Mohammad Taufiqul Arif

Estimation of Energy Storage and Its Feasibility Analysis

Storage significantly adds flexibility in Renewable Energy (RE) and improves energy management. This chapter explains the estimation procedures of required storage with grid connected RE to support for a residential load. It was considered that storage integrated RE will support all the steady state load and grid will support transient high loads. This will maximize the use of RE. Proper sized RE resources with proper sized storage is essential for best utilization of RE in a cost effective way. This chapter also explains the feasibility analysis of storage by comparing the economical and environmental indexes.

Investigation of Energy Storage Systems, Its Advantage and Requirement in Various Locations in Australia

Storage minimizes the intermittent nature of renewable sources. Solar and wind are the two fostered source of renewable energy. However, the availability of useful solar radiation and wind speed varies with geographical locations, and also the duration of this energy sources varies with seasonal variation. With the available vast open land and geographical position, Australia has great potential for both solar and wind energies. However, both these sources require energy buffering to support load demand to ensure required power quality. Electricity demand is increasing gradually, and also Australia has target to achieve 20% electricity from renewable sources by 2020. For effective utilization of solar and wind energy potential location of these sources needs to be identified, and effective size of storage needs to be estimated for best utilization according to the load demand. Therefore this paper investigated wind speed and solar radiation data of 210 locations in Australia, identified the potential locations, and estimated required storage in various potential locations to support residential load demand. Advantages of storage were analyzed in terms of loading on distribution transformer and storage support during energy fluctuation from renewable energy. Further analysis showed that storage greatly reduces greenhouse gas emission and reduces overall cost of energy by maximizing the use of solar and wind energies.

An investigation for improved home energy management

Increasing household energy consumption and increasing primary energy cost urged to improve home energy efficiency. Improved energy management can suggest the ways to improve home energy efficiency. Various home appliances are the prime cause to the increased power demand. Appliances energy rating information helps to develop awareness and reduce energy consumption. Load shifting can help to reduce overall cost of used energy bill by shifting peak time load to off-peak time. However most of the present appliances remains in standby mode (active or passive) for a significant part of the day, and load shifting cannot reduce the total energy consumption. Therefore investigation is required to identify any possible scopes to improve energy management at home. This paper investigated several home appliances and monitored daily time of use power consumption. It was found that by controlling standby power from a daily home load of 4.482 kWh, power demand can be reduced 12.56% moreover energy related greenhouse gas (GHG) emission can be reduced 133.08kg/year.

Impacts of distributed generators on utility grid — An experimental and simulation analysis

This paper investigates the impacts of distributed generator such as solar PV and energy storage on the utility grid. Initially experiment was conducted by increasing PV penetration into the grid and analysed the voltage fluctuation at PCC and harmonic emission on the network. Later, a software model was developed and same impacts were investigated with increased penetration of solar PV. The model was further extended and energy storage was integrated into the network to investigate the voltage fluctuation and harmonic emission in the network. From both experimental investigation and model simulation (load flow and load profile analysis), it was found that, increased PV penetration increases node voltage and harmonic current in the network. Energy storage improves voltage fluctuation by supporting load demand and storing excess energy from PV but storage adds additional harmonic current into the network. By minimizing fluctuating power in the network due to the fluctuating nature of PV output, energy storage improves the loading condition of the distribution transformer which eventually improves the capacity of the distribution transformer. Thus this investigation provides the strategic information of the impacts due to the integration of distributed generators in the utility grid.

Renewable energy integration : opportunities and challenges

Renewable energy (RE) is staring to be used as the panacea for solving current climate change or global warming threats. Therefore, government, utilities and research communities are working together to integrate large-scale RE into the power grid. However, there are a number of potential challenges in integrating RE with the existing grid. The major potential challenges are as follows: unpredictable power generation, week grid system and impacts on power quality (PQ) and reliability. This chapter investigates the potential challenges in integrating RE as well as distributed energy resources (DERs) with the smart power grid including the possible deployment issues for a sustainable future both nationally and internationally. Initially, the prospects of RE with their possible deployment issues were investigated. Later, a prediction model was proposed that informs the typical variation in energy generation as well as effect on grid integration using regression algorithms. This chapter also investigates the potential challenges in integrating RE into the grid through experimental and simulation analyses.

Impacts of Distributed Generators on the Protection System of Distribution Networks

Integration of renewable energy (RE) into the grid comes with a number of technical challenges including grid stability, voltage rise, and power quality problems. One aspect of RE integration into the power network, which is often overlooked, is its effect on existing conventional protection systems in the network. Due to the simple, reliable, and economical nature, the most commonly used form of electrical protection in power systems, particularly in distribution networks (DNs), is overcurrent (OC) protection. This involves the use of overcurrent relays (OCRs) which are responsible for generating trip signals to breakers in case they sense persistent and abnormally large amounts of current through the lines they protect. Without OC protection, a DN is susceptible to the risk of damage due to short circuit and ground-fault conditions. These conditions in turn lead to the compromise of safety when it comes to electrical equipment, infrastructure, and personnel. The contribution of fault current from distributed nonconventional sources can lead the operation of existing OC protection system to situations such as false tripping and protection blinding. False tripping, also known as sympathetic tripping, is when a healthy part of a network isolates from the utility due to a fault in an adjacent network section. This phenomenon is often brought about due to contribution of current from distributed generators (DGs), through the OCRs and toward the fault location. On the other hand, protection blinding takes place as a result of DG’s current contribution directly toward the fault location in cases where the fault is located downstream of the DG. This implies a division of total fault current contribution between the DG and the utility. A relay placed upstream the DG will therefore sense a lower than usual fault current from the utility. Hence a failure to trip or delayed trip may be experienced as a result. False tripping and protection blinding therefore forfeit selectivity and sensitivity traits of the protection system, respectively.

Relevance and Applicability of Standards in Wind Farm Collector Circuit Design Process and Balance of Plant Selection

Insulation breakdown in wind farm collector circuits indicates components are operating well above design ratings. Excessive temperatures exceeding 90 °C for long periods result in immediate damage to cross-linked polyethylene (XLPE) insulation. Long-term continuous damage will lead to insulation and componentry failure. The objective of this paper is to critically interrogate type testing parameters for extruded power cables and power cable accessories. All findings were sourced from IEC and AS/NZS standards, with assessment focusing on comparisons of relevance and applicability to wind farm applications. Design standards on which product testing is based for XLPE power cables and power cable accessories are not directly relevant to wind farm applications. The repetition of heating cycles utilized in the heating cycle type tests represents what’s known as cyclic load profiling. This is aligned closely to typical load profiles of traditional distribution networks. The high number of cable joint failures across Australian wind farms provides significant evidence to suggest that operating conditions across wind farms differ substantially to traditional distribution networks. Furthermore, it supports the disparity between component type test parameters and wind farm application parameters.

Energy Storage: Applications and Advantages

Energy storage (ES) is a form of media that store some form of energy to be used at a later time. In traditional power system, ES play a relatively minor role, but as the intermittent renewable energy (RE) resources or distributed generators and advanced technologies integrate into the power grid, storage becomes the key enabler of low-carbon, smart power systems for the future. Most RE sources cannot provide steady energy supply and introduce a potential unbalance in energy supply and load demand. ES can buffer sizable portion of energy generated by different intermittent RE sources during low demand time and export it back into the network as required. ES can be utilized in load shifting, energy management and network voltage regulations. It can play a large role in supplementing peaking generation to meet short-period peak load demand. ES technologies are classified considering energy and power density, response time, cost, lifetime and efficiency. Different application requires different types of ES system (ESS). IEEE 1547 and AS 4777 provide guideline to connect RE and storage into the distribution network. Based on the standards, utility operators plan in gradual integration of RE into the grid. Storage can play significant role in reduction in greenhouse gas (GHG) emission by maximizing RE utilization. As the utility operator needs to support costly peak load demand which could be supported by storage and as a consequence, storage can help in energy cost reduction. Although, the present cost of storage considered a barrier for extensive use, however, research is going on for low-cost, high-performance storage system. Therefore, in the low-carbon future power system, ES will play a significant role in increasing grid reliability and enabling smart grid capabilities for sustainable future by balancing RE output.