Virtual storage capacity using demand response management to overcome intermittency of solar PV generation

Abstract

The integration of solar photovoltaic (PV) systems into the distribution network creates various stability and reliability issues associated with the intermittency of solar PV power generation. Energy storage is a vital component required for overcoming the intermittency of solar PV. This study presents a priority-based demand response management (DRM) for loads with large time constants to create virtual energy storage. The virtual energy storage thus created can be used for partial levelling of intermittent output from solar PVs. The proposed DRM algorithm involves controlling loads with large time constants such as air conditioning systems and refrigerators based on the forecasted solar PV generation. The proposed method is evaluated using data-driven simulations, weather data and mathematical models. The proposed algorithm is highly suitable for megacities that have high number of multi-storey residential buildings. Utilising the virtual storage capacity available from the appliances will reduce the investment as well as the operation cost of renewable energy such as solar PV. Analyses on impact on temperature, percentage of interruptions, cost savings and impact on energy storage sizing are also presented for evaluating the performance of the proposed algorithm. Nomenclature T n ac, on(max) usual turn ON time of the nth air conditioner T n ac, off(max) usual turn OFF time of the nth air conditioner T n ref, on(max) usual turn ON time of the nth refrigerator T n ref, off(max) usual turn OFF time of the nth refrigerator x ac, on , x ac, off proportion of turn ON and turn OFF time for air conditioners x ref, on , x ref, off proportion of turn ON and turn OFF time for refrigerators T n ac, on current turn ON time of the nth air conditioner T n ac, off current turn OFF time of the nth air conditioner T n ref, on current turn ON time of the nth refrigerator T n ref, off current turn OFF time of the nth refrigerator p j vsc, c estimated virtual storage capacity (charging) during jth interval p j vsc, d estimated virtual storage capacity (discharging) during the jth interval p j bpd power required from the battery during the jth interval p ave_pv_op average solar PV output on a given day N off ref number of refrigerators that can be turned off N off ac number of air conditioners that can be turned off N on ref number of refrigerators that can be turned on N on ac number of air conditioners that can be turned on

Impacts of Demand-Side Management on Electrical Power Systems: A Review

“…Many studies have assessed the intermittency of renewable energy sources either at the supply side as bulk units or at the demand-side as medium units. A priority-based demand response management and energy storage system for solar photovoltaic systems have been proposed to overcome the intermittency of power generation by solar photovoltaic [60]. DSM has been used to integrate the growing number of renewable energy sources in Portugal [61].…”

Research on Modeling and Hierarchical Scheduling of a Generalized Multi-Source Energy Storage System in an Integrated Energy Distribution System

“…When applied to ultra-short-term scheduling, the energy storage capacities required, as well as the investment costs and the power losses of GMSES-CES, will increase significantly, while the GMSES-MFR is not suitable for frequent adjustment due to the microturbines' inherent response characteristics [33]. Therefore, to accommodate the forecast errors flexibly and economically, DRR with fast-response characteristics is utilized to manage the energy consumption of different load groups [33]. With the corresponding control strategy, DRR could be implemented to provide the required power increase or decrease, which is similar to the energy storage effect.…”

“…By means of the general parameter serialization (GPS)-based control strategy, responsive groups on the demand side and priority sequence of GMSES-DRR will be determined to respond to the scheduling target [33][34][35]. The implementation of the GPS is introduced as follows:…”

“…Owing to the fast response service required, GMSES-DRR is called on to maintain the energy balance and handle aperiodic power fluctuations. This objective can be expressed in Equation (33). Additionally, in order to control and determine the proportion of different types of controllable loads in GMSES-DRR, the regulation cost minimization is defined as a further optimal DRR objective in Equation (34).…”

Future Challenges and Mitigation Methods for High Photovoltaic Penetration: A Survey

“…The use of large time constant loads to create a virtual energy storage which is used to smoothen the intermittent output of PVs through DRMs [208]. • An IoT-based, real time smart-direct load control (S-DLC) was proposed by [209].…”