Performance Comparison of a Distributed Energy System under Different Control Strategies with a Conventional Energy System

Abstract

The distributed energy system (DES) has increasingly attracted considerable attention from researchers due to its environmental friendliness and high efficiency. In the hot summer and cold winter areas, DES is an efficient alternative for district cooling and heating. A case study located in Changsha, China, which is a typical hot summer and cold winter area, is analyzed. Four control strategies are proposed in this study. The four cases under different control strategies are compared in terms of energy, economy, environment, solar fraction, and soil annual heat imbalance rate. Results show that the DES can be an energy saving and environmentally friendly alternative. The primary energy saving (PES) is more than 36.70% and can reach up to 48.04%, whereas DES can realize economical operation and reduce the emission of carbon dioxide, sulphur dioxide, and dust. In addition, DES consumes more electricity and less natural gas than the conventional energy system. These features are beneficial to the optimization of China’s energy consumption structure. Moreover, the operation of seasonal thermal storage for the ground soil is effective in maintaining the balance of soil annual heat. The control strategy combining geothermal and solar energies is recommended due to its good performance and high flexibility. This study may provide guidance in the development of DESs in hot summer and cold winter climate zones.

The Performance Gap in Energy-Efficient Office Buildings: How the Occupants Can Help?

“…Signs of the performance gap as discussed in this research started appearing from the mid-1990s [48] and are still discussed as a core issue [20,40,49]. This gap is addressed in a diverse context in different studies, such as the difference between predicted and actual energy performance of a building, including all the complications of sub-systems, occupant behavior, atmospheric conditions, control settings, and others [5,27,28]. Tang et al [5] found that a primary energy saving between 36.7% to 48% is attainable by introducing a distributed energy system in buildings.…”

“…This gap is addressed in a diverse context in different studies, such as the difference between predicted and actual energy performance of a building, including all the complications of sub-systems, occupant behavior, atmospheric conditions, control settings, and others [5,27,28]. Tang et al [5] found that a primary energy saving between 36.7% to 48% is attainable by introducing a distributed energy system in buildings. Further, a control strategy combining geothermal and solar energies is recommended due to its good performance and high flexibility.…”

“…This will also help policymakers in devising subtle but effective behavior training strategies to reduce energy usage. Such behavioral retrofitting comes at a much lower cost than the physical or technological retrofit options to achieve the same purpose and this study establishes the foundation for it.Energies 2020, 13, 1480 2 of 27 explored from various angles including predictive controls for refrigeration [3], green performance evaluation system for construction site layout [4], performance comparisons of energy systems [5], indoor air quality assessments [6] and others.The modern ways of living drive substantial energy use inside the buildings. United Nations Energy Program (UN-Energy) reports that buildings consume 30-40% of the total global energy [7,8].…”

“…Energies 2020, 13, 1480 2 of 27 explored from various angles including predictive controls for refrigeration [3], green performance evaluation system for construction site layout [4], performance comparisons of energy systems [5], indoor air quality assessments [6] and others.…”

A Modified Artificial Bee Colony for Probabilistic Peak Shaving Technique in Generators Operation Planning: Optimal Cost–Benefit Analysis

“…The main goal of the electric utility is concise for providing electrical as may be demanded by the customers at the lowest possible operating cost, in tandem with maintaining the system security, reliability, and economics of the system. Furthermore, reducing the environmental damage caused by the conventional thermal units, guaranteed consistent supply of energy on the secure condition and reducing the electricity bills of customers are parts of the goal [1][2][3]. However, load demand variation is largely uncontrollable, with any interruptions very costly.…”