In July last year, more than half of India’s population was plunged into darkenss following a series of blackouts Credit: Keith Brown

India’s dramatic grid failure last year unmistakingly demonstrated the greater need for decentralized energy in the sub-continent, writes Richard Baillie.

It is no secret that India’s national electricity grid is in urgent need of a major overhaul.

Just last year, 10% of the world’s population faced a series of power cuts – India’s Northern and Eastern grids came to halt and 600 million people were confronted with the perilous state of the country’s network system. Moreover, a grid failure of this magnitude has focused attention on the massive demand for power in India and its struggle to generate a much-needed supply.

The bottom line is that although India’s generation capacity is the fifth largest in the world behind the US, China, Japan, and Russia, its power development is much further behind. There are still almost 289 million people without access to electricity, accounting for up to 25% of the total population. In rural areas, the figure is more like 33%. Some big states, especially those in the south, often have a power shortage of 12% during peak hours, and even the capital New Delhi suffers regulalry from supply shortages.

The root cause of last year’s blackout can be traced to the weak grid structure that has been allowed to develop for many years. There is also a lack of a centralized authority with overall responsibility for the grid. As things stand, the Power Grid Corporation of India Limited is responsible for the inter-state transmission of electricity and controls the national grid infrastructure, which comprises more than 10,000 km of power lines. Local power bureaus or private suppliers control the distribution networks. There is no unified operation and management system. In this sense, different states act on their own and often draw more power than they are allowed to from the national grid, leading to overloaded grid operation.

To further complicate matters, its national network system is categorised into five regional grids – the Northern Grid, Southern Grid, Western Grid, Eastern Region and North Eastern Regional Grids. All are interconnected with synchronous links – i.e. power transfer between regional grids is based on supply and demand, with the except of the Southern Grid, which is connected via asynchronous links. However, it is proposed However, it is proposed that by 2013-14 the latter is connected to the other grids synchronously, thereby creating a single national grid. This could help to alleviate matters.

India aims to expand its generation capacity by 44% over the next five years. In June 2012, the country’s power supply fell short by 5.8% against a peak-hour demand for 128 GW, according to government data.

Another problem, however, is that most of India’s grid system transmits electricity by back-to-back DC interconnections. In this type of infrastructure, if there is a breakout in one state’s grid system, connected grids will also be affected, experiencing substantial drops in their power carrying capapcity. Because of this, it is not possible for different districts cannot provide strong support to each other or share their resources in case of an emergency.

Thus, serious concerns have been once again raised about the country’s growing infrastructure needs and inability to meet its energy demand. Government officials concluded, “The grid failed because of the overloading of power,” and contend that “many states” tried to draw more power from the grid than they were allotted.

The country’s lack of energy security is a major constraint to its development. The slow pace of tariff reforms is hindering infrastructure investment at the state level in most parts of the country. Furthermore, the government has allowed wheeling of power and recommended a 2% charge. However, some states do not allow wheeling, while others have imposed excessive charges of over 15%. Thus, the centralized model of power generation, transmission and distribution is growing more and more costly to maintain at current levels to meet increasing energy needs. The continuing blackout and shortage of power are clearly hampering India’s economic growth and its capacity for growth.

For economic, as well as environmental reasons, India is now looking to shift towards a decentralized off-grid model, including renewable-based sources like solar, wind, hydro, biomass, biogas, geothermal and hydrogen-fuelled fuel cells.

Projects are moving fastest in the industrial state of Maharashtra. There, cogeneration projects with installed capacity to generate 374 MW of power are now on line, bringing the total power generation from cogeneration plants in the state to 1101 MW. Of the total power generation, 58%, about 638 MW, will be pumped in the state grid and remaining would be utilised by sugar factories to meet their daily energy requirements.

The leftovers after crushing sugarcane are dried and converted into bagasse. The bagasse is used for combustion to generate power. It meets the power requirement of the sugar factories and surplus can be pumped into the state grid. Cogeneration has become additional source of income for many sugar factories in the state.

Speaking to the Times of India, State Sugar Commissioner Vijay Singhal said, “As many as 22 sugar factories in the state have started construction of cogeneration project in the vicinity of the factories. The power is primarily used for running the sugar factory, generally during the period between November and April. In the last few years, the crushing capacity of sugar factories from Western Maharashtra has increased, leading to increase in power generation. Today, 601.4 MW power is generated by cogen plants of 37 sugar factories and another 22 factories are nearing completion of their cogen plants. They will add 374.5 MW and once these 22 projects start operating, total power output will be 1,101 MW by the end of this fiscal.”

Tata Power, an independent power producer and division of Tata, an industrial giant with businesses in steel, software, cars, chemicals, and telecommunications, is also exploring whether the economics of smaller-scale distributed energy can be made to add up to a cost-effective business plan that can be rolled out across India.

Tata Power is projecting rapid growth from about 3,000 MW of capacity now to 25,000 MW later this decade. As part of a long-term sustainability plan, Tata Power intends to beef up its use of clean, renewable power, notably hydropower, where it already has some projects under development.

Tata Power is also putting smaller bets on other clean-energy technologies for distributed power generation, for example, Tata Power is pursuing a model where a cooperative of farmers would sell agricultural residue to Tata Power, which would operate an on-site power generation unit to sell power to that community. To generate power, Tata expects to use a small-scale 100 kW gasification system, while exploring other technologies, such as wind or solar, should be explored as well, he said.

“The nation and Tata Power are on a growth path and it is [a] difficult hill [to climb] to become clean. We hope that once we are at [the summit], the next phase of growth after 2025 will [require] these [clean] technologies and [we will] expand on those,” said Tata head of business development Suresh Malhotra.

If Tata Power does have an economic interest in pursuing distributed clean energy, its near future is mostly centralized dirty power. Of its 3000 MW of capacity, about two-thirds of that comes from coal, gas, or oil. There are another 450 MW from hydro and 200 MW from wind. In the next 10 to 15 years, sadly much of the new power to come on line will come from burning fossil fuels.

India’s Ministry of New and Renewable Energy (MNRE) plans and promotes the development of all sources of renewable energy. MNRE is looking to see renewables’ share of the energy mix rise from around 8% currently to more than 15% by 2020.

“First of all, it’s the right thing to do, but we think we’ll have a competitive advantage when CO2 regulation comes down the [line] two or five years from now,” Malhotra said. “From a clean-tech point of view, we are taking a proactive approach…We think in the longer term, grid parity will be achieved cost-wise.”

Furthermore, with the announcement of the National Action Plan on Climate Change (NAPCC), there is a marked shift in policy to diversifying the generation mix to lower-carbon intensity options. The NAPCC calls for boosting renewable energy’s share of the national generation from 2% to 5%, with specific emphasis on significantly increasing solar’s share. It envisions the increased use of distributed solar photovoltaic (PV) cells, but also, as technology permits, commercial-scale concentrating solar power.

The Electricity Act 2003 and the NAPCC together provide a roadmap for increasing the share of renewables in the total generation mix. However, the utilities’ policy on renewable and distributed generation units seems to overlook the benefits of the latter in remote areas.

The potential for using microturbines and heat recovery boilers from small generators is significantly increasing. For example, NEERU, a biogas company in Andhra Pradesh, and Capstone Turbines of the US are working with Mukund Dairy Farms in Andhra Pradesh to set up a microturbine-based cogeneration system to generate electricity and use the residual heat in a pasteurization plant. Unfortunately, renewable energy resources are not evenly spread across the country and the high cost of reneable-based distributed generation can discourage local distribution companies from purchasing more than their obligatory amount of renewable generation.

To combat this, the Energy and Resources Institute (TERI) is looking to build distributed generation-based power system or mini-grids, which can be installed and subsequently integrated into the conventional utility grid or used to provide electricity for localised loads.

TERI has designed, developed, and demonstrated India’s first-of-its-kind ‘Smart Mini-Grid’ system based on renewable energy. The aim was to optimally use smarter control of distributed energy sources, combined with intelligent management of loads to improve the efficiency and reliability of the overall mini-grid system.

TERI maintains that its Smart Mini-Grid has greater resistance to loading as compared to the conventional grid system because it optimises the use of multiple energy resources to meet different loads

The Smart Mini-Grid also has the capability to respond automatically to network problems and minimise network disruptions. It can anticipate and respond to problems and avoid or mitigate power outages, power quality problems and service disruptions by using real-time information from embedded sensors and automated controls. The grid is also equipped with a self-healing system that enables it to rapidly detect, analyze, respond to disturbances and restore supply.

The TERI Smart Mini-Grid facility combines the following resources — a 3.3 kWp wind generator, a 1 kWp thin-film solar PV, a 12.5 kW solar PV, a 100 kWe biomass gasifier and a 600 Ah, 48 V storage battery. A diesel generator has also been added to the system to negate the intermittency of the renewable resources and hence ensure a reliable power supply.

Such smart min-grid systems have great potential, not only in commercial and industrial complexes, but also in hospitals, shopping malls, apartments, residential complexes, educational institutions and remote unelectrified, as well as electrified locations to ensure maximum flexibility, reliability, and safety, with an enhanced efficiency of the overall system.

TERI’s Smart Mini-Grid model can provide solutions to problems of energy security and sustainability, and ensure reliable quality power. And TERI firmly believe that such a model can be used to strengthen the India’s electricity sector and enhance the performance of rural electricity supply systems. This system enhances efficiency and offers maximum reliability flexibility and safety in the overall electricity distribution network.

Large-scale implementation of such systems will go a long way in helping to meet the energy needs of the country. It can also be integrated with the existing programmes of MNRE, such as the Jawaharlal Nehru National Solar Mission, which aims to achieve 20 GW of grid-connected solar power by 2022, as well as the national rural electrification programme.

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