For decades now, India has been unsuccessful when it comes to bridging the power demand-supply gap. This has directly affected its economy and development. Utilities have long been faced with the challenge of balancing electricity generation with consumer demand, and the lack of innovative proficient installations, along with ageing grid constituents, has resulted in highly inefficient and insecure power systems.
With new power generation modes like decentralised distributed generation (DDG) and renewable energy systems (RESs), it has become vital to control and monitor existing networks more efficiently. The increase in grid complexity has meant that grid operators must adhere to real-time monitoring for generation resources and consumer demand to maintain balance and stability.
For developing countries like India that are experiencing rapid economic growth (translating into more grid-connected homes and buildings), the adoption of smart grids has become all the more ne-cessary. The power grid design at present is not suitable for continued power growth, and, moreover, the country’s transmission and distribution losses are still in the range of 20-30 per cent. Environment-friendly sources of power generation like mini-hydro, solar and wind are gaining importance at a rapid rate, but their integration with existing power networks is the biggest challenge on the technical front.
Another key driver for adopting intelligent power grids is the National Action Plan on Climate Change, as per which India has committed itself to maintaining its per capita greenhouse gas emissions within the levels of developed countries. Apart from this, increased consumer awareness regarding energy use substantiates the need for smart grids in India.
With smart grids, utilities can manage costs in a better manner by being able to discern many problems before they occur. Grid load balancing and distribution automation services can aid continuous power flow and alert utilities about possible blackouts.
This article discusses the architecture of smart grids, the global technology demonstrations that have taken place, and the benefits and challenges of demand response (DR).
Smart grid architecture
Virtual power plant development
Virtual power plants (VPPs) are a solution to the requirement of a power system as they integrate all power generation sources in a secure and robust manner. VPPs aim to aggregate different distributed energy resources (DERs)/RESs through an advanced information and communication technology (ICT) platform for their better utilisation. A VPP is a plant that is locked in the digital domain and can shift from traditional generation to smart grid-enabled renewable gener-ation. VPPs exist only on software and can be used for managing different options, measuring real-time situations, and dispatching solutions in electric form.
The VPP concept has already been tested in Europe via a project titled FENIX, which is aimed at promoting DERs. FENIX depicts the way in which distributed energy can contribute to the power system through large-scale VPPs and demonstrations of decentralised energy management. The project achieved its objective of conceptualising, designing and demonstrating a VPP’s technical architecture through two specific projects in Europe: in Spain and the UK.
VPPs can revolutionise the Indian power sector by channelising the energy generated from one part of India to others where the energy demand is extremely high. Utilities have a major role to play in the evolution of the VPP market in India because of their great dependence on distribution grid infrastructure, comprising smart meters and customised billing services.
Aggregation is the process of assimilating sub-groups of industrial, commercial and residential consumers into a superior unit to enable their participation in the power system. The creation of hamlets in DDG projects is an example of such a scenario.
At present, the demand and generation figures of individual consumers and generators appear as negligible units in the power system. Since this process of combining consumers and generators decreases operating costs, increases profitability and introduces more flexibility, the implementation of smart grids becomes easier through this accumulation model. It empowers aggregators to operate DERs and provide services to the power system in an efficient manner.
The European Distributed Energy Partnership (EU-DEEP) was created for enhancing DER deployment. The project was aimed at developing and validating a pioneering approach, based on future energy market scenarios, for efficient DER arrangement. EU-DEEP examined three diverse business prototypes of distributed generation and individual load amassing.
One business model aimed at balancing intermittent generation by combining commercial and industrial DR. The second aimed at integrating residential-scale flexible micro-combined heat and power systems into electricity markets. The third business model aimed at expanding conventional energy service company businesses through the flexibility of aggregated combined heat and power units and DR.
For the efficient operation of a smart grid, unique ICT-based applications are required for real-time process control, communications, portfolio management and adaptive protection.
The IntelliGrid charter was initiated in Europe to integrate electrical and intelligent infrastructure. This involved determining the business needs of the present power system and the possible power systems of the future. Future energy systems will be an architectural blend of two arrangements: an energy delivering set-up and an ancillary distributed computing infrastructure.
In Europe, the Supporting Energy Efficiency in Smart Generation Grids through ICT programme was developed to provide a set of priorities for fast-tracking the introduction of ICT in smart distributed power generation grids. The other objective of the project was to investigate requirements and barriers and propose appropriate solutions.
In India, there is a need to integrate computers and electrical domains under a single frame. At present, both departments are treated as different entities.
Enlargement of the active distribution network
Active network management (ANM) increases the potential of renewable energy by utilising distribution network assets efficiently and supporting distribution networks through subordinate facilities from customer-owned resources. Demand-side management, reactive power compensation and direct load control are the existing controllable resources to which DDG can be added in an active network scenario.
Europe has implemented ADINE, an active distribution network project based on ANM. The concept of the project is based on supervisory control and data acquisition, advanced metering infrastructure, distribution management systems, and substation and distribution automation.
Some additional features present in this model were fault location schemes, islanding operations and automatic network restoration. The project established new methods for electrical distribution network management comprising various DERs.
DR refers to the ability of a consumer to reduce electricity consumption at his or her location when wholesale prices are high or the electrical grid is overloaded. It is a competitive resource that can be used for maintaining a balance between demand and supply for grid operations through the introduction of load flexibility instead of concentrating only on the adjustment of generation levels at all operational time periods.
Reductions in peak loads can be achieved in the longer term via DR, thereby postponing the need for new power plants. It can also be used for overcoming network constraints at the distribution level.
While DR has a number of potential benefits, there are some challenges that must be overcome. These are wide-ranging and are related to the establishment of an efficient market environment, building a profitable business case, coordinating with energy efficiency programmes, etc. A key challenge is posed by the absence of ancillary services, which are necessary for supporting transmission. There also needs to be an appropriate pricing signal to encourage consumer participation. In addition, there is a need for a higher degree of automation and better technology to strengthen the grid, and for the deployment of smart meters to monitor electricity consumption.
India has recently concluded the interconnection of its regional grids as its earlier grid system was not designed for great capacity and long distance power transfers. As the demand for power continues to grow at a high speed, efforts should be made to strengthen the existing grid rather than expanding it. For this purpose, advanced technologies need to be adopted in a strategic manner, keeping in mind future compatibility. n
Based on a presentation by Kartik Arunachalam, Research Scientist at University of Petroleum and Energy Studies at India Smart Grid Week 2015