Indian economy depends on development of many sectors like industry, agriculture, transport etc. and these sectors demand primary need of energy. The energy demand from these sectors has been increasing abundantly since 1950’s. It is necessary to supply the energy demanded by these sectors to increase their growth rate to achieve better economic standard. Unfortunately, major part of the energy supplied to the Indian sectors is dependent on the fossil fuels such as oil, gases and coal.
Due to the continuous threat of increasing the fossil fuels cost and its availability questions the security of continuous energy supply and it also threats the economic growth locally and globally.
It is well known that the supply of fossil fuels to Indian sectors is not easy task because of its cost and non-availability. It is also known that India is a great importer of fossil fuels. India holds fourth rank of importer of oil and the sixth largest importer of petroleum products globally. So, there is continuous oscillation of fuel price and thereby variation in the Indian market at major sectors.
Hence, it is very much essential to utilize the available renewable energy sources as much as possible because India has the capability to produce trillions of Megawatts form renewable energy such as solar, wind, hydro, biomass etc. But the installed capacity of renewable energy in India is only 28% of total installed capacity and the remaining 78% from Non-renewable energy sources.
If the renewable energy is harnessed efficiently form available sources especially from solar, wind and hydro can reduces the usage of fossil fuels. This reduction leads to strengthen the economic status of India globally. The utilization of renewable sources not only raises the economic rate, but also avoids the carbon emission from fossil fuels. The increasing usage of renewable resources can lead to reduce India’s dependence on expensive importing fossil fuels.
Ministry Of New and Renewable Energy (MNRE)
The government of India has established integrated agencies in the development of renewable energy sector like MNRE. This ministry was established in 1992 as the Ministry of Non-Conventional Energy Sources and it was renamed as MNRE in October 2006.
The MNRE has successfully deployed the capacity of 26.3GW of grid-based, off-grid capacity of 787.53 MW and 8846 villages were electrified under the scheme of Remote village electrification as on October 2012.
Ministry of New and Renewable Energy has the specialized technical institutions across the country such as Solar Energy Centre (SEC) in Haryana, Centre for Wind Energy Technology (C-WET) in Chennai, The Sardar Swaran Singh National Institute of Renewable Energy (SSS-NIRE) in Punjab and Alternate Hydro Energy Centre in Indian Institute of Technology-Roorkee.
More number of projects is in progress financed by these institutions headed by MNRE. This agency also distributes the loans and fund assist to renewable projects through specialized financial institution “Indian Renewable Energy Development Agency” (IREDA).
Investment And Financial Assistance
The government of India has also established “Make in India” to attract the corporate companies to invest in renewable energy development and it also offers full exemption of excise duty of solar tempered glass, machineries and equipment back sheet and EVA sheet, flat copper wire which are used in manufacture of solar photovoltaic (PV) cells/modules. Foreign Direct Investment (FDI) up to 100% is permitted under the automatic route for renewable energy generation and distribution projects subject to provisions of The Electricity Act, 2003. The MNRE also furnishes central financial assistance to build small/micro hydro projects both in the public and private sectors. It provides the 400 fellowship for students and researchers from graduate to Doctorate level.
The various mode of support is also provided to state governments for the selection of new potential sites, including surveys, the preparation of detailed project reports and the renovation and modernization of old projects. State Electricity Regulatory Commissions in Tamil Nadu, Andhra Pradesh, Madhya Pradesh, Haryana, Maharashtra, Punjab, Rajasthan,Gujarat, Kerala, Orissa and West Bengal have announced preferential tariffs for purchase of power from wind power projects.
Solar Energy – An Overview
Solar energy starts with the thermonuclear fusion reactions occurring in the sun. It represents as an entire electromagnetic radiation (visible light, infrared, ultraviolet, x-rays, and radio waves) as shown in Figure 1. This energy consists of radiant light and heat energy from the sun.
Because of the demand for electric energy and environmental issues such as pollution and an issue of global warming, renewable energy sources such as sun, wind, bio fuels and etc. are considered as an option for generating clean energy technologies. Among them, sun power is the most important one because of its availability and relatively easy way to handle.
PV Cells
A PV array is the solar “generator” working based on the principle of “photovoltaic effect”. The photovoltaic effect is the way in which PV cells create electricity from the energy residing in photons of sunlight. When sunlight hits a PV cell, the cell absorbs some of the photons and the photons’ energy is transferred to an electron in the semiconductor material. With the energy from the photon, the electron can escape its usual position in the semiconductor atom to become part of the current in an electrical circuit as shown in Figure 2.
Most of the PV cells are manufactured based on solar technologies (Figure 3) like crystalline silicon or thin-film. Crystalline silicon modules can be fashioned from either mono-crystalline, poly-crystalline silicon. Thin-film is a term encompassing a range of different technologies, including amorphous silicon, and a host of variations using other semiconductors like cadmium telluride or CIGS (copper indium gallium di-selenide).
PV array still have relatively low conversion efficiency because of variations in irradiation, temperature and load. The PV array has a particular operating point that can supply the maximum power to the load which is generally called maximum power point which varies according to the solar irradiance and the cell temperature. Therefore, maximum power point tracking (MPPT) of the solar array is essential in a PV system. To increase the efficiency of PV system, the maximum power point has to be tracked. A view of location of solar cell is given in Figure 4.
Solar-electric System
A solar-electric system consists of PV array and other components, such as MPPT charge controllers, inverters, and batteries. The components required depends on type of solar system. The various solar electric systems are:
1. PV-Direct Systems
These are the simplest form of solar-electric systems, with the PV array and the load. The batteries are absent since power is supplied to the load when the sun is shining. One example is water pumping as shown in Figure 5.
2. Off-Grid Systems: (Stand Alone System)
It can be used in remote locations where there is no utility service; off-grid solar-electric systems can work anywhere. These systems operate independently from the grid to provide all of a household’s electricity.
These systems require a battery bank to store the solar electricity for use during night time or cloudy weather, an inverter to convert the DC PV array power to AC for use with AC household appliances as given in Figure 6.
3. Grid-Tied Systems With Battery Backup
This type is similar to an off-grid system in design and components, but adds the utility grid, which reduces the need for the system to provide all the energy all the time.
4. Grid-Tied Systems
These most common PV systems are also known as grid-tied system. They generate solar electricity and route it to the loads and to the electric utility grid. This type of System consists of the PV array, converter, inverter, and required electrical safety gear as shown in Figure 7.
Utilization Status Of Renewable Energy
The installed capacity of renewable energy connected to grid in India is around 33.8GW as on December 2014. The total of 66% is from wind energy system, 4.6% from Solar Photovoltaic system and remaining from small hydro unit, Biomass, power from waste and others.
The utilization of wind energy placed top order of 66% compared to other sources. India ranked fifth in the generation of power from Wind energy in the world which is mainly from various states: Tamilnadu, Maharashtra, Gujarat, Karnataka, Rajasthan etc in which maximum of Tamilnadu provides around 7162.18 MW.
Tentative Target
The Ministry of New and Renewable Energy (MNRE) have aimed to attain around 175GW by the year 2022 across the country. The breakup of region wise target is given in the table.
Conclusion
The implementation of renewable power generations are increasing rapidly because of their merits compared with fossil fuel-based generation. The equipment cost of wind energy system fallen dramatically owing to technological innovation, increasing manufacturing scale and experience curve gains. Similarly, cost of solar modules has also reduced by almost 80% since 2008. The price of wind turbine has fallen by more than 25% during the same period. The continuous utilization of renewable energy sources in India leads to achieve the aim of MNRE to generate 175GW of power by 2022. This impact will meet the major demand of electricity in India by renewable energy. Hence the dependent of fossil-fuel is rapidly decreased and this will strengthen the economic standard of India in future.
