GM Shafiullah

Solid Gravity Energy Storage (SGES) Systems are an innovative way to store energy by using the force of gravity. These systems can use the excess energy from solar photovoltaic power systems to lift large blocks of concrete usually around mid-day and later as the sun sets and power demand is high, the blocks are released and generate gravitational energy which is converted to electricity. Colliecrete is a low-carbon, waste-derived, geopolymer concrete developed in 2021, from the Collie power plants' flyash, by the Mudlark geopolymer lab at Murdoch University and geopolymer precursors can come from a number of waste-derived materials. Colliecrete can be used in the blocks for SGES. In Australia, most coal power plants will shut by 2030, while in Indonesia, the expectation is to achieve carbon-neutrality by 2060. There are many methods and pathways to achieve this goal with low-carbon geopolymer concrete one of them. Geopolymer precursor material is abundant with flyash available from 200 coalfired power stations and slag from dozens of steel mills and nickel smelters. Rice husk is disposed of in millions of tonnes by farmers across the archipelago by burning and this ash can be converted to the geopolymer activator. All these make the possibility of an enormous new geopolymer concrete industry to at least partially replace the high-carbon, Portland cement industry. Geopolymer concrete blocks in the SGES system provide long-duration energy storage, assist firming the renewables and reduce carbon emissions while creating a new industry for the energy transition.

At Bantaeng in South Sulawesi a new industrial scale port will be built to serve the KIBA industrial precinct where smelters produce nickel for global electric vehicle battery markets. A 1-2Mtpa low-carbon geopolymer concrete plant is proposed for precast production of some 1,600 port modules as well as other infrastructure requiring some 750,000 cum of concrete and thereafter the plant can be repurposed for other products for local markets such as reef modules and wall panels. Geopolymer concrete can be the replacement for conventional concrete and be made from wastederived materials thereby having a significantly lower carbon footprint. The plant is designed to be operated by renewable energy and an energy audit estimated that a 1Mtpa geopolymer production plant needs 100-200 GWh pa to operate. This could be served by a renewable energy power station with a mix of wind turbines and solar PV farm producing green hydrogen for energy storage and electric fuel cells. In the option of PV50%+wind50%+hydrogenstorage the total cost was estimated to be ∃20-30M USD. If electricity is assumed ∃100/MWh then this is worth ∃10-20M USD pa and the payback is 15 years approx.

Electric Vehicles (EVs) play a crucial role in advancing environmental and economic sustainability, yet their widespread adoption poses risks to the electrical grid, including voltage instability and increased peak load stress. Research has highlighted the potential of V2G-enabled EV chargers to mitigate these issues by providing reactive power support to the grid. Despite these advancements, the impact of reactive power injection on different types of networks, such as resistive versus inductive distribution networks, remains inadequately studied. This paper addresses this gap by investigating how reactive power affects various low-voltage (LV) distribution networks, providing insights into optimizing EV integration and enhancing grid stability. The analysis employs a modified IEEE 13-bus network to evaluate the effects of V2G support by EVs across different network types. The results demonstrate a strong correlation between the type of distribution network and key performance metrics, including the grid's voltage profile, charging rates, and EV charging times. These findings emphasize the importance of considering distribution networks when assessing the potential benefits of V2G technology for grid stability and EV charging efficiency.

The rapid integration of Electric Vehicles (EV s) poses a significant concern for energy producers, transmitters, and distributors regarding the capability of the existing grid topology and technology. EV owner prefers to use high-rated chargers to reduce the charging time, negatively impacting the grid. This paper focuses on the impact of different power ratings of chargers and the abilities of EV s for reactive power support to the utility grid. This analysis considers two sizes of popular EV chargers to assess their impact on the utility grid. An IEEE 14 bus network is employed in this study to investigate the grid performance with three different levels of EV penetration (small, medium, and high). The simulation results show that the fast chargers can significantly impact the power system, mainly when the EV penetration is very high.

This research work presents the comparative study of the performance of constant IQ droop, Constant Q and voltage Q droop controller on a dispatch controlled optimized hybrid grid tied microgrid system having electrical, industrial and EV (electric vehicle) loads. The optimized configuration of the microgrid on top of load following (LF) and cycle charging (CC) dispatch methods have been determined using a propri-etary derivative free algorithm and their voltage, active power, frequency and reactive powers have been evaluated for the three different control strategies. For the planned microgrid, it has been determined through the analysis in the proposed location, the two dispatch strategies offer similar optimization results and constant IQ droop control offers slightly better performance among the others. The results demonstrate the feasibility of the microgrid system with the proposed controller and operating strategy.

Demand side management can play a pivotal role in balancing the supply and demand. Application of demand re-sponse (DR) facilitates load reduction or load shifting at peak demand times. A utility facing under frequency drop issue when its generation capability is lower than the power demand can employ DR. However, every DR action in either form of dim-ming, delaying, or disconnecting loads basically reduces the cus-tomers' comfort level. This study presents a DR strategy for the group of controllable and shed-able loads that minimizes customer discomfort. As such, the customer comfort limits are predefined as the reference for the DR's execution. The proposed DR algorithm aims to minimize the standard deviation of com-fort reduction among the controllable loads and minimizes the number of loads to be shed, using discrete combinatorial optimi-zation. The DR algorithm is executed sequentially from the least to the higher priority load so that loads with higher priority are less affected. Simulation results indicate that the proposed DR strategy has evenly distributed customer comfort reductions among the controllable loads while the number of shed loads is minimized.