Flexible dispatch of a building energy system using building thermal storage and battery energy storage. (1st June 2019)

• Record Type: Journal Article
• Authors: Niu, Jide; Tian, Zhe; Lu, Yakai; Zhao, Hongfang
• Is Part Of: Applied energy. Volume 243(2019)
• Page Start: 274
• Page End: 287
• Publication Date: 2019-06-01
• Subjects: Flexibility -- Building thermal storage -- Battery energy storage -- Optimal dispatch -- Autoregressive model; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2019.03.187
• Languages: English
• ISSNs: 0306-2619

Abstract

Highlights: Accuracy index and complexity index were introduced to identify ARX model. The ARX model shows good accuracy in predicting building cooling load. A MILP model integrated dynamic building thermal storage model for economically dispatch building energy system was proposed. An objective-equivalence method was introduced to quantify the flexibility potential of the building thermal storage. Building thermal storage could provide great flexibility to the power grid. Abstract: The increasing development of renewable energy sources requires more flexible technologies to be applied in building energy systems and a flexible controlled resource for the power grid. This work focuses on investigating the flexibility potential of building thermal storage and battery energy storage. Firstly, an autoregressive model with exogenous inputs is proposed to forecast the dynamic cooling demand and, based on that, a mixed integer linear model is formulated to optimize the dispatch of building energy systems with minimal operating costs. A factory building located in Huizhou, China is used as a case study. The results show that the ARX model can accurately predict the thermal load hourly. The model's level of fit is above 81%. The optimization objectives influence the development of the flexibility potential when building thermal storage and battery energy storage are considered. In this work, the economic objective is applied first to discuss the flexibility potential. The results show that, in this studied case, the operational cost decreased by 5.3% by using battery energy storage and further decreased by 4.0% by using building thermal storage. However, the results also reveal that unilaterally pursuing minimal operational costs results in larger peak valley difference of feeder power. The peak-valley difference of the feeder power increased from 714 kW to 1245 kW and 1689 kW respectively when the battery energy storage and building thermal storage were employed for the economic dispatch of the building energy system. Therefore, this work retests the flexibility potential of battery energy storage and building thermal storage by adding a constraint for feeder power difference. The results show that the operational costs can be still reduced greatly without damaging the stability of the power feeder.