Economic operation of networked flexi-renewable energy hubs with thermal and hydrogen storage systems based on the market clearing price model

Abstract

This paper presents the energy management of flexi-renewable energy hubs in electric and thermal networks based on the market clearing price model and participation of hubs in the energy market. Renewable sources include wind sources and bio-waste units, where the latter simultaneously plays a role in electrical and thermal energy generation. Hydrogen and thermal storage are used as a source of flexibility in the hub. The proposed scheme has a two-level formulation. Its upper level considers the participation of hubs in the energy market. It maximizes the expected profit of energy hubs by observing the operational constraints of power sources and storage devices (in the form of a hub) and the hub's flexibility limitation. The lower-level problem presents the market clearing price model. In this problem, the expected operation cost of the generation units in the electric and thermal networks is minimized subject to satisfying the constraints of the optimal power flow of the mentioned networks. The Karush-Kuhn-Tucker method provides a single-level formulation of the scheme. Also, stochastic optimization is adopted to model the uncertainties of load and renewable power to examine the flexibility of energy hubs accurately. Finally, by evaluating the numerical results obtained from different study cases, the scheme can improve the operating conditions of energy networks and obtain optimal flexibility and economic conditions for energy hubs. The hydrogen storage device next to the thermal storage device can achieve 100% flexibility conditions for the hubs. Storage devices can enhance the economic status of renewable hubs by about 9.2%. The energy management of flexi-renewable hubs improves energy networks' operational and economic status by 21–24% and 8.8% compared to power flow studies.