Globally, electric power networks are experiencing a revolutionary change in the domains of electricity generation, power transmission, and energy distribution. Increased population density, rapid industrialization, urbanization, increase in energy demand and utilization of fossil fuel-based power generation and carbon dioxide emission to the atmosphere are the reasons for shifting the paradigm towards the alternative energy resources.
As per the Paris agreement it’s a huge challenge to limit the average global warming temperature to 1.5°C. Achieving the goals of the Paris agreement demands extensive economic and social reforms, relying on the available sustainable resources of power generation to avoid the excessive emission of CO2 and GHG (Greenhouse Gas). Replacement with low carbon options takes a center stage for limiting carbon emission.
For the growing population the only traditional grid is no longer a suitable option to meet the high growth of demand and supply need of electricity. To make the grid network more sustainable and eco-friendlier, there is a need to integrate green energy resources to the grid for decarbonization of the power generation, transmission, and distribution system. As a result, there are ample opportunities to replace the fossil fuel generating units by alternative generating units such as solar, wind, biomass, energy storage system, hydrogen/ ammonia etc., which are sustainable in nature.
Through this integrated approach, conventional grid should transform to a low carbon power system. Traditional fossil fuel-based power stations were centralised and through long transmission and distribution system power used to be catered to the end users. With availability of alternative and renewable energy resources distributed across regions, now availability of power has become more reliable, flexible, resilient enabling energy security to the consumers at affordable cost.
Distributed Energy Resources (DER) can be used to form smart grids and microgrids across urban and rural areas that can reduce the requirements of long transmission and distribution infrastructures resulting in optimisation of energy loss. Figure-1 typically shows the landscape of grid interconnection of conventional and sustainable energy resources.
To satisfy the maximum load requirements across both urban and rural areas, the microgrid and smart grid are introduced into the power system. To ensure the power reliability for all kinds of users, two-way power flow must be needed. As technology has advanced and energy regulations have developed to support renewable energy, more small-scale power generation systems have been added. New technologies like energy storage, systems for controlling power flow, virtual inertia, and electric vehicles are emerging. These advancements help give users more control, flexibility, and reliability in managing their energy use. This article focuses on sustainable energy generation, modernisation of the increasingly complex, dynamic and active distribution grid and its implication on distribution planning, operation modes, and regulatory process. In recent market trends, the Distributed Energy Resources (DER) has created more opportunities for consumers and businesses.
Technology landscape for grid modernisation
In the past few years, there has been a significant rise in the contribution of renewable energy sources to power networks, which is permitted to meet energy demand in a cleaner pathway. Conventional fossil fuel-based energy generation is a concern for causing environmental pollution. The reserves of fossil fuels are also going to be depleted over a period of time. Utilizing Distributed Energy Resources (DERs) that are in cleaner forms can help improve the environment and extend the lifecycle of fossil fuel-based plants.
In the clean technology pathway solar energy is now most popular and proving to be the pillar of renewable sector due to abundant availability of solar irradiance, technology maturity and affordability. Along with land mounted solar plants roof top solar and floating solar plants are also getting popularity and slowly becoming essential pertinent to the power network. Onshore wind power generation is being widely deployed in India, and the capacity of wind power generating has increased significantly in recent years. Nowadays the government has taken several steps to deploy the offshore wind power generation plants in the country.
Both wind and solar generation are highly variable and intermittent in nature. To support those renewable energy resources, energy storage devices are highly needed for reliable and firm energy supply to the consumers. Storage technologies include pumped hydro storage, hydrogen fuel cells, Battery Energy Storage System (BESS) etc.
With advancement of the battery storage technology, EV is now getting much popularity for pollution free vehicle and its energy storing capability that helps in two-way power flow operation. In Automotive applications, Fuel Cell Electric Vehicles (FCEV) use fuel cells along with small batteries. Most of the fuel cell vehicles are classified as zero-emissions vehicles since their only byproducts are heat and water. Hydrogen fuel cell technology is presently used in automobile industry, but its feasibility – as backup power generation that will help in reducing the carbon footprint and generate sustainable green energy – needs to be explored.
Hydrogen fuel cells are also used as residential heating devices. Green hydrogen and ammonia play crucial roles in net zero economy because they produce no carbon emission at the time of generation. They also aid in achieving net zero objectives for energy storage, transportation, power production and temperature control. Green hydrogen provides a zero-carbon method of separating hydrogen from water by electrolysis using renewable power. Combination of hydrogen and nitrogen in a chemical process using renewable energy produces green ammonia (NH3), which is also a good energy carrier.
Integration of DERs to smart grid
Growth of the energy demand, rising electricity costs for consumers, depletion threat of fossil fuel reserves, environmental challenges linked to fossil-fuel based power plants, and difficulties in integrating renewable energy into existing grid systems are key issues facing present-day power grids. Along with this, there is a growing concern of congestion and overloading of the power transmission and distribution infrastructures. Conventional techniques are not adequate to solve the increasing complexity of existing networks.
To overcome this, smart grid technology can be deployed to optimize the advantages for utilities and their customers, and to deliver cost-effective, reliable electricity services through the efficient use of available resources and advanced technologies.
A smart grid is a cohesive network that links electric utilities, consumers, and Distributed Energy Resources (DERs) as shown in the Figure 2. Distributed energy resources refer to a diverse range of energy-generation technologies that are connected to the electrical grid at a local level. Centralized power generation relies on large-scale power plants and takes a high initial cost for its overall infrastructure and operational cost. DERs are decentralised and located closer to the point of demand which is the best alternative solution for power generation and helps in reducing T&D congestion and line losses.
Smart grid has self-healing capability, and it is capable of bidirectional power flow as well as communication of data. In other words, the smart grid makes use of information technology to enhance the traditional power grid’s automation, interconnection, and communication, predictability and monitoring of power system assets. This makes easier availability of data to energy providers and consumers on a real time basis. This process enhances reliability, flexibility, security, and optimization of power systems by decongesting the transmission infrastructures.
Due to the intermittent characteristics of some renewables, sources like solar and wind energy are unable to continuously provide reliable electricity throughout the day. In absence of utility grid, the islanded mode of smart grid operation may lead to voltage & frequency instability and power quality issues. Effective real and reactive power management can be ensured through the usage of stable sustainable energy resources and FACTS (flexible AC transmission system) devices that can be deployed for integration of energy resources and reliability of the grid.
There must be equal thrust on deployment of energy efficient system along with optimisation on energy usage. The utilisation of energy-efficient equipment by individuals actively contributes to fostering a sustainable future, as it not only helps cut down on greenhouse gas emissions but also leads to long-term savings on utility bills. As a result, utility companies implement Demand-Side Management (DSM) programs to efficiently manage and influence consumer energy usage. These programs encompass various strategies, including demand response and consumer load management.
In an integrated control system utilising Supervisory Control and Data Acquisition (SCADA) technology, Programmable Logic Controllers (PLC), and smart meters, these components collaborate to manage and optimise consumer energy usage. Within the framework of consumer load management strategies, utility focuses on consumption pattern of electricity and implement variance of tariff rate depending on the usage of electricity over a period of time. This Time of Day (ToD) approach will encourage consumers to utilize electricity during off-peak hours and supply surplus electricity to the grid during peak hours as consumers are now becoming prosumers. Smart grid encourages electricity users through the load management strategy to make a balance between supply and demand.
One of the most significant advantages of DERs in smart grids is their ability to empower energy consumers and the integration of DERs transforms consumers into active participants. Smart meters integrate a variety of IoT (Internet of Things) sensors, which is capable of collecting more and more data in real time basis. IoT sensors can be deployed to continuously monitor the health of various major equipment of the grid. Using the analytical tools, centralized controller processes the data that helps in improving predictive maintenance instead of routine maintenance. Predictive maintenance enhances plant efficiency, reduces maintenance costs and prevents unplanned power outages.
Challenges & mitigation
The world is transitioning from the conventional grid to the smart grid at a rapid pace. The grid infrastructure is still expanding in developing nations like India. The existing grid infrastructure is not equipped to handle the increasing demands to decentralised generation and clean energy in the future. This could lead to several challenges in terms of operation, maintenance, infrastructure design, and the expansion of Transmission and Distribution (T&D) lines. Integration of renewable energy sources, data management, stability, cyber security, etc., are major difficulties in smart grid technology. Utilities are working hard to overcome obstacles as they strive to convert outdated power grids into intelligent distributed power systems all around the world.
Initially solar PV technology required a high capital cost to installation. Consumers are not tempted to use rooftop solar power technology and there is a lack of promotion also. Developers are facing the ‘Land Acquisition’ problem for deployment of large-scale solar plants. A potential mitigation strategy is to integrate solar PV with existing infrastructure by incentivising the use of under-utilised spaces such as highways, railway corridors, and industrial rooftops. This reduces the need to buy land and encourages more people to use solar power. The government can support a leasing system where property owners allow solar panels on their land or buildings and earn money without paying for installation.
While the intermittency of wind power, caused by varying wind speeds and directions, is a well-known constraint, it remains one of the primary renewable energy sources due to its vast potential. The variability in wind conditions does present challenges in ensuring consistent power generation. However, ongoing advancements in energy storage solutions, as well as grid integration, are continuously improving the reliability and performance of wind farms, helping mitigate these challenges and maximizing the contribution of wind energy to the overall energy mix.
Batteries, while common for energy storage, remain costly and pose environmental disposal challenges. Electric Vehicles (EVs) offer efficient power utilisation through (grid-to-vehicle) during the off-peak loads and (vehicle-to-grid) during peak demand periods. Although this advanced technology enhances energy efficiency, it faces issues like battery life, charging infrastructure, range, and higher costs than conventional cars. Lithium-ion batteries support renewables, but recycling is crucial due to rare materials like lithium. To boost EV adoption, utilities and policymakers should expand public charging in underserved areas, provide financial incentives, and support R&D in energy storage technologies.
Although hydrogen is a perfectly clean fuel, Green Hydrogen costs more as compared to grey hydrogen. And the main challenge associated with hydrogen storage and transportation is its low density and high flammability in nature. As a result, hydrogen requires substantial energy expenditure to transform it and keep it in the liquid state. On the other hand, emerging technologies like hydrogen powder storage provide alternatives that improve safety, optimise efficiency, and simplify logistics.
Smart grids involve multiple stakeholders, leading to vast data exchange and increased vulnerability due to more devices and DERs. Advanced technologies like IoT and sensors raise cyber risks, threatening grid security. Advance techniques can defend the smart grid from outside threats like malware infections and hacking by offering secure management services including strong monitoring protocols, encryption techniques for data transfer and storage, and authentication management rules.
Current codes and regulations fail to address the complexities of integrating renewable energy, advanced storage, and smart grids. Lack of strong leadership, R&D, and investment incentives hinder progress. A robust policy framework is needed to attract private capital, with benefits like ‘green certification’ for eco-friendly energy users. Government support through subsidies and active community involvement can drive effective grid modernisation.
Conclusion
Today’s biggest challenge is minimisation of carbon footprint throughout the globe. Grid modernisation technique plays a vital role in reducing carbon emissions and giving more options to sustainable electricity generation.
For achieving the net-zero goal, microgrid, smart grid and the DER system are the best alternative solution for efficient electricity generation. Low-carbon electricity production through these evolving grid technologies would allow us to take better control of the adverse effects of climate change.
Through the grid modernisation, energy production becomes more reliable and sustainable. With these concerted plans and actions, we can reduce the carbon and greenhouse gas emissions that directly helps in reducing global warming.
Haripriya Sahoo has completed her graduation in Electrical Engineering from Government College of Engineering, Kalahandi, and post-graduation (M-Tech) in Power System Engineering from Odisha University of Technology and Research. She has two years of experience in the power sector, focusing on electrical design, power quality, system studies, and technology integration. She is currently working as a Senior Engineer in the Technology Vertical at Tata Consulting Engineers Ltd.
