to demonstrate effectiveness of the method

The challenges for social and economic policy related to the energy transformation : analysis of profitability and minimizing the risk of deciding to invest in a home micro-installation

PURPOSE: The aim of the article is to analyze the profitability and minimize the risk of making a decision in the investment of a home PV micro-installation. Particular emphasis was placed on the determinants of the boundary conditions at which there is an investment and economic justification for potential investors to make business decisions in the implementation of the project of electricity production for their own needs.APPROACH/METHODOLOGY/DESIGN: The research was carried out using the NPV - Net Present Value of Investment and IRR - Internal rate of Return methods. These methods allowed the authors to calculate the market value of investments with the assumed boundary criteria and to determine the economic efficiency of the investment. The research was carried out in April-March 2021-2022 on a test PV installation in a household.FINDINGS: Installing a photovoltaic system in your household brings many benefits. It should be noted that each kWh produced in a PV installation makes the investor independent of the grid distributor, reduces the consumption of energy from conventional sources, minimizes the emission of pollutants into the atmosphere and favors economic development. In addition, investment in such installations allows for obtaining income from the sale of surplus energy produced.PRACTICAL IMPLICATIONS: The presented models have shown that the project for their implementation is fully economically justified and will allow investors to make a rational investment decision. These models can be effectively used in other countries, and can also be a starting point for a discussion on the direction of energy development.ORIGINALITY/VALUE: Obtaining this data allowed the authors to indicate the directions of improvements that may contribute to obtaining a more reliable assessment of the profitability of the tested installations.peer-reviewe

Data security and trading framework for smart grids in neighborhood area networks

Due to the drastic increase of electricity prosumers, i.e., energy consumers that are also producers, smart grids have become a key solution for electricity infrastructure. In smart grids, one of the most crucial requirements is the privacy of the final users. The vast majority of the literature addresses the privacy issue by providing ways of hiding user’s electricity consumption. However, open issues in the literature related to the privacy of the electricity producers still remain. In this paper, we propose a framework that preserves the secrecy of prosumers’ identities and provides protection against the traffic analysis attack in a competitive market for energy trade in a Neighborhood Area Network (NAN). In addition, the amount of bidders and of successful bids are hidden from malicious attackers by our framework. Due to the need for small data throughput for the bidders, the communication links of our framework are based on a proprietary communication system. Still, in terms of data security, we adopt the Advanced Encryption Standard (AES) 128bit with Exclusive-OR (XOR) keys due to their reduced computational complexity, allowing fast processing. Our framework outperforms the state-of-the-art solutions in terms of privacy protection and trading flexibility in a prosumer-to-prosumer design