Analysis of Load Matching and Grid Interaction of a Zero Energy Building

Abstract

Zero energy buildings apply energy efficiency measures and renewable energy systems to maintain a zero energy consumption balance over a specific time. Renewable energy systems installed in zero energy buildings produce energy to cover their energy demand, and the surplus energy can be transmitted to the grid. Conversely, the building can receive power from the grid when the energy consumption is greater than the energy production. However, the greater fluctuation of transmitted and received power in the transfer process results in lower grid stability. Therefore, for zero energy buildings, it is necessary to evaluate the load matching rate and power transmission between the building and the grid. However, in the case of zero-energy building certification in Korea, it is impossible to evaluate the load matching rate because it only considers the building's annual energy consumption and production volume. This study investigated the energy balance of a zero energy building-certified case in terms of load matching and grid interaction evaluation indicators. Based on the results, the Load Cover Factors (LCF) analyzed at intervals of 10 minutes, 1 day, and one month were 0.421, 0.929, and 0.996, and, correspondingly, the Supply Cover Factors (SCF) were 0.228, 0.544, and 0.536 under the same analysis conditions. In addition, the variabilities of the amount of transmitted and received power were confirmed to be 0.203, 0.286, and 0.305, respectively.