Small Prosumers Research Articles

Technical and Financial Analysis for the Implementation of Small-scale Self-generation Projects, based on Grid-Tied Photovoltaic Solar Energy, for Residential Users under Colombian Regulations

The study focuses on integrating non-conventional renewable energy sources into Colombia's power system. The regulatory framework allows small prosumers to trade energy surpluses with grid operators. The research analyzes the financial feasibility of implementing photovoltaic systems for residential users. Technical aspects governing energy production and implementation costs are examined. Colombian residential users, divided into six socioeconomic strata, undergo individual analysis based on their energy rates and consumption patterns. The study area is Bucaramanga, known for intermediate solar potential. Precise cost estimates for implementing photovoltaic systems that meet user energy requirements are provided. Financial viability indicators (NPV, IRR, Payback Time) are evaluated for three scenarios: existing energy prices, 50% government financing, and a 10% tariff reduction due to government intervention. Results show financial viability for strata 4, 5, and 6, but not for strata 1, 2, and 3. Government intervention can make strata 2 and 3 feasible. Lowering the kWh price adversely impacts the project's financial feasibility for all strata, particularly the lower-income ones. The study is valuable for potential investors and policymakers seeking to promote photovoltaic systems in the residential sector. It provides insights into economic viability and helps develop effective policies for Colombia's sustainable energy transition.

Romania in the energy transition, for small prosumers - post pandemic and the Ukraine war

Prior to the COVID 19 pandemic, Romania demonstrated enormous progress in the context of sustainable electricity production from renewable sources. Mainly motivated by easy access to the electricity exchange for these new producers and the appetite of the younger generation for clean energy. However, outside all development and improvements on the production side, and added new production capacity, the distribution and quality of the electricity supplied to end customers kept deteriorating. Small consumers, both private and industrial, must bear all the disturbances caused by the ageing distribution installations. For such situations, the solution came in the form of micro-grids and expansion of new electricity generation capabilities at local level, more adapted to consumers. This paper follows up on two previously introduced practical examples with such solutions, with new advantages and disadvantages, from, both, a technological and commercial perspective.

A decentralized stochastic bidding strategy for aggregators of prosumers in electricity reserve markets

Recent years have seen an increasing interest in demand response as a means to provide flexibility and support the penetration of renewable resources in the power system. Aggregators play a key role, in this regard, by enabling the participation of small-scale distributed energy resources and loads connected at the distribution network into local and central markets.This paper proposes an optimal strategy to support aggregators of a large number of small prosumers to participate in the tertiary reserve procurement market. In particular, a two-stage decentralized approach is proposed in which, first, prosumers individually optimize their flexible appliances schedule according to their own requirements and preferences, without sharing any information with the aggregator. At the aggregator level, a trading strategy is proposed for participation in the reserve market aiming at maximizing the aggregator’s profit under the pay-as-bid pricing scheme, while only requiring a linear programming formulation ensuring the efficiency of the trading problem. In the developed approach, a scenario-based stochastic programming method is introduced to capture the uncertainties of market prices, weather conditions, loads, and user behavior.To demonstrate the applicability of the proposed method, using real data, simulations on 2500 small prosumers in a realistic setting are carried out. The proposed linear and decentralized method can be executed within a few minutes, enabling its applicability for aggregators with a large number of customers.

Prosumers Flexibility as Support for Ancillary Services in Low Voltage Level

The prosumers flexibility procurement has increased due to the current penetration of distributed and variable renewable energy sources. The prosumers flexibility is often able to quickly adjust the power consumption, making it well suited as a primary and secondary reserve for ancillary services. In the era of smart grids, the role of the aggregator has been increasingly exploited and considered as a player that can facilitate small prosumers' participation in electricity markets. This paper proposes an approach based on the use of prosumers flexibility by an aggregator to support ancillary services at a low voltage level. An asymmetric pool market approach is considered for flexibility negotiation between prosumers and the local marker operator (aggregator). From the achieved results it is possible to conclude that the use of flexibility can bring technical and economic benefits for network operators.

Are the current incentives sufficient to drive the use of solar PV in the Colombian residential sector? - An analysis from the perspective of the game theory

It is necessary to increase the use of renewable energy sources to supply the world's energy demand to mitigate the harmful effects of climate change. Many countries have incorporated the use of solar energy on a large scale. However, the use of photovoltaic (PV) systems at the residential level has been rather limited because many barriers to their implementation persist (e.g., high investment costs, insufficient government policies and incentives, and lack of knowledge in the implementation and operation of these systems). This paper aims to investigate how the interaction between prosumers and consumers can drive the use of PV systems at the residential level. The interaction is analyzed from the field of game theory. The payoffs of the players' strategies determine not only the Nash equilibrium but also the desirability of the interaction for both investment in the case of prosumer and consumption costs in the case of the consumer. Prosumer strategies consisted of selling power to the grid and to the consumer; selling only to the consumer; selling only to the grid; selling to the grid and giving to the consumer; and only giving to the consumer. The consumer strategies were to buy only from the grid or to buy from both the grid and the prosumer. The prosumer's investment in three sizes of PV systems (2.3, 2.7 and 3.6 kW) were analyzed; the amount of electricity produced was estimated using PVWatts and data from a Typical Meteorological Year in the city of Barranquilla, Colombia. The Net Present Value of each investment was calculated considering the prosumer's strategies and this indicator was taken to an equivalent annual cost to represent the prosumer's payment in the Nash equilibrium. On the other hand, for the consumer's payments, the annual energy purchase costs to supply their demand were used, according to the consumer's strategies. Analysis found that PV systems that can produce surpluses can be attractive to the prosumer if the tax on revenues received from the sale of energy to the grid is eliminated. Profitability is further improved if the prosumer is allowed to sell their surplus to other consumers, with the purchase price to the grid being the maximum price at which they can sell to other consumers. In turn, the cost savings for consumers will be greater to the extent that they can buy cheaper energy from prosumers. Based on these findings, countries such as Colombia, where there has not been a massive use of solar photovoltaic energy at the residential level, can stimulate investments in this sector by eliminating the income tax on the sales of surplus energy of small prosumers, without representing a loss of income for these countries.

An integrated smart home energy management model based on a pyramid taxonomy for residential houses with photovoltaic-battery systems

Smart home energy management (SHEM) with residential photovoltaic (PV)-battery systems is a complicated issue with different facets. An integrated SHEM model covering the essential functions is missing. Meanwhile, residential PV-battery systems' optimal operations with renewable energy exchanges and imperfect forecasts are still open challenges. In this study, the research activities in SHEM are firstly organized by a pyramid with four functional layers: (i) Monitoring; (ii) Analyzing and forecasting; (iii) Scheduling; and (iv) Coordinating, which can serve as a standard pathway for developing SHEM. Second, guided by the pyramid taxonomy, an integrated SHEM model is developed for residential houses with PV-battery systems. Assuming a perfect Monitoring layer, we obtain the probabilistic load/PV forecasts and user preference vectors of shiftable appliances based on historical data. Then, we develop a two-stage stochastic programming model for optimal scheduling of single houses with a grid-connected PV-battery system, incorporating the probabilistic forecasts and user preference vectors. A retail electricity market with day-ahead (DA) and real-time (RT) markets is employed for leveraging imperfect forecasts. Finally, we design a distributed coordinating algorithm - Asynchronous Scheduling and Iterative Pricing for PV power-sharing among multiple prosumers based on the single-house scheduling model. Numerical simulations based on realistic loads and PV generation data validated the two-stage stochastic programming model's economic superiority and the distributed PV power-sharing approach compared with the rule-based dispatching and selfish scheduling strategies. We concluded that 1) the modeling of load/PV forecast uncertainties is valuable than averaging or ignoring them, 2) the two-stage stochastic programming model and the DA-RT retail electricity market are beneficial for utilizing imperfect forecasts, and 3) coordinating multiple prosumers could benefit each household by sharing PV and battery investments for revenue or trading with local small prosumers for cost reductions.

Optimal Peer-to-Peer energy sharing between prosumers using hydrokinetic, diesel generator and pumped hydro storage

Abstract In this paper, an optimal Peer-to-Peer energy sharing model between two small prosumers is developed and simulated in the south African context. For this purpose, a case study of a commercial type prosumer sharing power with a residential prosumer, both on the same premise, is used to demonstrate the effectiveness of the model. The commercial prosumer owns a small hydrokinetic system operating in conjunction with a pumped hydro storage while the residential prosumer has a diesel generator. The developed model aims to minimize the resulting cost of energy linked to the diesel generator, while optimizing the power flow between the two prosumers. Using actual data, the developed model has been used to simulate and analyze the complex interaction between the different power sources, the energy storage and the demands within the proposed system sizing and operation constraints. The simulation results show that the power flows can be optimally managed, resulting in a substantial reduction in the residential prosumer's operation cost which can now rely not only on its diesel generator but also on the power shared by the hydrokinetic and pumped hydro system of the commercial prosumer.

Market design for integration of renewables into transactive energy systems

One of the major challenges of integrating distribution level producers/consumers (prosumers) into the transactive energy market is that the prosumers are not able to precisely predict their energy exchange with the market. This is because small prosumers usually operate intermittent renewable sources and have highly uncertain consumptions. As a consequence, traditional wholesale market mechanisms cannot be implemented in the transactive environment, as they penalise the participants with uncertain energy transactions, and therefore discourage the small prosumers from participating in the market. To this end, novel market design is introduced in this study, which enables distribution system operator to incorporate both the submitted price–quantity bids and the associated risks of prosumers into the settlement process. The proposed market design maximises the social welfare while managing the undesired costs caused by the stochastic nature of participants. The settlement mechanism is formulated as a quadratic problem, which can be efficiently solved for the transactive energy markets with a large number of participants. To demonstrate the merits of the proposed approach, it is implemented on a sample transactive energy market, and the results are discussed.

Trading Small Prosumers Flexibility in the Energy and Tertiary Reserve Markets

This paper addresses the participation of an aggregator of small prosumers in the energy and tertiary reserve markets. A two-stage stochastic optimization model is proposed to exploit the load and generation flexibility of the prosumers. The aim is to define energy and tertiary reserve bids to minimize the net cost of the aggregator buying and selling energy in the day-ahead and real-time markets, as well as to maximize the revenue of selling tertiary reserve during the real-time stage. Scenario-based stochastic programming is used to deal with the uncertainties of photovoltaic power generation, electricity demand, outdoor temperature, end-users’ behavior, and preferences. A case study of 1000 small prosumers from MIBEL is used to compare the proposed strategy to two other strategies. The numerical results show that the proposed strategy reduces the bidding net cost of the aggregator by 48% when compared to an inflexible strategy typically used by retailers.

Application of an optimization-based curtailment service provider in real-time simulation

The use of demand response programs and distributed renewable energy resources are intensively discussed. These concepts play a key role in the distribution network, especially smart grids and microgrids. Nowadays, most of the implemented demand response programs are considered for large-scale resources, which make small and medium resources unable to participate in electricity market negotiations. In order to overcome this barrier, a third-party entity, namely an aggregator, can be considered as an intermediate player between the demand side and grid side. For this purpose, curtailment service provider is considered as an aggregator, which aggregates small and medium-scale resources, who do not have adequate capacity of reduction or generation and allow them to participate in wholesale electricity markets as a unique resource. However, before massive implementation of business models, the performance of the curtailment service provider should be adequately surveyed and validated in order to prevent future problems. This paper proposes a real-time simulation model of a curtailment service provider, which employs several real and laboratory hardware equipment considered as hardware-in-the-loop in the real-time simulator. Furthermore, an optimization problem is developed for a curtailment service provider in order to optimally schedule the available resources including several demand response programs and distributed renewable resources, aiming at minimizing its operation costs. The implemented case study considers a distribution network with 20 consumers and prosumers, and 26 renewable-based producers including wind and photovoltaic generation, where the developed model is performed in real-time for 12 min and behaviors of small and medium prosumers and producers is surveyed.

Optimal supply and demand bidding strategy for an aggregator of small prosumers

This paper addresses the problem faced by an aggregator of small prosumers, when participating in the energy market. The aggregator exploits the flexibility of prosumers’ appliances, in order to reduce its market net costs. Two optimization procedures are proposed. A two-stage stochastic optimization model to support the aggregator in the definition of demand and supply bids. The aim is to minimize the net cost of the aggregator buying and selling energy at day-ahead and real-time market stages. Scenario-based stochastic programing is used to deal with the uncertainty of electricity demand, end-users’ behavior, outdoor temperature and renewable generation. The second optimization is a model predictive control method to set the operation of flexible loads in real-time. A case study of 1000small prosumers from the Iberian market is used to compare four day-ahead bidding strategies and two real-time control strategies, as well as the performance of combined day-ahead and real-time strategies. The numerical results show that the proposed strategies allow the aggregator to reduce the net cost by 14% compared to a benchmark typically used by retailers (inflexible strategy).