Power transmission losses in India are among the highest in the world at around 4 to 4.5 per cent. Distribution losses, which ideally should be confined to a single digit, hover around 20-30 per cent. This gives ample scope to technology providers to come up with solutions that help counter these losses
By Uma Gupta
Monday, March 25, 2013: India currently suffers from a major shortage of electricity generation capacity, even though it is the world’s fourth largest energy consumer after United States, China and Russia. The International Energy Agency estimates India needs an investment of at least $135 billion to provide universal access of electricity to its population—reports Wikipedia.
The International Energy Agency expects India to add between 600 GW and 1200 GW of new power generation capacity before 2050. The technologies and fuel sources India adopts, as it adds this electricity generation capacity, may make significant impact to global resource usage and environmental issues.
Electronics in power sector
In power sector, energy efficiency in electricity generation depends on the machines used for generation of electric power. The key to efficiency in energy generation is to control auxiliary power consumption at a plant.
“Auxiliary power consumption at a conventional plant is assumed at around 10 per cent, while at a modern power plant the same is estimated at 8 to 8.5 per cent. With the application of variable-drive frequency technology, auxiliary power consumption can be reduced by approximately two per cent directly. This will also help improve heat rate of boiler, thus helping overall fuel efficiency of the boiler,” says N. Venu, president and head of Power Systems Division, ABB Ltd, India.
This variable-frequency drive technology is contemporary technology used as a standard measure across the globe.
However, as machines used for generation of electric power are synchronous machines, these don’t have much to do with power electronics. Transmission and distribution systems, on the other hand, have a lot of power electronic applications. In India, we use the same technology as in the developed world but with fewer installations.
“The quality of electric power is determined by the flat frequency and sinusoidal voltage profile it can maintain. Any deviation from the set values will affect the performance of the devices connected to the system. Hence it is absolutely essential to maintain proper quality of power at the user end,” explains Prof. (Mrs) Mini Shaji Thomas, member, IEEE Educational Activities Board, chair, Section Outreach Committee (SEOC), and professor and CPIO, Jamia Millia Islamia, New Delhi.
“The task of maintaining quality power is performed very efficiently by power electronics devices such as uninterrupted power supplies (UPS), harmonic filters and other power-quality-enhancing devices. All these devices are a combination of converters/inverters and rectifiers, which are power electronic devices,” Prof. Thomas adds.
Transmission and distribution losses: current status
Power transmission losses in India are among the highest in the world at around 4 to 4.5 per cent and a matter of concern for international funding agencies like World Bank. The target for all power plants is to further bring this down by 1 per cent, making it around 3.5 per cent.
Efficiency in electricity generation, transmission and distribution and use of renewable energy sources like solar PV cells are important to achieve the goal of electricity for all.
As regards distribution loss, ideally it should be confined to a single digit. However, in India this figure hovers around 20-30 per cent (this number is clubbed in the term AT&C losses).
Aggregate technical and commercial (AT&C) losses are the total of technical losses, commercial losses and the shortage due to non-realisation of the billed amount. All-India AT& C losses are shown in the table here.
“The dream would be to achieve the loss figures of Korea, which stands at the lowest in the world at an enviable 4 per cent. Ministry of Power, government of India, had tied up with the Korean Electric Power Corporation (KEPCO) with the aim of bringing down the losses drastically by 15 per cent in the eleventh plan,” says Prof. Thomas.
Under RADRP, work is under progress to collect online data of power and energy flow at distribution transformer level. This will help segregate technical and commercial losses. Once we have a clear picture, appropriate action can be planned to handle technical losses as well as focus on commercial losses by improved metering, billing, collection and other associated areas.
Technical loss reduction measures
Power plants today incorporate a mix of technology systems to help counter transmission and distribution losses.
“Reactive power flow in transmission and distribution lines causes many problems such as voltage reduction, low power factor and increase in the line losses. Compensation devices for supplying reactive power to the loads at the load end—rather than reactive power flowing from the generating stations—will reduce the line currents and hence the line losses, which is proportional to the square of the current flowing. These devices also improve the power factor and voltage profile. The device may be installed primarily for reactive power supply, power factor correction, and increasing the transmission capability of a line or reducing losses,” informs Prof. Thomas.
Power electronic devices termed as FACTS (flexible alternating current transmission system) are a family of thyristor-controlled high-power electronic devices, which are used for a variety of applications in transmission and distribution systems.
“FACTS technology enhances the security, capacity and flexibility of power transmission networks. FACTS solutions help power companies increase transmission capacity over existing AC power lines, providing fast voltage regulation, active power control and load flow control in meshed power systems. These help to minimise bottlenecks in existing transmission systems and improve the availability, reliability, stability and quality of the power supply,” explains Venu.
FACTS technology is a comparatively inexpensive and fast way to provide more power and control in existing networks, with minimal environmental impact. ABB has a complete portfolio in the field of FACTS and in-house manufacturing of key components.
FACTS devices are classified as shunt compensation devices (static VAR compensators, static compensators, etc), series compensation devices (thyristor-controlled series capacitors, static series synchronous compensators, etc) and a combination of series and shunt compensation devices (unified power flow controllers).
Static VAR compensation systems help compensate reactive power in dynamic mode, thus helping better regulation on transmission line, reducing over-voltage and transmission line losses.
Prof. Thomas informs, “In India PGCIL has installed many thyristor-controlled series capacitors and static VAR compensators in transmission systems. Distribution companies are using extensive capacitor compensation with thyristor control.
“High-voltage direct current (HVDC) transmission is another application of power electronic devices in transmission of electric power. HVDC lines are used for transmitting a large quantity of power over long distances, at 550 kV and above voltages.
“India has many HVDC lines and PGCIL is a world leader in this technology implementation. There are also HVDC back-to-back stations to connect two asynchronous systems and to enable controlled transfer of power.”
Balancing load and generation
The smart grid concept tries to achieve a balance between load and generation. With increased focus on renewable sources of energy such as wind, solar and hydro, this imbalance is likely to increase. Hence a smart grid application is important to help store electric energy. Whenever the load is in excess of generation, energy can be tapped from these storage devices and thus load demand managed.
“The government of India has identified 20 pilot projects where this concept is to be implemented before scale-up. In its full scope, the concept also covers smart devices at home that can be preprogramed to ‘switch on, switch off’ based on the power scenario. For example, in a dairy or a large air-conditioning plant, the chiller can be switched on when there is surplus power at night, helping meet daytime peak demand,” informs Venu.
Betting big on solar power
With its growing electricity demand, India has turned its focus on solar energy based power generation. The country is already amongst the world’s most active players in renewable energy utilisation, especially wind energy. As of December 2011, India had about 22.4GW installed capacity of renewal technologies-based electricity, exceeding the total installed electricity capacity in Austria by all technologies—according to Wikipedia. However, the penetration of solar PV in India is only 4 per cent of the renewable energy production as of now.
Under the Jawaharlal Nehru National Solar Mission launched by the Indian government, India plans to generate 1 GW of power by 2013 and up to 20 GW grid-based solar power, 2 GW of off-grid solar power and cover 20 million square metres with solar energy collectors by 2020. The country plans utility-scale solar power generation plants through solar parks with dedicated infrastructure by state governments.
There are some roadblocks to overcome in order to realise full solar power potential. Solar plants are expensive as solar cells are still costly. The cost will come down when the efficiency of solar cells can be substantially enhanced.
Land acquisition is another challenge before solar farm developers in India. Some state governments are looking at addressing the problem of land availability through innovation; for example, they are exploring ways to deploy solar capacity above their extensive irrigation canal projects, thereby harvesting solar energy while reducing the loss of irrigation water by solar evaporation.
Thankfully, as volumes in solar plants have picked up, the overall investment in the sector has come down significantly. Three years ago, the amount of power generated through solar power systems was estimated to have cost approximately Rs 15 per unit. Today, this cost has reduced to Rs 7.50—equivalent to 50 per cent cost saving.
Managing pollution along with power generation is important. An increased focus on energy sources like solar will bring a decrease in pollution, alongside generation of power.
Early last year, India’s Bureau of Energy Efficiency (BEE) had launched its ‘Perform, Achieve and Trade’ (PAT) scheme to set energy efficiency targets for industries. Such schemes will go a long way in helping to improve overall energy efficiency.
Action plan to meet power deficit
Currently, the peak demand shortage in India is around 12 per cent and energy demand shortage is around 11 per cent, as per Central Electricity Authority (CEA) documents.
“The situation demands power deficit to be handled at different levels. As mentioned earlier, managing auxiliary power consumptions plays a vital role in the same. If today installed power capacities amount to 200,000 MW and if we can save at least 2 per cent on auxiliary power consumption, this would give us an additional 4000 MW, which would add up to 1 ultra-mega power project. This is an indication of how we can meet the power deficit situation. It is important that we focus equally on the transmission and distribution of power,” shares Venu.
At the same time, improving efficiency of generation, transmission and distribution alone cannot meet the power deficit. A new generation has to come up to cope with the ever-increasing growth in power and energy demands of this fast-developing country.
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The author is executive editor at EFY
Power electronics devices
Power electronic devices are classified as half controlled devices (thyristors) that are turned on by a control signal and turned off by the power circuit, whereas fully controlled devices such as power MOSFETs, IGBTs and IGCTs are turned on and off by control signals.
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Smart grid: concept and status
Smart grid combines power system infrastructure and communication infrastructure to create a power network with enhanced efficiency, reliability, safety and better utilisation of fast depleting natural resources. Rather than requiring a new power grid, it involves automated monitoring and control of the existing power infrastructure, ensuring uninterrupted power supply to consumers while reducing losses and increasing productivity.
Across the globe, remote monitoring and control power systems are being favoured to achieve benefits such as lower operating and maintenance costs, lesser peak demand, reduction in power theft, increased revenue, reliability and quality.
The government of India too has taken cognizance of this trend and is taking steps towards a smarter grid. Its accelerated power development and reforms programme (APDRP) provides funds to state electricity utilities to improve energy auditing and accounting systems in order to reduce losses by 15 per cent.
The Smart Grid Task Force set up by the government is an inter-ministerial group that creates a roadmap with the objective of accelerating the smart grid developments in India.
Consumers stand to gain from smart grid implementation in many ways. A fully automated distribution system will allow power utility companies to introduce flexible tariff systems, enabling consumers to select an electricity consumption pattern and reduce their electricity bills.
Power Grid Corporation of India Limited is implementing a smart grid test bed at Puducherry in partnership with public and private players. It has signed MoU with as many as 60 companies.
– Prof. (Mrs) Mini Shaji Thomas, Member, IEEE Educational Activities Board, Chair, Section outreach committee (SEOC), and Professor & CPIO, Jamia Millia Islamia, New Delhi
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Electronics makers seek relief from service tax for power sector
Indian Electrical and Electronics Manufacturers’ Association ( IEEMA), which is the apex representative body of manufacturers of electrical equipment, professional electronics and allied equipment, has extended a request to the government to extend service tax exemption for power generation, transmission and distribution-related services.
In its pre-budget memorandum to the union Finance Ministry, IEEMA reportedly mentioned, “With the mission of providing power to all on demand at an affordable cost, exempting all power projects from the levy of service tax would definitely be a step in the right direction and reduce the project cost.”
According to a Business Standard report, IEEMA also said that it wanted the government to encourage manufacturing and the creation of a level-playing field for the industry in order to maintain competitiveness.
“Higher and accelerated depreciation should be allowed for construction equipment at construction sites at 30 per cent from the present level of 15 per cent so that the equipment can be written off in ten years. This would enable companies to bring in better technology in the manufacturing sector where newer technologies can reduce project cycle time,” IEEMA added in the report. They also requested for refund of excise duty that is paid by domestic manufacturers as a deemed export benefit.
The generation equipment sector is 26 per cent of the total industry, while the transmission and distribution (T&D) equipment sector comprises 74 per cent.
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