IEEE Power and Energy Society BracU Student Branch Chapter, in collaboration with IEEE Power and Energy Society AUST Student Branch Chapter, arranged a webinar on “Decarbonisation of the Electricity Grid with High Renewables: Opportunities, Challenges and some Perspectives” on February 11, 2023. Tapan Saha, a Professor of Electrical Engineering at the University of Queensland, a fellow of IEEE, and an IEEE Distinguished lecturer, was the main speaker of this webinar. Mr Mohaimenul Islam hosted the webinar, is the Secretary of the IEEE Power and Energy Society, and is a lecturer in the Department of Electrical and Electronics Engineering at Brac University. The other guests in this webinar were Prof. Dr. Mohammed Mahbubur Rahman, Pro-Vice-Chancellor of AUST, and Prof. Dr. Shahidul Islam Khan, the Department of Electrical and Electronics Engineering Professor at Brac University, Md, Mosaddequr Rahman, Ph.D., the Professor and Chairperson of the Department of Electrical and Electronics Engineering at Brac University, and Prof. Dr Tareq Aziz, the professor of the Department of Electrical and Electronics Engineering at Ahsanullah University of Science and technology.

An electric grid is an interconnected network supplying electricity from producers to consumers. This network consists of transmission and distribution lines controlled by one or more control centers. This electric grid for producing electricity produces a lot of carbon dioxide when using non-renewable energy sources. However, renewable energy reduces these emissions to a great extent. To reduce these emissions, decarbonizing the grid is a necessity. This webinar discussed different aspects, prospects, and the complexities of using renewable and non-renewable energy sources in an electric grid. 

Our honorable speaker began his speech by acknowledging the traditional owners and the courtship of Australia. He briefly discussed his power and systems research team at the University of Queensland. Then, he spoke about the future national electricity market development in Australia. Currently, the electricity demand in Australia is 180TWh, which will increase to 320TWh by 2050. The electricity generation will be mainly from variable renewable energy and distributed PV as variable renewable capacity will triple every decade, distributed PV capacity will also grow from 15GW to 69GW by 2050, and coal-fired generation capacity will decrease by 60% in 2030. After that, the speaker discussed power generation in Bangladesh. The total installed electricity generation capacity of Bangladesh is 22512 MW. Coal, gas, hydrofuel oil (HFO), and high-speed diesel (HSD) have higher installed capacity than Hydro or Solar in Bangladesh. He also explained the installed PV generation capacity of Australia. The installation of PV has exponentially increased from 2010 onwards in Australia. Australia has over 3.2 million PV installations with a total capacity of more than 28 GW since September 30, 2030. However, the saturation of rooftop PV installations in urban areas and the rising trend of MW-scale PV applications in rural areas have created complexity in voltage regulations. Afterward, he explored the electricity generation process from PV in Bangladesh. Though the estimated total solar energy potential capacity is 2680MW, only 285.64 MW is achieved. The reasons behind this are significant obstacles like the unavailability of land, energy policy, and incentive environment. In industrial/commercial networks, solar power generation is fully utilized at the point of connection, whereas in residential networks, high PV penetration is primarily a problem on grid voltage. According to the PV/Load profile, the time for PV and load peaks are always different. Thus reverse power flow occurs resulting in over voltage, under voltage, voltage flicker, over current, unbalanced power systems, and many other problems. After that, he discussed the electricity demand projection in Bangladesh based on GDP and the power system master plan in 2016. After 2030, based on the economic modeling, the GDP growth will reduce slightly.

On the other hand, the electricity demand will increase. So, according to this master plan, the transmission line will be expanded, the demand will increase significantly, and the installed capacity will also increase. The speaker said that an increased penetration level could significantly impact voltage regulation. The Distribution system state estimation (DSSE) engine was introduced to estimate the operational state by deducing the state variables and increasing the hosting capacity. Another tool named dynamic operating envelope (DOE) was also introduced to allocate the available export/import power at different connection points in a time interval without violating the physical and operational limits of the networks. Following that, he spoke on the future changes in Australian power systems. Asynchronous renewables will replace traditional synchronous generators. These increasingly high instantaneous renewable energy penetration in NEM would create system reliability and security issues such as dispatch thermal constraints, system strength shortfall, and inertia shortfall. Therefore, a project named Enabling the Queensland Power Systems of the Future was introduced. This project aims to identify power systems operational challenges of the Queensland network’s 50% renewable energy target by 2030. The speaker also discussed better energy storage systems (BESS), the inadequacy of frequency response, and potential solutions. The frequency response with a high number of synchronous generators’ frequency drop is much lower than with a lower number of synchronous generators. BESS can significantly control inertia, respond faster, and support extended provisions.

At last, he summarised the potential solutions to improve grid stability. Firstly, a Pumped Hydro Energy Storage Power Plant can be used to store energy during off-peak hours and use it during peak time. It can also provide inertia. Secondly, large-scale battery energy storage systems can offer virtual inertial and system strength. Finally, Synchronous condensers can provide inertia, show the current fault level, and help increase the system’s stability.

He concluded by giving the key message, ‘Think about the system .’Through this line, he meant that we need to think about the system instead of individual power plants individual customers, or separate transmission lines. He suggested careful planning to reduce the supply and storage cost, to hinder exponential increment of electricity cost, and to give a good value proposition for private investors and the government sector. The optimal transition to a decarbonized power system is highly sensitive to deep future uncertainties due to the complexities of the power system. Massive innovation is needed across all aspects of the electricity system. Eventually, the webinar ended with a question-and-answer session where the speaker answered numerous queries and questions from the audience.