Cover Story | October 2011
Critical technology to improve power efficiency
Smart grid implementation needs optimisation on cost, efficiency and reliability in view of conditions in India, says Sudeep Edakkattu.
Indian power sector has seen tremendous growth in the last couple of years in terms of generation capacity addition, transmission network augmentation, reforms in distribution network , growth in end user consumption and transition to open market trading of electricity over power exchanges.According to the power ministry, India's total installed capacity as on 31 March 2011 is 172,626.40 MW. Central Electricity Authority's statistics show that for 2010-11 though the total ex-bus energy availability increased by 8.0 per cent over the previous year the peak met increased by 7.5 per cent. As India strides forward on its economic journey, the demand and supply of electrical energy by its populace is going to increase dramatically. Hence smart grids in India have different challenges and should focus around better quality power, eliminate voltage and frequency fluctuations, especially the low voltage and frequency conditions of summer, making power outages and load-shedding relics of a dark past.
Implementation of smart grids in India will need R&D to obtain the right design optimisation on cost, efficiency and reliability, knowing the unique conditions in India. In addition, standardisation of equipment modules and operating procedures is necessary to ensure systematic proliferation.
A smart grid is one that incorporates a combination of computation and communication technology into every aspect of electricity generation, delivery and consumption. The digital communication elements notify all parts of the grid rapidly in case of breakdowns so that alternative routes for power dispatch may be computed which will improve the following conditions:
– Minimise environmental impact
– Improve reliability and service
– Reduce costs and improve efficiency
Smart grids save energy, reduces cost and increase reliability and transparency using digital technology in delivering electricity from suppliers to consumers. It uses digital communications and control to monitor and control power flows, which in turn makes the power grid more resilient and efficient.
Smart grid technologies have emerged from earlier attempts at using electronic control, metering, and monitoring. In the 1980s, automatic meter reading was used to monitor loads from large customers and evolved into the advanced metering infrastructure of the 1990s, whose meters could store electricity for use at different times of the day. Smart meters add continuous communications so that monitoring can be done in real-time and can be used as a gateway to demand response-aware devices in the home.
Early forms of such demand-side management technologies were dynamic demand aware devices that passively sensed the load on the grid by monitoring changes in the power supply frequency. Devices such as industrial and domestic air-conditioners, refrigerators and heaters adjusted their duty cycle to avoid activation when the grid was suffering from a peak condition.
Smart Grid Drivers
Generation mix – Integrating renewable energy. Enabling decentralised power generation and consumption. A large percentage of India's rural population cannot afford to pay more than a few rupees per day on energy. Setting up smart mini/micro-grids, which are self-contained energy grids based on local renewable energy resources will bring low-cost electricity, enabling the country to leapfrog to total rural electrification.
Environmental concerns are increasing around the globe and are driving the development of renewable energy. The adoption of renewable resources like wind, solar and others presents certain operational challenges. Today's grid needs to handle a generation mix with high involvement of renewable and also enable consumers to generate electricity and feed excess power back into the grid.
Efficient & Reliable Energy - Increasing the reliability, efficiency and safety of the power grid.More than 20 percent of the electricity leaving a power plant is lost in the transmission and distribution network even in the modern systems. Reliability is the main concern for all utilities and grid operators and hence the focus is more towards power system planning, operation and management.
Demand Response – Serving the consumer at his demand. Application of the available technology can meet the energy consumer's demand and provide greater control over energy usage. The concept of time of use needs to be implemented to get the advantage on pricing. Regulators are also enhancing support to expand renewable generation, increase grid efficiency and enhance system reliability.
The main challenges and identified needs for distribution are mainly categorised based on the specific requirements of consumers and availability of power. To address these challenges, the smart grid focusses on providing the system with efficient billing and collection, efficient metering, adequate distribution networks, maintaining peak demand gap, etc.
Table 1: Electricity Market Needs
Advantages of Smart Grid
•The smart grid uses modern technology which provides more intelligent automation devices and optimised systems that enable utilities to meet customer requirements of reliable power from both conventional and renewable energy sources
•Power generators can take maximum advantage of renewable energy resources and optimise generation
•Increase in the stability and reliability in transmission, in turn reducing transmission losses for the transmission grid
•The distribution will become a source of power as well as point of delivery to end users
•Consumers on the other hand will benefit due to the improved demand management and optimising of power consumption through the use of local power generation. The same can be achieved with automation at all levels of usage
Looking ahead, the operation of the power system will be shared between central and distributed generators.Control of distributed generators could be aggregated to form micro grids or 'virtual' power plants to facilitate their integration with the physical system and the consumers.
In conclusion, the smart grid is not a revolution and will be a gradual transformation of the systems that have served us for many years into a more intelligent, effective and environmentally sensitive network.
Implementation of smart grid technologies is a continuously evolving process constrained by available resources, technology and other business issues. A planned process with an experienced technology business partner is required for successful implementation of the smart grid.