Distributed generation involves the decentralised production of electricity near load centres to cater to the needs of remote areas where traditional grid-connected modes of power may prove unviable, says Tarun Sharma.
India is the 5th largest producer of electricity and yet faces a peak demand shortage of around 14.8 per cent and an energy deficit of 8.4 per cent. The increased interest and participation of the private sector in the energy sector has paved the way for rapid increase in generation, transmission and distribution.
India currently has a total installed generation capacity of 114,000 MW. As per the ambitious mission of ‘Power for all by 2012’ initiated by the government, the total installed capacity should be 200,000 MW by 2012 and the power requirement is all set to double to 400,000 MW by 2020.
The government has also undertaken the setting-up of nine ultra-mega power plants with 4,000 MW of capacity, each at a total cost of Rs 16,000 crore. The majority of the power is generated at various thermal power stations in India.
The current installed capacity of thermal power is 104,424 MW which is 63.7 per cent of the total installed capacity. Of the total installed capacity, hydropower constitutes about 21 per cent and renewable energy constitutes only 10 per cent.
In view of a vast nation with a majority of its population residing in rural areas, there is an urgent need for decentralised power stations whereby power can be generated at the consumer’s end. This will enable a reduction in transmission and distribution (T&D) losses, as well as counter the menace of theft.
The transmission and distribution losses in India are extremely high and vary between 30-45 per cent. In India, the problem of T&D losses, the unreliability of the grid and the problem of remote and inaccessible regions can be resolved by implementation of decentralised energy production systems.
Distributed energy resource (DER) systems are small-scale power generation technologies (typically in the range of 3 KW to 10,000 kW) that are used to provide an alternative or to enhance the traditional power system.
Distributed generation involves decentralised production of electricity near load centres that is sufficient to cater to the needs of a small community or village. This can prove to be a highly economical and sustainable method of providing power to remote locations and villages wherein power distribution via traditional methods may not be possible.
The production of electricity can be either via non-renewable sources or renewable sources. The non-renewable resources include internal combustion engines that are fuelled by diesel, natural gas and micro-turbines and fuel cells fired by natural gas.
Renewable energy technologies, such as hydro (large and small), solar, geothermal, biomass and wind, can deliver power with virtually zero emissions.
Advantages of distributed generation:
• Provides the right energy solution at the right location.
• Ensures reliability of energy supply, ie, Intentional Islanding can be implemented. The islands can be designed to maintain a continuous supply of power during disturbances of the main distribution system.
• Offers efficiency gains for onsite applications by reducing line losses (both electricity and heat) and reduction in theft.
• Offers customers a choice while selecting a particular electricity source.
• Can easily be made a part of the smart grid or microgrid to improve the efficiency of the entire system.
• Reduces emissions and pollution.
Renewable energy in India
India has an estimated renewable power potential of 84,776 MW from different sources as per details given below:
In order to meet the increased energy requirement of the country and to be able to move towards greener and cleaner sources of energy, a combination of distributed generation along with renewable sources can prove to be the ultimate solution.
One of the most abundant sources of energy is the sun, ie, solar energy. For example, installing solar water heaters is a very realistic opportunity, be it in rural areas or metropolitan cities. Also, solar lanterns and solar power streetlights help reduce the burden on thermal-based generating plants. The government has already undertaken the prestigious Jawaharlal Nehru National Solar Mission (JNNSM), with an aim to develop solar energy in the country and establish India as a global leader in solar energy.
The major mission target of this scheme is to create an enabling policy framework for the deployment of 20,000 MW of solar power by 2022.
The other objectives of the scheme include:
• To ramp up capacity of grid-connected solar power generation to 1,000 MW in the next two years, that is by 2013, which means an additional 3,000 MW by 2017 through the mandatory use of the renewable purchase obligation (RPOs) by utilities backed with a preferential tariff. This capacity can be more than doubled—reaching 10,000 MW installed power by 2017 or more based on the enhanced and enabled international finance and technology transfer. The ambitious target of 20,000 MW by 2022 will be dependent on the ‘learning’ of the first two phases, which if successful, could lead to conditions of grid-competitive solar power.
• To create favourable conditions for solar manufacturing capability, particularly solar thermal for indigenous production and market leadership.
• To promote programmes for off-grid applications, reaching 2,000 MW by 2022 including 20 million solar lighting systems.
• To achieve a 20 million m2 solar thermal collector area by 2022.
Under the Jawaharlal Nehru National Solar Mission, NTPC Vidyut Vyapar Nigam (NVVN), the power trading arm of NTPC, has been designated as the nodal agency to purchase solar power generated by independent solar power producers, at rates fixed by the Central Electricity Regulatory Commission (CERC) and for a period of 25 years. The government will provide the equivalent MW of power from the unallocated quota of NTPC for bundling with solar power.
Recently, North Delhi Power (NDPL) commissioned a 1 MW solar power plant, which is designed to produce 1.58 million units of electricity annually, sufficient to light more than 1,000 homes.
Taking a step in the field of production of non-conventional energy, Mahagenco successfully connected its first 1 MW solar power project with the power grid in Chandrapur.
India’s wind energy sector’s growth has been significant with an aggregate installed capacity of 12,009.48 MW as on 30 June 2010, and this comprises 225 KW to 1,650 kW unit capacities. The details of the various states are given below:
A package of incentives which includes fiscal concessions such as 80 per cent accelerated depreciation, concessional custom duties for specific critical components, excise duty exemptions, income tax exemption on profits for power generation, etc, are available for wind power projects.
The State Electricity Regulatory Commissions (SERCs) in Andhra Pradesh, Gujarat, Haryana, Kerala, Madhya Pradesh, Maharashtra, Rajasthan, Tamil Nadu and West Bengal have announced preferential tariffs for purchase of power from wind power projects.
The potential for hydroelectric power in India is one of the greatest in the world. There is potential for an installed capacity of over 150,000 MW and for an additional 90,000 MW of pumped storage schemes. At a 55 per cent load factor, hydro schemes can produce around 82,500 MW of power. However, of the total hydropower potential in India, only 15 per cent has so far been harnessed with another seven per cent under various stages of development.
Also, geothermal energy is the earth’s natural heat available inside the earth. The potential for geothermal energy is vast and geothermal provinces can produce 10,600 MW of power. But geothermal power projects have yet not been exploited at all, due to a variety of reasons.
So it is very evident that in a fast-developing economy such as India, electricity needs have to be addressed to continue and improve the growth of people and the country as a whole.
Meeting these demands though challenging is not difficult due to the vast potential of renewable resources present in the country. It is imperative that electricity is available to every citizen at the earliest.
While ensuring electricity security, it is important to keep in mind the need to shift to cleaner sources to energy.
With a concerted push and a 40-fold increase in their contribution to primary energy, renewables may account for only five to six per cent of India’s energy mix by 2031-32. This will be totally inadequate and should be substantially increased to at least 25 per cent by 2031-32 in order to gain energy independence.
Renewable energy sources are environmentally-friendly and may be locally available, making it possible to supply energy earlier than in a centralised system. Grid-connected renewables could also improve the quality of electricity supply. Further, renewables may provide employment and livelihood to the poor.
The immense renewable resources clubbed with the active participation of the government, private companies, etc, will ensure that India’s growing energy needs are met and at the same time emissions and pollution are reduced.
In the ultimate analysis, distributed generation will be extremely effective in areas that are in accessible to connect to the central grid and will ensure reliable power supply to these areas. The integration of these distributed energy systems with the central grid will certainly help in the formation of a secure and smart grid infrastructure.
The author is a systems engineer (Manufacturing) at Infosys Technologies and can be contacted at email@example.com. Views are personal.