Inflexible combined heat and power (CHP) plants and uncertain wind power production result in excess power in distribution networks, which leads to inverse power flow challenging grid operations. Power to heat facilities such as electrolysers and electric boilers can offer extra flexibility to the integrated energy system. In this regard, we aim to jointly determine the optimal power to heat facility sizing and integrated energy system operations in this study. To account for wind power uncertainties, a distributionally robust chance-constrained model is proposed to characterize wind power uncertainties using ambiguity sets. Linear decision rules are applied to simulate recourse actions, which converts the proposed three-stage distributionally robust chance-constrained model into a computationally tractable single-stage mixed-integer conic model. A case study demonstrates the effectiveness of introducing the electrolyser and electric boiler into the integrated energy system, in terms of decreased system cost, expanded CHP plant flexibility and reduced inverse power flow. The proposed distributionally robust optimization model exhibits better effectiveness and robustness compared with a chance-constrained optimization model assuming wind forecast errors follow Gaussian distribution. Detailed profit analysis reveals that although the social welfare is enhanced, the profit is distributed unevenly across various stakeholders in the system. The profit mainly falls with the wind power plants, which are hence most motivated to make investments in flexibility resources. The CHP plant and external investors rely on additional policies such as bilateral contracts with the wind power plants to gain incentives to invest in flexibility resources. In conclusion, this study validates the effectiveness of introducing electrolysers and electric boilers to the integrated energy system. The findings from this study can be used to motivate policy-makers to make proper regulations to incentivize investments in flexibility resources and establish a more reliable power grid.
|Status||In voorbereiding - 2020|