Coalition Game Theory Enhancing P2P Trading in Energy Communities – pv International Magazine

May 24, 2024 Lior Kahana

An international group of researchers led by China’s Sichuan Normal University has developed a novel coalition gaming system that maximizes prosumers’ collective payoff in a community-wide peer-to-peer (P2P) energy trading market.

Coalition play is a part of game theory in which players form coalitions to achieve common goals and greater benefits.

“The methods presented in some publications are based on the assumption that renewable energy and load can be predicted accurately, which does not reflect the stochastic nature of real prosumer systems,” the researchers said. “There is a need and importance to develop new dinner gaming systems and algorithms that can be applied in a stochastic P2P energy trading environment involving different types of prosumers.”

To solve this problem, researchers introduced coalition rules into the game. Care is taken to ensure that prosumers have surplus energy to sell, which means that their energy consumption should not be higher than their production capacity. The second principle ensures that consumers assume that they are producing energy at the highest possible level, so that there are no shortages or constraints on the energy supply. To enforce these rules, participating prosumers may be liable for financial penalties and loss of collective compensation for losses.

The game system takes into account three types of prosumers – those who only have a renewable energy source, such as a photovoltaic installation or a wind turbine; participants with battery energy storage systems (BESS); and those that rely on both photovoltaics and batteries. The game takes into account, among other things, the size and load of the prosumer’s system.

“In the methodological part of the article, a strict theoretical analysis was carried out to demonstrate the effectiveness of the proposed system in terms of: (1) ensuring economic justice among coalition members; and (2) providing each coalition member with greater profitability in P2P energy trading compared to the situation if they had not joined the coalition,” the researchers explain.

After providing a series of equations confirming the above-mentioned claims, the researchers began to verify them. For this purpose, they performed numerical simulations in MATLAB. Solar radiation and power load data were retrieved from current Australian registries, and P2P power trading was performed with an interval of 1 hour.

“The areas of photovoltaic panels in prosumers’ premises are randomly set in the range of 10 m2 – 20 m2, and the energy conversion efficiencies of photovoltaic panels are randomly set in the range of 30% – 40%,” the researchers explained. “The energy capacities of prosumer BESSs are randomly set in the range of 4 kWh – 5 kWh, and the initial state of charge of the BESS is set in the range of 30% – 50%.

To assess the impact of uncertainty on a prosumer coalition, the research group created a simulation of 100 prosumers and compared their behavior in the system with and without coalition rules aimed at reducing risk. While in the case of a rule, the coalition’s income increases as more members join, in the absence of a rule they sometimes cause a decline.

The group considered coalitions of 10 and 50 prosumers, and the simulation showed that their total profits increased by 33.55% and 35.67%, respectively, compared to the system without cooperation. The researchers then examined the impact of four parameters on the total gain: the amount of energy stored in the BESS, the energy load of prosumers, the size of solar panels, and the relative error between forecast and actual net power values.

“From the numbers, it is clear that the total payout value of the P2P energy trading system increases with the increase in the number of prosumers, the amount of energy stored in the BESS and the size of photovoltaic panels. The common payout values ​​decrease as the energy burden of prosumers increases,” they emphasized.

“In a situation where the predicted net power of a prosumer is lower than the actual one, a reduction in the ratio of energy stored to energy produced causes prosumers to sell a small amount of energy to consumers, which results in a reduction of prosumers’ payout,” they added. “When the predicted net power of the prosumer is greater than the actual net power, increasing the ratio of energy stored to energy produced will lead to higher implicit costs; As a result, prosumers’ earnings will decrease.”

The coalition game and its analysis were presented in the publication “Coalition Prosumer Game Aware of Uncertainty in Peer-to-Peer Energy Trading in Social Micronetworks”, published in the journal International Journal of Electrical Power & Energy Systems. The research was conducted by scientists from China’s Sichuan Normal University, Chongqing University, Zhejiang Institute of Industry and Information Technology and Australia’s University of Sydney.